New
Jersey Department of Environmental Protection
2007
Land Use / Land Cover Update and Impervious Surface Mapping Project
In 2008, The New Jersey Department of
Environmental Protection (NJ DEP) contracted Aerial Information Systems, Inc.
(AIS) to revise the State’s existing GIS Land Use/Land Cover and Impervious
Surface, (hereinafter referred to as LU/LC) database.
The resulting LU/LC layer is intended as a
resource for trend analysis. The layer
will provide information for those who are interested in quantifying physical
changes made to LU/LC features over time using GIS for their particular area of
interest.
The LU/LC update mapping began in August 2008
and was completed in December 2009. The data
compilation and conversion efforts were conducted by AIS using computer
interactive photo interpretation techniques and limited on-site field
surveys. The baseline data set for the
update consisted of the 2002 LU/LC data layer.
Using heads-up digitizing techniques, AIS photo interpreters compared the
existing LU/LC information to year 2007 color-infrared digital orthophotography
to create the 2007 LU/LC layer.
The metadata contained herein describes for the
user the methods and mapping criteria used by AIS to capture and compile the
information used for the LU/LC update.
This document is divided into five sections.
·
Section 1 includes a general description
of photo interpretation methods and update mapping;
·
Section 2 lists the primary and ancillary
sources of information used for the data capture, including a brief history of
the baseline dataset;
·
Section 3 describes the LU/LC update
methodology, criteria, and project issues;
·
Section 4 details the specific criteria
used for the LU/LC update;
·
Section 5 contains the Data Dictionary;
and
·
Attachment A includes the project Land
Use/Land Cover Classification.
SECTION 1: General Concepts
This section contains a brief description of the
basic principles of photo interpretation and update mapping.
Photo Interpretation
Most LU/LC features can be recognized by photo
signature; i.e. characteristics unique to that feature. These signatures are defined by color,
texture, pattern, and tonal qualities on the aerial photography. By observing the extent of the photo
signatures associated with specific LU/LC types, the photo interpreter is able
to identify and delineate the boundaries of LU/LC features.
When the same photo signature exists for one of
more LU/LC types, the surrounding physical environment, or “context”, is an
important tool in determining the appropriate LU/LC class. An understanding of the current and
historical patterns of development for the area results in more accurate
interpretations. For example, a large
rectangular building viewed on the photo can represent either commercial or
industrial land use. Knowing that
industrial uses are often located next to rail corridors and away from high
traffic areas while commercial uses are usually located along major traffic
corridors and intersections, the interpreter can review the surrounding
environment of the building signature for those types of features.
Collateral sources are useful to the photo
interpreter as they help to identify specific LU/LC features and provide a
background context against which the photo signatures can be compared. County and city street maps, USGS topographic
maps, and existing vegetation maps are some of the more important sources used
during the photo interpretation process.
The usefulness of existing collateral sources is directly related to the
detail, accuracy, and timeliness of the information they provide.
If the above sources are not sufficient for the
interpreter to confidently assign a LU/LC class, on-site field visits are
required. In addition to answering
polygon specific questions flagged during the photo interpretation effort,
on-site field surveys serve to verify correlations previously established
between photo signatures and LU/LC types, ensuring that the interpretations are
as error free as possible.
Update Mapping
Update mapping is the process of revising the
spatial and attribute data of an existing dataset using current sources of
information for the purpose of change detection and trend analysis
studies. When the attributes of the finished
products are analyzed in a GIS, areas of change are exposed. Ideally the project classification, mapping
criteria, and data capture method of the update should be the same as the
previous data compilation effort in order to make accurate comparisons.
Terminology
The following are definitions of common terms found throughout this document.
· Below Resolution (BR)
This term describes LU/LC features that are smaller than the minimum mapping unit. Below resolution features are not mapped for their specific LU/LC class but are aggregated into an adjacent above resolution LU/LC polygon.
· Composite Coverage
Final LU/LC coverage delivered to NJ DEP containing both the 2002 and 2007 LU/LC delineations and codes.
· Cowardin (FWW) Wetland
Refers to freshwater non-tidal wetland legacy polygons originally mapped for NJ DEP’s Freshwater Wetlands mapping program.
· MMU (Minimum Mapping Unit)
The smallest polygon size (total area) mapped for each LU/LC class within a unique era. Does not apply to polygons in the composite LU/LC coverage.
·
MMW (Minimum Mapping Width)
The
smallest polygon width (linear features) mapped for each LU/LC class within a
unique era. Does not apply to polygons
in the composite LU/LC coverage.
·
Polygon
Can refer to either the polygons in the composite LU/LC coverage or the polygons created by aggregating the LU/LC classes for a specific era. Polygons in the composite LU/LC coverage can be smaller than the project mmu/mmw, i.e. below resolution (BR). Unique LU/LC polygons for a specific era are typically not BR unless they are remnant polygons.
·
Photomorphic
The polygon boundary for a LU/LC unit follows the morphology (boundary) of the photo signature. Where a LU/LC boundary follows a distinctive photo signature, the resulting polygon is said to be photomorphic
·
Remnant
polygon
Refers
to valid BR polygons created by the subdivision of previously mapped LU/LC
polygons due to changes in the LU/LC.
· Retroactive (Retro) Mapping
Revision of the 2002 LU/LC data due to changes in the 2007 mapping criteria, 2007 classification, differences in image registration and resolution between 2002 and 2007, or error of interpretation during previous update.
SECTION 2: Data
Sources
2007 Digital
Orthophotography
Digital Color Infrared (CIR) orthophotos, dated
2007 and provided by NJ DEP, served as the base for the 2007 LU/LC mapping effort and were used as the
primary source to interpret the LU/LC and IS.
As with the 2002 Update, digital photography gives the interpreters
virtually unrestricted viewing using ArcGIS tools. This capability, in conjunction with the
increased resolution and quality of the digital imagery, resulted in more
accurate and detailed delineations of the data for the 2007 mapping
efforts.
2002 LU/LC layer
The baseline coverage for the 2007 mapping effort
was the NJ DEP 2002 LU/LC coverage created by AIS during NJ DEP’s previous
update cycle. In addition to the LU/LC
data, the 2002 coverage contained legacy information from NJ DEP’s Freshwater
Wetlands (FWW) mapping program in the “Cowardin” field. This ensured the continuation of the legacy
FWW information in the 2007 data set.
2002 Digital Orthophotography
The digital 2002 CIR orthophotos that served as
the base for the previous LU/LC update were used as a supplemental source of
imagery for the 2007 effort. The
interpreters referred to this imagery to verify areas of change and where
corrections to the existing interpretations were required.
Collateral Sources
These sources were used to supplement the
project imagery to help the interpreters further identify the LU/LC
features. Features on the collateral
maps were compared with the imagery. If
the imagery did not support the information shown on the maps they were not
delineated into the thematic layers.
Internet
Sources
On-line sources such
as the Google search engine, Google Maps, MSN Bing, and other websites were a
significant resource for the 2007 LU/LC Update.
The photo interpreters used them to research information and view photos
from different eras to help classify the polygons for signatures that were not
readily identifiable on the project imagery.
Street Maps
Current city, county,
and regional hardcopy street maps were used to help the photo interpreters
classify the land use polygons. Although
stylized in their depictions, these maps were very useful for identifying land
use features, including major roads, parks, shopping malls, churches, and
municipal buildings.
USGS Digital Raster
Graphic (DRG) Maps
These maps were used
for determining land use, vegetation cover type, and topographic features. Specifically, they were very helpful in the
identification of utility right-of-ways, transmission line substations, small
mining operations, railroads, airstrips, and other features not typically shown
on street maps. Although available
for the entire state, the usefulness of these maps was
limited by their age. They are not
updated on a regular basis therefore the information is often outdated compared
to the project imagery.
SECTION 3: LU/LC Update
Overview
The 2007 LU/LC update was performed using the same data compilation methods and essentially the same mapping classification and criteria established during the 2002 LU/LC update. The state was divided into 20 Watershed Management Areas (WMAs) that were each further digitally subdivided into 1:12,000 scale quarter-quad modules based on the USGS topographic quadrangle system. NJ DEP prioritized the mapping order for each WMA based on the delivery schedule of the project image delivery. The baseline datasets consisted of digital CIR orthophotos, dated 2007 and the State’s existing 2002 LU/LC coverage.
The photo interpreters compared the 2007 digital imagery
to the existing LU/LC data and the 2002 digital CIR orthophotos to detect areas
of change. Using heads-up digitizing
techniques, the LU/LC units were delineated and classified per the modified
The 2007 LU/LC interpretations were incorporated directly into the baseline 2002 LU/LC coverage creating a final composite coverage containing both eras of LU/LC. This method ensured that the different layers seamlessly co-registered to each other, creating a sliver free coverage for use in change analysis studies.
Each polygon in the composite coverage was assigned an item for 2007 and 2002. Where no LU/LC change had occurred, the LU/LC class for both item years remained the same. Where a LU/LC change did occur, new boundaries were added to the data set as needed, subdividing the existing 2002 polygon, and the polygons were attributed for the appropriate 2007 LU/LC type. The original 2002 boundaries and codes were retained in the data thus keeping the polygon “history” intact.
The following section describes significant mapping
issues related to the 2007 LU/LC update.
·
Orthophoto Registration, Image Clarity and Retroactive Mapping
Because the 2002 and 2007 digital images had the same pixel resolution and ground accuracy specifications, registration correction between the two image sources was not a major issue as in the 1995 to 2002 update. However, because the 2002 and 2007 projects did use independent ground control points to ortho-rectify the images, some minor registration issues were encountered. Since correct polygon boundary placement is vital to the objectives of update mapping and some differences may be reflective of base image registration issues, AIS opted to go beyond the contracted scope of work and perform limited registration adjustments of the 2002 data, i.e. “retroactive mapping”, for the 2007 Update in order to create a more useful tool for the State’s GIS analysis needs.
The major issue affecting retroactive mapping, however, was the increased image clarity of the 2007 imagery versus the 2002 imagery. While both digital image sources were of 1 foot pixel resolution, and +/- 4 ft ground accuracy, the 2007 imagery was significantly better. This was due to the fact that the 2007 imagery was captured as 12-bit image files, while the 2002 imagery was captured as 8-bit image files. The increased bit depth means that more signature information is captured for each pixel, which is reflected in the 12-bit image generally having more detail than the 8-bit image, even though both have the same pixel dimensions. The clarity of the 2007 imagery resulted in more accurate delineations and classifications of the 2007 scene, but it also highlighted areas in which the 2002 interpretations or polygon boundary placements needed modification. Since change detection and trend analysis are major objectives of the update project, it is important that the data based on both image sources be as accurate as possible so that land use/land cover changes will be identified and mapped correctly. AIS again went beyond the scope of the project and performed needed retroactive mapping due to image clarity issues.
The LU/LC classification remained relatively
intact from the 2002 LU/LC update with some minor revisions. These included the removal and re-definition
of existing LU/LC types and the addition of new LU/LC types for the 2007
survey. AIS and NJ DEP collaborated on
defining the class descriptions and refining the mapping criteria, as needed,
for existing classes.
While most of the
classification revisions occurred prior to the start of the LU/LC interpretations,
some of the additions occurred after the production phase of the LU/LC
interpretations had commenced. While AIS
made the maximum effort possible, including re-reviewing previously mapped
data, to correctly represent the latest criteria and coding additions and
revisions, the User is advised that potential inconsistencies of interpretation
could exist in areas mapped prior to the addition/revision date for the new
codes.
Listed below are the
new
2007 LU/LC Code Additions
1411 Mixed Transportation Corridor
Overlap Areas
§
Applied to road/railroad intersections, including overhead (bridge) and
at grade crossings.
§
Does not include road to road intersections.
§
Code added during the final review process, therefore not applied to
all WMAs.
§
Retroactively mapped to 2002.
§
Previously mapped as 1400.
§
No “official” mmu; an attempt was made to capture all 1411s (excluding
areas that were not reviewed for this coded).
1420 Railroads
§
Applied to all railroad related features, excepting some spur lines.
§
Spur lines serving a single industry, i.e. oil refinery, etc., were not
captured as 1420.
§
Spur lines serving multiple industries were captured.
§
If tracks were still visible on the imagery, the area was captured as
1420 regardless of whether railway appeared to be abandoned.
§
Retroactively mapped to 2002.
§
Previously mapped as 1400.
§
No “official” mmu for the rail lines (tracks and ROW); an attempt was
made to capture all as 1420.
§
One acre mmu for all non-track related features, i.e. railroad
stations, yards, etc.
1741
Phragmites Dominate Urban Area
§
Previously mapped as 6113
Phragmites by AIS in 2002.
§
NJ DEP re-classified all 6113s into one of four Phragmites LU/LC types (1741, 4411, 6141, or 6241) prior to the
2007 update.
§
One acre mmu.
4411 Phragmites
Dominate Old Field
§
Previously mapped as 6113
Phragmites by AIS in 2002.
§
NJ DEP re-classified all 6113s into one of four phragmites LU/LC types
(1741, 4411, 6141, 6241) prior to the 2007 update.
§
One acre mmu.
6141 Phragmites
Dominate Coastal Wetlands
§
Previously mapped as 6113
Phragmites by AIS in 2002.
§
NJ DEP re-classified all 6113s into one of four phragmites LU/LC types
(1741, 4411, 6141, 6241) prior to the 2007 update.
§
One acre mmu.
6241 Phragmites
Dominate Interior Wetlands
§
Previously mapped as 6113 Phragmites
by AIS in 2002.
§
NJ DEP re-classified all 6113s into one of four phragmites LU/LC types
(1741, 4411, 6141, 6241) prior to the 2007 update.
§
One acre mmu.
5190 Exposed
Flats
§
Defines newly barren areas apparently created by stream course
meandering.
§
Located within or next to stream
courses.
§
Not applied to the Atlantic or
§
Code added during the latter stages of the project, therefore not
applied to all WMAs.
§
No official mmu applied.
6290 Un-vegetated
Flats
§
Defines newly barren areas apparently created by stream course
meandering and ice and water scouring.
§
Mapped as Wetlands or
§
Located within or next to stream courses.
§
Not applied to the Atlantic or
§
Code added during the latter stages of the project, therefore not
applied to all WMAs.
§
No official mmu applied.
Re-defined 2002 LU/LC Codes
1400 Transportation,
Communication, and Utilities/1410 Major Highways
In
2002, the 1410 Major Highways land
use class was added to the classification and applied to all road polygons. Upon receipt of the final 2002 dataset, and prior
to the 2007 update, NJ DEP decided they wanted to distinguish between major and
minor roads and revised the 2002 road polygons accordingly. Road polygons that meet the major road
criteria were left in the 1410 class, road polygons defined as non-major roads
were re-classified as 1400. Polygon
boundaries were adjusted by NJ DEP staff as needed. For the 2007 Update, AIS used the NJ DEP road
delineations and codes as a guide to determine whether new roads should be
categorized as 1400 or 1410.
Invalid 2002 LU/LC Codes(removed from the current LU/LC data
set)
1460 Power
Facilities (Electrical Substations)
Upon receipt of the final 2002 Update, NJ DEP
decided they no longer wanted to separate out electrical substations in the
LU/LC data. NJ DEP re-classified them as
1400s in the 2002 layer and the 1460 class was not used during the 2007 Update.
6113 Phragmites
The
6113 Phragmites class was added in 2002 as a
temporary place holder in the classification until NJ DEP could analyze the Phragmites data. During the interim period between the 2002
and 2007 updates, NJ DEP replaced the 6113 class with four new LU/LC types: 1741
Phragmites Dominate Urban Area, 4411 Phragmites Dominate Old Field, 6141
Phragmites Dominate Coastal Wetlands, and 6241 Phragmites Dominate Interior Wetlands.
NJ DEP staff revised the 2002 data set using the 1995/97 LU/LC data as a
reference to help them determine the correct Phragmites code assignment.
The 6113 class was removed from the classification.
The
Distressed Vegetation (DV) field was added to the 2007 LU/LC data to account
for situations where the vegetation had undergone significant change/disturbance
but the changes did not meet the criteria for a re-classification of the LU/LC
type for the polygon.
Three
major types of change were identified: large amounts of standing dead conifers,
major unaccountable changes in vegetation cover, and major changes due to
non-urban man-made disturbance (typically logging). Where these conditions were observed, the
polygon was subdivided (if the affected area met the mmu for each category) and
assigned one of the following codes in the DV field: 1 = Standing Dead Conifers
(SDC), 2 = Distressed Vegetation (DV), 3 = Man-made disturbance (PB). If the affected area did not meet the mmu,
the DV code was applied to the entire polygon.
The
data capture criteria for each Distressed Vegetation class is described below:
Standing Dead Conifers (SDC)
·
Only used where
dead conifer vegetation was still standing.
The SDC code was not applied to areas of downed trees (potential DV
modifier) or where trees were removed (potential PB modifier).
·
Applied to both upland
AND wetland vegetation types.
·
Only applied to non-urban
LU/LC types.
·
Applied only where
coniferous vegetation was present, i.e. trees and/or shrubs, regardless of the
land cover code attribute. Typically applied to coniferous vegetation types but
could also be applied to non-coniferous vegetation types as long as they
contained conifer vegetation.
·
Requires a significant
amount of standing dead conifers, loosely defined as approximately 50% conifer
death (not to be confused with 50% of all
vegetation in the polygon). Context was
also used to define whether the SDC code should be applied. In areas with lots of death, the modifier was
assigned to polygons with a smaller percentage of SDC due to the large-scale
death occurring in the area. Where there was little to no SDC in the area, the
50% number (or higher) was used before applying the modifier.
·
1 acre mmu.
·
The original
LU/LC class was not changed based on a SDC code assignment.
·
Areas of below
resolution (< 1 acre) SDC were aggregated across adjacent LU/LC types to
meet the one acre mmu, as long as the remaining “remnant” polygons were 1 acre
or greater. This could result in
multiple “below resolution” LU/LC polygons being delineated in order to create
one above mmu SDC polygon.
Disturbed Vegetation (DV), natural disturbance, not man-made
·
Used for upland
AND wetland vegetation types.
·
Used for both
deciduous and coniferous vegetation.
·
Used for polygons
where vegetation change has occurred that cannot obviously be attributed to
man-made vegetation removal. Does not
include areas of SDC. Examples of DV
include die-off along tidal/non-tidal wetland boundaries, unexplained reduction
in vegetation density, large areas of downed trees, burned areas that were not
classified as 4500/6500, etc.
·
Is not applied to
apparent die-off in 6112/non-Cowardin polygons.
·
Must be applied
to apparent die-off in 6112/Cowardin polygons.
·
Assigned to polygons
where significant DV is visible; “significant” being loosely defined as 25%.
Context also used to determine whether the DV code should be applied. In areas with lots of disturbance, the
modifier was typically assigned to smaller percentages of DV due to the
large-scale disturbance occurring in the area. Where little to no DV occurred
in an area, the 25% number (or higher) was used before applying the modifier.
·
Approximately
5acre mmu, although smaller size DV polygons were delineated.
·
The original
LU/LC class was not changed based on a DV code assignment.
·
All 4500 and 6500
LU/LC polygons were assigned a DV code.
Man-Made Disturbance (PB), large-scale man-made vegetation removal
·
Used ONLY for
upland vegetation types. Wetland vegetation
types experiencing this type of disturbance were coded as 7430.
·
Used for both
deciduous and coniferous vegetation.
·
Used for polygons
where significant areas of vegetation change occurred due to obvious man-made
vegetation removal. Does not include
areas of SDC or DV. Significant changes
in vegetation due to fire were assigned a DV code and a LU/LC class = 4500. Significant changes in vegetation density
that could not be attributed to man-made removal were also assigned a DV code.
·
Typically, PB occurs in logged areas although PB has
been observed near mining areas.
·
Does not include
clearing for man-made land uses, i.e. construction (7500), backyard additions,
etc.
·
Does not include
7430s.
·
Does not include
small-scale vegetation removal.
·
1 acre mmu.
·
Typically, the
original LU/LC class was changed, i.e. from 4220 to 4210 or 4410, etc. However, it’s possible that the LU/LC type did
remain the same – this typically occurred in existing 4110 and 4210 types.
Photo Signature versus On-Site Field
Observations
The user should be aware that the data
represents LU/LC as it existed at the date of the project photography, with
some exceptions. In general, if
subsequent on-site field surveys revealed that the LU/LC had changed since the
2007 photography, the polygon was coded for the 2007 photo signature, not necessarily
for the LU/LC observed in the field. Therefore, although the project
photography is relatively current, it should be assumed that LU/LC information
is approximately one and a half years old at the time of the project
completion.
The 2007 LU/LC update retained most of the criteria used for the 2002
mapping effort. However, there were
criteria changes resulting from the addition of new codes and the re-definition
of existing codes. The major criteria additions/changes
are described below.
1411 Mixed Transportation Corridor
Overlap Areas (2007)
·
1411s
were mapped at the intersection of road (1400/1410) and railroad (1420) polygons
where both polygons continued past the intersection. The intersections between 1400 and 1410s were
not classified as 1411; those types of intersections were coded as 1410s, since
the major road category takes precedence over the 1400.
·
If
a RR/road crossing was visible on the photography but the road was below mmu
and therefore not represented in the data, the visible intersection was not
mapped as a 1411. 1411s were only mapped
where road/railroad polygons crossed
over one another.
·
The 1411 polygons were mapped retroactively if
present on the 2002 image. If not, the
intersection was mapped as a change.
·
The
IS value for the 1411s were determined by the underlying land use. For example, if an overlap occurred where a
1420 was under a 1410 then the 1411 polygon was assigned the same IS value as
the 1420.
·
If
one or more of the transportation polygons did not continue past the
“intersection” of both, then a 1411 was not mapped. For example, if the road polygon stopped at
the RR, or vice versa, a 1411 was not delineated.
1419 Bridge Over Water
All road and railroad
bridges that crossed water polygons in the data were captured as 1419
regardless of the final polygon size per NJ DEPs request at the beginning of
the project. 1419s were only captured where they crossed over water polygons in
the data set. 1419s were not captured
where they crossed over below resolution water features visible on the project
photography. This type was
retro-actively mapped where appropriate.
1499
During the previous inventory all drainage basins
were mapped as 1499 regardless of whether there was water present or not. For the 2007 Update, NJ DEP wanted to identify
basins containing “permanent” water and re-classify them as 5300. These types were retro-actively mapped where
appropriate.
5XXX Water
Per NJ DEP’s request, there was virtually no minimum
mapping unit size applied to non-tidal, permanent water bodies (excluding
linear water features, i.e. streams, brooks, rivers, etc.). The original 2002 mmu was one acre. These features were retro-actively mapped
where appropriate.
5190 Exposed
Flats (2007)
·
No “official” minimum mapping unit applied; most 5190s were captured at a half acre or greater.
·
These areas formerly classed as 5100 in 2002 became exposed mud flats
in 2007 due to stream channel changes.
Left in Water category because changes may be only semi-permanent.
·
Not mapped along the Atlantic seaboard, Delaware Bay, or the southern
reaches of the
6290 Unvegetated
Flats (2007)
·
No “official” minimum mapping unit applied; most 6290s were captured at a half acre or greater.
·
These areas formerly classed as Wetlands or
·
Placed in Wetlands category since if the areas re-vegetate, it will be
with Wetlands species because of the low elevation and proximity to stream
channels of these sites.
·
Not mapped along the Atlantic seaboard, Delaware Bay, or the southern
reaches of the
The following outlines the basic procedures used for the update mapping effort. These are general in nature and grew out of the unique characteristics of the project. Additional criteria are discussed in Section 4.
1. Registration – A portion of
the linework from the 2002 update was corrected during the 2007 LU/LC update to
reflect the considerably superior photography.
This included the linework of both FWW and non-FWW polygons.
2. Comparison – concurrent with
the registration, the 2007 base imagery was compared to the baseline data and
the 2002 imagery for LU/LC feature changes.
3. Delineation – Areas of
change were added or removed from polygons, as needed, while existing features
not previously delineated, or delineated incorrectly were retroactively
mapped.
4. Classification – Each
polygon in the 2007 LU/LC data was coded for the appropriate
5. Impervious Surfaces – Each LU/LC feature was assigned an IS percentage, ranging from 0 – 100, in increments of 5%, based upon the estimate of experienced photo interpreters.
6. Where appropriate, a Distressed Vegetation modifier was assigned to the polygon.
7. Edgematching – The working modules, when completed, were edgematched to adjacent modules for consistency of polygon delineations and coding. As all of the modules within a WMA were completed, the WMAs were edgematched to each other to create a seamless statewide dataset.
8. Field Verification and Revision were performed in conjunction with the photo interpretation to ensure that the data produced was as error free as possible. Field plots containing the project imagery and preliminary LU/LC delineations were created and prepped with street names and daily routes. Polygons flagged for field were reviewed on-site, if possible, and resolved. Additional verification of non-flagged polygons occurred to ensure the accuracy of established correlations between photo signatures and specific LU/LC feature types. Upon return to the office, the interpreters entered the field corrections and changes directly into the 2007 LU/LC dataset.
Upon completion of these eight steps for each
WMA, a preliminary shapefile of the data was delivered to NJ DEP for
review. If necessary, the data were
revised per NJ DEP comments. The revised
data was returned to NJ DEP for their final review and approval.
2007 LU/LC Map
Validation Procedures
A series of quality control
and map validation procedures were performed to ensure the accuracy of the 2007
LU/LC data per the project classification and mapping criteria. The validation process consisted of on-site
windshield field surveys, review of multiple image sets representing different
eras, the use of on-line (internet) and hard-copy resources, a separate Quality
Control review of the draft delineations and attributes by AIS senior photo
interpreters, and NJDEP staff comments arising from AIS questions and their
review of the data.
1. On-site field visits
Two separate 10 day on-site
windshield field surveys, one in the northern portion of the state the other in
the south, were performed by AIS for the 2007 Update. The field surveys
typically targeted the developed areas of the state. Areas of pure vegetation were typically not
visited due to access issues and the limited scope of the windshield
survey. Polygons flagged for on-site
review during the initial photo interpretation and quality control review steps
were visited and the information recorded on hard-copy field plots. As part of the validation process, the LU/LC
types observed during travel from one flagged polygon to another were noted on
the field plots. Where problematic LU/LC
calls were observed directly in the field, the situation was investigated and
resolved by the field team.
For the 2007 update,
approximately 5,000 polygons underwent field reconnaissance during the two
field survey sessions. Since AIS also
performed the 1995-2002 update for NJDEP, field plots from the 1995-2002 update
project were also available for review.
In that project, there were 6 separate10 day field surveys undertaken
with over 30,000 polygons observed.
While a strict statistical accuracy assessment can not be performed
using these field investigation results, based on this relatively large number
of observations, and on the additional validation steps outlined below, it is
estimated that the data set has an overall minimum classification accuracy
of at least 85% , with an accuracy of >
90% for the developed land classes.
2. Ancillary Digital Imagery
In addition to the 2007 base
imagery, four additional digital image sets were used for the 2007 Update. They included the 2002 CIR and 2006 natural
color photography provided by NJDEP and the on-line imagery available through
Google Maps and MSN/Bing. The ancillary
imagery provided the interpreters with a more comprehensive picture of the
LU/LC by providing them with views of the study area under different seasonal conditions,
in different eras, and different formats (natural color and CIR). The interpreters used this information to
make more accurate informed decisions about the pattern of land use and types
of land use change for a given area.
3. On-line (internet) Resources
The internet proved to be a significant
collateral resource for the 2007 Update, especially the search engines provided
by Google Maps, Google, and MSN/Bing.
AIS GIS staff created a tool that allowed the interpreters to
instantaneously access information from Google Maps and MSN/Bing for a given
location by clicking on that location in the LU/LC layer.
Google Maps was an excellent
resource for built-up (urban) land use types as it provided the names and point
locations of private and public entities, often with additional links to other
websites. MSN/Bing was primarily used
by the interpreters for the “birds-eye” imagery, where available. The birds-eye imagery provided the
interpreters with a close-up view of the area in question in order to see more
clearly determine property boundaries, areas of change, and even the relative
height of vegetation when these features were not clearly visible on the
project imagery. MSN/Bing also provided
land use information but not to the same degree as Google Maps. The generic Google search engine was
frequently used by interpreters to further research the information obtained
from Google Maps, MSN/Bing, or observed in the field, in order to more accurately classify the
LU/LC type.
The amount and quality of
on-line information obtained by this “virtual” field survey method resulted in
a significant reduction in the number of polygons requiring actual on-site
verification and thereby allowed the field team to concentrate their limited
time in areas most urgently requiring visual on-site confirmation of the LU/LC
types.
4. Other Resources
Hard-copy county road maps
and map books, published by Hagstrom, Rand McNally, ADC, or Metro, were also
used to help the interpreters classify the LU/LC. The amount of LU/LC information included on
these maps varied from series to series but typically showed the location of
churches, schools, major shopping centers, government buildings and military
boundaries. During the 19995/97 and 2002
inventories these maps were used as the primary collateral resource by the
interpreters. However due to the quality
and quantity of information available through the internet, the road maps
assumed a secondary role for the 2007 mapping effort.
Hard-copy AIS field plots
from the 1995/97 and 2002 LU/LC Updates were also used as reference
material. Where the interpreters had
questions about the accuracy of an existing LU/LC type, the field plots were
reviewed to see if the area had been visited during the previous field visits
before making any changes to the data.
Digital USGS topographic
quadrangles (DRGs) were another collateral resource used to increase the
accuracy of the interpretations. Due to
the age of the DRG information, the interpreters primarily used these maps to
verify the general topography of an area and to get a historic perspective of
the vegetation and land use for a given area.
5. Quality control Review
In order to further ensure
the accuracy of LU/LC data, the draft data was reviewed by senior Quality
Control (QC) staff assigned specifically to the 2007 Update. The QC’ers reviewed the draft delineations
and code attributes for adherence to the project protocols. This included, but was not limited to, the
representation of the LU/LC feature relative to the photo signature, the aggregation
of below resolution LU/LC types, the interpretation and application of
reference information, and adherence to mapping criteria.
6. NJDEP review and comment (PIRFs)
Additional validation steps
of the LU/LC assignment were performed through consultation with NJDEP staff
over the course of the project. Unusual
issues that arose during the mapping project were documented and referred to
NJDEP for their review. In some
instances, the resolution coming from NJDEP resulted in global changes to the
criteria, i.e. the creation of the Distressed Vegetation field to address
unusual vegetation patterns observed on the photography. In other situations, the issues were
localized, only affecting a limited number of features. In both examples, the input from NJDEP
increased the accuracy and provided validation of the LU/LC types in question.
SECTION 4: General LU/LC Mapping
Criteria
Introduction
This section describes the final criteria as developed by AIS and NJ DEP. Many of these criteria were developed over the course of the project in response to new situations or to modify existing situations. As the procedures evolved they were submitted to NJ DEP for approval. Any discrepancies in mapping procedure from the beginning of this project to the end were due to this evolution, and were recognized by both AIS and NJ DEP.
These criteria supersede all previous criteria for this project.
Drafting Conventions
The following details
the drafting criteria used to delineate the LU/LC units.
General Drafting Criteria
·
When a road separated differing LU/LC
features, the polygons for these features followed the road centerline. Although roads often include a right-of-way
on either side, these slivers of land between the roads and the adjacent LU/LC
features were aggregated with the LU/LC unless they could be reasonably
extracted. The above criteria were
applied for the delineation of new LU/LC polygons. Existing LU/LC polygon boundaries that did
not follow road centerlines due to image registration issues were not corrected.
·
Where roads and features on the
orthophoto differed from those represented on other collateral sources, the
location on the orthophoto was used to depict the feature.
·
Boundaries are followed as closely as
possible. Where boundaries were particularly
jagged, however, some cartographic smoothing was deemed appropriate. This was generally for use along natural
boundaries and was rarely needed along man-made boundaries.
Urban/Built-Up Areas
Built-up land uses
usually follow man-made features such as fence lines, roads, and property
boundaries. To properly represent these
boundaries:
·
Linework was kept straight and used right
angle corners.
·
Lines were placed down the centerline of
boundaries (such as roads, railroads, and tree lines).
·
Structures were not dissected.
Non-Urban/Natural Areas
Natural vegetation
boundaries tend to be transitional therefore the line separating different
classes is often less distinct. These
polygons seldom contained straight edges or angles unless the vegetation unit
was adjacent to built-up or man-made features. Vegetation category polygons were
usually represented with flowing and curvilinear lines, reflecting the more
natural shape of the land cover.
Minimum Mapping
Unit/Width
The minimum mapping unit for the 2007 LU/LC was
established at one acre for all features, excluding the following classes: 5XXX non-tidal water bodies, 1419 Bridge
Over Water, 1411 Mixed Transportation Corridor Overlap Areas, and 9999 Unknown. Additionally, a minimum width of 60’ was applied
to non-water linear features, excluding 1420
Railroad Facilities, while a minimum width of 30’ was required for linear water
features.
Aggregation
Where a non-exempted
class did not meet the minimum mapping unit size, it was aggregated into an
adjacent LU/LC type per the following general guidelines:
·
Built-up land uses took precedence over
non-built up categories. For example, if
a below-MMU residential land use was adjacent to a below-MMU forest cover, the
forested area was typically absorbed into the residential land use.
·
In general, residential land uses took
precedence over other built-up land uses.
If a below-MMU residential land use was adjacent to a below-MMU
commercial land use, typically the commercial area was absorbed into the
residential land use.
·
If a below-MMU LU/LC feature was
surrounded by a number of other above-MMU LU/LC features, then the below-MMU
unit would be absorbed into the unit that most closely represented its
class. For example, if a below-MMU
residential class was next to above-MMU commercial, industrial, and forested
polygons, the residential land use was absorbed into the commercial
polygon.
·
An isolated below-MMU LU/LC feature
completely surrounded by a single LU/LC feature was absorbed into the surrounding
LU/LC class.
·
Some remnant polygons remaining from 2002
Update were merged according to the criteria above if they were not significant
to the overall classification of the area.
Below-MMU polygons
Below resolution
polygons were left intact or created in the following situations:
·
Isolated below-MMU roads completely
surrounded by FWW wetlands.
·
Below resolution LU/LC features were
mapped provided they were significant to the overall classification of the area. Typically this occurred where the LU/LC type
was present within a given area but no single feature attained the minimum
mapping size. If the 1.0-acre MMU had
been strictly observed, these units would not have been captured in the
database. By mapping certain LU/LC
classes smaller than the 1.0 acre MMU, the user is given a more accurate
depiction of LU/LC conditions in these areas.
·
Remnant polygons from the 2002 Update
were kept in the data provided they were significant to the overall
classification of the area. Typically
these included built-up land uses and wetland vegetation types. Upland vegetation remnants were usually
re-classified into surrounding LU/LC polygons.
·
When an unchanged FWW wetland incorrectly
included existing paved or otherwise disturbed areas, said areas were
delineated out of the wetland polygon and aggregated with the adjacent LU/LC
class. This process sometimes resulted in below-MMU wetland polygons that were
left over after the disturbed/built-up land use was coded out of them.
Impervious
Surfaces Mapping (IS)
Relationships between land uses and impervious
surfaces previously established by the National Resource Conversation Service
were used as baseline values for the built-up land use categories. Values were estimated based upon the
percentage of impervious surfaces within a given polygon.
·
IS was interpreted in 5% increments, from 0% to 100%.
·
Impervious surface percentages were assigned to each LU/LC unit based
on an estimate of the paved and/or built-up area within the polygon. The
estimates were rounded to the nearest 5% increment. For example, if the IS estimate for a polygon
was estimated at 2% impervious, it was assigned an IS value = 0. If a polygon was estimated to be 53%
impervious, it was assigned an IS value = 55.
·
Where a single LU/LC polygon contained areas of differing IS and each
area met the 1- acre MMU, the polygon was subdivided and assigned different IS
values.
·
Hard packed earthen areas (earthen dams excepted), gravel areas, and
natural rock areas (including road cuts) were mapped as pervious surfaces.
·
Compared similar land use signatures as a consistency check.
·
Compared similar IS-valued polygons as a consistency check.
·
IS for all water bodies, including concrete-lined reservoirs, were 0%
unless other below-MMU paved or built-up areas existed within the polygon.
·
IS for bridges (1400, 1410, and 1419) passing over vegetation or water
were 0%.
·
IS for 1411s represent the IS of the underlying transportation type.
Orders of Precedence
Land Use
·
If urban/built-up use occurred together with non-urban use, the urban
use took precedence over the non-urban.
For example, a heavily wooded residential area was coded as residential
unless vegetation could be extracted into above-MMU polygons.
·
Within urban areas, built-up land uses took precedence over non
built-up land uses.
·
Residential land uses generally took precedence over other built-up
land uses.
·
Mixed road/utility rights-of-way polygons, where both features were
below resolution but together they met the MMU, the polygon was coded for the
appropriate road type (1400/1410).
·
Where minor and major roads intersected one another (1400/1410) the
·
Utility rights-of-way were only mapped when they passed through vacant
land (1700, 4xxx, and 6xxx), except where the vegetation had obviously been
undisturbed for a significant period of time.
In those situations, the vegetation took precedence.
·
Drainage basins took precedence over utility rights-of-way and vacant
land (1700, 4xxx, and 6xxx).
Land Cover
·
Trees took precedence over shrubs; shrubs took precedence over
herbaceous ground cover.
·
The dominant vegetation class and type took precedence over the less
dominant class and type.
·
Dense trees in recreational areas were separated out if above-MMU and
no built-up areas were included within the tree polygon(s).
·
Above-MMU shrubs and trees within drainage basins took precedence over
the drainage basins.
·
In water polygons that contained landmasses, the water would take
precedence unless the landmass could be reasonably extracted into an above-MMU
polygon.
·
7000 categories normally took precedence over other, non-urban, land
cover.
LU/LC and IS Change Criteria
Change
is defined as a physical difference in the LU/LC type and/or percent of IS visible
when viewing the 2002 and 2007 images for the same geographical area. If the area of change conformed to the project
mapping criteria, the interpreters delineated new boundaries, as needed, and
assigned new codes for the 2002 LU/LC data item. The original polygon boundaries were not
deleted and each affected polygon carried both the original 2002 LU/LC code and
the new 2007 LU/LC class.
Urban, Upland, and Non FWW Wetland Polygons
·
Change was captured and the resulting polygons were coded appropriately
and delineated to match the 2007 imagery.
·
Linework between features was not adjusted when a change to
either one or both resulted in both units sharing the same 2007 LU/LC
and IS codes. This occurred in instances
of physical change to the LU/LC feature within unchanging boundaries and/or
actual changes to the dimensions of the LU/LC feature where both polygons ended
up carrying the same 2007 code structure.
FWW Wetlands (legacy Cowardin polygons)
·
All FWW polygons that underwent change were
delineated (including both built-up and non built-up land use), then it was
delineated and coded for the appropriate code and IS value. If the change took place throughout the
entire FWW polygon, then the entire polygon was coded as a change.
·
If an FWW polygon underwent a change to a specific non built-up urban
or agricultural land use, it was coded as the wetland equivalent of that land
use.
o
If the change resulted in an area of
maintained grassy lawn, it was coded as 1750.
o
If the change resulted in an athletic field,
golf course, ball field, or other recreational land use (but not built-up or
filled), it was coded as 1850.
o
If the change resulted in an agricultural
land use, it was coded as 2140
o
If a 2140 agricultural wetland was no longer
being cultivated and was not built-up, maintained lawn, or a recreational use,
then it was coded as 2150 (Former Agricultural Wetland).
·
If the change involved land cover growth, the FWW code was changed to
the appropriate land cover code. For
example, instances where trees grew from emergent or shrub categories, or where
coniferous shrubs overgrew deciduous shrubs would be coded with the appropriate
land cover value.
·
A
7430 wetland that changed naturally and significantly was changed to the
appropriate wetland vegetation category.
·
If the FWW polygon had changed, and it was considered “negative,” this
was manifested in portions of the imagery where a taller order of vegetation
was replaced with a shorter order. If
the negative change was in the form of man-made disturbance, such as logging,
then the 7430 Disturbed Wetland code was assigned.
·
If non man-made change was observed in an FWW polygon but the affected
area was below MMU and unable to be aggregated, then the linework and code were
left as is. However, if the affected
area was below MMU but able to be aggregated to an adjacent polygon due to
similarity of LU/LC types, the affected area was delineated and coded
appropriately.
·
One example is an above-MMU logged area contained for the most part
within upland tree polygons, but occasionally moving into adjacent below-MMU
sections of wetland polygons. The
below-MMU wetland sections will be delineated and the codes will be changed to
the corresponding upland disturbed code for aggregation purposes.
·
Where bridges crossed over FWW water bodies,
the resulting intersection was delineated as 1419 and assigned an IS value of
zero. The polygon would not contain a
Cowardin item unless supported by history.
·
Wetlands that were not included in the original FWW program, i.e.
saline and tidal wetlands, were mapped per the general LU/LC criteria.
Water
·
For the 2007 mapping effort, an attempt was
made to map all non-tidal water bodies visible on the photography, i.e. there
was no MMU associated with these features.
·
The 2007 imagery reflected exceedingly wet
conditions throughout the state. And
attempt was made to determine whether visible standing water was “permanent” or
the temporary result of spring flooding conditions and/or recent rain events.
·
The 2002 imagery reflected drought
conditions throughout the state. Visible
differences in water levels between the 2002 and 2007 images (wet conditions)
were assessed to determine whether the difference was due to real physical
change in the landscape or to other seasonal conditions.
·
Reservoirs that were drained due to man-made
influences were coded as water, not land.
·
Changes along coastlines, including the shoreline of the
Burned areas
·
In burned areas where there was still viable vegetation (the land cover
type could be readily determined), the polygon in which the burned area was
included was not coded out as burned.
·
For upland
areas where a severe burn occurred (blackened, tree crowns gone), the area was
delineated separately and coded as a change with a LU/LC code of 4500.
·
For wetland areas where a severe burn
occurred (blackened, tree crowns gone), the area was delineated separately and
coded as a change with a LU/LC code of 6500.
Retroactive Mapping
Retroactive (retro) mapping was defined as any
correction to the original 2002 LU/LC data due to changes in classification,
criteria, registration issues, or error in the original photo interpretations. To qualify for retro mapping, the photo
signature in 2007 and 2002 had to be the same, i.e. no detectable change in
LU/LC, and the corrections had to comply with the 2007 mapping criteria.
General Retroactive Mapping Criteria (Cowardin
and non-Cowardin LU/LC)
·
Polygons improperly coded during the 2002
effort were assigned the appropriate LU/LC values for the 2007 update. These values were then retro-mapped back to
the 2002 data.
·
Polygons improperly coded as a result of
the differences in criteria between the 2002 and the 2007 updates were given
the appropriate code in 2007. It was
then retro-mapped to the 2002 data set.
·
Features on the imagery meeting the
minimum mapping unit but not delineated due to photo interpretation error in
2002 were pulled out and retro-mapped.
Non-Cowardin Wetland Retroactive Mapping
Criteria
·
Any or all portions of linework that were
determined to be inaccurate were re-delineated to correlate with the 2007
imagery.
Cowardin Retroactive Mapping Criteria
·
The Cowardin retroactive mapping criteria
developed for the 2002 LU/LC Update was continued for the 2007 project. The FWW legacy criteria allowed for the
correction of registration and coding errors while still retaining the integrity
of the original FWW delineations by adding or sub-dividing the original wetland
units without deleting the original linework.
As a result, the legacy Cowardin code was retained as part of the
polygon history. Where the difference
between the correct location and the 2007 imagery was deemed insignificant, the
polygon boundary was simply adjusted.
·
Wetland polygons containing existing built-up or paved areas were
re-delineated if the non-wetland areas were above-MMU or capable of being
aggregated. Any new polygons were then
retro-mapped back to 2002.
·
Polygons containing below-MMU wetlands adjacent to polygons of like
land use were retro-mapped to re-aggregate the below-MMU wetland with the more
appropriate LU/LC class, using the FWW legacy mapping criteria. For example, where upland agriculture (2100) was adjacent to a wetland deciduous tree
polygon (6210) that included a BR wetland agriculture signature, the wetland
agriculture was delineated out of the 6210 as a separate polygon. The LU/LC class was then changed to 2100 and
retro-mapped back to 2002 but the original Cowardin wetland class for the 6210
was retained in the new polygon history.
Section
6: Data
Dictionary
LU/LC
Land Use
The
current LU/LC
Impervious
Surface.
The
current IS percentage.
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
Distressed Vegetation
1 =
Standing Dead Conifers
2 =
Distressed Vegetation
3 =
Man Made Disturbance (upland vegetation only)
ATTACHMENT A
2007 LAND USE/LAND COVER CLASSIFICATION
NJDEP MODIFIED
Derived from: A Land Use and Land Cover Classification System for Use
with Remote Sensor Data, U. S. Geological Survey Professional Paper 964, 1976;
edited by NJDEP, OIRM, BGIA, 1998, 2000, 2001, 2002, 2007)
(Classes used in current NJDEP mapping program shown in bold)
1000 URBAN OR BUILT-UP LAND
The Level 1 Urban or Built-up Land category
is characterized by intensive land use where the landscape has been altered by
human activities. Although structures
are usually present, this category is not restricted to traditional urban
areas. Urban or Built-up Land Level II
categories include Residential; Commercial and Service; Industrial;
Transportation, Communication and Utilities; Industrial and Commercial Complexes;
Mixed Urban or Built-up; Other Urban or Build-up and Recreational. Included with each of the above land uses are
associated lands, buildings, parking lots, access roads, and other
appurtenances, unless these are specifically excluded.
Urban or Built-up Land takes precedence over
other categories when the criteria for more than one category are met. For example, recreational areas that have
enough tree cover to meet
1100
RESIDENTIAL
The residential
category includes single-family residences, multiple-unit dwellings and mobile
homes. Also included is the mixed
residential group, which is comprised of two or more of the above groups. Residential areas are easily identified on
aerial photographs by the shapes and patterns of individual houses, housing
developments and multiple dwelling (apartment or condominium) complexes. They can also be identified by their
proximity to urban centers or roadways.
Residential areas
which are an integral part of other land uses and located on the site of that
land use are included in that land use category. For example, residential units may be found
on military bases or on college campuses in the form of barracks, apartments or
dormitories. These residences would be
mapped as their associated land use.
Residential area
categories are based on density in terms of dwelling units per acre
(DUPA). In order to determine density at
Level III mapping scale, an acre grid is placed over residential areas on the
photoquad base map and the number of residential structures or portions of a
structure is counted. An average number
of dwelling units per acre is determined and the area is mapped accordingly. Multiple unit structures, such as 2 or
3-family homes, may be included within single-unit residential areas since they
are not extensive enough to be mapped individually. Also, commercial areas too small to be mapped
separately may be found within residential areas.
1110 Residential (High Density or Multiple dwelling)
This category contains either high-density single
units or multiple dwelling units on 1/8 to 1/5-acre lots. These areas are found
in the densely populated urban zones.
1111 Single Unit, High Density
This category
contains single unit residential areas of more than 5 dwellings per acre. These
are generally found in densely populated urban areas.
1112 Multiple Dwelling, Low
Rise (3 stories or less)
This category
contains residential areas of 2 and 3 family homes, row houses and garden apartments of up to 3
stories. These are generally found in
the urban or urban fringe areas of cities.
1113 Multiple Dwelling,
High Rise (4 stories or more)
This category
includes residential areas comprised of condominiums, apartment complexes and
towers of 4 stories or more, generally found in or near urban areas. Multiple dwelling residences can be
identified on aerial photography by their size, height, construction pattern
and the location of driveways and parking lots.
1120 Residential (Single Unit,
Medium Density)
This category is comprised of residential
urban/suburban neighborhoods greater than 1/8 acre and up to and including ½
acre lots.
1130 Residential (Single Unit
Low Density)
This category contains single unit residential
neighborhoods with areas greater than ½ acre up to and including 1-acre lots.
1140 Residential
(Rural or Low Density, Single Unit)
This category contains single unit residential
neighborhoods with lots that are at least 1 acre or larger. This type is found in sparsely populated
regions surrounded by or adjacent to forested or agricultural lands. Also
included are estates or modern sub-divisions with large lot sizes providing a
density lessgreater than or equal to 1 dwelling unit per acre.
1150
Mixed Residential
The
mixed residential category is used for an area where various residential uses
occur and the individual uses cannot be separated at mapping scale (1 acre).
Where more than 1/3 intermixture of other residential use or uses occurs in a
specific area, it is classified as mixed residential. Where the inter-mixtures
of other residential land use or uses total less than 1/3 of the specified
area, the dominant land use category is applied.
Areas that contain structures predominantly used for
the sale of products and services are classified as Commercial and Services.
The main building, secondary structures and
supporting areas such as parking lots, driveways and landscaped areas are also
placed under this category, (unless the landscaped areas are greater than 1
acre in size in which case they are put into a separate category). Sometimes non-commercial uses such as
residential or industrial intermix with commercial uses making it difficult to identify
the predominant land use. These
categories are not separated out; but, if they exceed 1/3 of the total
commercial area, the Mixed Urban category (16) is used. Often, specific uses of some commercial and
services buildings cannot be easily identified from photography alone. Some supplemental information is required.
These areas generally have a high percentage of impervious surface
coverage. Any of the specific uses
listed below may be included in the 1200 category, with the exception of Military Installations
which are delineated separately under the code 1211, and Former Military;
Indeterminate Use which are delineated under the code 1214.
1201 Central Business
District (CBD)
These are the
"downtown" banking and commercial centers of cities or towns where
land use is largely undifferentiated.
Retail stores, banks, office buildings, post offices, libraries,
firehouses and courthouses are examples of structures that may comprise a
CBD. Some public land uses such as
schools and cemeteries are separated out into other categories if they are of a
mappable size.
CBDs can exist
in any size city or town. Metropolitan
CBDs can be easily identified by their large number of high-rise buildings
surrounded by parking lots. They are usually easily accessed by interstate
bypass routes. Medium-size CBDs contain
3 and 4 story buildings fronted by parking spaces. They are away from the main traffic
intersections of cities and often expand outward from railroad lines. Small towns CBDs contain 2 or 3 story
buildings that line the streets and are in close proximity to residential
structures. They usually parallel main
traffic arteries.
1202 Commercial Strip
Development
This is the
commercial activity developed along major highway and access roads to cities
and towns in a more or less single strip.
Motel accommodations, car dealers, fast food services, gas stations and
other similar goods and services establishments are examples that may comprise
a Commercial strip. Location of these
building along a main vehicular transportation route is the key criterion. Frequently, especially in suburban areas,
residential and industrial land uses intermix with Commercial Strip
Development. When these uses exceed 1/3
of the total contiguous length of the Commercial Strip, the Mixed Urban
category is used.
1203 Isolated Commercial
Establishments for Goods and/or Services
This category
pertains to commercial establishments providing goods and services for direct
consumer use. Isolated single commercial
buildings or isolated cluster of commercial buildings that are not part of a
Commercial Strip Development or a well-defined CBD are included in this
category.
These buildings
are distinguished from Isolated Commercial Office Buildings (1204) because they
provide goods and services for direct consumer use while 1204 does not. Some examples are fast food services, dry
cleaners, gas stations and banks.
Professional buildings that house medical offices, real estate brokers,
law firms and travel agents are included in this category as well.
1204 Isolated Commercial
Office Buildings
This category
pertains to scattered commercial development, specifically commercial office
buildings (not providing goods and services for direct consumer use). Isolated single commercial buildings or
isolated clusters of commercial buildings that are not part of a Commercial
Strip Development or well-defined CBD are included in this category. These buildings are distinguished from the
Isolated Establishments for Goods and Services because they do not provide
products and services directly to the consumer.
Buildings can house administrative and support staffs for large
corporations or staffs for several smaller businesses. These buildings can range in size from 2 to 3
stories to high-rise structures.
When several
Commercial Office Buildings exist together and share common driveways, parking
lots and lawns they are placed in the industrial and
1205 Shopping Centers
A Shopping
Center is a group of retail stores and other commercial establishments planned,
developed, owned and managed as a unit, with off-street parking provided on the
property. Shopping centers range in size
from those of just a few thousand square feet to plazas covering acres. Key identification features are large and
often interconnecting buildings surrounded by well-paved parking lots located
near interchanges and highways.
Retention ponds located on the property, if of a mappable size are
included in the
1206 Resorts, Hotels,
Motels & Related facilities
These facilities
usually associated with leisure time activities contain over-night
accommodations, dining facilities, services and recreational activities. They range in size from converted farm houses
to luxury resort hotels. Features that
help define them such as tennis courts, pools, golf courses, ski slopes and
well kept lawns and gardens are all included in the category. (These features are included with the resort
since they are private and not accessible to non-paying guests). Hotels within urban areas are generally not
mapped separately because they are difficult to distinguish from other
commercial buildings.
1207 Educational
Institutions
This category
includes all levels of public and private schools, colleges, universities and
training centers. All buildings, campus
open space, dormitories and parking areas are included. Not included are recreational facilities such
as ball fields, tennis courts, stadiums and swimming pools. These recreational facilities are included in
Recreation (18) if they are of a mappable size.
Universities can often be identified by a maze of walkways linking
various buildings. Elementary and
secondary schools are usually 1 or 2 story buildings surrounded by recreational
fields and located in residential areas away from high traffic volumes. Any educational activity associated with
religious institutions involving parish schools, seminaries, orphanages and
novitiates, if of a mappable size, are included in this category.
1208 Health Institutions
Any facility
providing direct health care to the public such as hospitals, mental health
institutions, sanitariums, special care centers, major clinics and nursing
homes are included in this category.
Some identifiable features may include circular drives, covered main
entrances, multi-story buildings with wings, large parking lots and spacious
grounds.
1209 Correctional
Institutions
Prisons and
rehabilitation centers make up this category.
They can be identified by high walls and controlled access points. Topographic maps should be consulted to make
sure minimum security prisons are not over-looked. Land uses, such as farmland or quarries
associated with prisons are mapped separately according to their appropriate
lane cover/land use category.
1210 Government Centers
This category
includes any state, regional, county or municipal office buildings. They can range in size from 1 or 2 story
buildings to high-rise complexes. Any
government office located in the CBD (1201) or along a Commercial Strip (1202)
is included in those categories unless it is of a mappable size.
1211 Military Installations
Military bases and camps, armories, ordinance
depots, missile sites, National Guard and Reserve armories are included in this
category. Boundaries of major military
installations are generally identified by fence lines and roads along their
perimeter. Military facilities have a
wide variety of conditions including training camps, missile sites, etc. Auxiliary land uses, particularly
residential, commercial and other supporting uses located on a military base
should be included in this category.
1212 Other Institutional
This category
includes any other institutions not included in the other categories. Some examples are churches, synagogues,
convents, special research facilities, medical research facilities not open to
the public, and social clubs associated with established organizations.
1213 Mixed Commercial &
Services
This category is
used when a mix of various commercial uses and services exist and no one
category predominates. When more than
1/3 of one commercial use is mixed with another use this Mixed category is
used. Where the intermixture total is less
than 1/3 then the dominant use is mapped.
1214 Former Military;
Indeterminate Use
Included in this category are portions of former
military installations that have been de-commissioned and sold. New development of these areas has not yet
begun, so particular use cannot be determined from the photography. Many of the undeveloped portions of these
former military sites may remain as preserved undeveloped open space. Developed areas may be re-developed for other
uses. However, in all cases, the new
intended use is not discernible from the latest available photography, or other
ancillary data.
1300 INDUSTRIAL
This category encompasses a great variety of structure types and land uses. Light and heavy industry are comprised of land uses where manufacturing, assembly or processing of products takes place. Power generation is included here because of its similarity to heavy industry. These areas generally have a high percentage of impervious surface coverage.
1310 Light Industrial
Light industry
deals with design, assembly, finishing, packaging, and storing of products or
materials that have usually been processed at least once. These activities are characterized as
"clean", since they produce a relatively small amount of smoke and
other effluents, noise, and dust.
Light industries
include facilities for administration, research, assembly, storage,
warehousing, and shipping. Examples are
electronics firms, trucking companies, small textile mills, and auto assembly
plants. Characteristic features may
include the nature of the buildings, parking and shipping arrangements, the
presence of outdoor storage facilities, trailer trucks, loading docks, rail
lines, power sources and smokestacks.
1320 Heavy Industrial
Heavy industry
involves the processing of raw materials such as iron ore, timber, petroleum or
coal, or the fabrication and assemblage of parts that are bulky and heavy
Examples of
heavy industry are steel, pulp, and lumber mills, oil refineries and tank
farms, chemical plants, and grain mills.
Recognizable features include blast furnaces, kilns, chemical processing
towers, large chimneys or stacks, fuel tanks, boiler house, transformer yards,
silos, bins and piles and ponds of water.
Also included in this category are surface structures associated with
mining operations: loading devices, trucks, access roads processing facilities,
stock piles, and storage sheds.
1330 Power Generation
There are three
main types of power generators: thermal, nuclear and hydroelectric. Features common to all three types are the
presence of transmission lines and transformer yards, and often, proximity to
water.
Both thermal and
nuclear plants usually have cooling towers for used water. Thermal plants often have associated coal
piles and conveyor belts leading to the main plants. Nuclear plants have a characteristic nuclear
reactor building. Hydroelectric plants
are usually at the dams of large reservoirs or impounded streams, or at an
elevation break on a watercourse.
Typical features include a dam and trailraces.
1400 TRANSPORTATION,
COMMUNICATION & UTILITIES
The transportation,
communication, and utilities land uses are often associated with the other
Urban or Built-up categories since they often do not meet the project minimum
mapping unit therefore they are often captured with the land use in which they
occur. The presence of major transportation
routes, utilities such as sewage treatment plants and power lines, and
communications facilities greatly influence both the present and potential uses
of an area.
1410 Major Highways
Major highways typically contain at least two lanes
in each direction, separated by a concrete barrier or median strip. There are usually no cross streets or traffic
lights, and access is limited to ramps.
Included in this category are service (rest) areas, right-of-ways,
interchanges, maintained hillsides, and other service and terminal
facilities. Examples are interstates,
Major highways are characterized by
"diamond" and "clover-leaf" patterns of ramps, crossroads
intersecting via underpasses or overpasses, and the lack of adjacent residential,
commercial, or industrial development, with direct connections to the
highway. Major highway right-of-ways are
often bounded by fences or drainage paths.
1411 Mixed Transportation Corridor Overlap Areas
(2007)
Mixed transportation overlap areas are places in the
data where railroads (1420) and roads (1400/1410) intersect. The 1411 captures segments of the
road/railroad that define the major point of intersection and includes at-grade
crossings as well as railroad and road bridges.
This category does not include road (1400) over road (1410)
intersections, auto or rail bridges over water (1419). This category was created to provide
continuity of the railroad and road transportation networks for analysis
purposes.
1419 Bridges Over Water
Bridges over water are areas in the data set where
polygonal water bodies intersect major highways. The 1419 code captures segments of road that
are considered bridges, as beneath them, water flow is continuous and uninterrupted. Only the section of road that is
representative of the criteria should be pulled out as a bridge over water; the
rest of the highway will remain in the 1400/1410 class.
1420 Railroad Facilities
Railway facilities include railroads and spurs as
well as stations, parking lots, roundhouses, power generators, and repair and
switching yards. Spurs that connect single
industrial or extractive pick-up points with main rail lines are included in
the appropriate industrial or extractive category. Spurs that connect multiple industrial uses
are included in the railroad class.
1430 Bus and Truck
Terminals
Bus and truck
terminals are characterized by long buildings with truck trailers or buses
adjacent to them. There are large paved
areas surrounding the garages, which are used for maneuvering and parking. Terminals are often located in close
proximity to major transportation routes.
1440 Airports
Airports are characterized by areas cleared of
vegetation and other obstructions; also, the presence of long, linear runway
surfaces. They vary from rural grass
landing strips to vast urban complexes.
Typical moderate to large-sized airports contain
parallel primary runways, smaller parallel taxi strips, intervening land,
aircraft parking aprons, hangars, terminals, service buildings, navigation
aids, fuel storage areas, parking lots, and limited buffer zones. This category also includes heliports and
land associated with seaplane bases. It
does not include small airports on rotated farmland.
1450 Port Facilities
Seaports are isolated areas of high
utilization with no well-defined intervening connections. Included in this category are docks, piers,
shipyards, drydocks, locks, waterway control structures, buildings, parking
lots and adjacent water utilized by ships in the loading or unloading of cargo
or passengers.
1460 Power
Facilities
Power facilities include power substations and transmission line
right-of-ways where the right-of-way is clearly visible on aerial photography
and not used for any other purpose. For
example, transmission line right-of-ways are clearly discernible where they
traverse forest: there are no trees, and vegetation growth is controlled
through mowing or herbicides.
Right-of-ways in agricultural land are difficult or impossible to see
because there is usually no demarcation from the surrounding land. Additionally, the surrounding agricultural
activity also occurs in the right-of-way most of the time. A right-of-way would
be mapped as a power facility when traversing forest, but would be mapped as a
Level III agricultural category when traversing agricultural land.
On aerial photography, power substations appear as geometric
configuration with associated transformers and transmission lines. Those associated with an industrial,
commercial, or extractive land uses are included in that category.
1461 Wetland Rights-of-Way
Included
in this category are rights-of-way that exist in former wetland areas, and
which still exhibit evidence of soil saturation on the photography. Because of alterations associated with
creating the rights-of-way, these areas may not support the typical natural
wetland vegetation found in adjacent unaltered natural areas. They do, however, exist in areas shown on the
Natural Resources Conservation Service soil surveys to have hydric soils, and
exhibit the darker tonal signatures associated with saturated soils on the
photography. Colors of these areas will
vary generally from blue-gray to black on winter CIR film and dark gray to
black on panchromatic film. Textures will
generally be smooth to slightly rough depending on whether the dominant
vegetation is low herbaceous species or taller shrubs.
1462 Rights-of-Way
(Developed)
Included
in this category are upland rights-of-way that exist in Developed non-Urban
areas. These rights-of-way are defined
for the purposes of this project as utilities, meaning they are not necessarily
electrical rights-of-way. This category
includes lands adjacent to agricultural areas but not visibly used in
connection with any agricultural land use. Because of alterations associated
with creating the rights-of-way, these areas may not support the typical
natural vegetation found in adjacent unaltered natural areas. Textures will generally be smooth to slightly
rough depending on whether the dominant vegetation is low herbaceous species or
taller shrubs.
1463 Rights-of-Way
(Undeveloped - Vegetated)
Included
in this category are upland rights-of-way that exist in undeveloped non-Urban
areas. As in the 1462 category, these
rights-of-way are also defined as utilities, meaning they do not only include
electrical rights-of-way. Lands adjacent
to agricultural areas but not visibly used in connection with any agricultural
land use are included in this category. Because of alterations associated with
creating the rights-of-way, these areas may not support the typical natural
vegetation found in adjacent unaltered natural areas. Textures will generally be smooth to slightly
rough depending on whether the dominant vegetation is low herbaceous species or
taller shrubs.
1470 Water Treatment
Facilities
Water treatment
facilities consist of buildings with adjacent circular or rectangular
tanks. They are usually restricted to
moderately sized towns and cities, rather than rural areas. Water treatment facilities and sewage
treatment facilities are often similar in appearance on aerial
photography. However, many water
treatment facilities are upstream from the community served, whereas the sewage
treatment facilities are often downstream.
1480 Sewage Treatment
Facilities
Sewage treatment
plants are often adjacent to streams or rivers.
Identifiable features include an array of rectangular or circular tanks
for initial processing, settling and aeration, and associated low buildings. Like water treatment facilities, they are
usually restricted to moderately sized towns and cities rather than rural
areas, where individual septic systems are prevalent. Also included in this category are pumping
stations, sewage mains, and tertiary treatment fields.
1490 Other
Transportation, Communication and Utilities
This category consists of related facilities not included in any of the
previous Level III categories. Included
are radio, radar, and television antennas, microwave stations, water towers,
and lighthouses. Towers include the land
enclosed by guide wires. Fence-lines,
trimmed or mowed grounds, and access roads are associated with many of these
facilities.
1499 Stormwater Basins
Stormwater
Basins are a common feature in newer developments. They are typically located in office parks,
commercial and industrial parks, and newer residential developments. They are often identifiable by the curved
boundaries, interior drainage lines, and characteristic depressional
shape. Water may or may not be present
at the time the photography is taken; since it is considered to be dynamic, the
drainage basin code should take precedence unless there are indications that
the water is a more permanent feature, i.e. aeration fountains, etc. In those situations, the water within the
basin should be placed in the 5300
This category
also includes drainage basins, which are not as well-maintained, and therefore
more difficult to map. In this
classification, land cover takes precedence over the drainage basin
structure. Those that have only
herbaceous vegetation covering their surfaces will be mapped as 1499; those
that are covered in shrubs and trees will be mapped in the appropriate
vegetation class (4XXX/62XX).
1500 INDUSTRIAL & COMMERCIAL COMPLEXES
The Industrial and Commercial Complexes category includes
those industrial and commercial land uses that typically occur together or in
close proximity. These areas are
commonly referred to as "Industrial or
Industrial and Commercial Complexes are usually located in suburban or rural areas. The key identifying feature is the planned layout of buildings exhibiting the same or very similar construction. Other identifying features include well kept lawns and landscaped areas, ample parking areas and common roadways connecting buildings that also provide access to major highways. The lack of smokestacks, storage tanks, raw materials or finished products, and waste signifies that no heavy industries are present. These areas generally have a high percentage of impervious surface coverage (~85%) and some may be up to 100%.
1510 Industrial and
See category 15
for description. Clusters of commercial
office buildings that happen to exist side by side but do not share common
roadways and landscaped areas are included in the Isolated Commercial Office
building category (1204).
1600 MIXED URBAN OR BUILT-UP
This category includes those urban or built-up areas for which uses cannot be separated into individual categories at the mapping scale employed. Areas are identified under the mixed urban category when more than one-third intermixture of another use or uses is evident.
Uses considered in mixed urban include primarily residential,
commercial/service, industrial and transportation/communication/utility. Not included in the category are areas
considered part of a definable commercial strip as described under 1202. In addition, open land that could be
classified for any agricultural use would not be included in the mixed urban
category.
Level 3 divisions of the Mixed Urban category involve separating the mixed areas based on the predominant use in the intermixture, if one is evident.
1610 - Predominantly Residential - (>50%,
but <66% of the use can be identified as Residential).
1620 - Predominantly Commercial/Service - (>50%, but <66%
of the use can be identified as Commercial/Service).
1630 - Predominantly Industrial - (>50%, but <66% of the
use can be identified as Industrial).
1640 - Predominantly Transportation/Communication/Utilities
- (>50%, but <66% of the use can
be identified as Transportation/Communication/Utilities).
1650 - Heterogeneous Mixture - (No single use in the
intermixture comprises more than 50%).
1700 OTHER URBAN OR BUILT-UP
Included are undeveloped, open lands within urban areas. Some structures may be visible, as in the
case of abandoned residential or commercial sites that have not yet been redeveloped. Other areas may be brush-covered or
grassy. Large, managed, maintained lawns
common to some residential areas, and those open areas of commercial/service
complexes, educational installations, etc., are also included. Undeveloped, but maintained lawns in urban
parks are also part of this category, if a specific recreational use is not
evident. In addition, areas that have
been partially developed or redeveloped but remain unfinished are included. Also included in this category are
cemeteries.
1710 Cemeteries (2002)
These areas represent large tracts of primarily open
land within urban areas. Large
cemeteries can be identified by layout of driveways, lots, mausoleums and
marking stones. Cemeteries associated
with small towns, individual churches or family estates may not be easily
identifiable. Supplemental information
is often needed to identify these smaller cemeteries.
1711 Cemeteries
in Wetlands (2002)
This category
represents those areas that lie within cemetery boundaries and can be
classified as wetlands. Maintained lawn
areas that are not part of the cemetery but instead lie adjacent to the
property will be mapped in the 1750 category.
As with the 1710 category, collateral information or field verification
is usually needed to delineate these boundaries.
1720 Undeveloped Land
Within Urban Areas
Within this
category are those areas generally considered vacant lots. These areas may never have been developed, or
may represent formerly built-up that have been entirely or partially cleared,
but not redeveloped. Included would be
abandoned manufacturing or commercial sites that could be redeveloped. Areas within this category are generally
brush or grass-covered and may or may not be maintained. Buildings may be present, interspersed with
brush areas and concrete or black top.
1730 Inactive Land With
Street Patterns
This category
represents areas for which development or redevelopment was started, but which
has been abandoned after some street construction has been completed. No active development is visible. These areas typically would support
residential developments if completed, but some industrial or commercial
development may be found here. These
areas generally have low vegetative cover, possibly with sporadic trees and may
or may not be maintained.
1740 Open Areas
Included in this
category are miscellaneous open areas within urban settings that do not fall
into any of the other categories. Many
areas identified as 174 have planned and maintained feature, such as a central
lawn area within a suburban development or a commercial and/or corporate
complex, that provides "open space.”
Some areas that are not maintained may be included here.
This category contains herbaceous vegetation in urban settings
dominated by Phragmites australis. The photographic signatures for these
areas are rough and puffy and range in color from tan to pale white.
Included in this category are former natural wetland areas
that now are part of an altered managed landscape, but which still exhibit
signs of soil saturation on the imagery.
These areas do not support typical wetland vegetation, but are vegetated
primarily by grasses and other planted vegetation that may be routinely mowed.
Examples of this category would be maintained open lawns and storm water
swales in residential, commercial or
industrial areas. None of the wetlands
included in this category are routinely inundated, although the swales may be
on occasion. These altered wetlands exist on areas shown on the
1800 RECREATIONAL LAND
Included in this category are those areas that have been specifically developed for recreational activities, provided they are open to the general public. Any facilities that are part of a resort complex and open only to patrons of the hotel or motel are not mapped under category 18, but under Commercial and Services category. Facilities mapped as recreational land may charge user fees to the public, such as public golf courses; or, they may be free to the public, such as ball fields on public school grounds. Level III divisions of this category involve identifying the predominant recreational uses of the areas.
1801 Golf Courses
All par 3
courses and above are included, both public and private, unless associated with
a resort hotel/motel. Courses can be
identified by greens, fairways, sand traps, water hazards, club houses, and
parking areas. Additional facilities
often associated with golf courses, such as tennis courts, pools, parking, etc.
are not identified separately but included in the 1801 category. Ponds, wetlands and other water bodies are,
however, identified separately under the appropriate category if they meet
minimum polygon size.
1802 Picnic and Camping
Parks
This category
includes areas that are set aside for picnicking and camping specifically and
associated activities (hiking, etc.).
Commercial and private tent and trailer campgrounds are included, unless
they are part of a resort complex. Any
open areas associated with either picnicking or camping areas that exceed one
acre are mapped out under category 1809.
Supplemental information may be needed to identify picnic or camping
areas in forested regions.
1803
Public and
private facilities consisting of docks, storage, storage buildings, boat ramps,
jetties, piers, and parking areas are included in this category. Boats may or may not be visible because of
photo scale. Small, primarily state-owned launching sites will generally not be
visible on the small scale air photos.
1804 Community
Recreation Areas
This category
encompasses athletic and recreational facilities that are only associated with
schools, such as football stadiums, soccer and baseball fields, pools, and
other miscellaneous recreational areas.
Not included in this category are maintained lawns that occur within the
boundaries of the school; these will instead be left in the 1200 category or
mapped as 1700 if above MMU. Also not
included in this category are athletic and recreational fields that are
associated with adjacent parks or residential areas.
1805 Parks
City, town,
county and state parks that are maintained by a government agency are included
in this category. What is actually
mapped in this category is park headquarters, parking lots and accessory
buildings. Open areas, swimming pools
and beaches, golf courses, picnic and camping facilities, etc. are mapped
separately under their appropriate category.
1806 Swimming Pools
Included are
public and commercial facilities such as swim clubs and city-operated
pools. Pools associated with country
clubs, motels, resorts and private residences are not mapped. Support buildings and parking areas are mapped
in this category, as are any tennis courts, etc. which may be associated with
the pool.
1807 Swimming Beaches
These areas are
specifically man-made beaches adjacent to lakes or ponds, which have been
developed for recreational activities.
Parking areas are included, but the water is identified under the
appropriate water category.
1808 Formal Lawns,
Arboretums and Landscaped Areas
Included are
landscaped areas that are associated with facilities open to the public such as
gardens. Similar areas associated with
private estates are not included within this category. Public facilities are identifiable by general
layout, associated roadways, parking areas, and support buildings, all of which
are mapped as part of 1808.
1809 Open Areas in Parks
This category
includes any open area within a city, town, county, or state park that meets
minimum mapping polygon size and which is not developed for any specific
recreation activity.
1810 Stadium, Theaters, Cultural Centers, and Zoos
Included in this category is any entertainment
facility that is developed for public use.
Stadiums, outdoor concert halls, racetracks (horse and car), drive-in
theaters, amusement parks, and zoos are the primary facilities involved. Such facilities are primarily commercial,
although some public recreation areas may be found. Not included are similar facilities on
private property, such as horse tracks within private farms that are open to
the public. Parking areas, driveways,
and support buildings are mapped in this category.
1811 Other Recreational
Included are
rifle, skeet, and archery ranges, ski and winter sport areas, fairgrounds,
etc., that do not fall into any of the above categories. These areas often have conspicuous signatures,
such as ski runs, but form a small part of the land area of
1850 Managed Wetland in
Built-up Maintained Recreation Area
Included in this category are former natural wetland
areas that now are part of an altered managed recreational area, but which
still exhibit signs of soil saturation on the imagery. These areas do not support typical wetland
vegetation, but are vegetated primarily by grasses and other planted vegetation
that may be routinely mowed. Examples of
this category would be saturated portions of golf courses, and fields used for
baseball and other sports in designated recreation areas. None of the wetlands included in this
category are routinely inundated, although portions may be on occasion. These
altered wetlands exist on areas shown on the
2000 AGRICULTURAL LAND
This Level I category includes all lands used
primarily for the production of food and fiber and some of the structures
associated with this production. These
areas are easily distinguished from the other categories and represent a
significant land use in
2100 CROPLAND AND PASTURELAND
This Level II category contains agricultural lands managed for the production of both row and field crops and for the grazing of cattle, sheep and horses. Also included in this category are croplands left fallow or planted with soil improvement grasses and legumes. Cropland and pastureland can easily be distinguished from other land uses with large-scale imagery.
2110 Harvested Cropland
This category
contains agricultural areas that are managed for the production of harvested
row or field crops. These include row
crops, such as corn, soybeans, cabbage, and potatoes; or field crops
predominately used as forage, such as hay or alfalfa. Row crops are easily identified on imagery
because of the striations and the regular patterns. However, there are problems distinguishing
between field crops, such as hay or winter wheat, from pastureland.
Pastureland can
be distinguished because of its close association with farm structures such as
barns or feeding stations. Also,
pastureland usually has a slightly more mottled or uneven tone than the
photographic signature of field crops.
2120 Pastureland
This category
contains agricultural areas that are managed as pasture areas for livestock
grazing. These areas may be either
permanent pastures or tillable cropland that is used as pasture at the time of
photography. The identification problems
using imagery alone are discussed in Section 2110. Identification of pastureland, field
cropland, and inactive cropland may require field verification or other
supplemental information. Pasture may be
covered by some brush but are included in 2120 if the predominant use is for
pasture.
2130 Inactive Cropland
This category
contains agricultural areas that have no physical indication of present
agricultural use. These areas include
both abandoned cropland and fields left fallow or planted in soil-improving
grasses and legumes. An indication of
inactive cropland is the presence of any woody stems in the field. The area is placed in the Brushland category
if the woody stems cover is abundant and the field appears to be abandoned
rather then left fallow for soil improvement.
An area is placed in Brushland as either Old Field (4410) or
Brush/Shrubland (4430,4440) depending on the percentage of brush cover.
2140 Agricultural Wetlands
Included
in this category are lands under cultivation that are modified former wetland
areas, and which still exhibit evidence of soil saturation on the
photography. Included in the 2140
category are cranberry bogs and blueberry farms, as well as other types of
wetland agriculture. These lands will
exhibit the textural signature characteristics described for the other
agricultural categories, but will have darker color and tonal signatures. Colors will range from blue-gray to black on
winter CIR film and dark gray to black on panchromatic film. In addition, these agricultural wetlands also
exist in areas shown on soil surveys of the Natural Resources Conservation
Service to have hydric soils.
2150 Former Agricultural Wetlands- Becoming
Shrubby, not Built-up
This
category was added to identify areas coded as 2140 in the baseline data set,
but which do not appear to be under active cultivation in subsequent
years. These areas have not undergone
any other alterations, such as filling, grading or development, and may again
be returned to the 2140 category if the farmland is again placed under
cultivation. However, these wetlands may
continue to develop into a scrub/shrub wetland area if active cultivation is
not resumed. As areas in a state of
flux, they have been given a separate code.
2200 ORCHARDS, VINEYARDS,
NURSERIES AND HORTICULTURAL AREAS
This Level II category contains agricultural areas, which are
intensively managed for production of fruits, trees, ornamental plants, and
vegetable seedlings. Wholesale
greenhouses where plants are grown are also included in this category as are
orchards, nurseries, blueberry farms, vineyards, sod and seed farms, and
commercial greenhouses. Areas delineated include actively cultivated lands as
well as land associated with the operations as, uncultivated lands, dirt roads,
dikes, etc.
2210 Orchards
This category
contains agricultural areas that are intensively managed as commercial
orchards. Established orchards are
easily recognized on the imagery by the regular grid patterns of the planted
trees. Newly planted orchards are more
difficult to identify, but the signature can be distinguished from adjacent
cropland.
2220 Vineyards
This category
contains agricultural areas of intensively managed vineyards. These areas can be recognized by a
"cross-hatched" pattern cause by the Vines trained on wires and the
poles used for support in the form perpendicular lines.
2230 Nurseries
This category is
comprised of areas that are intensively managed for commercial or private
nurseries. Nurseries can be recognized
as narrow fields with very regular and definite rows. The colors are usually darker in tones than
other cropland. Different shades and
tones are present in adjacent fields due to the different stages of seedlings
or saplings planted. These shades and tones
in the narrow fields present a different signature from other agricultural
areas. Christmas tree farms are included
in this category.
2240 Floriculture
This category
contains areas occupied by wholesale producers of flowers, nursery stock,
produce, and vegetable seedlings. These
areas consist of large greenhouse operations and the associated land and
buildings. Retail greenhouse should be
included in a Commercial and Services category.
Retail greenhouses can be distinguished from wholesale greenhouse
operations by their size, amount of associated land, available customer parking
and general location. Hobby greenhouse
associated with private homes will not by mapped.
2250 Sod and Seed Farms
This category
contains commercial sod and seed farms. These areas can be identified on the color
infrared (CIR) imagery by an even-tone deep red signature. This signature is similar to a
well-maintained golf course, but is a deeper shade of red (Note: red on CIR
represents green in true color). These
operations are usually substantial in size, occupying more than 50 acres. When harvesting procedures are in progress,
the signature may exhibit some strips of bare ground. These sod farms are often located near
potential markets.
2260 Cranberry Farms
This category is
comprised of intensively managed cranberry farms primarily located in southern
2270 Inactive
This one
category is used to represent lands occupied by abandoned or inactive orchards,
vineyards, nurseries, and cranberry and blueberry farms. For orchards, vineyards, and nurseries, the
inactive signature appears similar to the active signature, except the patterns
will be less regular. Natural vegetation
growing in the abandoned areas will cause irregular patterns and differing
textures in the signature. In some
cases, the trees may be removed and earlier photography or supplemental
information may be necessary to place the area in this category. Inactive
cranberry and blueberry farms may be difficult to distinguish from the Wetlands
Brushland/Bog areas.
2280 Blueberry Farms
This category is
comprised of intensively managed blueberry farms primarily located in southern
2300 CONFINED FEEDING OPERATIONS
This Level II category contains specialized livestock and poultry
production enterprises and other specialty farms. These operations have high populations in
relatively small areas, resulting in a concentration of waste material. Since this concentrated animal waste is a
critical environmental concern, these areas warranted a specific Level II
category. Normal structures [barns]
associated with a farmstead are not mapped in this category.
2310 Cattle and Swine
Feedlots
This category
contains mainly beef cattle feedlots and hog farms. Structures and attached corrals will be
mapped in this category, but any substantial acreage of associated pasture will
be mapped as Pastureland.
2320 Poultry Farms
This category is
comprised of chicken, turkey, and duck production enterprises. These farms may be for either egg or meat
production.
2330 Specialty Farms
This category
contains specialized farms, such as game farms [pheasant or quail], fish
hatcheries, goat farms, pigeon-raising areas, and rabbit production farms.
2400 OTHER AGRICULTURE
This category contains other miscellaneous
agricultural areas, including experimental fields, horse farms and isolated
dikes and access roads.
2410 Experimental
Agriculture Fields
This category
contains experimental crop areas associated with agriculture research stations,
universities, or industries. These areas
are for research purposes and contain many different crops in one field.
2420 Isolated Structures
for Crop or Equipment Storage
This category
contains storage buildings which are not adjacent to the farmsteads. These areas include isolated grain silos,
crop storage sheds, and sheds for storage of farm machinery.
2430 Horse Farm
This category
contains specialized farms for raising and training horses. This includes horse barns, corrals, and
training racetracks. The oval training
racetracks are easily recognized on aerial photography. Extensive acreage of pasture associated with
a horse farm is mapped as Pastureland (2120).
2440
Agricultural Dikes/Roadways
Included are non-cultivated portions of
special agricultural areas such as dikes or roadways found in blueberry or
cranberry farms. These features may be
the only portions of these farm categories that are not inundated during
certain portions of the growing season, and provide access to the wetter
cultivated portions of these farms.
3000
RANGELAND
Rangeland is not found in
4000 FORESTLAND
This Level I category
contains any lands covered by woody vegetation other than wetlands. These areas are capable of producing timber
and other wood products, and of supporting many kinds of outdoor
recreation. Forestland is an important
category environmentally, because it affects air quality, water quality,
wildlife habitat, climate, and many other aspects of the ecology of an
area. The Level II categories under
Forestland are Deciduous; Coniferous; Mixed Deciduous-Coniferous; and
Brushland.
4100
DECIDUOUS
This
Level II category includes forested lands that contain deciduous tree
species. The average height of the stand
is at least 20 feet. Areas with woody
vegetation less than 20 feet high should be placed in the Brushland category. A forest stand must have at least 75% canopy
coverage from deciduous tree species to be placed in this category.
Deciduous
trees are those species which lose their leaves at the end of the growing
season. These trees remain leafless
throughout the winter and sprout new leaves the following spring.
4110 Deciduous, 10-50% Crown
Closure
This category contains deciduous forest stands that
have crown closure greater than 10%, but less than 50%. Crown closure is the percentage of a forest
area occupied by the vertical projections of tree crowns. Crown closure percentages provide a
reasonable estimate of stand density.
An ocular estimate of percent crown closure is made
while viewing the area stereoscopically.
The ocular judgement is a reliable estimate since the category levels
for closure are relatively broad: 10-50%
and > 50%. This procedure will also
be followed to determine percent crown closure in the other categories.
4120 Deciduous > 50% Crown Closure
This category contains deciduous stands with crown
closures greater than 50%. The majority
of the deciduous forests in
4200
CONIFEROUS
This Level II category includes forested lands which contain coniferous tree species. The stand must be 20 feet high and must be stocked by at least 75% conifers to be labeled as a coniferous stand.
Coniferous species are those trees commonly known as evergreens. They do not lose their leaves (needless) at the end of the growing season but retain them through the year. Conifers can easily be distinguished from deciduous trees on wintertime color infrared photography because of their high infrared reflectance due to their leaf retention.
4210 Coniferous, 10-50% Crown Closure
This category contains natural coniferous stands
with crown closure > 10%, but less than 50%.
4220 Coniferous, > 50% Crown Closure
This category contains natural coniferous stands
with crown closure > 50%.
4230
This category contains conifer stands that have been
artificially planted. These include
stands planted for timber harvesting or aesthetics. Crown closure estimates will not be
determined for plantations. Plantations
appear as uniform blocks (usually rectangular) of conifers.
Other planted stands of conifers, such as Christmas
tree farms, will not be included in this category but in the nursery category
under Agriculture.
4300
MIXED DECIDUOUS/CONIFEROUS
This Level II category consists of forested areas where there is a mixture of coniferous and deciduous trees. If less than 75% of the forest is dominated by either type then the stand is placed in the mixed category. Only forest stands greater than 20 feet in height will be placed in this category.
4310 Mixed
with Coniferous Prevalent (> 50% Coniferous)
This category contains stands of mixed coniferous and deciduous trees.
The percentage of coniferous trees is higher than the deciduous (>50% of the
stand) but the coniferous species do not dominate the stand ( <75%).
4311 Mixed with Coniferous Prevalent (10%-50%
Crown Closure)
This category contains stands of mixed coniferous
and deciduous trees with the coniferous species > 50% and with crown
closures between 10% and 50%.
4312 Mixed
with Coniferous Prevalent (> 50% Crown Closure)
This category contains stands of mixed coniferous
and deciduous trees with the coniferous species > 50% and with crown
closures > 50%.
4320 Mixed
with Deciduous Prevalent (> 50% Deciduous)
This category contains stands of mixed deciduous and coniferous
trees. The percentage of deciduous trees
is higher than the coniferous (> 50%), but the deciduous species do not
dominate the stand (< 75%).
4321 Mixed with Deciduous Prevalent (10%-50%
Crown Closure)
This category contains stands of mixed deciduous and
coniferous trees with the deciduous species > 50% and crown closures between
10% and 50%.
4322 Mixed
with Deciduous Prevalent (> 50% Crown Closure)
This category contains stands of mixed deciduous and
coniferous trees with the deciduous species > 50% and crown closures >
50%.
4400
BRUSHLAND/SHRUBLAND (Height<20 feet)
This
Level II category contains forestlands, which are predominately between 0 and
20 feet in height. Vegetative
communities in these areas may range from early successional species which are
only a few years old, to climax or sub-climax communities which are many years
old. Also included in this category are
old fields that are covered primarily by grasses and some shrubs. Brushland areas represent critical habitat
for many species of wildlife in
4410 Old Field (<25% Brush Covered)
This category includes open areas that have less
than 25% brush cover. The predominant
cover types are grasses, herbaceous species, tree seedlings and/or
saplings. Old fields are distinguished
from inactive farmland (2130) by the amount of brush cover. If a field contains few woody stems (<5%),
it should be placed in the inactive farmland category. An area should be placed in the Old Field
category if the amount of brush cover requires extensive brush removal before
plowing. In some cases, it may not be established that the previous use was
agricultural.
4411 Phragmites Dominate Old
Field
This category contains herbaceous vegetation in upland vegetation
settings dominated by Phragmites australis. The photographic signatures
for these areas are rough and puffy and range in color from tan to pale white.
4420 Deciduous Brush/Shrubland (>25% Brush Covered with
Deciduous Species Predominant > 75%)
This category contains natural forested areas with
deciduous species less than 20 feet in height.
An area must have greater than 25% brush cover to be placed in this
category. This category also contains
inactive agricultural areas that have been grown over with brush.
There are photographic signature differences between
brushland and the pole or saw-timber stage trees (Categories 4100, 4200, 4300). Besides the obvious height difference visible
on stereo viewing, larger trees display much larger crown diameters than
brushland areas.
4430 Coniferous Brush/Shrubland (>25% Brush Covered with
Coniferous Species Predominant > 75%).
This category contains natural forested areas with
coniferous species less than 20 feet high.
This category is for natural areas; therefore, Christmas tree farms
should be placed in the Nursery category (2200).
4440 Mixed Deciduous/Coniferous Brush/Shrubland (>25% Brush Covered
with a Mixture of Deciduous Coniferous Species; <75% of One Type)
This category contains natural forested areas less
than 20 feet in height with a mixture of coniferous and deciduous trees.
4500 SEVERE BURNED
Included in this category are naturally vegetated upland areas that have been altered by intense burning. These burned areas have not re-vegetated sufficiently on the photography, or at the time of any field inspection undertaken to support a mapping effort, to make a determination of the type of vegetation that will re-appear in the burned area. The pre-burn cover type may be any of those listed above in the 4000 series. Where sufficient re-vegetation has occurred to determine a post-burn cover type, the burned area is given the appropriate land cover code. However, where the re-vegetation has been insufficient, the 4500 code has been applied. Note that many different upland forest types may be included in this category.
5000
WATER
All areas within the landmass of
5100 STREAMS & CANALS
This category includes river, creeks, canals and other linear water bodies that have a minimum width of 30 feet. For watercourses interrupted by control structures, the impoundments are placed in other appropriate water categories (see below), and the impoundment structures are included in the Urban or Built-up category. Remote sensing of these features is not difficult. Colors on infrared photography range from light blue to black, and on the black & white photography the tones range from medium gray to black. The signature can be smooth or rippled depending on the conditions at the time of the photography. The greatest difficulty occurs when overhanging vegetation or shadows obscure the extent of the watercourse.
5110 Streams
This category includes streams that are
no less than 80 feet wide. These
features are easily recognized on aerial photography because of their
meandering pattern and variable width due to natural fluvial processes. Short distances of WC constriction which fall
under the minimum width standard may be included for the sake of
continuity. The photographic characteristics
of streams are much too numerous and obvious to list. Specific comments on signature and problems
are discussed under category 5100.
5120 Canals
This feature may
be no less than 80 feet wide and like streams is easily recognized on aerial
photography. Canals are consistent in
width, do not meander, are sometimes bordered by a towpath and often utilize a
lock system. Along the length of the
canal are found clusters of buildings that formerly serviced the canal track
when it was a transportation entity. In
5190 Exposed
Flats
Exposed
flats are un-vegetated areas in riverine systems that were formerly classed as
water, but because of meandering of the stream course, are now exposed. They are felt to be semi-permanent changes in
the stream configuration and not the result of temporary water level reductions. Because these areas may again be under water
at some time in the feature, they remain in the WATER category
5200
Water bodies larger than one acre that are non-flowing and naturally enclosed, including regulated natural lakes but excluding reservoirs, are placed in this category. Islands that are below MMU are included in the water area. To identify this feature accurately, it is important to remember natural lakes are the results of ground water seepage and surface run-off of precipitation, whereas reservoirs are the result of man-made impoundments and are maintained primarily by linear watercourses. Remote sensing of this feature, once again is simple. The signatures and attendant problems are discussed under category 5100.
5210
These features
have an areal range of one (1) to two (2) acres. Confer with category 5200.
5220
These features
have an areal range of two (2) to ten (10) acres. Confer with category 5200.
5230 Large Lakes
These features
will be greater than ten (10) acres in area.
Confer with category 5200.
5300 ARTIFICIAL LAKES & RESERVOIRS
The 5300 category includes all artificial
impoundments of water. Water in this
category typically includes water impounded for irrigation, flood control,
municipal water supplies, recreation, landscaping and hydro-electric power or
the result of an active extractive operation.
Dams, bulkheads, spillways and other water control structures should be
evident and are critical for accurately identifying these features. Also important to remember is that artificial
lakes and reservoirs are charged primarily through linear WCs. Photo identification should key on the
non-linear shapes of these features, the water control structures, and the
signatures discussed in category 5100.
5310 Artificial Lakes
Water bodies one
acre or larger are included in this category.
Since the primary use for these artificial lakes is recreation, some
recreational characteristics such as beaches, refreshment stands, parking lots,
boat slips, etc. should be present.
Frequently, residential development approaches the lake shoreline. Aerial interpretation is discussed under
category 5300.
5320 Multiple Use
Reservoirs
Water bodies of
one acre or larger are included in this category. The two most common combinations are flood
control/recreation and hydro-electric/recreation. As in category 5310, the recreational and
water control characteristics should be present and obvious. In addition, if the water body is used for flood
control, the water level should be well below the maximum capacity, and, if the
water body is used for hydroelectric purposes, the generating station should be
present. Confer with category 53 for
more specific identification information.
5330 Restrictive Use
Reservoirs
Once again the
minimum size of this feature is one acre.
Most restricted use reservoirs are municipal water supplies. Thus, they are located in more remote, less
trafficked areas of the state. They are
characterized by limited road access and dense surrounding vegetation. No recreational characteristics should be
present. Confer with category 5300 for
more specific identification information.
5400 BAYS,
ESTUARIES & OTHER TIDAL WATERS
This category is comprised of salt-water inlets
and arms of the sea that extend inland and fall within the landmass of
5410 Tidal Rivers,
Included in this category are the tidal portions of
watercourses, enclosed tidal bays, and other tidal water bodies such as tidal
pools, ponds and natural lagoons. The
tidal watercourses may include everything from smaller entirely tidal features
commonly draining tidal marsh systems, to the tidal portions of intermediate
and large features such as the
5411 Open Tidal Bays
Included in this category are large tidal water
bodies such as
5420 Dredged Lagoon, Artificial
Artificial dredged lagoons are networks of
rectangular dredged areas, containing water, usually associated with
residential development or mobile home development. Dredged lagoons are generally in sites of
former wetlands and have characteristically bulkheaded shorelines. They usually feed into a central dredged
waterway that gives access to open tidal water.
5430
This category includes only open water off the
6000
WETLANDS
The wetlands are
those areas that are inundated or saturated by surface or ground waters at a
frequency and duration sufficient to support vegetation adapted for life in
saturated soil conditions. Included in
this category are naturally vegetated swamps, marshes, bogs and savannas which
are normally associated with topographically low elevations but may be located
at any elevation where water perches over an aquiclude. Wetlands that have been modified for
recreation, agriculture, or industry will not be included here but described
under the specific use category.
The wetlands of
6100 COASTAL WETLANDS
These areas are
associated with the tidal portions of the Delaware River system and the tidal
portions of the watercourses draining into the
6110 Saline Marshes
These are open
graminoid dominated regions associated with waters with salinities >1 part
per thousand (0/00). Saline marshes are
generally dominated by two growth forms of Spartina alterniflora
in regions with the highest salinities. Marshes
flowed by water less than 10 0/00 are generally brackish and co-dominated by Spartina
cynosuroides, S. alterniflora, Phragmites australis,
Typha angustifolia, and Scirpus pungens.
Marshes
exhibiting these characteristics are restricted to the Delaware Bay and
associated tributaries downstream of
The following Level III classifications of saline marshes have been added
for 2002 to further delineate the coastal marshes of previous delineation. The separation is primarily by visible
texture and species composition.
6111 Saline
Marshes (Low marsh vegetation)
This category contains herbaceous vegetation
dominated by Spartina alternifloria where the height is <1 foot and
is primarily flooded throughout. The
photographic signature for these areas ranges in color from blue to red.
6112 Saline Marshes
(High marsh vegetation)
This category contains herbaceous vegetation
dominated by Spartina patens (salt hay) where the height is 1 foot to 3
feet. The photographic signature for these areas ranges in color from red to
pink or pale white.
Phragmites (2002)
Phragmites is an invasive grass species that is
present throughout the state of
6120 Freshwater Tidal
Marshes
These marshes are co-dominated by annual and
perennial herbaceous vegetation on substrates associated with tidal waters with
salinities less than 1 0/00. Freshwater
marsh species are characterized by Nuphar lutea, Peltandra
virginica, Pontederia cordata, Zizania aquatica,
Polygonum punctatum, Bidens laevis, and Typha
latifolia. Marshes exhibiting
this cover are found on the tidal Delaware River and tributaries downstream of
6130 Vegetated Dune Communities
These are areas near the coast that are between
saline marsh and open beach. The
dominant vegetation can be Ammophila breviligulata, Prunus maritimus,
Rhus radicans, Juniperus virginicus, and Acer
rubrum. The areas have open to
partly closed canopied signatures that are rough in texture and exhibit a red
to red brown color on summer infrared photographs.
6141 Phragmites Dominate Coastal Wetlands
This category contains herbaceous vegetation in coastal wetland
settings dominated by Phragmites
australis. The photographic signatures for these areas are rough and puffy
and range in color from tan to pale white.
6200
INTERIOR WETLANDS
These are
generally found in non-tidal lowlands associated with primary, secondary and
tertiary watercourses, and isolated wetlands.
Included under this heading are all forested wetland (regardless of
tidal influences) dominated by deciduous and coniferous trees, and non-tidal
herbaceous marshes and savannas.
6210 Deciduous Wooded Wetlands
These wetlands are closed canopy swamps dominated by
deciduous trees normally associated with watercourses, edges of marshes, and
isolated wetlands. The important canopy
species includes Acer rubrum, Nyssa sylvatica, Fraxinus
pennsylvanica, Salix nigra, Quercus bicolor,
Q. phellos, Q. falcata, Liquidambar styraciflua,
and Platanus occidentalis.
These species combine to form a series of mixed hardwood lowland
habitats throughout the entire state.
These species have photographic signatures that exhibit height, rough
texture, and are dark blue-gray to dark gray or black on winter infrared, and
gray to dark gray on panchromatic film.
6220 Coniferous Wooded Wetlands
These wetlands are closed canopy, dominated by
coniferous tree species associated with watercourses, seeps, and low
topographic land. The northern areas
will support Tsuga canadensis, Larix laricina, and Picea
mariana as monotypic stands or mixed communities. The southern portion of the State has Pinus
rigida and P. taeda in monotypic communities or co-dominate with Acer
rubrum. Other species such as Nyssa
sylvatica and Chamaecyparis thyoides may also be
present. These species have photographic
signatures that are varied in texture and are red to dark red on winter
infrared film and dark gray to black on winter panchromatic film.
6221 Atlantic White Cedar
Wetlands
These wetlands are
predominantly closed canopy, seasonally flooded wetlands of southern
6230 Brush-Dominate
and Bog Wetlands
These wetlands are dominated by woody species that are less than 20 feet
tall. These areas may be an early
successionary stage to wetland dominated by canopy species or a shrub dominate
community associated with marshes, isolated wetlands or bogs. The brush category will include communities
composed of young saplings such as Acer rubrum, Acer negundo,
Liquidambar styraciflua, and areas dominated by shrub species
such as Cornus amomum, C. stolonifera, C. racemosa,
Spirea alba, S. tomentosa, Viburnum dentatum,
and Alnus serrulata. Bogs
are Ericaceae dominated and highly acidic, normally associated with glacial
areas in the north and pingoes or river ox bows in the south. Some bogs may also contain herbaceous
vegetation that is unique to these habitats yet classified by this system as
6240, non-tidal marsh. The photographic
signature for those cover types vary.
The brush-dominated areas will have a similar signature as 6210 with
more space and smaller stature. The bog
areas will be round to oval, low topographically and normally separated from major
watercourses. The color seen on winter
infrared photographs will be dark blue-gray to black and dark gray to black on
the panchromatic films.
6231 Deciduous Brush and Bog
Wetlands
This brush category will
include communities composed primarily of young samplings of deciduous tree
species such as Acer rubrum, A. negundo, Liquidamber
stryaciflua, Alnus serrulata, Cornus stolonifer,
and C. amomum; and woody shrubs such as Vaccinium corymbosum,
V. macrocarpon, Spirea alba, Viburnum dentatum,
Rosa palustris, Myrica pennsylvania, M. gale,
Clethra alnifolia, Cephalanthus occidentalis and Rhododendron
viscosum, among others.
6232 Coniferous Brush and
Bog Wetlands
This brush category will
include communities composed primarily of young samplings of coniferous tree
species such as Pinus rigida, Larix larcinia, Tusga
canadensis, and Picea mariana, and shrubs such as Chamaedaphne
calyculata, and Kalmia angustifolia.
6233 Mixed Brush and Bog
Wetlands with Deciduous Dominant
Included
in this category are brush and bog wetlands with a mixture of deciduous and
coniferous species, with the deciduous species > 50% but < 75%. Species will be similar to those described
under 6231 and 6232.
6234 Mixed Brush and Bog
Wetlands with Coniferous Dominant
Included in this category
are brush and bog wetlands with a mixture of deciduous and coniferous species,
with the coniferous species > 50% but < 75%. Species will be similar to those described
under 6231 and 6232.
6240 Non-Tidal Marshes
These are wetlands dominated by various herbaceous
species that are not connected or associated with tidal waters. Lake edges, open flood plains and abandoned
wetland agricultural fields are locations for this cover type. Leersia oryzoides, Phalaris
arundinacea, Nuphar lutea, Polygonum arifolium,
P. sagittatum, Typha latifolia and Phragmites
are species that may dominate this cover type.
Bog herbaceous vegetation will be covered by this section includes
numerous Cyperaceae genera, Juncus sp. and the carnivorous genera of Drosera
and Sarracenia. This cover type will
have a similar photographic signature as 6120, varied texture, and light
blue-gray or tan color on winter infrared and light gray on the panchromatic
photograph.
6241 Phragmites Dominate Interior Wetlands
This category contains herbaceous vegetation in interior wetland
settings dominated by Phragmites australis. The photographic signatures
for these areas are rough and puffy and range in color from tan to pale white.
6250
Mixed Wooded Wetlands
Included in this category are wetlands
inhabited by mixtures of deciduous
and coniferous species. Species of each
type will be similar to those identified under 6210 and 6220. The dominant type of vegetation will
generally be greater than 50% but less than 75%.
6251 Mixed Wooded Wetland
with Deciduous Prevalent
This category contains mixed wooded wetlands with
the deciduous tree species > 50 % but < 75%.
6252
Mixed Wooded Wetlands with
Coniferous Prevalent
This category contains mixed
wooded wetlands with the coniferous tree species > 50% but < 75%.
6290
Un-vegetated Flats
Un-vegetated flats are former vegetated area located adjacent to a stream or
river, in which the vegetation has been scoured away, so that at the time of
the photography, there is no vegetation visible. These areas may have been previously classed
as wetlands or as upland areas. However,
since all the vegetation in these areas was removed primarily because of
scouring by ice in the adjacent stream or river, all
of these areas are now included in the WETLAND category since any re-vegetation will most probably now be by wetland species
6500 SEVERE BURNED WETLANDS
Included in this category are naturally vegetated
wetland areas which have been altered by intense burning at the time of the
land cover analysis. These burned areas
have not re-vegetated sufficiently on the photography, or at the time of any
field inspection undertaken to support a mapping effort, to make a
determination of the type of vegetation that will re-appear in the burned
area. The pre-burn cover type may be any
of those listed above in the 6200 series.
Where sufficient re-vegetation has occurred to determine a post-burn
cover type, the burned area is given the appropriate land cover code. However,
where the re-vegetation has been insufficient, the 6500 code has been
applied. Note that many different
wetland types may be included in this category.
Barren lands are characterized by thin soil,
sand or rocks and a lack of vegetative cover in a non-urban setting. Vegetation, if present, is widely
spaced. Barren land such as beaches and
rock faces are found in nature but also result as a product of man's activities. Extraction mining operations, landfills and
other disposal sites compose the majority of man-altered barren lands.
7100 BEACHES
Beaches are predominantly composed of sand and may occur at the land-water interface of oceans, bays and estuaries. Beaches are generally elongated non-vegetated buffering systems subject to the action of waves and tides.
7110
The open beach
potentially includes the sandy area from mean low water (MLW) of the foreshore
to the berm crest and the backshore. The
open beach is characterized by sparse vegetative cover. Other substrate types may be intermixed with
sand, including pebbles, stones, silts and shells.
7120 Unvegetated Dune
Communities
Unvegetated dune
communities are comprised of areas with sparse vegetative cover, with sand
substrate and with notable changes in elevations. These areas have a wind-driven origin and
vary in size and shape. Dunes are found
in coastal areas near large sources of sand.
Vegetated dune areas are included in the Wetland categories.
7130 Other
This category
includes natural areas that have been sandy for long periods of time and
perturbed areas which have been sandy and for which no known land use is
evident.
7200 BARE EXPOSED ROCK, ROCK SLIDES, ETC.
Areas lacking vegetation and composed of rock or rock faces are included in this category. Exposed rock from highway construction is not included in this category.
7210 Rock Faces, Rock
Slides, Cliffs
This category
includes rock faces on mountains, rock slides and cliffs which are sparsely
vegetated. These exposed types have a
large vertical component.
7220 Exposed Rock
Areas consisting
of exposed bedrock or other accumulation of rocks lacking vegetative cover are
included. These areas have a small
vertical component compared to rock faces, etc.
7300 EXTRACTIVE MINING
Extractive operations include a wide variety of mining activities, both surface and subsurface. Included are stone quarries, gravel, sand and clay pits, and limestone quarries to mention a few. Extractive industries are characterized by disturbed ground usually with depth, extractive machinery, buildings and roads for and with heavy equipment. Open mining areas frequently contain water. Extractive mining areas may be large as stone quarries or small as borrow pits.
7310 Stone Quarries
Stone quarries
are characterized by right-angled rock cleavage, flat terraces, and straight
vertical walls. Drill stands, air
compressors and similar extractive machinery and buildings may be visible.
7320 Sand and Gravel Pits
(Borrow Pits)
Sand and gravel
pits have curved borders and sloping walls.
They often lack the vertical relief of quarries and do not generally
have exposed rock associated with them.
Steam shovels, bulldozers, and mechanical loaders are associated with
these tow types of extraction. Sand pits
may have water and consequently, dredging equipment associated with them. Sand and gravel pits show wide variability in
size.
7330 Other Mining
Other types of
mining are characterized by disturbed ground with depth, slag heaps, shafts,
buildings, and active transportation (trucks, roads for heavy machinery,
railways).
7340 Abandoned Mining Sites
Abandoned
operations are often partially vegetated and may be accompanied by machinery,
roads and buildings in disrepair. When
vegetation dominates the site, the parcel is characterized by cover type. In contrast, active operations show evidence
of operational equipment and buildings, roads for heavy machinery, etc. Current mining activity is not always
distinguishable, and inactive, unclaimed and active strip, mines, quarries
barrens pits and gravel pits are included in this category, until other cover
or use is established.
7400 ALTERED LANDS
Altered lands are areas outside of an urban setting that have been changed due to man's activities other than for mining.
7410 Solid Waste Disposal
Areas
Junkyards, open
dumps, landfills and incinerators compose the majority of solid waste disposal
sites. Junkyards are collection of old
automobiles, machinery or other vehicles.
Larger junkyards are fenced and have regular stacking and placing of
debris, with well-defined access roads.
Older abandoned yards may be vegetated and difficult to detect.
Open dumps and
sanitary landfills are usually located in abandoned pits, low-lying areas or
other areas of low economic importance.
They are characterized by steep banks, white fringes of expose debris,
rough texture and lack of vegetation.
Larger dumps/landfills are fenced and generally have one heavily used
access road.
7420 Dredge Material
Disposal Sites
Dredge material
disposal sites are barren areas separated from other land forms by dikes. Inside the rectangular dike systems are fine
grained sands and silts either deposited in piles but more likely forming a
slurry with varying amounts of water within the dike system. Old dredge material site may appear as
landfills with steep sides and rough texture but without exposed debris or
signs of active management.
7430 Disturbed Wetlands
Included in this category
are former natural wetlands that have been altered by some form of clearing,
leveling, grading, filling and/or excavating, but which still exhibit obvious
signs of soil saturation on the imagery.
Because of the alterations, these areas do not generally support typical
wetland vegetation, and may in fact be unvegetated. They do, however, exist in
areas shown on the US Soil Conservation Service soil surveys to have hydric
soils, and exhibit the darker tonal signatures associated with saturated soils
on the photography. Colors of these areas will vary from gray to blue-gray to
black on winter CIR film and gray to black on panchromatic film. These areas
may be in transition to a use or associated with a transitional development.
7500 TRANSITIONAL AREAS
This category encompasses lands on which site preparation for a variety
of development types has begun. However,
the future land use has not been realized.
Included are residential, commercial and industrial areas under construction. Also, areas that are under construction for
unknown use and abandoned structures are included. These areas are usually sparsely vegetated.
Transitional Areas
7510 Single Unit Residential
Under Construction
7520 Multiple Unit Residential
Under Construction
7530 Commercial/Service Under
Construction
7540 Industrial Under
Construction
7550 Transportation/Communication/Utilities
Under Construction
7560 Industrial/Commercial
Parks Under Construction
7570 Unknown Use Under
Construction
7580 Abandoned Structures
(Non-Urban)
7600 UNDIFFERENTIATED
Undifferentiated barren lands encompass cleared
lands that have no apparent site preparation or any indication of past
activities. Such areas vary in shape and
size but generally possess little vegetation, exposing the soil or surface
material only. Ancillary information
also gives no indication of former uses.
8000
MANAGED WETLANDS
This category was added to provide an