**FGDC *Working Draft* Wetland Mapping Standard**

FGDC Wetland Subcommittee and

Wetland Mapping Standard Workgroup

Submitted by:

> Number range CHAPTERMargarete Heber
>
> Environmental Protection Agency

Office of Water

Date: August 6, 2007

Table of Contents

[1 Introduction 1](#introduction)

[1.1 Background 1](#background)

[1.2 Objective 1](#objective)

[1.3 Scope 2](#scope)

[1.4 Applicability 3](#applicability)

[1.5 FGDC Standards and Other Related Practices
4](#fgdc-standards-and-other-related-practices)

[1.6 Standard Development Procedures and Representation
5](#standard-development-procedures-and-representation)

[1.7 Maintenance Authority 5](#maintenance-authority)

[2 FGDC Requirements and Quality Components
6](#fgdc-requirements-and-quality-components)

[2.1 Source Imagery 6](#source-imagery)

[2.2 Classification 7](#classification)

[2.3 Accuracy 7](#accuracy)

> [2.3.1 Target Mapping Unit and Producers Accuracy
> 8](#target-mapping-unit-and-producers-accuracy)
>
> [2.3.2 Horizontal Accuracy 9](#horizontal-accuracy)

[2.4 Data Verification 9](#data-verification)

> [2.4.1 Logical Consistency 10](#logical-consistency)
>
> [2.4.2 Edge Matching 10](#edge-matching)
>
> [2.4.3 Attribute Validity 10](#attribute-validity)

[2.5 Datum and Projection 11](#datum-and-projection)

[2.6 Metadata 11](#metadata)

[References 12](#__RefHeading___Toc174155222)

Appendix A: Workgroup Recommendations to the FGDC 13

Appendix B: Attributes for Wetland Classification 16

Appendix C: Implementation Recommendations in Support of Section 2.0 26

Appendix D: Known Issues with Existing Wetlands Mapping Data 32

Appendix E: Polygon Lineage and Unique Identifiers 37

Appendix F: Questions and Answers 40

Appendix G: Definitions (Informative) 44

Appendix H: Workgroup Members, Vetting Participants, and Workgroup
Activities 49

Table 1. Spatial Resolution Requirements of Source Imagery 6

Table 2. Classification Levels Required Based on Habitat Type 7

Table 3. TMU and Producer Accuracy Requirements 9

Table 4. Horizontal Accuracy (RMSE) Requirements 9

# Introduction

## Background

> Historically, the U.S. Fish and Wildlife Service (FWS) has had the
> responsibility for mapping wetlands in the United States. Those mapped
> products are currently held in the National Wetlands Inventory (NWI).
> As time has passed, more local and state and non-governmental
> organizations have become interested in mapping their wetlands, and at
> a more refined scale than has been available from NWI. For
> consistency, it has become increasingly important to develop a wetland
> mapping standard that everyone can use to map and share wetland data
> in a digital format. It is highly desirable to be able to reprocess
> dataset output from the NWI to support multiple mapping applications
> and digital products. It is also important for mapped wetland data to
> be "seamless" with other water data such as the features represented
> in the National Hydrography Dataset (NHD), so that wetlands can be
> mapped, coordinated, and understood in a more holistic environmental
> context, whether at the watershed, ecosystem, or regional level.

Historically, geographic data were stored as polygons and lines. In
early edition wetlands maps, small wetland features were represented as
points. These points were an artifact of the scale limitations of the
cartographic technology used to map the wetlands at the time. The use of
modern digital technology and on-screen mapping of wetlands allows
interpretation to be done at a much larger scale. Features previously
represented as points are now able to be delineated as polygons.

The intent of this standard is to support a consistent/seamless
transition from traditional paper-based map products to technology-based
mapping products and serve as the national standard for mapping wetland
inventories for inclusion into the National Spatial Data Infrastructure
(NSDI).

## Objective

> While this standard cannot change the National Wetlands Inventory Data
> produced prior to its implementation, this standard specifies a core
> set of data quality components necessary to add to the National
> Wetlands Inventory in a way that is consistent and supports multiple
> uses of the data, while meeting the requirements of the National
> Spatial Data Infrastructure (NSDI). This standard and is based largely
> on the existing draft standard used by U.S. Fish and Wildlife Service
> in support of the NWI. The intent of the standard is to support
> current and future digital mapping capabilities of wetland data. The
> standard will provide specification of minimum data quality components
> for wetland mapping activities for inclusion into the NSDI that are
> funded or conducted by the Federal government. The National Wetlands
> Inventory digital wetland data serves as the foundation for the
> wetlands data layer of the NSDI. The standard balances the burden on
> the end-user community with the need for consistency and documented
> quality of digital mapping products. Additionally, this standard is
> created to coordinate wetland mapping with the National Hydrography
> Dataset, a national geospatial framework recognized by the Federal
> Geographic Data Committee (FGDC). Although this standard is structured
> to be extensible over time, the standard is deliberately developed
> with a forward-looking perspective to accommodate technology and map
> scale enhancements, assure its long-term usability, and minimize the
> need for revisions and updates over time.

## Scope

> Number range CHAPTERThe Wetland Mapping Standard supports the
> incorporation of federally-funded wetland mapping data into the
> national wetland geospatial database (under direction of the Fish and
> Wildlife Service) and the National Spatial Data Infrastructure (NSDI).
> This standard provides minimum requirements and guidelines for
> wetlands inventory mapping. Implementation guidelines and technical
> recommendations have been included to facilitate the vetting process,
> and are included in Appendix C. Specific cartographic,
> photogrammetric, and classification conventions where applicable have
> been identified and are represented by other Federal standards.
> Exemptions from these mapping requirements include:

1.  Use of this standard for wetlands inventory mapping activities that
    are not federally-funded are strongly encouraged but not required.
    The NSDI will not incorporate non-compliant data from any source
    except National Wetlands Inventory maps created prior to the
    implementation of this standard (note these past NWI maps may be
    provided as scanned images only, for historical purposes only).

2.  This standard exempts National Wetlands Inventory mapping and other
    federally-funded projects that began prior to the standard's
    effective date. Also exempt are federally-funded projects for which
    contract execution occurred prior to the standard's effective date,
    even if the actual work had not begun prior to that date.

3.  This standard exempts change detection efforts that seek to
    extrapolate the amount of change in wetland area, type,
    functionality, value, integrity or quality, from samples. An
    intermediate step in these change detection efforts may include
    mapping individual wetlands in sample plots. This standard does not
    prevent Federal funding for this intermediate step.

4.  The standard is neither designed, nor intended, to support legal,
    regulatory, or jurisdiction analyses of wetland mapping products,
    nor does it attempt to differentiate between regulatory and
    non-regulatory wetlands.

5.  The standard is designed to support polygonal wetland datasets and
    does not apply to plot/point transects, and linear datasets.

6.  This standard exempts data collected for site-specific wetland
    assessments for scientific research, environmental assessments (EAs)
    and environmental impact statements (EIS), and wetland
    determinations for regulatory purposes, when these site-specific
    activities necessitate the use of definitions and classifications
    which are incompatible with the FGDC wetland classification
    standard.

7.  Certain mapping products are used as ancillary data in the
    development of wetland mapping; these mapping activities may remain
    independent of wetlands inventory mapping efforts and include:

-   *Deepwater substrate types*

-   *Vegetation Types*

-   *Soil types (including hydric soil units)*

-   *Topography*

-   *Geology*

-   *Forest Cover Maps*

-   *Hydrography*

-   *Navigation or bathymetry*

> Other mapping activities may include wetlands or deepwater as a
> subset. Any new, updated or revised wetland mapping shall conform to
> this standard. More general mapping activities may use an existing
> compliant wetlands inventory to incorporate a wetlands subset rather
> than conducting new wetland mapping. Mapping activities of which
> wetlands may be a subset include but are not limited to:

-   *Land Use Land Cover (LULC) classifications*

-   *Forest cover maps*

-   *Floodplains*

## Applicability

> This standard is intended for all Federal or federally-funded wetlands
> inventory mapping including those activities conducted by Federal
> agencies, states, and federally recognized tribal entities,
> non-governmental organizations, universities, and others.
> Specifically, if Federal funding is used in support of wetlands
> inventory mapping activities, then use of this standard is mandatory.
> The adoption of the standard for all other wetlands inventory mapping
> efforts (non-federally funded) is strongly encouraged to maintain and
> expand the wetland layer of the NSDI.

## FGDC Standards and Other Related Practices

> The following standards and applications are listed as core components
> to the Wetlands Mapping Standard effort. Some of these standards are
> included because the Wetlands Mapping Standard was developed in
> consideration and conformance with their requirements and intent.
>
> The related FGDC standards include:

-   Classification of Wetlands and Deepwater Habitats in the United
    States, FGDC-STD-004
    <http://www.fws.gov/stand/standards/cl_wetl.html>

-   Content Standard for Digital Geospatial Metadata (version 2.0)
    FGDC-STD-001-1998,
    <http://www.fgdc.gov/metadata/geospatial-metadata-standards>

-   Geospatial Positioning Accuracy Standards Part 3. National standard
    for spatial data accuracy. FGDC-STD-007.3-1998

```{=html}
<!-- -->
```
-   *National Vegetation Classification Standard,* FGDC-STD-005

-   *Soil Geographic Data Standard,* FGDC-STD-006

> Other related practices include:

-   *Canadian Wetland Inventory* maintained by Agriculture and Agri-Food
    Canada (AAFC) at <http://www.cwi-icth.ca/>

```{=html}
<!-- -->
```
-   *Number range CHAPTERNational Hydrography Database* (NHD) maintained
    by the USGS at <http://nhd.usgs.gov/>

```{=html}
<!-- -->
```
-   *Fish and Wildlife Service National Standards and Quality Components
    for Wetlands, Deepwater and Related Habitat Mapping*,
    [http://www.fws.gov/stand/standards/dl_wetlands_National%20Standards.doc](http://www.fws.gov/stand/standards/dl_wetlands_National Standards.doc)

```{=html}
<!-- -->
```
-   *Draft FGDC Riparian Standard* maintained by FGDC at
    <http://www.fgdc.gov/standards/projects/FGDC-standards-projects/riparian-mapping/index_html>

-   *Guidance for Benthic Habitat Mapping: An Aerial Photographic
    Approach* maintained by the U.S. NOAA Coastal Services Center.
    Available for download at
    http://www.csc<http://www.csc.noaa.gov/benthic/mapping/pdf/bhmguide.pdf>.noaa.gov/benthic/mapping/pdf/bhmguide.pdf

-   Nature Serve's *Coastal/Marine Systems of North America: Framework
    for an Ecological Classification Standard at
    <http://www.natureserve.org/publications/coastal_marine_classification.pdf>*

```{=html}
<!-- -->
```
-   *RAMSAR Classification for Wetland Type* maintained by Convention on
    Wetlands (Ramsar, Iran, 1971) at
    <http://www.ramsar.org/ris/key_ris_types.htm>

-   Primary Indicators Method. Tiner, R.W. 1993. *The primary indicators
    method - a practical approach to wetland recognition and delineation
    in the United States*. Wetlands 13(1): 50-64. (This method is
    typically used for verifying NWI wetlands on the ground).

## Standard Development Procedures and Representation

> Stakeholder representation from the Federal, State, non-profit, and
> private sectors was included in the development of this standard to
> ensure that the end-user information requirements are reflected in the
> final product. Technical development of the content of this standard
> began in June 2006 with a 3-day meeting of the workgroup comprised of
> members representing multiple Federal agencies and stakeholder groups.
> It was emphasized again that the standard would benefit from a wide
> vetting process targeting diverse members of the end-user community.
> Workgroup members and vetting participants, as well as workgroup
> activities are listed in Appendix H.
>
> The development of this standard generated findings for minor
> revisions to other existing FGDC standards, including an expansion of
> the FGDC Wetlands and Deepwater Habitat Classification System (see
> Appendix A), additional tools for handling wetland unique identifiers,
> and publishing new FGDC standards for related wetland habitat types.

## Maintenance Authority

> The maintenance authority for the *Wetland Mapping Standard* resides
> with the FGDC Wetland Subcommittee. This workgroup recommends review
> of this standard at five-year intervals.

# FGDC requirements and Quality components

> The sections below delineate the specification for the technical
> components of the Wetlands Mapping Standard. To further the
> Information Quality Act and conform to NWI Quality Review Procedures,
> all image-interpretation will receive a first level of 100% quality
> control review by a technically skilled person other than the person
> doing the original image interpretation and producers must provide an
> opportunity for review by other interested agencies and stakeholders
> prior to submission to the Service for inclusion in the NSDI. Names
> and affiliations of the reviewers of the data must be included in the
> metadata.

## Source Imagery

> The minimum requirement for this standard is that all source imagery
> must have a true spatial resolution and scale based on the geographic
> context of the mapping effort (Table 1).
>
> NWI will conduct data verification, quality control, and quality
> assurance to meet current Quality Review Procedures before including
> data in the NSDI.

**[Table 1. Spatial Resolution Requirements of Source
Imagery]{.underline}**

  ---------------- -------------- -------------- -------------- --------------
                   **Lower 48     **Alaska**     **In-Shore     **Off-Shore
                   States and                    Deepwater**    Deepwater**
                   Hawaii\***                                   

  **Resolution**   1m\*\*         5m             3m             N/A\*\*\*

  **Scale**        1:12,000\*\*   1:63,360       1:24,000       N/A\*\*\*
  ---------------- -------------- -------------- -------------- --------------

\*Includes the lower 48 states, Hawaii, District of Columbia and Trust
Territories. In-shore and deepwater habitats are excluded. Alaska is
also excluded.

\*\*When imagery is not available at this scale or resolution; 1:24,000
or 3m is sufficient.

\*\*\*Imagery is not suitable for bottom analysis for off-shore
deepwater habitats.

> Incorporation of any one or more of the following imagery source(s)
> will enhance data quality:

-   Near-infrared wavelength imagery

-   Stereoscopic imagery

-   Multi-seasonal imagery

> In some environments, especially those with low contrast,
> interpretation of these imagery sources may be necessary to achieve
> the completeness and accuracy requirements specified in this standard.

## Classification

> This standard is based upon classification using the FGDC Wetlands and
> Deepwater Habitat Classification System. The minimum standard for
> wetland classification is: ecological system, subsystem (where
> applicable), class, subclass for forested, scrub-shrub, and emergent
> classes, water regime, and special modifiers. The minimum standard for
> deepwater habitat classification is: system, subsystem, class, and the
> water regime. Table 2 on the next page represents required
> classifications based on habitat type. Further recommendations for
> classification are discussed in appendices B & C.

**[Table 2. Classification Levels Required Based on Habitat
Type]{.underline}**

+--------------+--------+--------+--------+--------+--------+--------+
|              | **Sy   | *      | **C    | **S    | *      | **S    |
|              | stem** | *Subsy | lass** | ubclas | *Water | pecial |
|              |        | stem** |        | s**^^ | Re     | Modif  |
|              |        |        |        |        | gime** | iers** |
+--------------+--------+--------+--------+--------+--------+--------+
| **Lower 48   | Yes    | Yes    | Yes    | Yes    | Yes    | Y      |
| States and   |        |        |        |        |        | es\*\* |
| Hawaii\***   |        |        |        |        |        |        |
+--------------+--------+--------+--------+--------+--------+--------+
| **Alaska**   | Yes    | Yes    | Yes    | Yes    | Yes    | Y      |
|              |        |        |        |        |        | es\*\* |
+--------------+--------+--------+--------+--------+--------+--------+
| **In-Shore   | Yes    | Yes    | Yes    | Yes\*  | Yes    | No     |
| Deepwater    |        |        | \*\*\* | \*\*\* |        |        |
| Habitat**    |        |        |        |        |        |        |
+--------------+--------+--------+--------+--------+--------+--------+
| **Offshore   | Yes    | Yes    | Yes    | Yes\*  | Yes    | No     |
| Deepwater**  |        |        | \*\*\* | \*\*\* |        |        |
|              |        |        |        |        |        |        |
| **Habitat**  |        |        |        |        |        |        |
+--------------+--------+--------+--------+--------+--------+--------+

^^Users should include Subclass for forested, scrub-shrub, and emergent
Classes.

\*Includes the lower 48 states, Hawaii, District of Columbia and Trust
Territories. In-shore and deepwater habitats are excluded. Alaska is
also excluded.

\*\*Farmed wetlands need only include system and farmed modifier;
cultivated cranberry bogs may be classified as PSSf.

\*\*\*Unconsolidated bottom unless data indicates otherwise for inshore
and deepwater habitats.

\*\*\*\*Users should include Class and Subclass when data are available
for inshore and offshore deepwater habitats; for other areas Class will
suffice.

## Accuracy 

> For wetland mapping, accuracy may be dependent upon several factors
> affecting identification including:

-   Scale of imagery

-   Mapping scale or base map scale

-   Quality of imagery

-   Season of imagery (leaf-off or leaf-on)

-   Type of imagery or emulsion of imagery

-   Environmental conditions when imagery was captured

-   Difficulty of identifying particular types of wetlands

-   Availability and quality of ancillary data sources

> Accuracy is a function of data quality and technology as well as
> proper training of the image interpreter. Classification accuracy of
> the final map product should be measured by two metrics: Target
> Mapping Unit (TMU) and Producer's Accuracy (PA). This standard
> presents no requirement for User's Accuracy (UA). Implementation
> recommendations for UA are presented in Appendix C.  

-   **The Target Mapping Unit (TMU)** is an estimate of the size class
    of the smallest wetlands that can be consistently mapped and
    classified at a particular scale of imagery, and that the
    image-interpreter attempts to map consistently. The size of a TMU is
    based on a simple square or a circle shape (a polygon with
    significant interior area relative to its perimeter) and not a long,
    narrow rectangle (i.e., a linear feature with little or no
    discernable interior area at the scale of interest). Therefore,
    wetlands which appear long and narrow (less than 15 feet wide at a
    scale of 1:12,000), such as those following drainage-ways and stream
    corridors, are excluded from consideration when establishing the
    TMU, and such wetlands may or may not be mapped, depending on
    project objectives.

-   **Producer\'s Accuracy (PA)** measures the percentage of features
    that are correctly classified on the imagery.

-   **User's Accuracy (UA)** measures the percentage of reference sites
    on the ground (field-check) sites that are correctly classified on
    the map.

> Spatial accuracy is a function of two metrics: Horizontal Accuracy
> (HA) and Vertical Accuracy (VA). This standard presents no requirement
> for Vertical Accuracy; however, implementation recommendations are
> included in Appendix C.

-   **Horizontal Accuracy (HA)** refers to a features spatial
    relationship to the source imagery.

-   **Vertical Accuracy (VA)** measure of the positional accuracy of a
    dataset with respect to a specified vertical datum.

> Requirements for these accuracy metrics are presented in the following
> sub-sections.

### Target Mapping Unit and Producers Accuracy

> Ninety-eight percent of all wetlands visible on an image, at the size
> of the TMU or larger must be mapped regardless of the origin (natural,
> farmed, or artificial). The minimum technical requirements are
> specified in Table 3. Habitat changes that have occurred between the
> date of the source imagery and the date of field
> observation/groundtruthing are not considered errors because the
> wetland was correctly classified on the source imagery. Wetland data
> that exceed the minimum TMU requirements will be accepted for
> submission to the NSDI.

**[Table 3. TMU and Producer Accuracy Requirements]{.underline}**

  --------------- ------------- ------------- ------------- -------------
                  **Lower 48    **Alaska**    **In-Shore    **Off-Shore
                  States and                  Deepwater**   Deepwater**
                  Hawaii\***                                

  **TMU**         0.5 acres     5.0 acres     1.0 acre      N/A
                  (0.2 ha)      (2.0 ha)      (0.4ha)       

  **Producer's    98%           98%           98%           N/A
  Accuracy**                                                
  --------------- ------------- ------------- ------------- -------------

\*Includes the lower 48 states, Hawaii, District of Columbia and Trust
Territories. In-shore and deepwater habitats are excluded. Alaska is
also excluded.

> For the lower 48 states and Hawaii and the Trust Territories, features
> that are at least 0.5 acre would be mapped with a demonstrated
> Producer Accuracy (PA) of 98% or higher documented, through external
> quality assessment of samples. The actual TMU and PA for the project
> area must be declared in the metadata, along with an associated
> justification.

### Horizontal Accuracy

> When the requirement states that the Horizontal Accuracy must be 5m
> root mean square error (RMSE) then the features must fall within 5m of
> the location of the features on the source imagery at least 68% of the
> time. This nominal positional accuracy conforms to FGDC Digital Ortho
> Quarter Quadrangle requirements used by many Federal agencies. This
> standard requires a nominal horizontal root mean square error (RMSE)
> commensurate with the context of the mapping as specified in Table 4.

**[Table 4. Horizontal Accuracy (RMSE) Requirements]{.underline}**

  --------------- ------------- ------------- ------------- -------------
                  **Lower 48    **Alaska**    **In-Shore    **Off-Shore
                  States and                  Deepwater**   Deepwater**
                  Hawaii\***                                

  **Horizontal    5m            25m           15m           N/A
  Accuracy                                                  
  (RMSE)**                                                  
  --------------- ------------- ------------- ------------- -------------

\*Includes the lower 48 states, Hawaii, and the District of Columbia.
In-shore and deepwater habitats are excluded. Alaska is also excluded.

## Data Verification

> The overall guiding principle is that the wetlands data generated are
> added to the wetlands layer of the NSDI. To ensure quality control,
> the following verification checks outlined in this section (2.4)
> should be followed prior to submission for inclusion in the NSDI.
> Additional quality control recommendations are found in Appendix C.

### Logical Consistency

> Logical consistency refers to the internal consistency of the data
> structure, and particularly applies to topological consistency. This
> standard's intent is to ensure the ability to generate seamless
> digital mapping products within a project area. Tests for logical
> consistency must be performed that verify topology validity for
> submission to NSDI.
>
> The minimum requirement for topological verification includes:

-   Polygons intersecting the border of a project area must be closed
    along the border.

-   Segments making up the outer and inner boundaries of a polygon tie
    end-to-end to completely enclose the area.

-   Line segments are a set of sequentially numbered coordinate pairs.

-   No duplicate features exist nor duplicate points in a data string.

-   Intersecting lines are separated into individual line segments at
    the point of intersection.

-   All nodes are represented by a single coordinate pair which
    indicates the beginning or end of a line segment.

> Additional discussion on topology verification is presented in
> Appendix C.

### Edge Matching

> Edge-matching of wetland interpretation is required for a seamless
> wetland database. There are two types of edge-matching: 1) internal
> ties along the borders of source images and 2) external ties to
> pre-existing wetland data immediately adjacent to the project area.
>
> The standard requires that in all cases, internal edge-matching shall
> be performed. Wetland mapping units lying along the outer borders of
> source images within a project area, whenever practical shall be
> edge-matched with interpretations on all adjacent images within the
> project area. All linear and polygon features shall be edited to
> ensure an identical or coincident transition across images in the
> entire project area. At a minimum, features located on the outer edge
> of the project area will be closed exactly at the border of the
> project area.

### Attribute Validity

> This standard requires that all polygons have a valid attribute code
> to depict wetland habitat type. To avoid attribute errors, all data
> submissions must be run through attribute verification checks prior to
> submission to FWS for inclusion in the NSDI. Implementation
> recommendations for ensuring attribute validity reside in Appendix C.
>
> The USFWS Attribution Tools have been constructed to attribute map
> features that may depict wetlands, riparian areas, uplands or other
> natural resource features. These tools can also serve as a reference
> for uncommon or rarely used codes or to assist users who are not
> familiar with the alphanumeric wetland mapping codes. The main
> Attribution Tool contains the entire hierarchical scheme for the
> classifying wetlands and deepwater habitats (Cowardin *et al*, 1979).
> Additional information regarding the USFWS Attribution Tools is
> presented in Appendix C.

## Datum and Projection

> In accordance with the NWI and NSDI, the standard requires all data to
> be re-projected to Albers Equal-Area projection prior to submission.
> The standard requires the datum to be North American Datum 1983
> (NAD83).

## Metadata

> Metadata must be provided and conform to the most recent FGDC Content
> Standard for Digital Geospatial Metadata (CSDGM). Adherence to the
> standard requires metadata to be produced for all the core accuracy
> requirements listed in this standard.
>
> All metadata for derived wetland classifications must contain a
> reference to the FGDC-STD-004 Wetlands and Deepwater Habitat
> Classification System.

[]{#__RefHeading___Toc174155222 .anchor}References

> Classification of Wetlands and Deepwater Habitats in the United
> States, FGDC-STD-004 <http://www.fws.gov/stand/standards/cl_wetl.html>
>
> Content Standard for Digital Geospatial Metadata (version 2.0)
> FGDC-STD-001-1998,
> <http://www.fgdc.gov/metadata/geospatial-metadata-standards>
>
> *Number range CHAPTERNational Hydrography Database* (NHD) maintained
> by the USGS at <http://nhd.usgs.gov/>
>
> *Draft FGDC Riparian Standard* maintained by FGDC at
> <http://www.fgdc.gov/standards/projects/FGDC-standards-projects/riparian-mapping/index_html>
>
> *Fish and Wildlife Service National Standards and Quality Components
> for Wetlands, Deepwater and Related Habitat Mapping*,
>
> [http://www.fws.gov/stand/standards/dl_wetlands_National%20Standards.doc](http://www.fws.gov/stand/standards/dl_wetlands_National Standards.doc)
>
> Geospatial Positioning Accuracy Standards Part 3. National standard
> for spatial data accuracy. FGDC-STD-007.3-1998
>
> *Guidance for Benthic Habitat Mapping: An Aerial Photographic
> Approach* maintained by the U.S. NOAA Coastal Services Center.
> Available for download at\
> <http://www.csc.noaa.gov/benthic/mapping/pdf/bhmguide.pdf>
>
> *National Vegetation Classification Standard,* FGDC-STD-005
> <http://biology.usgs.gov/npsveg/classification/sect2.html>
>
> *RAMSAR Classification for Wetland Type* maintained by Convention on
> Wetlands (Ramsar, Iran, 1971) at
> <http://www.ramsar.org/ris/key_ris_types.htm>
>
> U.S. Geological Survey. 2001. Standards for revised primary service
> quadrangle maps. Part 2 specifications. National Mapping Technical
> Instructions. U.S. Department of the Interior, U.S. Geological Survey,
> Reston, VA. 76p. plus appendices.
>
> Primary Indicators Method. Tiner, R.W. 1993. *The primary indicators
> method - a practical approach to wetland recognition and delineation
> in the United States*. Wetlands 13(1): 50-64.

Appendix A: Workgroup Recommendations to the FGDC

> **1) FGDC Riparian Standards**
>
> Riparian habitats are integrally related to and/or highly interspersed
> with many wetland types. To exclude them from wetland maps would
> likewise be ecologically unsound and technically impractical.
> Inclusion of riparian habitat mapping in the NWI provides additional
> values in the western U.S. since wetlands are so limited in
> arid/semi-arid regions, and riparian habitats there are so critical to
> providing some of those limited functions; political, environmental
> and land-management concerns are at issue.
>
> The developers of this standard recommend that the current *Draft*
> *FGDC Riparian Standard* be updated and expanded to align with the
> efforts of this wetland mapping standard. Riparian methodologies for
> classifying and mapping specific riparian habitat types that include
> wetland habitats need to be investigated further. More information
> regarding riparian habitat classification and mapping can be found in
> Appendix C.
>
> **2) Marine Benthic Standards**
>
> Marine benthic habitats are integrally related to and/or highly
> interspersed with many wetland types. Methodologies for mapping and
> classifying marine benthic habitat types need to be investigated
> further. NOAA maintains guidance for mapping benthic habitats,
> *Guidance for Benthic Habitat Mapping: An Aerial Photographic
> Approach* and classifying benthic habitats, *Coastal and Marine
> Ecological Classification Standard (CMECS).*
>
> Through the development of this standard, it is encouraged that a FGDC
> committee be established to create and seek Federal approval for a new
> mapping standard that addresses marine and benthic habitat mapping
> activities. The committee should use the existing NOAA guidance for
> benthic habitat mapping as a baseline for creating an official FGDC
> standard. Additional informative information pertaining to marine and
> benthic habitat mapping resides in Appendix C.
>
> **3) Proposed Future Tools for Unique Identifiers and Tracking**
>
> The history of an individual feature in a geodatabase is referred to
> as a feature's "lineage." Geodatabases allow a user to query
> historical versions of a data layer and inspect the history of an
> individual feature. The ability to track wetland feature lineage
> becomes increasingly important as the national wetlands geodatabase
> grows and matures, especially when frequent edits are necessary.
> "Unique identifiers" are attributes which uniquely identify each
> mapped feature. Stable unique identifiers for wetland features would
> also be helpful for associating wetland data with other data sets
> (such as water quality and monitoring data), expanding the
> possibilities for analysis. The proposed National Wetland Mapping
> Standard endorses the adoption of technical standards for tracking
> polygons. Until such technical guidelines are developed, see Appendix
> E for technical implementation guidance regarding polygon lineage and
> unique identifiers.

Appendix B: Attributes for Wetland Classification

> The following keys provide a list of other descriptors that have been
> developed by the U.S. Fish and Wildlife Service to describe other
> wetland properties not currently addressed in Cowardin et al. 1979
> wetland classification system. When added to existing NWI wetland
> classifications, the expanded wetland database becomes a more powerful
> analytical tool allowing users to predict wetland functions for large
> geographic areas, to better characterize wetlands (e.g., palustrine
> wetlands associated with lakes, rivers, streams, and ponds), and to
> generate information of interest to policymakers and others (e.g., how
> many and how much of the wetland resource is isolated or connected to
> waters of the United States and how many and what kind of ponds are
> being created). When the Cowardin et al. classification is reviewed in
> the future, it is likely that these attributes in whole or part will
> be added to the classification. This operational draft system is
> referred to informally as LLWW (for Landscape, Landform, Water Flow
> path, and Waterbody type).

The following keys in Figures 1 and 2 provide a list of codes for
writing alpha-numeric designations for wetland and deepwater habitats as
defined by the wetland classification system developed by the U.S. Fish
and Wildlife Service (Cowardin et al. 1979).

<table>
<colgroup>
<col style="width: 1%" />
<col style="width: 5%" />
<col style="width: 0%" />
<col style="width: 7%" />
<col style="width: 1%" />
<col style="width: 0%" />
<col style="width: 4%" />
<col style="width: 5%" />
<col style="width: 0%" />
<col style="width: 5%" />
<col style="width: 0%" />
<col style="width: 3%" />
<col style="width: 6%" />
<col style="width: 0%" />
<col style="width: 11%" />
<col style="width: 0%" />
<col style="width: 5%" />
<col style="width: 0%" />
<col style="width: 1%" />
<col style="width: 0%" />
<col style="width: 10%" />
<col style="width: 0%" />
<col style="width: 6%" />
<col style="width: 5%" />
<col style="width: 11%" />
<col style="width: 3%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="4"></td>
<td colspan="14"><strong>M - MARINE</strong></td>
<td colspan="8"></td>
</tr>
<tr class="even">
<td colspan="4"></td>
<td colspan="7"></td>
<td colspan="7"></td>
<td colspan="8"></td>
</tr>
<tr class="odd">
<td colspan="4"></td>
<td colspan="14"></td>
<td colspan="8"></td>
</tr>
<tr class="even">
<td colspan="7"><strong>1 - SUBTIDAL</strong></td>
<td colspan="16"><strong>2 - INTERTIDAL</strong></td>
<td colspan="3"></td>
</tr>
<tr class="odd">
<td></td>
<td colspan="3"></td>
<td colspan="6"></td>
<td colspan="2"></td>
<td colspan="5"></td>
<td colspan="9"></td>
</tr>
<tr class="even">
<td></td>
<td></td>
<td colspan="4"></td>
<td colspan="3"></td>
<td></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="4"></td>
<td colspan="2"></td>
<td colspan="4"></td>
<td></td>
</tr>
<tr class="odd">
<td colspan="24"><p>RB – ROCK UB – UNCONSOLIDATED AB – AQUATIC BED RF -
REEF OW - <em>OPEN WATER/</em> AB – AQUATIC BED RF– REEF RS – ROCKY
SHORE US - UNCONSOLIDATED</p>
<p>BOTTOM BOTTOM <em>Unknown Bottom</em> SHORE</p></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="24"></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="3">1 Bedrock</td>
<td colspan="2">1 Cobble-Gravel</td>
<td colspan="3">1 Algal</td>
<td colspan="6">1 Coral</td>
<td colspan="2">1 Algal</td>
<td colspan="4">1 Coral</td>
<td colspan="2">1 Bedrock</td>
<td colspan="2">1 Cobble-Gravel</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="3">2 Rubble</td>
<td colspan="2">2 Sand</td>
<td colspan="3">3 Rooted Vascular</td>
<td colspan="6">3 Worm</td>
<td colspan="2">3 Rooted Vascular</td>
<td colspan="4">3 Worm</td>
<td colspan="2">2 Rubble</td>
<td colspan="2">2 Sand</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="3"></td>
<td colspan="2">3 Mud</td>
<td colspan="9">5 <em>Unknown</em></td>
<td colspan="2">5 <em>Unknown Submergent</em></td>
<td colspan="6"></td>
<td colspan="2">3 Mud</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="3"></td>
<td colspan="2">4 Organic</td>
<td colspan="9"><em>Submergent</em></td>
<td colspan="2"></td>
<td colspan="6"></td>
<td colspan="2">4 Organic</td>
<td colspan="2"></td>
</tr>
</tbody>
</table>

  ---------------- ---- ------ -- ------- ---- ---- ---- --- -- ---- -------------- ---- -- ------ ---- --- -- ---
  **E -                                                                                                        
  ESTUARINE**                                                                                                  

                                                                                                               

                                                                                                               

  **1 - SUBTIDAL**                                                   **2 -                                     
                                                                     INTERTIDAL**                              

                                                                                                               

                                                                                                               

  RB - ROCK UB --                                                                                              
  UNCONSOLIDATED                                                                                               
  AB -- AQUATIC RF                                                                                             
  -- REEF OW -                                                                                                 
  *OPEN WATER/* AB                                                                                             
  -- AQUATIC RF--                                                                                              
  REEF SB --                                                                                                   
  STREAMBED RS -                                                                                               
  ROCKY US --                                                                                                  
  UNCONSOLIDATED                                                                                               
  EM -EMERGENT SS                                                                                              
  -- SCRUB- FO --                                                                                              
  FORESTED                                                                                                     

  BOTTOM BOTTOM                                                                                                
  BED *Unknown                                                                                                 
  Bottom* BED                                                                                                  
  SHORE SHORE                                                                                                  
  SHRUB                                                                                                        
  ---------------- ---- ------ -- ------- ---- ---- ---- --- -- ---- -------------- ---- -- ------ ---- --- -- ---

  --------- --------------- -------------- --------- -------------- --------- --------- --------- --------------- --------------- --------------- ---------------
  1 Bedrock 1 Cobble-Gravel 1 Algal        1 Mollusc 1 Algal        1 Mollusc 1 Cobble  1 Bedrock 1 Cobble-Gravel 1 Persistent    1 Broad-Leaved  1 Broad-Leaved
                                                                              Gravel                                                              

  2\.       2 Sand          3 Rooted       2 Worm    3 Rooted       2 Worm    2 Sand    2 Rubble  2 Sand          2 Nonpersistent Deciduous       Deciduous
  Rubble                    Vascular                 Vascular                                                                                     

            3 Mud           4 Floating               4 Floating               3 Mud               3 Mud                           2 Needle-Leaved 2 Needle-Leaved
                            Vascular                 Vascular                                                                                     

            4 Organic       5 *Unknown*              5 *Unknown*              4 Organic           4 Organic                       Deciduous       Deciduous
                            *Submergent*             *Submergent*                                                                                 

                            6 *Unknown               6 *Unknown                                                                   3 Broad-Leaved  3 Broad-Leaved
                            Surface*                 Surface*                                                                                     

                                                                                                                                  Evergreen       Evergreen

                                                                                                                                  4 Needle-Leaved 4 Needle-Leaved

                                                                                                                                  Evergreen       Evergreen

                                                                                                                                  5 Dead          5 Dead

                                                                                                                                  6 *Deciduous*   6 *Deciduous*

                                                                                                                                  7 *Evergreen*   7 *Evergreen*
  --------- --------------- -------------- --------- -------------- --------- --------- --------- --------------- --------------- --------------- ---------------

  -------------- ------------- --------------- -- ------------- ---------------- ---------
  **R -                                                                          
  RIVERINE**                                                                     

                                                                                 

                                                                                 

  **1 -- TIDAL 2                                                                 
  -- LOWER                                                                       
  PERENNIAL 3 --                                                                 
  UPPER                                                                          
  PERENNIAL 4 --                                                                 
  INTERMITTENT 5                                                                 
  -- *UNKNOWN                                                                    
  PERENNIAL***                                                                   
  -------------- ------------- --------------- -- ------------- ---------------- ---------

+-----+---------+------+------+--------+---------+---------+--------+
| RB  | UB --   | \*SB | AB   | RS --  | US --   | \*\*EM  | OW --  |
| --  | UNCONSO | --   | --   | ROCKY  | UNCONSO | --      | *OPEN  |
| R   | LIDATED | S    | AQU  | SHORE  | LIDATED | E       | WATER* |
| OCK |         | TREA | ATIC |        |         | MERGENT |        |
|     |         | MBED | BED  |        |         |         | */*    |
+-----+---------+------+------+--------+---------+---------+--------+
| BOT | BOTTOM  |      |      |        | SHORE   |         | #      |
| TOM |         |      |      |        |         |         | ##  Un |
|     |         |      |      |        |         |         | known  |
|     |         |      |      |        |         |         | Bottom |
|     |         |      |      |        |         |         |  {#unk |
|     |         |      |      |        |         |         | nown-b |
|     |         |      |      |        |         |         | ottom  |
|     |         |      |      |        |         |         | .unnum |
|     |         |      |      |        |         |         | bered} |
+-----+---------+------+------+--------+---------+---------+--------+

  --------- --------------- ----------- -------------- --------- --------------- --------------- ----------
  1 Bedrock 1 Cobble-Gravel 1 Bedrock   1 Algal        1 Bedrock 1 Cobble-Gravel 2 Nonpersistent 

  2 Rubble  2 Sand          2 Rubble    2 Aquatic Moss 2 Rubble  2 Sand                          

            3 Mud           3 Cobble    3 Rooted                 3 Mud                           
                            Gravel      Vascular                                                 

            4 Organic       4 Sand      4 Floating               4 Organic                       
                                        Vascular                                                 

                            5 Mud       5 *Unknown*              5 Vegetated                     
                                        *Submergent*                                             

                            6 Organic   6 *Unknown                                               
                                        Surface*                                                 

                            7 Vegetated                                                          
  --------- --------------- ----------- -------------- --------- --------------- --------------- ----------

<table>
<colgroup>
<col style="width: 1%" />
<col style="width: 6%" />
<col style="width: 8%" />
<col style="width: 0%" />
<col style="width: 1%" />
<col style="width: 9%" />
<col style="width: 3%" />
<col style="width: 5%" />
<col style="width: 0%" />
<col style="width: 6%" />
<col style="width: 0%" />
<col style="width: 10%" />
<col style="width: 0%" />
<col style="width: 1%" />
<col style="width: 6%" />
<col style="width: 7%" />
<col style="width: 11%" />
<col style="width: 8%" />
<col style="width: 1%" />
<col style="width: 6%" />
<col style="width: 0%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="4"></td>
<td colspan="10"><strong>L- LACUSTRINE</strong></td>
<td colspan="7"></td>
</tr>
<tr class="even">
<td colspan="4"></td>
<td colspan="5"></td>
<td colspan="5"></td>
<td colspan="7"></td>
</tr>
<tr class="odd">
<td colspan="4"></td>
<td colspan="10"></td>
<td colspan="7"></td>
</tr>
<tr class="even">
<td colspan="7"><strong>1 - LIMNETIC</strong></td>
<td colspan="12"><strong>2 - LITTORAL</strong></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="6"></td>
<td colspan="6"></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td></td>
<td colspan="3"></td>
<td></td>
<td colspan="3"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td></td>
<td></td>
<td colspan="3"></td>
</tr>
<tr class="odd">
<td colspan="21"><p>RB – ROCK UB – UNCONSOLIDATED AB – AQUATIC OW –
<em>OPEN WATER/</em> RB – ROCK UB – UNCONSOLIDATED AB – AQUATIC RS –
ROCKY US – UNCONSOLIDATED EM – EMERGENT OW – <em>OPEN WATER</em>/</p>
<p>BOTTOM BOTTOM BED <em>Unknown Bottom</em> BOTTOM BOTTOM BED SHORE
SHORE <em>Unknown Bottom</em></p></td>
</tr>
<tr class="even">
<td colspan="21"></td>
</tr>
<tr class="odd">
<td colspan="2">1 Bedrock</td>
<td colspan="3">1 Cobble-Gravel</td>
<td colspan="3">1 Algal</td>
<td colspan="2">1 Bedrock</td>
<td colspan="2">1 Cobble-Gravel</td>
<td colspan="3">1 Algal</td>
<td>1 Bedrock</td>
<td>1 Cobble-Gravel</td>
<td colspan="4">2 Nonpersistent</td>
</tr>
<tr class="even">
<td colspan="2">2. Rubble</td>
<td colspan="3">2 Sand</td>
<td colspan="3">2 Aquatic Moss</td>
<td colspan="2">2. Rubble</td>
<td colspan="2">2 Sand</td>
<td colspan="3">2 Aquatic Moss</td>
<td>2. Rubble</td>
<td colspan="5">2 Sand</td>
</tr>
<tr class="odd">
<td colspan="2"></td>
<td colspan="3">3 Mud</td>
<td colspan="5">3 Rooted Vascular</td>
<td colspan="2">3 Mud</td>
<td colspan="4">3 Rooted Vascular</td>
<td colspan="5">3 Mud</td>
</tr>
<tr class="even">
<td colspan="2"></td>
<td colspan="3">4 Organic</td>
<td colspan="5">4 Floating Vascular</td>
<td colspan="2">4 Organic</td>
<td colspan="4">4 Floating Vascular</td>
<td colspan="5">4 Organic</td>
</tr>
<tr class="odd">
<td colspan="5"></td>
<td colspan="7">5 <em>Unknown</em> <em>Submergent</em></td>
<td colspan="4">5 <em>Unknown</em> <em>Submergent</em></td>
<td colspan="5">5 Vegetated</td>
</tr>
<tr class="even">
<td colspan="5"></td>
<td colspan="7">6 <em>Unknown Surface</em></td>
<td colspan="9">6 <em>Unknown Surface</em></td>
</tr>
</tbody>
</table>

  ---------------- ------- ---------- ------- --- ----- ------- ------- ------- ------- ----- --
  **P -                                                                                       
  PALUSTRINE**                                                                                

                                                                                              

                                                                                              

  RB -- ROCK UB --                                                                            
  UNCONSOLIDATED                                                                              
  AB -- AQUATIC                                                                               
  BED US --                                                                                   
  UNCONSOLIDATED                                                                              
  ML --                                                                                       
  MOSS-LICHEN EM                                                                              
  -- EMERGENT SS                                                                              
  -- SCRUB-SHRUB                                                                              
  FO -- FORESTED                                                                              
  OW -- *OPEN                                                                                 
  WATER/*                                                                                     

  BOTTOM BOTTOM                                                                               
  SHORE *Unknown                                                                              
  Bottom*                                                                                     
  ---------------- ------- ---------- ------- --- ----- ------- ------- ------- ------- ----- --

  --------- --------------- -------------- --------------- -------- --------------- --------------- ---------------
  1 Bedrock 1 Cobble-Gravel 1 Algal        1 Cobble-Gravel 1 Moss   1 Persistent    1 Broad-Leaved  1 Broad-Leaved
                                                                                                    Deciduous

  2\.       2 Sand          2 Aquatic Moss 2 Sand          2 Lichen 2 Nonpersistent Deciduous       2 Needle-Leaved
  Rubble                                                                                            Deciduous

            3 Mud           3 Rooted       3 Mud                                    2 Needle-Leaved 3 Broad-Leaved
                            Vascular                                                                Evergreen

            4 Organic       4 Floating     4 Organic                                Deciduous       4 Needle-Leaved
                            Vascular                                                                Evergreen

                            5 *Unknown*    5 Vegetated                              3 Broad-Leaved  5 Dead
                            *Submergent*                                                            

                            6 *Unknown                                              Evergreen       6 *Deciduous*
                            Surface*                                                                

                                                                                    4 Needle-Leaved 7 *Evergreen*

                                                                                    Evergreen       

                                                                                    5 Dead          

                                                                                    6 *Deciduous*   

                                                                                    7 *Evergreen*   
  --------- --------------- -------------- --------------- -------- --------------- --------------- ---------------

<table>
<colgroup>
<col style="width: 12%" />
<col style="width: 12%" />
<col style="width: 9%" />
<col style="width: 10%" />
<col style="width: 10%" />
<col style="width: 6%" />
<col style="width: 7%" />
<col style="width: 6%" />
<col style="width: 13%" />
<col style="width: 9%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="10"><p>MODIFIERS</p>
<p>In order to more adequately describe the wetland and deepwater
habitats one or more of the water regime, water chemistry,</p>
<p>soil or special modifiers may be applied at the class or lower level
in the hierarchy. The farmed modifier may also be applied to the
ecological system.</p></td>
</tr>
<tr class="even">
<td colspan="4">WATER REGIME</td>
<td colspan="3">WATER CHEMISTRY</td>
<td>SOIL</td>
<td colspan="2">SPECIAL MODIFIERS</td>
</tr>
<tr class="odd">
<td colspan="4"></td>
<td colspan="3"></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="4"><h2 id="section" class="unnumbered"> </h2></td>
<td colspan="3"><h2 id="section-1" class="unnumbered"> </h2>
<h2 id="all-fresh-water"> all Fresh Water </h2></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>A Temporarily Flooded</td>
<td>H Permanently Flooded</td>
<td>K <em>Artificially Flooded</em></td>
<td>*S Temporary-Tidal</td>
<td>1 Hyperhaline</td>
<td>7 Hypersaline</td>
<td></td>
<td>g Organic</td>
<td>b <em>Beaver</em></td>
<td>h <em>Diked/Impounded</em></td>
</tr>
<tr class="even">
<td>B Saturated</td>
<td>J Intermittently Flooded</td>
<td>L Subtidal</td>
<td>*R Seasonal-Tidal</td>
<td>2 Euthaline</td>
<td>8 Eusaline</td>
<td>a Acid</td>
<td>n Mineral</td>
<td>d <em>Partially Drained/Ditched</em></td>
<td>r Artificial Substrate</td>
</tr>
<tr class="odd">
<td>C Seasonally Flooded</td>
<td>K Artificially Flooded</td>
<td>M Irregularly Exposed</td>
<td>*T Semipermanent-Tidal</td>
<td>3 Mixohaline <em>(Brackish)</em></td>
<td>9 Mixosaline</td>
<td>t Circumneutral</td>
<td></td>
<td>f Farmed</td>
<td>s <em>Spoil</em></td>
</tr>
<tr class="even">
<td>D S<em>easonally Flooded/</em></td>
<td>W Intermittently</td>
<td>N Regularly Exposed</td>
<td>*V Permanent-Tidal</td>
<td>4 Polyhaline</td>
<td>0 Fresh</td>
<td>i Alkaline</td>
<td></td>
<td></td>
<td>x Excavated</td>
</tr>
<tr class="odd">
<td><em>Well Drained</em></td>
<td>Flooded/Temporary</td>
<td>P Irregularly Flooded</td>
<td>U <em>Unknown</em></td>
<td>5 Mesohaline</td>
<td></td>
<td></td>
<td rowspan="6"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>E <em>Seasonally Flooded/</em></td>
<td>Y Saturated/Semipermanent/</td>
<td></td>
<td></td>
<td>6 Oligohaline</td>
<td></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td><em>Saturated</em></td>
<td>Seasonal</td>
<td></td>
<td></td>
<td>0 Fresh</td>
<td></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>F Semipermanently Flooded</td>
<td>Z Intermittently</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>G Intermittently Exposed</td>
<td>Exposed/Permanent</td>
<td colspan="2" rowspan="2"><p>*These water regimes are only used in</p>
<p>tidally influenced, freshwater systems.</p></td>
<td></td>
<td></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td></td>
<td>U <em>Unknown</em></td>
<td></td>
<td></td>
<td></td>
<td colspan="2"></td>
</tr>
</tbody>
</table>

NOTE: Italicized terms were added for mapping by the National Wetlands
Inventory program.

The following keys provide a list of other descriptors that have been
developed by the U.S. Fish and Wildlife Service to describe other
wetland properties not currently addressed in Cowardin et al. 1979
wetland classification system. When added to existing NWI wetland
classifications, the expanded wetland database becomes a more powerful
analytical tool allowing users to predict wetland functions for large
geographic areas, to better characterize wetlands (e.g., palustrine
wetlands associated with lakes, rivers, streams, and ponds), and to
generate information of interest to policymakers and others (e.g., how
many and how much of the wetland resource is isolated or connected to
waters of the United States). When the Cowardin et al. classification is
reviewed in the future, it is likely that these attributes in whole or
part will be added to the classification. This operational draft system
is referred to informally as LLWW (for Landscape, Landform, Water Flow
path, and Waterbody type).

**Simplified Keys for Classifying Tidal and Nontidal Wetlands by**

**Landscape Position, Landform, and Water Flow Path** (Adapted from
Tiner 2003)

**Landscape Position**

1\. Wetland borders a river, stream, lake, reservoir, in-stream pond,
estuary, or ocean........2

1\. Wetland does not border one of these waterbodies; it is surrounded
by upland or

borders a pond that is surrounded by
upland....................................................Terrene

2\. Wetland lies along an ocean shore and is subject to tidal
flooding...........................Marine

2\. Wetland does not lie along an ocean shore or if oceanside, it is not
subject to tidal

flooding\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...3

3\. Wetland lies along an estuary (salt-brackish waters) and is subject
to tidal flooding......Estuarine

3\. Wetland does not lie along an estuary or if along the estuary, it is
not subject to tidal

flooding...............................................................................................4

4\. Wetland lies along a lake or reservoir or within its basin (i.e.,
the relatively flat plain

contiguous to the lake or reservoir)..................................
.............................Lentic

4\. Wetland lies along a river or stream, or in-stream pond, or borders
a marine or estuarine

wetland or associated waters but is not flooded by tides (except
episodically)..........\....5

5\. Wetland is associated with a river or
stream.....................................................6

5\. Wetland is not associated with a river or stream; it is a freshwater
nontidal wetland

bordering a marine or estuarine wetland or associated
waters...............................Terrene

6\. Wetland is the source of a river or stream and this watercourse does
not flow through

the
wetland.........\..................................................................................Terrene

6\. A river or stream flows through or alongside the wetland
.................................\...7

7\. Wetland is periodically flooded by river or stream
............................................Lotic[^1]

7\. Wetland is not periodically flooded by the river or stream
.................................\...Terrene

**Landform**

1\. Wetland occurs on a slope
\>2%\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\.....Slope

1\. Wetland does not occur on a
slope\>2%\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\....2

2\. Wetland forms an island completely surrounded by water
....................................Island

2\. Wetland does not form an
island..................................................................3

3\. Wetland occurs in the shallow water zone of a permanent nontidal
waterbody, the

intertidal zone of an estuary with unrestricted tidal flow, or the
regularly flooded

(daily tidal inundation) zone of freshwater tidal
wetlands....................................Fringe

3\. Wetland does not occur in these waters or in estuarine intertidal
zones with

unrestricted tidal
flow...............................................................................4

4\. Wetland occurs in a portion of an estuary with restricted tidal flow
due to tide gates,

undersized culverts, dikes of similar
obstructions.............................................Basin

4\. Wetland does not occur in such
location......\...................................................5

5\. Wetland forms a nonvegetated bank or is within the banks of a river
or stream...........Fringe

5\. Wetland is a vegetated river or stream bank or not within the
banks........................6

6\. Wetland occurs on an active alluvial plain of a river (a polygonal
feature)[^2]......... Floodplain\*

6\. Wetland does not occur on an active
floodplain................................................7

7\. Wetland occurs on a broad interstream divide (including headwater
positions)

associated with coastal or glaciolacustrine plains or similar
plains..................\....Interfluve\*

7\. Wetland does not occur on such a
landform\.....................................................8

8\. Wetland occurs in a distinct
depression.......................................................\...Basin

8\. Wetland occurs on a nearly level
landform.....................................................Flat

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

\*Basin and Flat sub-landforms can be identified within these landforms
when desirable.

**Water Flow Path**[^3]

1\. Wetland is typically surrounded by upland (nonhydric soil); receives
precipitation

and runoff from adjacent areas with no apparent
outflow[^4]...............................Isolated\*\*

1\. Wetland is not geographically
isolated.......................................................2

2\. Water flow is mainly bidirectional from tides or lake/reservoir
fluctuations...........3

2\. Water flow is essential one-directional
(downstream)..............................\........4

3\. Wetland is subjected to tidal
flooding.................................\..............Bidirectional-Tidal

3\. Wetland is located along a lake or reservoir and not along a river
or stream

entering this type of waterbody; water levels are mainly affected by the
rise

and fall of lake or reservoir water levels
..................................Bidirectional-Nontidal\*\*\*

4\. Wetland is a sink, receiving water from a river, stream, or other
surface water

Source and lacking surface-water
outflow..................................................Inflow

4\. Wetland is not a sink; surface water flows through or out of the
wetland............\...5

5\. Water flows out of the wetland, but does not flow into this wetland
from

another
source..................................................................................Outflow

5\. Water flows through the wetland, often coming from upstream or
uphill

sources (typically wetlands along rivers and
streams)...................................Throughflow

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

\*\*Wetland is geographically isolated; hydrological relationship to
other wetlands and watercourses may be more complex than can be
determined by simple visual assessment of surface water conditions. If
groundwater relationships are known can apply other water flow paths as
appropriate, but add "groundwater" to the term (e.g.,
outflow-groundwater).

\*\*\*Bidirectional-Nontidal flow should be expanded to reference the
water flow path of the associated waterbody: BH --
bidirectional-nontidal/throughflow, BN -- Bidirectional-nontidal/inflow,
BO -- Bidirectional-nontidal/outflow, and BS --
Bidirectional-nontidal/isolated.

**Source**: Tiner, R.W. 2003. Dichotomous Keys and Mapping Codes for
Wetland Landscape Position, Landform, Water Flow Path, and Waterbody
Type Descriptors. U.S. Fish and Wildlife Service, National Wetlands
Inventory Program, Northeast Region, Hadley, MA. 44 pp.

**\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

**Waterbody Types from Dichotomous Key**

**List of Estuary, Ocean, River, Stream, Lake, and Pond Types**

**(with corresponding map codes assigned)**

> EY Estuary
>
> 1 drowned river valley estuary
>
> a open bay (fully exposed)
>
> b semi-enclosed bay
>
> c river channel
>
> 2 bar-built estuary
>
> a coastal pond-open
>
> b coastal pond-seasonally closed
>
> c coastal pond-intermittently open
>
> d hypersaline lagoon
>
> 3 river-dominated estuary
>
> 4 rocky headland bay estuary
>
> a island protected
>
> 5 island protected estuary

6 shoreline bay estuary

> a open (fully exposed)
>
> b semi-enclosed
>
> 7 tectonic
>
> a fault-formed
>
> b volcanic-formed
>
> 8 fjord
>
> 9 other
>
> [Note]{.underline}: If desired, you can also designate river channel
> (rc), stream channel (sc),and inlet channel (ic) by modifiers.
> *Examples*: EY1rc = Drowned River Valley Estuary river channel; EY2ic=
> Bar-built estuary inlet channel. If not, simply classify all estuarine
> water as a single type, e.g., EY1 for Drowned River Valley or EY2 for
> Bar-built Estuary.
>
> OB Ocean or Bay
>
> 1 open (fully exposed)
>
> 2 semi-protected oceanic bay
>
> 3 atoll lagoon
>
> 4 other reef-protected waters
>
> 5 fjord
>
> RV River
>
> 1 low gradient
>
> a connecting channel
>
> b canal
>
> 2 middle gradient
>
> a connecting channel
>
> 3 high gradient
>
> a waterfall
>
> b riffle
>
> c pool
>
> 4 intermittent gradient
>
> 5 tidal gradient
>
> 6 dammed gradient
>
> a lock and dammed
>
> b run-of-river dammed
>
> c other dammed
>
> ST Stream
>
> 1 low gradient
>
> a connecting channel
>
> 2 middle gradient
>
> a connecting channel
>
> 3 high gradient
>
> a waterfall
>
> b riffle
>
> c pool
>
> 4 intermittent gradient
>
> 5 tidal gradient
>
> 6 dammed
>
> a lock and dammed
>
> b run-of-river dammed
>
> c beaver dammed
>
> d other dammed
>
> 7 artificial
>
> a connecting channel
>
> b ditch

LK Lake

> 1 natural lake (*see also Pond codes for possible specific types*)
>
> a main body
>
> b open embayment
>
> c semi-enclosed embayment
>
> d barrier beach lagoon
>
> 2 dammed river valley lake
>
> a reservoir
>
> b hydropower
>
> c other

3 other dammed lake

> a former natural
>
> b artificial
>
> 4 other artificial lake
>
> PD Pond
>
> 1 natural
>
> a bog
>
> b woodland-wetland
>
> c woodland-dryland
>
> d prairie-wetland (pothole)
>
> e prairie-dryland (pothole)
>
> f playa
>
> g polygonal
>
> h sinkhole-woodland
>
> i sinkhole-prairie
>
> j Carolina bay
>
> k pocosin
>
> l cypress dome
>
> m vernal-woodland
>
> n vernal-West Coast
>
> o interdunal
>
> p grady
>
> q floodplain
>
> r other
>
> 2 dammed/impounded
>
> a agriculture
>
> a1 cropland
>
> a2 livestock
>
> a3 cranberry
>
> b aquaculture
>
> b1 catfish
>
> b2 crayfish
>
> c commercial
>
> c1 commercial-stormwater
>
> d industrial
>
> d1 industrial-stormwater
>
> d2 industrial-wastewater
>
> e residential
>
> e1 residential-stormwater
>
> f sewage treatment
>
> g golf
>
> h wildlife management
>
> i other recreational
>
> o other

3 excavated

> a agriculture
>
> a1 cropland
>
> a2 livestock
>
> a3 cranberry
>
> b aquaculture
>
> b1 catfish
>
> b2 crayfish
>
> c commercial
>
> c1 commercial-stormwater
>
> d industrial
>
> d1 industrial-stormwater
>
> d2 industrial-wastewater
>
> e residential
>
> e1 residential-stormwater
>
> f sewage treatment
>
> g golf
>
> h wildlife management
>
> i other recreational
>
> j mining
>
> j1 sand/gravel
>
> j2 coal
>
> o other
>
> 4 beaver
>
> 5 other artificial

Appendix C: Implementation Recommendations in Support of Section 2.0

> In developing Section 2, "FGDC Requirements and Quality Components,"
> this standard acknowledges the need for additional implementation
> recommendations above and beyond the existing minimum technical
> requirements. This appendix provides technical recommendations for
> implementing the Wetland Mapping Standard.

**1) Classification** *(Standard Section 2.2)*

> **A. Riparian Habitats**
>
> Riparian habitats are plant communities that are contiguous to rivers,
> streams, lakes or drainage ways. Riparian areas are usually
> transitional between aquatic and upland, or wetland and upland. In
> addition to providing a vertical transition between aquatic and
> terrestrial ecosystems, riparian areas also possess a distinct
> horizontal structure. Drainage patterns form an extensive, dendritic
> network throughout the country. The associated riparian zones form
> corridors that extend within and into different regions. The general
> spatial pattern of riparian areas thus forms a gradient of height and
> width and becomes a network within an overall matrix (Malanson 1993).
>
> Current mapping standards for riparian habitats are based both on
> vegetation and the geomorphology of the channel. Riparian habitats in
> the U.S. may be broken down into two distinct categories: Arid
> (including Hyper-Arid, Semi-Arid and Dry-Subhumid) and Humid. Arid
> riparian habitat occurs in areas where mean annual evaporation exceeds
> mean annual precipitation, primarily WEST of the Mississippi River.
> Humid riparian habitat occurs in areas where mean annual precipitation
> exceeds mean annual evaporation, primarily EAST of the Mississippi
> River. Using current technology, riparian habitats can only be readily
> mapped only from aerial imagery in the Western U.S. where evaporation
> exceeds precipitation and where the habitats are therefore distinct
> from the surrounding vegetation. Since humid riparian habitats cannot
> currently be mapped as easily as arid riparian habitats, they are not
> considered further in this version of the mapping standard. However,
> it is recommended that efforts be undertaken to develop technology to
> map humid riparian habitats for possible inclusion in updates of the
> Wetland Mapping Standard.
>
> Arid riparian habitats are currently mapped/included within the NWI
> geospatial data layers. ["Arid Riparian Habitat"]{.underline} is
> defined based on FWS guidance entitled "A System for Mapping Riparian
> Areas in the Western United States" (USFWS 1997 \[and draft revision
> 2007\])^5^.
>
> Arid Riparian areas, including Hyper-Arid, Semi-Arid and Dry-Subhumid,
> are the non-wetland and non-aquatic plant communities contiguous to
> and affected by surface and subsurface hydrologic features of
> perennial or intermittent lotic and lentic water bodies (rivers,
> streams, lakes or drainage ways). Arid Riparian areas have one or both
> of the following characteristics: 1) distinctively different
> vegetative species than adjacent areas, and 2) species similar to
> adjacent areas but exhibiting more vigorous or robust growth forms.
>
> Arid riparian habitats are defined in the mapping system as being
> "non-wetland and non-aquatic" to separate wetlands in a riparian
> landscape position from riparian areas. This prevents the overlap of
> polygons and allows mapping of these features in the same data layer
> with wetlands and other aquatic habitats. However, in practice, arid
> riparian habitats may include unintentional inclusions of wetland and
> other aquatic habitat.
>
> **B. Upland Areas**
>
> This standard recommends against labeling Upland areas. However, if
> these features must be mapped to maintain topology or for quality
> control, the "U" symbol should be used. For the wetland data layer for
> the National Spatial Data Infrastructure (NSDI), the "U" or "upland"
> features/polygons are eliminated for several reasons, one of which is
> these areas may contain undetectable wetlands given the limitations of
> the Service\'s wetlands data collection methods. Another important
> reason for the elimination of the "U" or upland features relates to
> the sheer size of the database.
>
> **C. Wetland and Deepwater Attribute Parsing**
>
> The classification attribute table should be designed such that the
> code for each level of the classification scheme is placed in a
> separate field (or column) in the table (i.e., SYSTEM, SUBSYSTEM,
> CLASS, SUBCLASS, WATER_REGIME, SPECIAL_MODIFIER, etc.), in order to
> better facilitate incorporation and analysis of the data.
>
> When separate fields are used for the classification levels,
> additional fields may be created to hold the concatenated codes in
> order to simplify labeling. For example, a data field "Label \_1" may
> contain all the Cowardin classification levels put together
> (e.g.,"PFO1Fh"), and likewise another field "Label_2" might contain
> all the LLWW classification levels put together.
>
> **This standard does not recommend using "mixed codes".** However, two
> (or rarely three) codes may, in unusual instances, be needed to
> attribute a particular level of the classification (for example, in a
> wetland with a mixture of scrub-shrub and emergent covers which are
> inseparable at the interpretation scale used, and that has a resulting
> Class code of "SS1/EM1"). This situation is informally referred to as
> \"mixed codes\" or \"split classes\". In very rare instances, three
> classes may be mixed, but the NWI database is not designed to accept
> this level of data at this time.
>
> Mixed codes (or split classes) should not be used unless at least one
> of the following conditions is met: (1) the wetland contains two or
> more distinct cover types, each encompassing at least 30% aerial
> coverage, but the wetland is too small in size to allow separate
> delineation of each cover type; OR (2) the wetland contains two or
> more classes or subclasses, each compromising at least 30% aerial
> coverage, which are so evenly interspersed that separate delineation
> is not possible. If it is necessary to use mixed codes, the class
> covering greater area within the polygon is considered the dominant
> class, and the other class is sub-dominant (listed second). For
> example, PFO1/SS1C is a wetland where FO1 (broad-leaved deciduous
> forested wetland) covers more of the wetland polygon than the SS1
> (broad-leaved deciduous scrub-shrub) component.
>
> Where mixed codes are possible within a classification level,
> additional attribute fields may be utilized for each level of the
> classification to facilitate analysis of the data (e.g. CLASS_1 and
> CLASS_2, or SPECIAL_MODIFIER_1 and SPECIAL_MODIFIER_2); however the
> NWI database is not designed to accept this level of data at this
> time.  Slashes are used to separate mixed codes (as is done in the
> existing NWI data) when the codes are concatenated for labels (e.g.,
> PSS1/EM1Hh).
>
> The implementation of parsing rules and procedures will be pursued as
> a result of this standard.
>
> **D. Adding Additional Classification Descriptors**
>
> The producer may add additional descriptors including subclass, water
> chemistry modifiers, special modifiers and other descriptors such as
> LLWW descriptors (e.g., landscape position, landform, water flow path,
> and waterbody type) to satisfy regional or local needs. This standard
> recommends the use of LLWW descriptors to enhance characterization of
> wetlands and to predict wetland functions.

**2) Accuracy** *(Standard Section 2.3)*

> **A. User's Accuracy (UA)**
>
> This standard recommends use of field accuracy assessment techniques
> to assess UA and the documentation of these results in the metadata.
> Field accuracy can be determined by applying the primary indicators
> approach to field-checked wetlands (Tiner 1993).
>
> **B.** **Quality Control**
>
> The *Wetland Mapping Standard* seeks to ensure the consistent
> identification of a specified percentage of wetlands that are above a
> specified size in the submission of digital data by all users, in
> order to support and document the data quality requirements of the
> national data layer. To this end, the contractual requirements
> established for the use of Federal funding when mapping in accordance
> with this standard do require the demonstration of TMU, PA and/or UA.
> Prior to NSDI inclusion, all products are subject to being verified by
> either general inspection, 100% inspection, or inspection by sampling.
> Inspection of the digital wetlands data will involve both visual and
> software evaluation procedures. The inspections are intended to
> satisfy compliance with file format, content completeness, positional
> accuracy, attribute accuracy, topological fidelity, and edge matching.

**3) Data Verification** *(Standard Section 2.4)*

> **A. Logical Consistency and Edge Matching**
>
> The standard recommends tying new polygons to existing polygons in
> adjacent areas in the NSDI to maintain a seamless national wetlands
> database. To maintain a seamless national wetlands database, it is
> advisable to tie the interpretations for the project area to adjacent
> pre-existing wetland data in the national database. Such external
> edge-matching should be performed if the age, scale, and emulsion of
> the source images are compatible. In some cases, this will not be
> possible, such as where the project area is a watershed, county,
> State, reservation or any other area of interest and funds or source
> imagery are not available for external ties, where changes in wetland
> boundaries or types have occurred during the intervening time period,
> or where wetlands were inaccurately delineated on the original maps.
> The standard encourages producers to tie their new data to
> pre-existing national wetlands data and include plans and costs for
> doing so in project proposals. This will expedite data posting in the
> national database and aid efforts to maintain a seamless database.
> Implementation of this recommendation would likely require
> considerable overlap of both source imagery and map production with
> adjacent mapping efforts.
>
> **B. Attribute Validity**
>
> The USFWS Topology and Attribute Verification Tools have been
> constructed to automate (to the extent possible) the quality control
> functions necessary to ensure the data are cartographically accurate.
> This suite of functions has been designed to address cartographic
> errors, digital anomalies, and some logic checks that make use of the
> power of geographic information system technology. The verification
> tools will flag potential problems but provides the image interpreter
> the option of editing or ignoring the feature. This is to accommodate
> the image interpreter's ability to ultimately determine the best
> ecological portrayal of the data. For example, a small lake that is
> only 18 acres has been identified during the data verification process
> as a potential problem based on its size (18 acres) and classification
> (lacustrine). The interpreter has information that the lake depth
> exceeds 90 feet and determines that lacustrine is the best ecological
> descriptor for this feature.
>
> The verification tools allow the user to easily find attribute
> problems with the wetlands polygons. There are two types of procedures
> involved. The first procedure is a non-interactive, intensive process
> that checks all the attribute codes, repairs some of them and flags
> others for subsequent checks. The second type of procedure is an
> interactive process where the interpreter uses the interactive mapping
> capabilities of the GIS application to visually identify specific
> topological and attribute features that may need adjustment.
>
> The tools incorporate the following:

1.  Allows the image interpreter to perform a series of verification
    tests and optionally visualize the results of those tests through
    the use of "graphic elements."

2.  Stores and manages results of the tests in a special field added to
    the layer's attribute table.

3.  Provides the image interpreter with a count of the number of errors
    found by a particular test.

4.  Provides the image interpreter with an estimate of the processing
    time remaining until completion of a verification test through the
    use of a "progress bar.

5.  Provides a function that runs the most critical tests and produces
    either a "pass" or "fail" assessment of the QA/QC procedure.

Appendix D: Known Issues with Existing Wetlands Mapping Data

> During the development of this standard, several wetland mapping
> issues have been discussed and presented. This appendix describes
> known technical issues related to wetland mapping and data collection.

**1) Nominal Scale Issues**

> Wetland maps produced using data from the wetlands layer of NSDI as
> thematic or topical data using U.S. Geological Survey topographic
> maps, digital raster graphics (DRG) or digital orthophotography as a
> base will comply with the standard for USGS digital spatial wetlands
> for maps produced from data[^5] with a nominal scale of 1:24,000 or
> 1:63,360 (Alaska).
>
> Organizations engaged in producing wetlands data are encouraged to
> exceed this nominal scale as source materials (e.g., Digital Ortho
> Quarter Quads) and technology capabilities allow.

**2) Completeness and Errors**

> Every mapping project has errors of omission and commission. For
> wetland mapping, omission errors are wetlands that are not shown on
> the map. Wetlands may be omitted due to several factors that preclude
> their identification or delineation including scale and emulsion of
> imagery, mapping scale or base map scale, quality of imagery,
> environmental conditions when imagery was captured, and difficulty of
> identifying particular types of wetlands. Commission errors are errors
> related to misclassification or limits of scale. For wetland mapping,
> commission errors include: 1) misclassification (e.g., nonwetland
> areas mapped as wetlands or misidentification of the wetland type), 2)
> small uplands included within a large wetland mapping unit, and 3)
> small wetlands of different type included within a larger wetland unit
> of another type (e.g., a small scrub-shrub wetland within a palustrine
> forested wetland mapping unit) simply because they are too small to
> map (below the target mapping unit). The latter two situations are
> commonly referred to as "inclusions." Habitat changes that have
> occurred between the date of the source imagery and date of field
> observation/groundtruthing are not considered errors as the wetland
> was correctly classified on the source imagery.
>
> NWI maps and geospatial data tend to err more by omission than by
> commission. This means that if a NWI map indicates the presence of a
> wetland in a given area, it is highly likely that a wetland is there.
> Yet, if a NWI map does not show a wetland, one would usually not be
> there, but users should be aware that small unmapped wetlands on the
> ground may exist, particularly in landscape positions favoring wetland
> formation (e.g., floodplains, flat areas along streams, in
> depressions, and along drainageways). The following section "NWI
> Mapping Limitations" discusses some causes of omissions in NWI
> mapping.

**3) NWI Mapping Limitations**

> 1\. [Target Mapping Unit (TMU)]{.underline} -- A TMU is an estimate of
> the minimum sized wetland that the NWI is attempting to consistently
> map. It is not necessarily the smallest wetland shown on the maps. The
> TMU for wetlands generally varies with the scale of the source imagery
> used, wetland type, project design, and funding.
>
> 2\. [Spring imagery]{.underline} - Where spring imagery is used,
> aquatic beds and nonpersistent emergent wetlands are usually
> undermapped. These areas are classified as open water, unless
> vegetation was observed during field investigations. In a few cases,
> scrub-shrub wetlands are submerged, avoiding imagery-detection; they
> too are included within mapped open waterbodies.
>
> 3\. [Summer (leaf-on) imagery]{.underline} - This imagery makes it
> difficult to identify many forested wetlands as well as seasonal
> wetlands. For example, the presence of a leafy canopy makes it
> extremely difficult to separate all but the wettest forested wetlands
> from upland forests. The wetness of the forest floor is obscured,
> except where canopy openings exist. In some areas, such as the Pacific
> Northwest, spring imagery is difficult to acquire due to cloud cover
> so leaf-on imagery was used for wetland mapping. In Alaska, most of
> the source imagery is acquired in mid-summer. In both these examples,
> the NWI Project is conservative in mapping forested wetlands. Also,
> summer imagery makes it more difficult to recognize seasonal wetlands
> that are flooded in winter and spring, but dry out before the imagery
> is acquired.
>
> 4\. [Forested wetlands]{.underline} - These are among the more
> difficult types to interpret. Consequently, these types are
> conservatively mapped. Forested wetlands on glacial till are often
> difficult to interpret, so many of these wetlands do not appear on NWI
> maps. The location of temporarily flooded or seasonally saturated
> forested wetlands are among the most difficult to identify on the
> ground as well as through imagery interpretation, so many of these
> wetlands do not appear on the NWI maps. This limitation is common
> along the Coastal Plain and perhaps in glaciolacustrine plains such as
> the Ontario Plain (New York). In areas where 1:80,000 black and white
> imagery was used, many forested wetlands were not interpretable.
> Consulting USDA soil survey maps and locating undeveloped portions of
> hydric soil map units may help identify locations where more of these
> wetlands may be found.
>
> 5\. [Upland inclusions]{.underline} - Small upland areas may occur
> within delineated wetlands due to target mapping unit size. Field
> inspections and/or use of larger-scale imagery may be used to refine
> wetland boundaries when necessary.
>
> 6\. [Estuarine and tidal waters]{.underline} - Delineation of
> estuarine and riverine (tidal) systems and the oligohaline (slightly
> brackish) segment of estuaries should be considered approximate based
> on available reports or limited field checking.
>
> 7\. [Intertidal flats]{.underline} - Since imagery is not always
> captured at low tide, all intertidal flats are not visible; boundaries
> of these nonvegetated wetlands are often approximated from coastal and
> geodetic survey maps and topographic maps.
>
> 8\. [Coastal wetlands]{.underline} - Identification of high marsh
> versus low marsh in estuarine wetlands is often approximated, since
> the imagery of these zones is not distinctive in many instances.
>
> 9\. [Water regimes]{.underline} - Water regimes are identified based
> on imagery coupled with limited field verification; they should be
> considered approximate. Long-term hydrologic studies are required to
> accurately describe the hydrology of any particular wetland.
>
> 10\. [Linear wetlands]{.underline} - Wetlands which appear long and
> narrow (less than 50 feet wide at a scale of 1:24,000), and follow
> drainage-ways and stream corridors, may or may not have been mapped,
> depending on project objectives. Such linear wetlands may be
> relatively short or miles in length. The categorization of wetlands as
> linear features depends on the specific project objectives as well as
> on the limitations of the imagery and scale used. On the ground,
> linear wetlands may be found to be wider in places than what is shown
> on the map due to seasonal vegetation patterns and hydrologic
> conditions at the time the image was acquired. Most NWI maps identify
> at least some of these linear features. In most cases, no attempt was
> made to map all linear wetlands. Users can infer the possible
> occurrence of linear wetlands by looking for pertinent topographic
> features on the NWI maps.
>
> 11\. [Farmed wetlands]{.underline} - In general, only five types of
> farmed wetlands are shown on NWI maps: cranberry bogs, prairie
> potholes, pothole-like depressions, playa lakes, and seasonally
> flooded diked former tidelands in California. This is based on
> technical considerations and an interagency agreement between the U.S.
> Fish and Wildlife Service and the U.S.D.A. Natural Resources
> Conservation Service, developed in the 1970s.
>
> 12\. [Partly drained wetlands]{.underline} - Partly drained wetlands
> are mapped based on recognizable image signatures. Many of these
> wetlands may have been missed. Consulting USDA soil survey maps and
> locating hydric soil map units not mapped as wetlands by NWI may help
> identify locations where more of these wetlands may be found.
>
> 13\. [Tundra]{.underline} - Moist tundra (usually wetland) is often
> difficult to separate from dry upland tundra due to lack of definitive
> image signatures. This is especially true where wide transition zones
> exist between the two types.
>
> 14\. Date of wetlands geospatial data -- The dates of the NWI
> geospatial map data are based on the dates of the source imagery. Data
> does not show losses or gains in wetlands since that date.
>
> 15\. Submerged Aquatic Beds in Tidal Waters. NWI maps may show some of
> these beds -- where they were visible on the aerial photography used
> by NWI. A more complete survey of these habitats, however, requires
> capturing special photography (e.g., larger scale, low tide, clear
> water, and no wave action) to maximize their identification and
> delineation.

Appendix E: Polygon Lineage and Unique Identifiers

> Changes in wetlands either in spatial extent or physical
> characteristics will be maintained through feature lineages and
> versioning without losing any legacy data on the original polygon.
> Moreover, technologies that allow direct association of feature
> metadata with individual features have simplified maintenance of
> documentation. In the case of wetland inventories derived from
> previous inventories (i.e., where original data are edited through
> GIS), the GIS systems can track changes automatically (See Figure 1
> for ideal Polygon Lineage).
>
> **Figure 1.**
>
> ![](media/image1.png){width="4.009722222222222in" height="2.2875in"}
>
> However, attributing the cause for the wetland changes requires
> additional editing and the development of change code descriptors (See
> Figure 2 for Polygon Lineage Scale Deviations).
>
> **Figure 2.**
>
> ![](media/image2.png){width="3.279861111111111in" height="2.475in"}
>
> It is anticipated that the effort to develop these codes and other
> detailed Technical Guidelines for implementing the standard in
> practice will take place after the adoption of the FGDC National
> Wetland Mapping Standard.
>
> Until such Technical Guidelines are developed, it is recommended that
> in lieu of attributing the reason for changes in every polygon,
> wetland mappers should consider focusing on attributing "new
> wetlands" - wetlands that were not there (in time one) and separating
> these wetlands into three categories. These categories are "newly
> established", "re-established" and "pre-existing." This would require
> re-examination of the source imagery from the prior inventory to
> determine whether the wetland was actually present at that time. For
> example, if an area classified as forested wetland in time two, was
> observed as a forest on the aerial image for time one, it is likely
> that the area was a forested wetland in time one; the area should be
> added as forested wetland to the time one wetland acreage. It is not a
> "newly established wetland," but rather a "pre-existing wetland." The
> situation is not as clearcut for agricultural areas where an area may
> appear as dryland during a drought or dry year (and even be
> cultivated) and later "reappear" as an emergent wetland in a wet year.
> While it is a "new" wetland in one sense, the wetland was always
> there, but undetectable during dry conditions. This wetland should
> also be added to the time one wetland acreage statistics. If, however,
> the area was drained in time one, and in time two, ditches were
> blocked and a wetland formed, then this wetland should be considered a
> "newly re-established wetland," and it would not be added to the time
> one base acreage since it was not a wetland at that time. This may not
> be as easy to interpret as one might think, so appropriate cautions,
> concerns, and limitations should be referenced in the metadata for the
> inventory.
>
> After doing this comparative analysis, the recalculated wetland
> acreage summaries for the prior period (time one) will better reflect
> actual conditions for that era and can then be compared with the more
> recent data (i.e., the "missing" wetlands will have been added to the
> time one base).
>
> In the interim, historic NWI data will be made available for use.
> Polygon lineage may be accomplished where NWI data are edited,
> however, in most cases; new NWI data are derived from better imagery
> and completely replace the older data. This complicates the issue of
> polygon lineage since the polygon is replaced and not simply edited;
> alignment and configuration may be quite different due to scale and
> image quality differences. In any event, polygon lineage issues
> identified in this appendix should be further examined and a practical
> solution developed for possible inclusion in future versions of NWI.

Appendix F: Questions and Answers

> **Q: What is a wetland and why map it?**
>
> **A:** Wetland Maps are essential to view a complete and accurate
> picture of wetland resources in the US, calculate (not estimate)
> wetland loss and gain, see wetland geospatial distribution, and
> complete the watershed picture on the National Map. Once wetlands are
> mapped, many types of assessments can be performed. Wetland
> assessments are critical to: monitor wetland health, make permit
> decisions, target volunteer wetlands restoration, maintain
> biodiversity, restore species, measure mitigation success, undertake
> watershed management, protect water supplies, and better community
> planning.
>
> **Q: What is the geographic area covered by features stored in the
> Geodatabase?**
>
> **A:** Five discrete geographic areas were designated as wetland
> mapping areas. These were named CONUS (conterminous United States),
> Alaska, Hawaii, PR-VI (Puerto Rico and the U.S. Virgin Islands), and
> Pac Trust (Pacific Trust Territories). Alaska contains the state of
> Alaska including the Aleutians. Hawaii contains the principle islands
> of Hawaii, including Hawaii, Maui, Kahoolawe, Lanai, Molokai, Oahu,
> Kauai and Niihau. CONU contains the 48 conterminous states. PR - VI
> contains the islands of Puerto Rico and the U. S. Virgin Islands. Pac
> Trust contains the U.S. island possessions and trust territories of
> the south Pacific.
>
> **Q: What is the background on the development of the Wetlands Mapping
> Standard?**
>
> **A:** There is currently no FGDC-approved (Federal Geographic Data
> Committee) standard for wetland mapping. USFWS (U.S. Fish & Wildlife
> Service) will never have will never have the resources to undertake
> wetland mapping and updating alone, especially on a continual basis --
> a partnership (Fed, State, Tribal, Local and others) can accomplish
> this. The mapping standard is essential the production of compatible
> data .
>
> **Q: Why develop a national standard?**
>
> **A:** A Wetland Mapping Standard will:

-   streamline mapping efforts for greater consistency and efficiency,

-   enable any entity to map using the standard and construct or update
    the National Wetlands Inventory (NWI) Geodatabase and the National
    Map,

-   facilitate consistent mapping layers that can be used across
    geopolitical and watershed boundaries, and

-   ensure that Federal funding for wetland mapping produces data for
    improving and updating the NWI Geodatabase and the National Map.

> **Q:** **What Was Proposed to and Approved by the FGDC in February
> 2006?**
>
> **A: The Wetlands Subcommittee proposed to base development of a**
> FGDC wetland mapping standard on the existing FWS wetlands mapping
> standard and coordinate with other pertinent standards: NHD, NOAA
> classifications, FGDC classification standards, etc.; coordinate with
> stakeholders; and propose draft for comment in February 2007.
>
> **Q: What if you use old data to create new maps?**
>
> **A:** This is acceptable provided old data are suitably registered to
> the new map base and data are updated to reflect more current
> conditions. Existing data may also be portrayed on new base maps such
> as digital ortho quarter-quads, so users can identify areas of change,
> but such data are not considered a new map as no new digital data will
> be generated for inclusion in the NSDI.
>
> **Q: Can this standard support traditional mapping?**
>
> **A:** Yes, conventional photointerpretation techniques using aerial
> photography and traditional cartographic techniques may still be
> employed, but such techniques will require that maps be digitized to
> create geospatial data for inclusion in the NSDI.
>
> **Q: What classifies wetlands as Pf (palustrine farmed)?**
>
> **A:** Farmed wetlands are wetlands that are cultivated to grow one or
> more crops (e.g., corn, soybeans, or cranberries) and are still wet
> enough to meet the definition of wetlands; they are not former
> wetlands that are effectively drained and planted with crops.
> Cultivated cranberry bogs should be mapped as PSSf (palustrine
> scrub-shrub farmed).
>
> **Q: What is the difference between "inshore deepwater" and "offshore
> deepwater"?**
>
> **A:** [Inshore deepwater:]{.underline} includes nontidal waters
> (e.g., rivers and lakes) deeper than 2m (at annual low water) and
> subtidal waters below the extreme spring low tide mark in estuaries
> and tidal freshwater rivers: "deepwater" excludes shallow waters of
> upper perennial mountain streams, other wadable rivers and streams,
> and lakes (lacustrine littoral wetlands) as well as intermittent
> rivers and streams.
>
> [Offshore deepwater:]{.underline} includes subtidal waters lying below
> the extreme spring low tide mark in the marine ecosystem (ocean and
> embayments); these waters lie seaward of the break between estuarine
> and marine waters. Deepwater excludes the intertidal zone (tidal
> wetland).
>
> **Q: What is the difference between internal vs. external edge
> matching?**
>
> **A:** Internal edge matching involves tying all linework within a
> project area to ensure that all polygons are closed and linears are
> connected, while external edge matching addresses ties to pre-existing
> wetland data outside, but contiguous to, the project area (e.g.,
> matching a wetland polygon within project area to a continuation of it
> on an adjoining map outside the project area).
>
> **Q: What does federally funded mean?**
>
> **A:** Federal Funding Sources include both mandatory and
> discretionary funding. Mandatory funding is controlled by laws other
> than appropriations acts.  Discretionary funds are controlled by
> appropriation acts.  Examples of mandatory funds are Coastal Wetlands
> Planning, Protection, and Restoration Act funds and those collected
> from the sale of Duck Stamps.  All appropriated funds are considered
> to be discretionary funds. All contracts, agreements, or grants, etc.
> funded fully or in part by Federal agencies either through mandatory
> or discretionary funds are federally funded sources.
>
> **Q: How will the standard be implemented?**
>
> A: The standard will be made widely published and it is will be
> written into Federal contracts, agreements and grants. Any entity
> receiving Federal money must use FGDC standard. The federal agencies
> will encourage others to adopt/use the standard and use grant money as
> seed money to encourage its use. The standard will facilitate
> states/tribes to establish wetlands mapping funding coalitions. .
>
> **Q: Why can't you just use publicly available, Web-based mapping
> products to map wetlands?**
>
> A: We currently are unable to use publicly available, Web-based
> mapping products to map wetlands because the features required for
> mapping are only available as layers in pc-based mapping software. In
> the future, wetlands data may be added to publicly available,
> Web-based mapping products if they conform to the standards
> requirements.

Appendix G: Definitions (Informative)

> *classification error \--* commission errors are areas mapped as
> wetlands that are not in fact wetlands on the ground. For example,
> small uplands may be included within a large wetland mapping unit or
> small wetlands of a different type may be included within a larger
> wetland unit of another type (e.g., a small scrub-shrub wetland within
> a palustrine forested wetland mapping unit) simply because they are
> too small to map (below the target mapping unit). These types of
> situations are commonly referred to as "inclusions." Misclassification
> results in both omission and commission errors since one class is
> missing features while another has surplus features.
>
> *Cowardin classification system \--* the U.S. Fish and Wildlife
> Service's official wetland and deepwater habitat classification system
> written by Cowardin, Carter, Golet, and LaRoe and published in 1979,
> approved by the FGDC as the National Standard in 1996.
>
> *deepwater habitats* \-- "Other Aquatic Habitats" are equivalent to
> "Deepwater Habitats" as defined by the FWS Wetlands Classification
> System (Cowardin *et al*, 1979):
>
> *Deepwater habitats are permanently flooded land lying below the
> deepwater boundary of wetlands. Deepwater habitats include
> environments where surface water is permanent and often deep, so that
> water, rather than air, is the principal medium in which the dominant
> organisms live, whether or not they were attached to the substrate.*
>
> The Wetlands Classification System further defines the limits of
> deepwater habitats:
>
> *The boundary between wetland and deepwater habitat in the Marine and
> Estuarine Systems coincides with the elevation of the extreme low
> water of spring tide; permanently flooded areas are considered
> deepwater habitats in these Systems. The boundary between wetland and
> deepwater habitat in the Riverine and Lacustrine Systems lies at a
> depth of 2 m (6.6 feet) below low water; however, if emergents,
> shrubs, or trees grow beyond this depth at any time, their deepwater
> edge is the boundary. The 2-m lower limit for inland wetlands was
> selected because it represents the maximum depth to which emergent
> plants normally grow (Welch 1952; Zhadin and Gerd 1963; Sculthorpe
> 1967).*
>
> *inshore deepwater* -- nontidal waters (e.g., rivers and lakes) deeper
> than 2m (at annual low water) and subtidal waters below the extreme
> spring low tide mark in estuaries and tidal freshwater rivers:
> "deepwater" excludes shallow waters of upper perennial mountain
> streams, other wadable rivers and streams, and lakes (lacustrine
> littoral wetlands) as well as intermittent rivers and streams.
>
> *offshore* *deepwater* -- subtidal waters lying below the extreme
> spring low tide mark in the marine ecosystem (ocean and embayments);
> these waters lie seaward of the break between estuarine and marine
> waters; "deepwater" excludes the intertidal zone (tidal wetland).
>
> *federally-funded \--* financial support for the mapping project comes
> directly or indirectly from one or more federal agencies.
>
> *horizontal accuracy \--* refers to a features spatial relationship to
> the source imagery.
>
> *logical consistency \--* logical consistency refers to the internal
> consistency of the data structure, and particularly applies to
> topological consistency.
>
> *non-federally funded --* financial support comes from state, local,
> or private funds with no contribution either directly or indirectly
> from Federal sources.
>
> *National Spatial Data Infrastructure (NSDI) \--* consistent means to
> share geographic data among all users could produce significant
> savings for data collection and use and enhance decision making.
> [Executive Order
> 12906](http://www.fgdc.gov/nsdi/policyandplanning/executive_order)
> calls for the establishment of the National Spatial Data
> Infrastructure defined as the technologies, policies, and people
> necessary to promote sharing of geospatial data throughout all levels
> of government, the private and non-profit sectors, and the academic
> community.
>
> The goal of this Infrastructure is to reduce duplication of effort
> among agencies, improve quality and reduce costs related to geographic
> information, to make geographic data more accessible to the public, to
> increase the benefits of using available data, and to establish key
> partnerships with states, counties, cities, tribal nations, academia
> and the private sector to increase data availability.
>
> The NSDI has come to be seen as the technology, policies, criteria,
> standards and people necessary to promote geospatial data sharing
> throughout all levels of government, the private and non-profit
> sectors, and academia. It provides a base or structure of practices
> and relationships among data producers and users that facilitates data
> sharing and use. It is a set of actions and new ways of accessing,
> sharing and using geographic data that enables far more comprehensive
> analysis of data to help decision-makers chose the best course(s) of
> action. Much has been accomplished in recent years to further the
> implementation of the NSDI, but there is still much to be done to
> achieve the vision of current and accurate geographic data being
> readily available across the country.
>
> *producer's accuracy (PA) \--* measures the percentage of features
> that are correctly classified on the imagery.
>
> *project area --* a geographic area where wetland mapping is to be
> performed through some form of remote sensing (e.g.,
> photointerpretation, satellite or other image processing). It may
> range in size from a region, state, county, or municipality to portion
> thereof. For purposes of this standard, a project area is not a
> site-specific area where construction, restoration, or similar actions
> are proposed or where on-the-ground wetland delineations are
> performed.
>
> *spatial resolution \--* The detail with which a map depicts the
> location and shape of geographic features. The larger the map scale,
> the higher the possible resolution. As scale decreases, resolution
> diminishes and feature boundaries must be smoothed, simplified, or not
> shown at all; for example, small areas may have to be represented as
> points.
>
> *target mapping unit (TMU) \--* is an estimate of the size class of
> the smallest wetlands that can be consistently mapped and classified
> at a particular scale of imagery, and that the image-interpreter
> attempts to map consistently.
>
> *upland* **\-- "**Upland" or "U" is the default classification for
> regions of the map that are not classified as wetlands or other
> aquatic habitats. As such, the designation "Upland" represents
> generalized terrestrial areas which have not been further subdivided
> or categorized by type. While "Upland" primarily includes terrestrial
> (non-wetland) areas and former wetlands that are effectively drained
> or filled, it may include unclassified wetlands such as human-modified
> areas (e.g., farmed wetlands), wetlands that are too small to be
> differentiated, wetlands that couldn't be detected on the type of
> imagery used (e.g., small wetlands under forest cover), and other
> unintentional wetland omissions (errors). According to the FWS
> Wetlands Classification System (Cowardin *et al*, 1979):
>
> *The upland limit of wetland is designated as (1) the boundary between
> land with predominantly hydrophytic cover and land with predominantly
> mesophytic or xerophytic cover; (2) the boundary between soil that is
> predominantly hydric and soil that is predominantly nonhydric; or (3)
> in the case of wetlands without vegetation or soil, the boundary
> between land that is flooded or saturated at some time during the
> growing season each year and land that is not.*
>
> *vertical accuracy --* the measure of the accuracy of the vertical
> measure of a reference point.
>
> *wetland classification \--* in support of maintaining an ecological
> perspective, wetlands are defined as below, based upon the FWS
> Wetlands Classification System (Cowardin *et al*, 1979). This
> definition is the national standard for wetland mapping, monitoring,
> and data reporting as recognized by the FGDC on December 17, 1996.
>
> *Wetlands are lands transitional between terrestrial and aquatic
> systems where the water table is usually at or near the surface or the
> land is covered by shallow water.*
>
> *For purposes of this classification wetlands must have one or more of
> the following three attributes: (1) at least periodically, the land
> supports predominantly hydrophytes, (2) the substrate is predominantly
> undrained hydric soil, and (3) the substrate is nonsoil and is
> saturated with water or covered by shallow water at some time during
> the growing season of each year.*
>
> *wetlands inventory mapping* \-- more detailed mapping of wetlands
> beyond distinguishing between simple categories of forested and
> non-forested or vegetated and non-vegetated.
>
> *user's accuracy (UA)* \-- measures the percentage of reference sites
> on the ground that are correctly classified on the map.

Appendix H: Workgroup Members, Vetting Participants, and Workgroup
Activities

> **Workgroup Members and Vetting Participants**

-   Environmental Protection Agency (EPA)

-   National Oceanic and Atmospheric Administration (NOAA)

-   United States Geological Survey (USGS)

-   U.S. Fish and Wildlife Service (USFWS)

-   Tennessee Valley Authority (TVA)

-   Environmental Council of the States (ECOS)

-   Indiana Department of Environmental Management (IDEM)

-   Office of the Secretary of Defense (OSD)

-   Advisory Committee on Water Information (ACWI)

-   Association of State Wetland Mangers (ASWM)

-   National States Geographic Information Council (NSGIC)

-   National Water Quality Monitoring Council (NWQMC)

-   Ducks Unlimited Inc. (DU)

-   National Association of Counties (NACo)

-   National Association of Home Builders (NAHB)

-   River Network

-   Army Corp of Engineers (COE)

-   FEMA Floodplain Mapping Division

> **Workgroup Activities**
>
> The framework for a draft proposal for the Wetlands Mapping Standard
> was presented and discussed at the following meetings:

-   Association of State Wetland Managers (ASWM) annual meetings in 2005
    and 2006.

-   Society of Wetland Scientists (SWS) annual meeting in 2005, *26^th^
    Annual International Wetlands Meeting, Coastal Plain Wetlands:
    Ecological, Landscape, and Regulatory Transformations.*

-   National States Geographic Information Council (NSGIC) Annual
    Conference in Annapolis 2006.

-   National Association of Counties (NACo) Winter meetings in February
    and March of 2006.

-   2006 Tennessee Valley Authority (TVA) Regional Natural Heritage
    Program's 11^th^ Annual eMap User Meeting.

-   Surface Water Monitoring and Standards (SWiMS) Region 5 meeting in
    2007.

-   2007 Tennessee Federal and State GIS User Group Meeting

-   2007 Southeastern Wetlands Data Workshop, May 2007.

-   Tennessee Geographic Information Council's 2007 Annual Conference,
    June 2007.

-   ASWM Wetlands 2007 National Symposium, August 2007.

[^1]: Lotic wetlands are separated into river and stream sections (based
    on watercourse width - polygon = Lotic River vs. linear = Lotic
    Stream at a scale of 1:24,000) and then divided into one of five
    gradients: 1) high (e.g., shallow mountain streams on steep slopes),
    2) middle (e.g., streams with moderate slopes), 3) low (e.g.,
    mainstem rivers with considerable floodplain development and
    slow-moving streams), 4) intermittent (periodic flows), and 5) tidal
    (hydrology under the influence of the tides).

[^2]: For practical purposes, floodplain is restricted to rivers (i.e.,
    polygonal watercourses); similar areas along streams (i.e., linear
    watercourses) are designated as basins or flats.

[^3]: Surface water connections are emphasized because they are more
    readily identified than groundwater linkages (see footnote below for
    paludified landscapes).

[^4]: Water flow path for some bogs and similar wetlands may be
    paludified; paludification processes occur in areas of low
    evapotranspiration and high rainfall, peat moss moves uphill
    creating wetlands on hillslopes (i.e., wetland develops upslope of
    primary water source).

[^5]: U.S. Geological Survey. 2001. Standards for revised primary
    service quadrangle maps. Part 2 specifications. National Mapping
    Technical Instructions. U.S. Department of The Interior, U.S.
    Geological Survey, Reston, VA. 76p. plus appendices.