Zafer Defne Neil K. Ganju Kate V. Ackerman 20240402 1.0 Vector Digital Data Set (Polygon) data release DOI:10.5066/P14MB99B Woods Hole Coastal and Marine Science Center, Woods Hole, MA U.S. Geological Survey, Coastal and Marine Hazards and Resources Program Suggested citation: Defne, Z., Ganju, N.K., and Ackerman, K.V., 2024, Lifespan of marsh units in New York salt marshes: U.S. Geological Survey data release, https://doi.org/10.5066/P14MB99B. https://doi.org/10.5066/P14MB99B https://www.sciencebase.gov/catalog/item/65b3ee2fd34e36a390458aa4 Lifespan of salt marshes in New York are calculated using conceptual marsh units defined by Defne and Ganju (2018) and Welk and others (2019, 2020a, 2020b, 2020c). The lifespan calculation is based on estimated sediment supply and sea-level rise (SLR) predictions after Ganju and others (2020). Sea level predictions are local estimates which correspond to the 0.3, 0.5, and 1.0 meter increase in Global Mean Sea Level (GMSL) scenarios by 2100 from Sweet and others (2022). 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 present lifespan estimates for each salt marsh unit in New York as defined by the USGS (Defne and Ganju, 2018; Welk and others, 2019, 2020a, 2020b, 2020c). 2024 publication date Complete None -74.2460 -71.8853 41.6797 40.5021 ISO 19115 Topic Category oceans inlandWaters environment elevation USGS Thesaurus geospatial datasets wetland ecosystems wetland functions coastal ecosystems coastal processes sea-level change sediment transport estuarine processes vegetation None salt marsh marsh health lifespan estuary USGS Metadata Identifier USGS:65b3ee2fd34e36a390458aa4 None United States Atlantic New York Long Island Sound Hudson River Great South Bay Jamaica Bay Moriches Bay Shinnecock Bay Great Peconic Bay None The lifespan estimate 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 Zafer Defne Oceanographer mailing and physical address

384 Woods Hole Road

Woods Hole MA 02543 508-548-8700 x2254 508-457-2310 zdefne@usgs.gov https://www.sciencebase.gov/catalog/file/get/65b3ee2fd34e36a390458aa4/?name=mu_lifespan_NY.png&allowOpen=true Graphic of shapefile showing lifespan estimates for New York salt marshes. PNG Environment as of Metadata Creation: Microsoft Windows 10 Version 0.1 (Build 19042); Esri ArcGIS Pro 2.8.8 and 3.0.3 N.K. Ganju Z. Defne S. Fagherazzi 2020 publication Geophysical Research Letters v. 47, issue 3 https://doi.org/10.1029/2019GL086703 J.T. Morris D.C. Barber J.C. Callaway R. Chambers S.C. Hagen C.S. Hopkinson B.J. Johnson P. Megonigal S.C. Neubauer T. Troxler C. Wigand 2016 publication Earth’s Future v. 4, issue 4 https://doi.org/10.1002/2015EF000334 W.V. Sweet B.D. Hamlington R.E. Kopp C.P. Weaver P.L. Barnard D. Bekaert W. Brooks M. Craghan G. Dusek T. Frederikse G. Garner A.S. Genz J.P. Krasting E. Larour D. Marcy J.J. Marra J. Obeysekera M. Osler M. Pendleton D. Roman L. Schmied W. Veatch K.D. White C. Zuzak 2022 1 Silver Spring, MD NOAA https://oceanservice.noaa.gov/hazards/sealevelrise/sealevelrise-tech-report-sections.html Zafer Defne Neil K. Ganju 2018 1.0 Vector Digital Data Set (Polygon) data release DOI:10.5066/P95U2MQ7 Reston, VA U.S. Geological Survey https://doi.org/10.5066/P95U2MQ7 Robert J. Welk Zafer Defne Neil K. Ganju 2019 1.0 Vector Digital Data Set (Polygon) data release DOI:10.5066/P9GAGLXB Reston, VA U.S. Geological Survey https://doi.org/10.5066/P9GAGLXB Robert J. Welk Zafer Defne Neil K. Ganju 2020 1.0 Vector Digital Data Set (Polygon) data release DOI:10.5066/P9UNOMM8 Reston, VA U.S. Geological Survey This is referred to as "Welk and others (2020a)" throughout this metadata. https://doi.org/10.5066/P9UNOMM8 Robert J. Welk Zafer Defne Neil K. Ganju 2020 1.0 Vector Digital Data Set (Polygon) data release DOI:10.5066/P9XV0JMJ Reston, VA U.S. Geological Survey This is referred to as "Welk and others (2020b)" throughout this metadata. https://doi.org/10.5066/P9XV0JMJ Robert J. Welk Kate V. Ackerman Zafer Defne Neil K. Ganju 2020 2.0 Vector Digital Data Set (Polygon) data release DOI:10.5066/P91H426U Reston, VA U.S. Geological Survey This is referred to as "Welk and others (2020c)" throughout this metadata. https://doi.org/10.5066/P91H426U Marsh units, and water and land boundaries inherit their accuracy from accuracy of the source data, New York marsh units. The vertical accuracy of the marsh unit elevation is inherited from the 1-meter resolution U.S. Geological Survey Coastal National Elevation Database (USGS CoNED) data. The uncertainty in the lifespan estimates is large because of the nature of the empirical equations used and the uncertainty in the source data. For example, a 20% variation in each of the unvegetated to vegetated marsh ratio (UVVR), elevation, bulk density and sea-level rise variables, when all in favor of reducing lifespan, may result in a combined reduction of 50% in lifespan estimate. Negative lifespan indicates the estimated lifespan is depleted and loss is imminent. Some flagged units (see description for the FLG variable) are assigned a lifespan estimate of -9999. The results are specific to the marsh polygons definition within the boundaries of the New York salt marsh system. 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 of marsh unit elevation depends on both the horizontal accuracy of NWI dataset and the vertical accuracy of source elevation data. CoNED vertical elevation accuracy was 0.2 meters. No additional accuracy assessment of the vertical accuracy has been conducted. Zafer Defne Neil K. Ganju 2018 Vector Digital Data Set (Polygon) data release DOI:10.5066/P91K4FZP Reston, VA U.S. Geological Survey https://doi.org/10.5066/P91K4FZP https://www.sciencebase.gov/catalog/item/5bb7833de4b0fc368e9030df online 2018 publication date mu_elev_FIIS Used the marsh unit elevation (MU_ELEV) and vegetated fraction elevation (VG_ELEV) as inputs. Projection was WGS 1984 Web Mercator Auxiliary Sphere. Data was downloaded 09/16/2019. Zafer Defne Neil K. Ganju 2018 Vector Digital Data Set (Polygon) data release DOI:10.5066/P9RHUSWY Reston, VA U.S. Geological Survey https://doi.org/10.5066/P9RHUSWY https://www.sciencebase.gov/catalog/item/5bb77b87e4b0fc368e8fb9f2 online 2018 publication date mu_UVVR_FIIS Used the unvegetated to vegetated ratio (UVVR) as input. Projection was WGS 1984 Web Mercator Auxiliary Sphere. Data was downloaded 09/16/2019. Robert J. Welk Zafer Defne Neil K. Ganju 2019 Vector Digital Data Set (Polygon) data release DOI:10.5066/P9GAGLXB Reston, VA U.S. Geological Survey https://doi.org/10.5066/P9GAGLXB https://www.sciencebase.gov/catalog/item/5cfe97f9e4b0156ea5644fd1 https://www.sciencebase.gov/catalog/item/5cfe981fe4b0156ea5644fd3 online 2019 publication date mu_elev_JB; mu_UVVR_JB From the elevation dataset, we used the marsh unit elevation (MU_ELEV) and vegetated fraction elevation (VG_ELEV) as inputs. From the unvegetated to vegetated ratio (UVVR) dataset, we used the UVVR as input. Projection was WGS 1984 Web Mercator Auxiliary Sphere. Data was downloaded 06/03/2020. Robert J. Welk Zafer Defne Neil K. Ganju 2020 Vector Digital Data Set (Polygon) data release DOI:10.5066/P9UNOMM8 Reston, VA U.S. Geological Survey https://doi.org/10.5066/P9UNOMM8 https://www.sciencebase.gov/catalog/item/5e84e973e4b01d50927b9cc4 https://www.sciencebase.gov/catalog/item/5e84de2be4b01d50927b7164 online 2020 publication date mu_elev_NSLI; mu_UVVR_NSLI From the elevation dataset, we used the marsh unit elevation (MU_ELEV) and vegetated fraction elevation (VG_ELEV) as inputs. From the unvegetated to vegetated ratio (UVVR) dataset, we used the UVVR as input. Projection was WGS 1984 Web Mercator Auxiliary Sphere. Data was downloaded 06/03/2020. Robert J. Welk Zafer Defne Neil K. Ganju 2020 Vector Digital Data Set (Polygon) data release DOI:10.5066/P9XV0JMJ Reston, VA U.S. Geological Survey https://doi.org/10.5066/P9XV0JMJ https://www.sciencebase.gov/catalog/item/5ede4b1782ce7e579c6e568c https://www.sciencebase.gov/catalog/item/5ede3acc82ce7e579c6e5611 online 2020 publication date mu_elev_HvNYC; mu_UVVR_HvNYC From the elevation dataset, we used the marsh unit elevation (MU_ELEV) and vegetated fraction elevation (VG_ELEV) as inputs. From the unvegetated to vegetated ratio (UVVR) dataset, we used the UVVR as input. Projection was WGS 1984 Web Mercator Auxiliary Sphere. Data was downloaded 02/11/2021. Robert J. Welk Kate V. Ackerman Zafer Defne Neil K. Ganju 2020 Vector Digital Data Set (Polygon) data release DOI:10.5066/P91H426U Reston, VA U.S. Geological Survey https://doi.org/10.5066/P91H426U https://www.sciencebase.gov/catalog/item/5ddd7472e4b04a30051ac165 https://www.sciencebase.gov/catalog/item/5ddd6ee7e4b04a30051ac157 online 2020 publication date mu_elev_ELI; mu_UVVR_ELI From the elevation dataset, we used the marsh unit elevation (MU_ELEV) and vegetated fraction elevation (VG_ELEV) as inputs. From the unvegetated to vegetated ratio (UVVR) dataset, we used the UVVR as input. Projection was WGS 1984 Web Mercator Auxiliary Sphere. Data was downloaded 03/15/2024. This process step was performed by Kate Ackerman, using ArcGIS Pro (ver.2.8.8). For simple operations the name of the geoprocessing tool used is given in capital letters; for complex operations, the name of the geoprocessing tool used is given in capital letters and 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. Merge input datasets. a) Download elevation (mu_elev_HvNYC.shp, mu_elev_NSLI.shp, mu_elev_ELI.shp, mu_elev_FIIS.shp, mu_elev_JB.shp) and unvegetated to vegetated marsh ratio (UVVR) (mu_UVVR_HvNYC.shp, mu_UVVR_NSLI.shp, mu_UVVR_ELI.shp, mu_UVVR_FIIS.shp, mu_UVVR_JB.shp) layers from the publications that cover the salt marshes of New York. For each dataset (elevation and UVVR), add a new field (Reg_FIDCMU) to include the concatenation of the region and FID_CMU of the source datasets. The region values are: (1) Hudson Valley and New York City (2) North Shore Long Island (3) Eastern Long Island (4) Fire Island National Seashore and central Great South Bay (5) Jamaica Bay to western Great South Bay. b) MERGE the elevation datasets to create one dataset for New York. MERGE the UVVR datasets to create one dataset for New York. c) JOIN (Join field= Reg_FIDCMU) the New York elevation and UVVR datasets to create one shapefile with both datasets in it. d) Convert the coordinate system from Web Mercator to the North American Datum of 1983 (NAD 1983) geographic coordinate system and add the coordinates for polygon centroids (X_POINT, Y_POINT) in decimal degrees to the data table using CALCULATE_GEOMETRY_ATTRIBUTES tool. e) Export following variables to a comma separated values file [NY_mu.csv]: X_POINT, Y_POINT, FID_CMU, UVVR, ATOT_M2, AVEG_M2, mu_ELEV, vg_ELEV, FLG. mu_elev_HvNYC mu_elev_NSLI mu_elev_ELI mu_elev_FIIS mu_elev_JB mu_UVVR_HvNYC mu_UVVR_NSLI mu_UVVR_ELI mu_UVVR_FIIS mu_UVVR_JB 2024 NY_mu.csv U.S. Geological Survey Kate Ackerman Geologist mailing and physical address

384 Woods Hole Road

Woods Hole MA 02543 508-548-8700 x2331 508-457-2310 kackerman@usgs.gov This processing steps was performed by Zafer Defne using VDatum online (VDatum ver.4.6.1) and Matlab (ver.2021b). Convert datums and calculate lifespan. a) Convert marsh unit elevations from the North American Vertical Datum of 1988 (NAVD88) to Mean Tide Level (MTL) referenced elevations. Input the ASCII file of latitude and longitude coordinates and elevation from NY dataset (NY_mu.csv) to VDatum software, and transform vertical datum from the NAVD88 to MTL. Do this for the marsh unit elevation (MU_ELEV) and elevation of the vegetated part of the marsh unit (VG_ELEV) to calculate MU_ELEV_MTL and VG_ELEV_MTL, respectively. Use value from the nearest Vdatum point for any point where VDatum has no data. b) Calculate sediment budget from UVVR based on Ganju and others (2020) with SB=-0.416*log(UVVR)-1.0749, where SB is sediment budget in kilograms per square meter per year, and log() indicates natural logarithm function. c) Calculate total sediment flux under background relative SLR (BGRND) with SF=SB*ATOT_M2, where SF is sediment flux in kilograms per year and ATOT_M2 is total surface area of marsh unit in square meters. d) Calculate total sediment flux under global mean sea level (GMSL) scenarios (for example, GMSL03 scenario means GMSL rise of 0.3 meters). SLR reduces vegetated marsh area, therefore, causes reduction in sediment flux. The sediment flux under SLR is calculated with SF_SLR=(SB-SLR_RATE*RHO_F)*ATOT_M2, where SF_SLR is sediment flux under SLR, RHO_F is dry bulk density of future deposited sediment. RHO_F was assigned 159 kilograms per cubic meters from Morris and others (2016). SLR_RATE is the SLR rate, calculated as SLR_RATE=(RSL2100+RSL_OFFSET)/100-RSL_VLM, where RSL2100 is the relative sea level by 2100 under a global mean sea level rise scenario, RSL_OFFSET is the offset to initiate the projection at year 2000, and RSL_VLM is the relative sea level contribution from vertical land motion. For sea level rise projections, Sweet and others (2022) SLR data within the region were used. A total of 29 points including 14 stations and 15 grid points were within the bounding box with lower left corner of (39.9333N, -75.1417W) and upper right corner of (42.3539N, -71.0000W). Interpolate the SLR_RATE from 29 points over a regular grid using GRIDDATA function with natural neighbor interpolation (grid size by 41 longitudinal by 24 latitudinal points). Assign to each marsh unit the interpolated SLR_RATE value from the nearest grid point. Do this for the three scenarios considered: GMSL rise of 0.3 meters, 0.5 meters and 1.0 meters by year 2100 and calculate sediment flux for each of them. e) Total sediment mass in the vegetated plain above MTL is calculated with TS=vg_ELEV_MTL*AVEG_M2*RHO_E, where TS is total sediment mass, AVEG_M2 is the surface area of the vegetated part of the marsh unit and RHO_E is the dry bulk density of existing marsh substrate sediment. RHO_E was assigned 373 kilograms per cubic meters from Morris and others (2016). f) Calculate lifespan (in years) for the background relative SLR with the equation BGRND= -TS/SF. Calculate lifespan (in years) for global mean sea level rise by 0.3 meters, 0.5 meters and 1.0 meters by year 2100 scenarios with the equation GMSL= -TS/SF_SLR for each scenario (GMSL03, GMSL05, GMSL10, respectively). g) Output Matlab data as a comma separated text file [NY_lifespan.csv]. NY_mu.csv 2024 NY_lifespan.csv U.S. Geological Survey Zafer Defne Oceanographer mailing and physical address

384 Woods Hole Road

Woods Hole MA 02543 508-548-8700 x2254 508-457-2310 zdefne@usgs.gov This processing step was performed by Zafer Defne using ArcGIS Pro (ver. 3.0.3). Finalize the feature dataset and change projection. a) JOIN lifespan calculation results file with the marsh unit features using ADD_JOIN and join field as FID_CMU. b) For marshes that are more stable, lifespan calculation sometimes results in large numbers that are far beyond the lifespan horizon of interest. Also, positive sediment budget implies unlimited lifespan. For these units, set the maximum lifespan value to 10,000 years. c) Set lifespan values to -9999 for units with no vegetated area or with missing elevation values (FLG values that contain any of -1 or -200 values in them) so that they can be labeled as not available or excluded while plotting the data. d) Set legend label for lifespan values less than 0 as imminent. e) Rearrange field names and change the projection for better performance of web services with online base maps. PROJECT(Input coordinate system= NAD 1983 Geographic coordinate system; Output coordinate system=WGS 1984 Web Mercator Auxiliary Sphere; Geographic transformation= WGS 1984 (ITRF00) to NAD 1983) the feature dataset to obtain the lifespan values [mu_lifespan_NY.shp]. NY_lifespan.csv 2024 mu_lifespan_NY.shp Vector G-polygon 8658 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 meters D_WGS_1984 WGS_1984 6378137.0 298.257223563 mu_lifespan_NY.shp Attribute Table Attribute information associated with the lifespan estimates for the conceptual marsh units of New York salt marsh system. USGS FID Internal feature number. Esri Sequential unique whole numbers that are automatically generated. Shape Feature geometry. Esri Coordinates defining the features. FID_CMU Sequential unique whole number that represents the identification number for each conceptual marsh units. USGS 0 8657 none ATOT_M2 Total surface area of a marsh unit in square meters. USGS 8.87608778056 1278469.79671 square meter AVEG_M2 Surface area of vegetated part of a marsh unit in square meters. USGS 0.0 1189344.84656 square meter MU_ELEV Mean elevation of a marsh unit in meters referenced to NAVD88. USGS -9999 No Data USGS -4.083 8.554 meter MU_ELEVMTL Mean elevation of a marsh unit in meters referenced to MTL. USGS -9999 No Data USGS -4.003 8.554 meter VG_ELEV Mean elevation of the vegetated area in a marsh unit in meters referenced to NAVD88. Value is set to -9999 if there is no vegetated area in the marsh unit. USGS -9999 No Data USGS -4.051 6.82 meter VG_ELEVMTL Mean elevation of the vegetated area in a marsh unit in meters referenced to MTL. Value is set to -9999 if there is no vegetated area in the marsh unit. USGS -9999 No Data USGS -3.971 6.926 meter UVVR Ratio of unvegetated surface area to vegetated surface area. Ordinarily, UVVR ranges from zero (completely vegetated) to infinity (completely unvegetated). However, it is assigned the value of -1 when completely unvegetated. USGS -1.0 2506.494 none BGRND Lifespan for a marsh unit (in years) for nonclimatic background relative sea level rise. Negative lifespan (other than No Data) indicates the estimated lifespan is depleted and loss is imminent. USGS -9999 No Data USGS 10000 Value larger than or equal to 10000 USGS -2086 10000 year GMSL03 Lifespan for a marsh unit (in years) for global mean sea level rise of 0.3 meters by 2100. Negative lifespan (other than No Data) indicates the estimated lifespan is depleted and loss is imminent. USGS -9999 No Data USGS 10000 Value larger than or equal to 10000 USGS -690 10000 year GMSL05 Lifespan for a marsh unit (in years) for global mean sea level rise of 0.5 meters by 2100. Negative lifespan (other than No Data) indicates the estimated lifespan is depleted and loss is imminent. USGS -9999 No Data USGS 10000 Value larger than or equal to 10000 USGS -407 10000 year GMSL10 Lifespan for a marsh unit (in years) for global mean sea level rise of 1.0 meters by 2100. Negative lifespan (other than No Data) indicates the estimated lifespan is depleted and loss is imminent. USGS -9999 No Data USGS 10000 Value larger than or equal to 10000 USGS -279 10000 year FLG Marsh unit flag indicating anomalous marsh units based on absence of vegetation, elevation, surface area and tidal range extrapolation. FLG values indicate: (-1) no vegetated area in the marsh unit; (-10) marsh unit elevation higher than the 99.8 percentile; (-100) marsh unit elevation less than the 0.2 percentile; (-200) greater than 25 percent of the marsh unit elevation is hydro-flattened; (-1000) marsh unit surface area less than 900 m^2; (-10000) mean tidal range of marsh unit is extrapolated; and (0) no flag. Combination of negative values indicates a combination of flags. For example, -1001 indicates no vegetated area and area less than 900 m^2. USGS -11201 0 None Reg_FIDCMU This field contains the region and FID_CMU of the source datasets. The regions are: (1) Hudson Valley and New York City (2) North shore Long Island (3) Eastern Long Island (4) Fire Island National Seashore and central Great South Bay (5) Jamaica Bay to western Great South Bay. USGS The concatenation of the region and FID_CMU of the source dataset In this dataset, lifespan estimates for each conceptual salt marsh unit in the New York salt marsh system 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 The dataset contains polygon marsh unit lifespan data (mu_lifespan_NY.shp and other shapefile components), browse graphic, and the FGDC 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. 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. Shapefile ArcGIS Pro 3.0.3 This zipped file contains a polygon shapefile and its components, a style layer descriptor file, metadata in xml format and a browse image. 49 https://www.sciencebase.gov/catalog/file/get/65b3ee2fd34e36a390458aa4 https://doi.org/10.5066/P14MB99B The first link in network resources is to download data directly. The second link points to a landing page with metadata and data. WMS https://www.sciencebase.gov/catalogMaps/mapping/ows/65b3ee2fd34e36a390458aa4?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/65b3ee2fd34e36a390458aa4?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 data set. 20240402 U.S. Geological Survey Zafer Defne Oceanographer mailing and physical address

384 Woods Hole Road

Woods Hole MA 02543 508-548-8700 x2254 508-457-2310 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