Conceptual salt marsh units for wetland synthesis: Edwin B. Forsythe National Wildlife Refuge, New Jersey

Metadata also available as - [Outline] - [Parseable text] - [XML]

Frequently anticipated questions:


What does this data set describe?

Title:
Conceptual salt marsh units for wetland synthesis: Edwin B. Forsythe National Wildlife Refuge, New Jersey
Abstract:
The salt marsh complex of the Edwin B. Forsythe National Wildlife Refuge (EBFNWR), which spans over Great Bay, Little Egg Harbor, and Barnegat Bay (New Jersey, USA), was delineated to smaller, conceptual marsh units by geoprocessing of surface elevation data. Flow accumulation based on the relative elevation of each location is used to determine the ridge lines that separate each marsh unit while the surface slope is used to automatically assign each unit a drainage point, where water is expected to drain through. Through scientific efforts associated with the Hurricane Sandy Science Plan, the U.S. Geological Survey has started to expand national assessment of coastal change hazards and forecast products to coastal wetlands. The intent is to provide federal, state, and local managers with tools to estimate their vulnerability and ecosystem service potential. For this purpose, the response and resilience of coastal wetlands to physical factors need to be assessed in terms of the ensuing change to their vulnerability and ecosystem services. EBFNWR was selected as a pilot study.
Recent research shows that sediment budgets of microtidal marsh complexes on the Atlantic and Pacific coasts of the United States consistently scale with areal unvegetated/vegetated marsh ratio (UVVR) despite differences in sea-level rise, tidal range, elevation, vegetation, and stressors. This highlights UVVR as a broadly applicable indicator of microtidal marsh stability. It is also relatively quicker and less labor intensive compared to quantifying integrative sediment budgets and the associated transport mechanisms that requires extended tidal-timescale observations of sediment transport. UVVR indicates the link between open-water conversion processes and sediment transport, providing consistent results across a geomorphic and climatic spectrum of microtidal marshes, hence can be an independent measure of marsh health. Potentially, tracking future changes to UVVR may allow for widespread mapping of spatially variable vulnerability across microtidal marshes worldwide.
  1. How might this data set be cited?
    Defne, Zafer, and Ganju, Neil K., 2016, Conceptual salt marsh units for wetland synthesis: Edwin B. Forsythe National Wildlife Refuge, New Jersey: data release DOI:10.5066/F7QV3JPG, U.S. Geological Survey, Reston, Virginia.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -74.484623118
    East_Bounding_Coordinate: -74.051158122
    North_Bounding_Coordinate: 40.053798801
    South_Bounding_Coordinate: 39.435117592
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/57fe81fbe4b0824b2d148389/?name=marshUnitsEBFNWR.png (PNG)
    Graphic that shows conceptual marsh units of EBFNWR salt marsh complex overlaying Esri Shaded World Relief Map.
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2016
    Currentness_Reference:
    The marsh unit polygons were derived by geoprocessing of the 1/3 arc second resolution USGS National Elevation Data (NED) with the publication date of 2011-2012. For more details see: Data Quality Information: Lineage: Source Information.
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Vector Digital Data Set (Polygon)
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • G-polygon (2600)
    2. What coordinate system is used to represent geographic features?
      The map projection used is WGS 1984 Web Mercator Auxiliary Sphere (ESRI Full Name: WGS_1984_Web_Mercator_Auxiliary_Sphere).
      Projection parameters:
      Standard_Parallel: 0.0
      Longitude_of_Central_Meridian: 0.0
      False_Easting: 0.0
      False_Northing: 0.0
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.6096
      Ordinates (y-coordinates) are specified to the nearest 0.6096
      Planar coordinates are specified in Meter
      The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
  7. How does the data set describe geographic features?
    marshUnitsEBF
    Attribute information associated with the features delineating conceptual marsh units in Edwin B. Forsythe National Wildlife Refuge, New Jersey. (Source: U.S. Geological Survey)
    FID
    Internal feature number. (Source: Esri) Sequential unique whole numbers that are automatically generated.
    Shape
    Feature geometry. (Source: Esri) Coordinates defining the features.
    FID_CMU
    Sequential whole numbers that represents the identification number for each conceptual marsh units. These numbers are duplicated when a marsh unit has both vegetated and unvegetated sub-polygons. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:1337
    Units:none
    COLORID
    Recycling sequential whole numbers (1-10) that are used for display purposes when plotting conceptual marsh units. These numbers are duplicated when a marsh unit has both vegetated and unvegetated sub-polygons. (Source: USGS)
    Range of values
    Minimum:1
    Maximum:10
    Units:none
    AVEG_M2
    Vegetated area of feature within a marsh unit in square meters (Source: USGS)
    Range of values
    Minimum:0
    Maximum:7076365.12545
    Units:meters
    AUNV_M2
    Unvegetated (if applicable) area of feature within a marsh unit in square meters (Source: USGS)
    Range of values
    Minimum:0
    Maximum:2138546.2463
    Units:meters
    ATOT_M2
    Total area of feature in square meters (Source: USGS)
    Range of values
    Minimum:28.8035509447
    Maximum:7624400.41687
    Units:meters
    UVVR
    Ratio of unvegetated marsh area to vegetated marsh area calculated by UVVR=AUNV_M2/AVEG_M2 for each unique FID_CMU. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:4.04753017425537
    Units:none
    CLASS
    Classification of the salt marsh unit to vegetated and unvegetated (water) coverage (Source: USGS)
    ValueDefinition
    unvegetatedUnvegetated salt marsh unit
    vegetatedVegetated salt marsh unit (water)
    Entity_and_Attribute_Overview:
    In this dataset, the salt marsh complex EBFNWR has been delineated to conceptual salt marsh units to facilitate unit by unit evaluation of response and resiliency of marsh system to physical and biogeochemical drivers. Each unit is also analyzed based on the vegetated and unvegetated surface area coverage, the ratio of which can be an independent measure of marsh health for microtidal marshes on the Atlantic and Pacific coasts of the United States. It is calculated by UVVR=AUNV_M2/AVEG_M2, where UVVR is the unvegetated area to vegetated area ratio, AUNV_M2 and AVEG_M2 are unvegetated area and vegetated area in square meters, respectively. Decimal values in the attribute table are a result of double precision calculations while significant digits are considered in defining the attribute measurement resolutions. Therefore, the smallest unit increment for area values and UVVR are assumed to be 1 meter and a thousandths, respectively. COLORID is defined to limit the legend entries to 10 instead of the total number of entites for practical reasons. It is used for display purposes only.
    Entity_and_Attribute_Detail_Citation: USGS

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Zafer Defne
    • Neil K. Ganju
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    U.S. Geological Survey
    Attn: Zafer Defne
    Ocean Scientist
    384 Woods Hole Road
    Woods Hole, MA

    508-457-8700 x2254 (voice)
    508-457-2310 (FAX)
    zdefne@usgs.gov

Why was the data set created?

These polygons were created to be used in evaluating the spatial variation of the response and resiliency of the salt marsh complex based on consistently defined marsh units while facilitating a better understanding of the relative importance of the processes involved. An unvegetated area to vegetated area ratio was defined as a potential indicator of health of a salt marsh unit.

How was the data set created?

  1. From what previous works were the data drawn?
    NED (source 1 of 3)
    U.S. Geological Survey, 20110215, USGS National Elevation Dataset (NED) 1/9 arc-second: U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    The following USGS NED ned19 tiles were used in analyses (11 tiles):
    1) USGS NED ned19 n39x50_w074x50_nj_3coastalcounties_2011 1/9 arc-second 2012 15_x_15 minute IMG
    2) USGS NED ned19 n39x50_w074x75_nj_3coastalcounties_2011 1/9 arc-second 2012 15_x_15 minute IMG
    3) USGS NED ned19 n39x75_w074x25_nj_3coastalcounties_2011 1/9 arc-second 2012 15_x_15 minute IMG
    4) USGS NED ned19 n39x75_w074x50_nj_3coastalcounties_2011 1/9 arc-second 2012 15_x_15 minute IMG
    5) USGS NED ned19 n39x75_w074x75_nj_3coastalcounties_2011 1/9 arc-second 2012 15_x_15 minute IMG
    6) USGS NED ned19 n40x00_w074x25_nj_3coastalcounties_2011 1/9 arc-second 2012 15_x_15 minute IMG
    7) USGS NED ned19 n40x00_w074x50_nj_3coastalcounties_2011 1/9 arc-second 2012 15_x_15 minute IMG
    8) USGS NED ned19 n40x00_w074x75_nj_3coastalcounties_2011 1/9 arc-second 2012 15_x_15 minute IMG
    9) USGS NED ned19 n40x25_w074x25_nj_3coastalcounties_2011 1/9 arc-second 2012 15_x_15 minute IMG
    10) USGS NED ned19 n40x25_w074x50_nj_3coastalcounties_2011 1/9 arc-second 2012 15_x_15 minute IMG
    11) USGS NED ned19 n40x25_w074x75_nj_3coastalcounties_2011 1/9 arc-second 2012 15_x_15 minute IMG
    
    Type_of_Source_Media: online
    Source_Contribution:
    Elevation data from eleven USGS NED ned19 tiles (see Other Citation Details) were used in analyses. Download date was 20160801.
    EBFNWR (source 2 of 3)
    Jones, William R., 2016, Hurricane Sandy 2013 National Wetlands Inventory Habitat Classification (Habitat Analysis of Coastal Federal Lands located within High Impact Zones of Hurricane Sandy, October 2012) - EdwinBForsythe_FWS_2013NWI.: U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details: U.S. Geological Survey, Wetland Aquatic Research Center
    Type_of_Source_Media: online
    Source_Contribution:
    Downloaded and used the classification of features in EBFNWR ("Class" attribute) to determine the boundaries of the analyses and the final product.
    TRI (source 3 of 3)
    Thatcher, Cindy, Danielson, Jeff, and Gesch, Dean, Unpublished Material, Delineation of Water Bodies in Emergent Wetlands in Coastal New Jersey.

    Other_Citation_Details:
    At the time of publication, this source dataset was under review in the the USGS Information Product Data System (IPDS).
    Type_of_Source_Media: online
    Source_Contribution:
    Downloaded and used the classification of features ("TRI_NWI" attribute) to expand the boundaries of analysis beyond EBFNWR boundaries.
  2. How were the data generated, processed, and modified?
    Date: 2016 (process 1 of 9)
    This process step and all subsequent process steps were performed by the same person, Zafer Defne, in ArcMap (ver. 10.3.1) using tools from ArcToolbox, unless otherwise stated. Names of specific tools used are given in CAPITAL letters (any critical parameters used are given in parentheses, separated by a semicolon, immediately after the tool name). The input and output file names are provided in [square brackets] when necessary. Units for length and area calculations are meters (m) and square meters (m2) unless otherwise stated.
    Prepare elevation dataset to be clipped to the boundaries polygon. MOSAIC TO NEW RASTER(Pixel type= 32 bit float; Mosaic operator=Mean; Cellsize=1 m) all of the USGS NED 1/9 sec. tiles to a new raster dataset with 1m resolution. Resolution is increased from 3 m to 1 m to have a finer representation of the polygon boundaries in the horizontal during this step. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Zafer Defne
    Ocean Scientist
    384 Woods Hole Road
    Woods Hole, MA

    508-457-8700 x2254 (voice)
    508-457-2310 (FAX)
    zdefne@usgs.gov
    Data sources used in this process:
    • NED
    Data sources produced in this process:
    • NED03all
    Date: 2016 (process 2 of 9)
    Prepare mask polygon for boundaries: In order to account for the possible influence of the surrounding terrain on the analysis, first a larger mask area than the salt marsh extent is used in calculations. This mask is obtained by union of TRI and EBFNWR datasets and creating a 25 m buffer around them. At the end of the analysis the results are clipped to the boundaries of the EBFNWR sat marsh.
    a) EXPORT features from TRI dataset after SELECT BY ATTRIBUTES("TRI_NWI" LIKE '%Wetland').
    b) EXPORT features from EBFNWR dataset after SELECT BY ATTRIBUTES("Class" LIKE 'Wetland%', 'Mud%', 'Marsh%').
    c) UNION the exported EBFNWR and TRI features.
    d) DISSOLVE features and BUFFER features with 25 m.
    e) ELIMINATE POLYGON PART(Condition=Percentage; Percentage=50; Eliminate contained part only) to obtain the mask polygon [TriEBF25m.shp]. Data sources used in this process:
    • EBFNWR
    • TRI
    Data sources produced in this process:
    • TriEBF25m
    Date: 2016 (process 3 of 9)
    Define preliminary boundaries for marsh units by basin analysis:
    a) EXTRACT BY MASK from mosaicked elevation dataset using mask polygon.
    b) FILL(no Z limit) sinks in extracted elevation raster.
    c) Calculate FLOW DIRECTION(do not force edge cells flow outward) raster.
    d) Calculate BASIN based on flow direction raster.
    e) Convert RASTER TO POLYGON [basin25mbuff.shp] Data sources used in this process:
    • TriEBF25m
    • NED03all
    Data sources produced in this process:
    • basin25mbuff
    Date: 2016 (process 4 of 9)
    This step merges the "orphan marsh units", units that are less than 5000 m2 in area to the nearest to "parent marsh units", units that are larger than 5000 m2 to obtain the preliminary marsh units. A Python script that iteratively calls a list of ArcMap tools to aggregate orphan units on parent units is used:
    a) Create orphan marsh units features by exporting marsh units with an area less than 5000 m2 [lt5000.shp].
    b) Create parent marsh units features by exporting marsh units with an area greater than or equal to 5000 m2 [ge5000.shp].
    c) Run Python script (hydUnitloop.py). At each iteration step the script uses NEAR tool to find orphan marsh units within 25 m of a parent marsh unit and merges them to the parent using UNION and DISSOLVE tools. The orphan units merged with a parent unit are removed from the orphan units data set. Script will iterate until there is no change in the number of parent or orphan marsh units.
    d) The remaining orphan marsh units are those that are more than 25 m away from any parent. DISSOLVE them to create larger orphan units by grouping the orphans attached together into larger units.
    e) MULTIPART TO SINGLEPART to have single part polygons with unique identifiers.
    f) UNION(with gaps) single part features with parent units to obtain preliminary marsh units [preMUopt1.shp]. Data sources used in this process:
    • basin25mbuff
    Data sources produced in this process:
    • preMUopt1
    Date: 2016 (process 5 of 9)
    Define final marsh unit boundaries by intersecting them with the salt marsh and salt water:
    a) SMOOTH POLYGON(with PAEK algorithm, 15 m tolerance).
    b) MULTIPART TO SINGLEPART to separate marsh units from geoprocessing artifacts to be deleted before the final step.
    c) EXPORT features from EBFNWR dataset after SELECT BY ATTRIBUTES("Class" LIKE '%Salt%') to select all salt marsh, salt mud, salt wetland scrub shrub and salt water [MUopt1EBFsalt.shp].
    d) INTERSECT smoothed preliminary marsh polygon with salt marsh and salt water features [MUopt1EBFsalt.shp] to obtain the marsh units [MUopt1.shp]. Data sources used in this process:
    • preMUopt1
    Data sources produced in this process:
    • MUopt1
    Date: 2016 (process 6 of 9)
    Define vegetated and unvegetated areas in marsh units.
    a) SELECT BY ATTRIBUTES("Class" LIKE 'Wetland % Salt' OR "Class" = 'Marsh Salt') and DISSOLVE(None of the optionals selected) selected features [MUopt1EBFveg_diss.shp].
    b) INTERSECT marsh unit features [MUopt1.shp] with vegetated polygon features [MUopt1EBFveg_diss.shp] to obtain the vegetated marsh units [MUopt1veg.shp].
    c) ERASE vegetated marsh units from marsh units features to to obtain the unvegetated marsh units [MUopt1unveg.shp] Data sources used in this process:
    • MUopt1
    Data sources produced in this process:
    • MUopt1veg
    • MUopt1unveg
    Date: 2016 (process 7 of 9)
    Calculate vegetated unvegetated and total marsh unit areas:
    a) ADD GEOMETRY(Geometry Properties= Area geodesic; Area Unit= Square meters) to calculate polygon areas of vegetated marsh units.
    b) ADD GEOMETRY(Geometry Properties= Area geodesic; Area Unit= Square meters) to calculate polygon areas of unvegetated marsh units.
    c) UNION(Join Attributes= All; Gaps Allowed) vegetated, unvegetated and marsh unit features.
    d) Remove artifacts of geoprocessing by deleting features with "FID_marshU" smaller than zero. Delete marsh units with total area smaller than 50 m2 and land area smaller than 10 m2.
    e) REPAIR GEOMETRY(Delete features with null geometry)
    f) Add new fields "ATOT_M2", "AUNV_M2", "AVEG_M2" to store total, water, and land surface area, respectively. "UVVR" field to store the unvegetated area to vegetated area ratio calculated by AUNV_M2/AVEG_M2. Remove all other attributes to obtain the final product [marshUnitsEBF.shp]. Data sources used in this process:
    • MUopt1
    • MUopt1veg
    • MUopt1unveg
    Data sources produced in this process:
    • marshUnitsEBF
    Date: 2016 (process 8 of 9)
    Add field "COLORID" to cycle through integers from 1 to 10 to be used for coloring the marsh units. This field used for display purposes only to distinguish between each marsh unit.
    Date: 2016 (process 9 of 9)
    PROJECT the feature dataset to WGS 1984 Web Mercator (auxiliary sphere). Data sources used in this process:
    • marshUnitsEBF
    Data sources produced in this process:
    • marshUnitsEBFp
  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    Water and land boundary inherit from accuracy of source data EBFNWR. Marsh units accuracy depend on vertical and horizontal accuracy of source data NED.
  2. How accurate are the geographic locations?
    Horizontal accuracy is inherited from NED 1/9 sec (~3-meter) dataset. Although the analyses were performed at 1-meter resolution for smoother conformity with the clipping polygons, the resolution of the final product should be considered to be greater than 3 meters.
  3. How accurate are the heights or depths?
    A formal accuracy assessment of the vertical positional information in the data set has either not been conducted, or is not applicable.
  4. Where are the gaps in the data? What is missing?
    The marsh polygons are bound to the boundaries of the EBFNWR areas that include 1) Marsh Salt, 2) Wetland Scrub Shrub Salt, and 3) channels of Open Water Salt that are wider than 50 meters. Sliver polygons of open salt water along the marsh edges may also be included in some instances as a result of geoprocessing. Any polygons with an area smaller than 50 square meters were removed from the final product. A detailed on-the-ground analysis of a single site may result in a different interpretation of the wetland and marsh unit boundaries than established through this analysis.
  5. How consistent are the relationships among the observations, including topology?
    Topological errors occurred during geoprocessing were automatically removed by the topological rules used for the analysis. The polygons are checked for correct geometry and do not overlap. Small (less than 50 square meters) marsh polygons that were assumed to be artifacts of geoprocessing analysis were removed from the final dataset. A visual comparison between Esri World Imagery (~0.3 meters resolution) was performed at randomly selected sites to verify the land and water boundaries.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None
Use_Constraints:
These polygons are defined for scientific research purposes and should not be used as a sole source of reference for any regulations and policy making. Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the source of this information.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - ScienceBase
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? marshUnitsEBFp.shp
  3. What legal disclaimers am I supposed to read?
    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Not for navigational use.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 04-Oct-2016
Metadata author:
U.S. Geological Survey
Attn: Zafer Defne
Ocean Scientist
384 Woods Hole Road
Woods Hole, MA

508-457-8700 x2254 (voice)
508-457-2310 (FAX)
zdefne@usgs.gov
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/data_release/DR_F7QV3JPG/marshUnitsEBFp.faq.html>
Generated by mp version 2.9.49 on Mon Sep 10 17:44:58 2018