Robert Welk Kate V. Ackerman Zafer Defne Neil Ganju 20200331 2.0 Vector Digital dataset (Polygon) data release 10.5066/P91H426U Woods Hole Coastal and Marine Science Center, Woods Hole, MA U.S. Geological Survey, Coastal and Marine Geology Program https://doi.org/10.5066/P91H426U https://www.sciencebase.gov/catalog/item/5ddd7472e4b04a30051ac165 Robert Welk Kate V. Ackerman Zafer Defne Neil Ganju 2020 2.0 data release 10.5066/P91H426U Reston, VA U.S. Geological Survey Suggested citation: Welk, R., Ackerman, K.V., Defne, Z., and Ganju, N.K., 2020, Coastal wetlands of eastern Long Island, New York (ver. 2.0, March 2024): U.S. Geological Survey data release,https://doi.org/10.5066/P91H426U. https://doi.org/10.5066/P91H426U https://www.sciencebase.gov/catalog/item/5dd56511e4b0695797628ca6 This data release contains coastal wetland synthesis products for the geographic region of eastern Long Island, New York, including the north and south forks, Gardiners Island, and Fishers Island. Metrics for resiliency, including unvegetated to vegetated ratio (UVVR), marsh elevation, and mean tidal range, are calculated for smaller units delineated from a Digital Elevation Model, providing the spatial variability of physical factors that influence wetland health. Through scientific efforts initiated with the Hurricane Sandy Science Plan, the U.S. Geological Survey has been expanding national assessment of coastal change hazards and forecast products to coastal wetlands with the intent of providing Federal, State, and local managers with tools to estimate the vulnerability and ecosystem service potential of these wetlands. 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. The purpose of this shapefile is to calculate the mean elevation for each marsh unit and its vegetated component. Analysis of marsh elevation is part of a comprehensive assessment to identify the factors and their weights in determining the vulnerability and resiliency of salt marshes. Elevation distribution in the eastern Long Island salt marsh complex is given in terms of mean elevation of conceptual marsh units. The elevation data is based on the 1-meter resolution National Elevation Database (NED). 2020 Publication date of original release. Complete None -72.748198 71.885316 41.291362 40.766433 USGS Metadata Identifier USGS:5ddd7472e4b04a30051ac165 USGS Thesaurus geospatial datasets wetland ecosystems wetland functions coastal ecosystems coastal processes None salt marsh vegetation marsh health estuary Long-Term Ecological Research LTER ISO 19115 Topic Category oceans inlandWaters environment elevation None Atlantic Ocean United States New York Suffolk County Peconic Bay Moriches Bay Shinnecock Bay Long Island Sound None The mean elevation for each marsh unit is 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. U.S. Geological Survey Robert Welk Hydrologic Technician mailing and physical address

2045 NY 112

Coram NY 11727 631-736-0783 x141 rwelk@usgs.gov https://www.sciencebase.gov/catalog/file/get/5ddd7472e4b04a30051ac165?name=elev_ELI_browse.png&allowOpen=true Graphic that shows elevation of conceptual marsh units of the eastern Long Island salt marsh complex. PNG Environment as of Metadata Creation: Microsoft 10 Version 6.2 (Build 9200); Esri ArcGIS 10.7.1 (Build 11595) Service Pack N/A (Build N/A) Marsh units and water and land boundaries inherit their horizontal accuracy from the accuracy of the source data, the eastern Long Island marsh units, and their vertical accuracy from the 2015 U.S. Geological Survey National Elevation Database (USGS NED). Positive elevation indicates above sea level. Marsh units with extremely low elevation (smaller than 0.2 percentile value), extremely high elevation (larger than 99.8 percentile value) or areas less than 900 square meters were flagged. The results are specific to the marsh polygons as defined within the boundaries of the eastern Long Island salt marsh complex. A detailed on-the-ground analysis of a single site may result in a different interpretation of the wetland and marsh unit boundaries. Horizontal accuracy is inherited from the source dataset that delineates the marsh units, and can be considered to be +/-6 meters. Because the elevation values are averaged over delineated polygons, vertical accuracy depends on both the horizontal accuracy of the NWI dataset and the vertical accuracy of the source elevation data, NED. NED vertical elevation accuracy is 0.2 meters. U.S. Geological Survey 2015 Raster Digital dataset Reston, VA U.S. Geological Survey https://nationalmap.gov/viewer.html Digital 2015 publication date NED Downloaded NED Digital Elevation Model from the National Map. Projection was NAD 1983 UTM Zone 18N with the North American Vertical Datum of 1988 (NAVD 88). Download date was 2019/08/01. U.S. Geological Survey 2017 Remote-sensing image Salt Lake City, Utah USDA-FSA-APFO Aerial Photography Field Office https://earthexplorer.usgs.gov https://www.sciencebase.gov/catalog/item/51355312e4b0e1603e4fed62 Digital 2017 publication date NAIP Downloaded NAIP 1-meter resolution imagery from the USGS Earth Explorer. Projection was WGS 1984 Web Mercator Auxiliary Sphere. Download date was 2019/08/01. U.S. Fish and Wildlife Service 2017 Vector Digital dataset (Polygon) Madison, WI U.S. Fish and Wildlife Service https://www.fws.gov/wetlands/data/Data-Download.html Digital 2017 publication date NWI Downloaded wetlands data for the state of New York in Shapefile format from the NWI download page. Projection was NAD 1983 Albers. Download date was 2018/08/01. New England Interstate Water Pollution Control Commission, Prepared by Cameron Engineering and Associates, LLP 2015 Vector Digital Data Set (Polygon) http://www.dec.ny.gov/lands/5113.html Digital 2015 publication date NYSDEC Wetland polygon shapefile prepared for Long Island Tidal Wetlands Trends Analysis. Data available by request. Data acquired 2019/05/01. This process step and all subsequent process steps were performed by the same person, Robert Welk, in ArcMap (ver. 10.6.1) using tools from ArcToolbox, unless otherwise stated. For complex operations, 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. a) Set the data frame coordinate system and projection to NAD 1983 UTM Zone 18N. 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) the entire NED raster to a new raster dataset with 1 m resolution [elev_mosaic.tif]. b) Calculate values for each marsh unit. DISSOLVE(Input features=[CMU_ELI]; Dissolve field=FID_CMU; Statistics field=ATOT_M2 and FLG with Statistics type= First) to dissolve the vegetated and unvegetated classes in each marsh unit. FLG flags anomalous marsh units based on absence of vegetation, elevation and surface area, and is set to (-1) no vegetated area; (-10) marsh unit elevation higher than the 99.8 percentile; (-100) marsh unit elevation less than 0.2 percentile; (-1000) marsh unit surface area less than 900 m2; and (0) no flag. Combination of negative values indicate a combination of flags. For example, -1001 indicates no vegetated area and area less than 900 m2. PROJECT(Input coordinate system=WGS 1984 Web Mercator Auxiliary Sphere; Output coordinate system=NAD 1983 UTM Zone 18N; Geographic transformation=WGS 1984 (ITRF00) to NAD 1983) the feature dataset to obtain dissolved marsh units [mu_diss.shp]. c) Clip the raster with the polygon features by using EXTRACT BY MASK to obtain [elev_idw_mu.tif]. d) ZONAL STATISTICS AS TABLE(Feature Zone Data=[mu_diss.shp]; zone field=FID_CMU; Value Raster=[elev_idw_mu.tif]; Output Table=mu; Statistics type=MEAN) e) ADD JOIN(Layer name=[mu_diss.shp]; Input join field=FID_CMU; Join Table=mu; Output join field=FID_CMU) to marsh units layer based on the "FID_CMU" field f) Export dataset as a shapefile [mu_elev.shp] and keep the 'mu_MEAN" and "mu_ATOT_M2" fields from the join operation. g) Calculate elevation of the vegetated areas only. SELECT BY ATTRIBUTES FROM [CMU_ELI] where "CLASS"= 'vegetated'. Follow steps (c) to (f) using the selected features to export [veg_elev.shp]. h) JOIN FIELD(Input table=[mu_elev.shp]; Input join field=mu_FID_CMU; Join table=[veg_elev.shp]; Output join field=vg_FID_CMU; Join fields=vg_AVEG_M2,vg_ATOT_M2,vg_MEAN). Change the field names to VG_ELEV and MU_ELEV respectively for the fields with the mean elevation for the vegetated area only and mean elevation for the entire marsh unit. Set VG_ELEV to -9999 if there is no vegetated area in the marsh unit. Name AVEG_M2 and ATOT_M2 for vegetated and total area, respectively, and export to a new shapefile. [mu_elev_ELI.shp]. i) Calculate metrics that quantify the distribution of marsh unit elevation values. SKWNSS is the measure of skewness of the elevation distribution in the vegetated part of a marsh unit. Positive skewness values, i.e. right-skewed distributions, indicate clustering of elevation distributions towards lower elevations. Negative numbers indicate a left-skewed distribution and clustering towards higher elevations. LOW3RD is the percent of elevation values that fall within the lowest third of the elevation range within the vegetated part of a marsh unit. SKWNSS and LOW3RD parameters are calculated by applying the formulation of Raposa et al. (2016) to the elevation raster within the vegetated part of each marsh unit. j) SELECT BY ATTRIBUTES FROM [CMU_ELI] where "CLASS"= 'vegetated', and join field "APGN_M2" from CMU_ELI.shp on the feature dataset [mu_elev_ELI.shp]. k) Calculate ratio of hydroflattened area in each marsh unit. Reclassify NED elevation raster with RASTER CALCULATOR (expression: SetNull('elev_mosaic.tif' == -1, 'elev_mosaic.tif') to get [elev_null.tif]. ZONAL STATISTICS AS TABLE (Input table=[mu_elev.shp, Zone field=FID_CMU], Input value raster=elev_null.tif, Statistics type=Mean) to get [hfar_mu]. ADD FIELD to output table 'MU_HFAR' and use FIELD CALCULATOR ((1-MEAN/2)). JOIN FIELD(Input Table=mu_elev.shp, Input Join Field=FID_CMU, Join Table=hfar_mu, Output Join Field=FID_CMU). If 'MU_HFAR' > 0.25, set 'mu_elev' = 0. l) Calculate ratio of hydroflattened area in the vegetated area of each marsh unit. ZONAL STATISTICS AS TABLE (Input table=[veg_elev.shp, Zone field=FID_CMU], Input value raster=elev_null.tif, Statistics type=Mean) to get [hfar_veg]. ADD FIELD to output table 'VG_HFAR' and use FIELD CALCULATOR ((1-MEAN/2)). JOIN FIELD(Input Table=mu_elev.shp, Input Join Field=FID_CMU, Join Table=hfar_veg, Output Join Field=FID_CMU). If 'MG_HFAR' > 0.25, set 'vg_elev' = 0. m) Rearrange field names and change the projection for better performance of web services with online base maps. PROJECT(Input coordinate system=NAD 1983 UTM Zone 18N; Output coordinate system=WGS 1984 Web Mercator Auxiliary Sphere; Geographic transformation=WGS 1984 (ITRF00) to NAD 1983) the feature dataset to obtain the final conceptual marsh units [mu_elev_ELI.shp]. Reference: Raposa, K. B., Wasson, K., Smith, E., Crooks, J. A., Delgado, P., Fernald, S. H., et al. (2016). Assessing tidal marsh resilience to sea-level rise at broad geographic scales with multi-metric indices. Biological Conservation, 204, 263–275. https://doi.org/10.1016/J.BIOCON.2016.10.015 elev_mosaic CMU_ELI NAIP 2019 Added keywords section with USGS persistent identifier as theme keyword. 20200806 U.S. Geological Survey VeeAnn A. Cross Marine Geologist Mailing and Physical

384 Woods Hole Road

Woods Hole MA 02543-1598 508-548-8700 x2251 508-457-2310 vatnipp@usgs.gov Version 2 updates. Updates were performed in ArcGIS Pro 2.8.8. Duplicate marsh units were manually identified and compared to make sure the most appropriate duplicate marsh unit was deleted. Seventy-six duplicate marsh units were identified (out of 2828) in Mecox Bay, Sagaponack Pond and Georgica Pond and have been removed. After the duplicate marsh units were deleted, the elevation, hydroflattened percentage and elevation flag values were recalculated. Authorship was updated to include Kate Ackerman. 20240116 Kate Ackerman U.S. Geological Survey Geologist mailing address

384 Woods Hole Road

Woods Hole MA 02543 US 508-548-8700 x2331 508-457-2310 kackerman@usgs.gov Vector G-polygon 2752 WGS 1984 Web Mercator Auxiliary Sphere (ESRI Full Name: WGS_1984_Web_Mercator_Auxiliary_Sphere) 0.0 0.0 0.0 0.0 coordinate pair 0.6096 0.6096 Meter D_WGS_1984 WGS_1984 6378137.0 298.257223563 North American Vertical Datum of 1988 0.001 meters Attribute values mu_elev_ELI Attribute information associated with the mean elevation of the conceptual marsh units of the eastern Long Island salt marsh complex. U.S. Geological Survey FID Internal feature number. Esri Unique whole numbers that are automatically generated. Shape Feature geometry. Esri Coordinates defining the features. FID_CMU Unique whole numbers used to identify each conceptual marsh unit. USGS 2 3455 none ATOT_M2 Total surface area of a marsh unit in square meters USGS 8.876088 1278469.79671 square meters AVEG_M2 Surface area of vegetated part of a marsh unit in square meters. Value is set to -9999 if there is no vegetated area in the marsh unit. USGS 0 1189344.84656 square meters MU_ELEV Mean elevation of a marsh unit in meters. MU_ELEV is set to -9999 if a no data cell value is provided in the input DEM to indicate the absence of real elevation values. USGS -9999 No Data USGS -1.49903 6.82453 meters VG_ELEV Mean elevation of the vegetated area in a marsh unit in meters. VG_ELEV is set to -9999 if a no data cell value is provided in the input DEM to indicate the absence of real elevation values. USGS -9999 No Data USGS -1.38023 6.819696 meters MU_HFAR Ratio of DEM hydroflattened area in marsh unit. If MU_HFAR > 0.25, MU_ELEV is set to -9999. USGS 0 1 VG_HFAR Ratio of DEM hydroflattened area in marsh unit. If VG_HFAR > 0.25, VG_ELEV is set to -9999. USGS -9999 No Data USGS 0 1 SKWNSS SKWNSS is the measure of skewness of the elevation distribution in the vegetated part of a marsh unit. Positive skewness values i.e. right-skewed distribution indicate clustering of elevation distribution towards lower elevations. Negative numbers indicate a left-skewed distribution and clustering towards higher elevations. Values of -9999 indicate no vegetated area within the marsh unit. USGS -9999 No Data USGS -7.49949 7.65854 LOW3RD LOW3RD is the percent of elevation values that fall within the lowest third of the elevation range within the vegetated part of a marsh unit. Values of -9999 indicate no vegetated area within the marsh unit. USGS -9999 No Data USGS 0.0227015 99.66590118 FLG Marsh unit flag indicating anomalous marsh units based on elevation, surface area, and absence of vegetation. FLG values indicate: (-1) no vegetated area; (-10) marsh unit elevation higher than the 99.8 percentile; (-100) marsh unit elevation less than 0.2 percentile; (-200) greater than 25% of marsh unit has hydroflattened area (and has -9999 as its elevation value; (-1000) marsh unit surface area less than 900 m2; and (0) no flag. Combination of negative values indicate combination of flags. For example, -1001 indicates no vegetated area and area less than 900 m2. USGS -11201 0 None In this dataset, mean elevation for each conceptual salt marsh unit in the eastern Long Island salt marsh complex has been calculated based on the 1-meter resolution raster source dataset. 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 elevation is assumed to be 1 meter and 0.01, respectively. USGS U.S. Geological Survey - ScienceBase mailing and physical address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 1-888-275-8747 sciencebase@usgs.gov mu_elev_ELI.shp (and other files associated with a shapefile), browse graphic, and CSDGM metadata in XML format. Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. shapefile ArcGIS Pro 2.8.8 This dataset contains a polygon shapefile and its components and metadata in xml format. https://www.sciencebase.gov/catalog/file/get/5ddd7472e4b04a30051ac165 https://www.sciencebase.gov/catalog/item/5ddd7472e4b04a30051ac165 https://doi.org/10.5066/P91H426U The first link in network resources is to download data directly. The second link points to a landing page with metadata and data. The third link is to the main page of the data release. WMS https://www.sciencebase.gov/catalogMaps/mapping/ows/5ddd7472e4b04a30051ac165?service=wms&request=getcapabilities&version=1.3.0 The link in network resources points to the Web Mapping Services (WMS) end point. WFS https://www.sciencebase.gov/catalogMaps/mapping/ows/5ddd7472e4b04a30051ac165?service=wfs&request=getcapabilities&version=1.0.0 The link in network resources points to the Web Feature Service (WFS) end point. None. No fees are applicable for obtaining the dataset. 20240312 U.S. Geological Survey, Northeast Region Robert J Welk Hydrologic Technician mailing address

2045 Route 112

Coram NY 11727 US 631-736-0783 x141 whsc_data_contact@usgs.gov The metadata contact email address is a generic address in the event the person is no longer with USGS. FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998