Metadata: Identification_Information: Citation: Citation_Information: Originator: Robert Welk Originator: Zafer Defne Originator: Neil Ganju Publication_Date: 20200602 Title: Conceptual marsh units of north shore Long Island salt marsh complex, New York Edition: 1.0 Geospatial_Data_Presentation_Form: Vector Digital dataset (Polygon) Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P9UNOMM8 Publication_Information: Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, MA Publisher: U.S. Geological Survey, Coastal and Marine Geology Program Online_Linkage: https://doi.org/10.5066/P9UNOMM8 Online_Linkage: https://www.sciencebase.gov/catalog/item/5e84cfa5e4b01d50927b7147 Larger_Work_Citation: Citation_Information: Originator: Robert Welk Originator: Zafer Defne Originator: Neil Ganju Publication_Date: 2020 Title: Coastal wetlands of north shore Long Island, New York Edition: 1.0 Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P9UNOMM8 Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Other_Citation_Details: Suggested citation: Welk, R., Defne, Z., and Ganju, N.K., 2020, Coastal wetlands of north shore Long Island, New York: U.S. Geological Survey data release, https://doi.org/10.5066/P9UNOMM8 Online_Linkage: https://doi.org/10.5066/P9UNOMM8 Online_Linkage: https://www.sciencebase.gov/catalog/item/5e849ee4e4b01d50927b70b9 Description: Abstract: This data release contains coastal wetland synthesis products for the geographic region of north shore Long Island, New York. 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. Purpose: 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. The salt marsh complex of north shore Long Island was delineated to smaller, conceptual marsh units by the 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. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2020 Currentness_Reference: Publication date Status: Progress: Complete Maintenance_and_Update_Frequency: None Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -73.7523079 East_Bounding_Coordinate: -72.7695214 North_Bounding_Coordinate: 40.9750166 South_Bounding_Coordinate: 40.7771079 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:5e84cfa5e4b01d50927b7147 Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: geospatial datasets Theme_Keyword: wetland ecosystems Theme_Keyword: wetland functions Theme_Keyword: coastal ecosystems Theme_Keyword: coastal processes Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: salt marsh Theme_Keyword: vegetation Theme_Keyword: marsh health Theme_Keyword: estuary Theme_Keyword: Long-Term Ecological Research Theme_Keyword: LTER Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: oceans Theme_Keyword: inlandWaters Theme_Keyword: environment Place: Place_Keyword_Thesaurus: None Place_Keyword: Atlantic Ocean Place_Keyword: United States Place_Keyword: New York Place_Keyword: Suffolk County Place_Keyword: Nassau County Place_Keyword: Long Island Sound 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. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Northeast Region Contact_Person: Robert J Welk Contact_Position: Hydrologic Technician Contact_Address: Address_Type: mailing address Address: 2045 Route 112 City: Coram State_or_Province: NY Postal_Code: 11727 Country: US Contact_Voice_Telephone: 631-736-0783 x141 Contact_Electronic_Mail_Address: rwelk@usgs.gov Browse_Graphic: Browse_Graphic_File_Name: https://www.sciencebase.gov/catalog/file/get/5e84cfa5e4b01d50927b7147?name=CMU_NSLI_browse.png Browse_Graphic_File_Description: Graphic that shows conceptual marsh units overlaying Esri basemap. Browse_Graphic_File_Type: PNG Native_Data_Set_Environment: 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) Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Marsh units and water and land boundaries inherit their accuracy from the 2017 U.S. Fish and Wildlife Service National Wetland Inventory (USFWS NWI). However, the lineage of the source data indicates that the underlying data span multiple years and the mapped features may have changed since the date of imagery. Accuracy of marsh unit delineation depends on the vertical and horizontal accuracy of the 1-meter resolution U.S. Geological Survey Coastal National Elevation Database (USGS CoNED) data from 2015. Accuracy of the vegetated and unvegetated polygons is based on the 1-meter resolution National Agriculture Imagery Program (NAIP) products from 2017. Any vegetated or unvegetated polygons less than 9 square meters(m^2) were merged with the surrounding majority class. When creating marsh units, conterminous polygons smaller than 900 m^2 were merged with the larger polygon of the same type. Since small marsh islands are common in north shore Long Island, many polygons in this dataset could not be merged with larger units. Logical_Consistency_Report: Topological errors that occurred during geoprocessing were automatically removed by the topological rules used for the analysis. The polygons were checked for correct geometry and do not overlap. Small polygons (less than 9 m^2) were assumed to be marginal and were assigned the classification from the surrounding majority value. This resulted in polygons that were removed from the dataset and FID CMU values that are not sequential. A visual comparison between NAIP imagery was performed at randomly selected sites to verify the land and water boundaries. Completeness_Report: The marsh polygons are bound to the borders of the north shore Long Island estuarine intertidal areas that include 1) emergent wetlands, 2) scrub-shrub areas, 3) rooted vascular aquatic beds, 4) organic unconsolidated shores, and 5) channels of open water that are wider than 10 meters. Sliver polygons of open salt water along the marsh edges may also be included in some instances as a result of geoprocessing. A detailed on-the-ground analysis of a single site may result in a different interpretation of the wetland and marsh unit boundaries than those established through this analysis. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Horizontal accuracy is inherited from CoNED Digital Elevation Models. Vegetated and unvegetated polygons were based on the 1-meter resolution NAIP imagery. Although the analyses were performed at 1-meter resolution, the horizontal accuracy is superseded by NAIP imagery accuracy which is +/-6 meters. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: 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, CoNED. CoNED vertical elevation accuracy was 0.2 meters. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 2015 Title: National Elevation Dataset Geospatial_Data_Presentation_Form: Raster Digital dataset Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: https://nationalmap.gov/viewer.html Type_of_Source_Media: Digital Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2015 Source_Currentness_Reference: publication date Source_Citation_Abbreviation: CoNED Source_Contribution: Downloaded CoNED 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. Source_Information: Source_Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 2017 Title: NAIP Digital Ortho Photo Image Geospatial_Data_Presentation_Form: Remote-sensing image Publication_Information: Publication_Place: Salt Lake City, Utah Publisher: USDA-FSA-APFO Aerial Photography Field Office Online_Linkage: https://earthexplorer.usgs.gov Online_Linkage: https://www.sciencebase.gov/catalog/item/51355312e4b0e1603e4fed62 Type_of_Source_Media: Digital Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2017 Source_Currentness_Reference: publication date Source_Citation_Abbreviation: NAIP Source_Contribution: 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. Source_Information: Source_Citation: Citation_Information: Originator: U.S. Fish and Wildlife Service Publication_Date: 2017 Title: National Wetland Inventory New York Wetlands Geospatial_Data_Presentation_Form: Vector Digital dataset (Polygon) Publication_Information: Publication_Place: Madison, WI Publisher: U.S. Fish and Wildlife Service Online_Linkage: https://www.fws.gov/wetlands/data/Data-Download.html Type_of_Source_Media: Digital Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2017 Source_Currentness_Reference: publication date Source_Citation_Abbreviation: NWI Source_Contribution: 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 2019/08/01. Source_Information: Source_Citation: Citation_Information: Originator: New England Interstate Water Pollution Control Commission prepared by Cameron Engineering and Associates, LLP Publication_Date: 2015 Title: Long Island Tidal Wetlands Trends Analysis Geospatial_Data_Presentation_Form: Vector Digital Data Set (Polygon) Online_Linkage: http://www.dec.ny.gov/lands/5113.html Type_of_Source_Media: Digital Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2015 Source_Currentness_Reference: publication date Source_Citation_Abbreviation: NYSDEC Source_Contribution: Wetland polygon shapefile prepared for Long Island Tidal Wetlands Trends Analysis. Data available by request. Data acquired 2019/05/01. Process_Step: Process_Description: This process step and all subsequent process steps were performed by the same person, Robert Welk, in ArcMap (ver. 10.7.1) 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 m^2 (m^2) unless otherwise stated. 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 CoNED raster to a new raster dataset with 1 meter resolution [elev_mosaic.tif]. Source_Used_Citation_Abbreviation: CoNED Process_Date: 2020 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Northeast Region Contact_Person: Robert J Welk Contact_Position: Hydrologic Technician Contact_Address: Address_Type: mailing address Address: 2045 Route 112 City: Coram State_or_Province: NY Postal_Code: 11727 Country: US Contact_Voice_Telephone: 631-736-0783 x141 Contact_Electronic_Mail_Address: rwelk@usgs.gov Process_Step: Process_Description: Prepare mask polygon to define analysis boundaries. In order to account for the possible influence of the surrounding terrain on the analysis, a mask area larger than the salt marsh extent is first created [UVVR_mask]. At the end of the analysis the results are clipped to the boundaries of the salt marsh area [MU_mask]. Both UVVR_mask and MU_mask are edited to determine which interior polygons are removed. a) MERGE NWI wetland polygons with NYSDEC wetland polygons to obtain [NWI_DEC.shp]. b) EXPORT features from NWI_DEC.shp dataset after SELECT("ATTRIBUTE" LIKE 'E2%EM%' OR "ATTRIBUTE" LIKE 'E2AB3%' OR "ATTRIBUTE" LIKE 'E2EM%' OR "ATTRIBUTE" LIKE 'E2SS%' OR "ATTRIBUTE" LIKE 'E2US4%') to select from estuarine intertidal areas of 1) emergent wetland, 2) scrub-shrub area, 3) rooted vascular aquatic bed, 4) organic unconsolidated shore classes [NWI_exclusive_select.shp]. c) BUFFER(Input features=[NWI_exclusive_select.shp]; Linear unit=5 meters; Dissolve type=All) to obtain the mask polygon [buff5m.shp] and ELIMINATE POLYGON PART(Condition=Percentage; Percentage=99; Eliminate contained part only) to obtain [UVVR_mask01.shp]. Apply buffer with -5 meters to obtain [MU_mask01.shp]. d) EXPORT features from NWI dataset after SELECT("ATTRIBUTE" NOT LIKE 'E%' OR "ATTRIBUTE" LIKE '%FO') to obtain features that are not estuarine or are forested estuarine. MULTIPART TO SINGLEPART to separate individual polygons [NWI_inclusive_single.shp]. e) To exclude the voids in the NWI map during the analysis, these interior polygons need to be removed from the mask. Create a rectangular polygon that covers the domain [extent.shp]. ERASE [NWI_excusive_select.shp] from [extent.shp] and MULTIPART TO SINGLEPART to get [NWI_voids_single.shp]. f) SELECT BY LOCATION from [NWI_inclusive_single.shp] that are completely within the [MU_mask01.shp] and SELECT BY LOCATION from [NWI_voids_single.shp] that are completely within the [MU_mask01.shp]. If any of additional polygons need to be removed from the mask include them in a new feature layer [erase_mask_manual.shp]. Merge all three feature sets to get polygons to be excluded [erase_inside.shp] from the final masks. g) ERASE [erase_inside.shp] from [MU_mask01.shp] and [UVVR_mask01.shp] to obtain [MU_mask.shp] and [UVVR_mask.shp], respectively. Source_Used_Citation_Abbreviation: NWI Source_Used_Citation_Abbreviation: NYSDEC Process_Date: 2020 Process_Step: Process_Description: Define preliminary boundaries for marsh units by basin analysis: a) EXTRACT BY MASK from mosaicked elevation dataset using [UVVR_mask.shp] polygon. b) FILL(no Z limit) sinks in extracted elevation raster. c) Calculate FLOW DIRECTION(do not force edge cells to flow outward) raster. d) Calculate BASIN based on flow direction raster [basin_buff5m.tif]. e) Apply MAJORITY FILTER(Number of neighbors=8) to clean the raster and convert RASTER TO POLYGON. CLIP the polygon with 1-meter buffered marsh units mask [MU_mask_buff1m.shp]. This additional buffer is necessary to prevent any polygon smoothing algorithm from changing the exterior boundaries and will be removed by clipping to the [MU_mask.shp] later. MULTIPART TO SINGLEPART and ADD GEOMETRY ATTRIBUTES(Geometry properties=Area_geodesic; Area unit=Square_meters) to get [basin_single.shp] Process_Date: 2020 Process_Step: Process_Description: This step merges the "orphan marsh units", units that are less than 5000 m^2 in area to the nearest to "parent marsh units", units that are larger than 5000 m^2 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 m^2 [lt5000.shp]. b) Create parent marsh units features by exporting marsh units with an area greater than or equal to 5000 m^2 [ge5000.shp]. c) Run Python script (hydUnitloop.py). At each iteration step, the script uses NEAR tool to find orphan marsh units within 1 meter 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 dataset. 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 1 meter 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 [pMUopt1.shp]. g) SMOOTH POLYGON(Smoothing algorithm=PAEK; Smoothing tolerance=15 meters) to get the smoothed marsh units polygon [pMUopt1_smooth.shp]. h) CLIP the extra buffer around the smoothed marsh units using the marsh units mask, [MU_mask.shp]. If this results in any additional marsh units with an area less than 5000 m^2, dissolve into the nearest parent units repeating the same steps above to obtain [pMUopt1_clip_final.shp] i) Compute the final marsh units by removing any artefacts from [pMuOpt1_clip_final.shp] using ELIMINATE and REPAIR GEOMETRY tools. ELIMINATE(Expression="Area_geo" less than 900; Eliminating by border) polygon slivers smaller than 900 m^2 by merging them to the main polygon. MULTIPART TO SINGLEPART to get conceptual marsh units [CMU.shp]. This only applies to polygons that are bordering other polygons. Polygons that are not bordering other polygons are not affected as those are more likely to be real features as opposed to geoprocessing artefacts. j) DISSOLVE the conceptual marsh units to get the final outlines for the marsh complex [CMU_mask_final.shp]. Process_Date: 2020 Process_Step: Process_Description: Determine the vegetated and unvegetated areas by image processing. a) EXTRACT BY MASK from elevation raster [elev_mosaic.tif] using [UVVR_mask.shp] polygon. Rescale the elevation raster values to the same range with 8-bit NAIP imagery (0 to 255) using min-max scaling. Perform ISO CLUSTER UNSUPERVISED CLASSIFICATION with 4-bands (Near Infrared, Blue, Green, and Red from the NAIP imagery and the rescaled elevation raster with 32 classes and a minimum class size of 5000 cells. RECLASSIFY the classified raster by visually comparing the NAIP imagery to obtain the unvegetated-vegetated raster [UVVc.tif]. For marsh units with invalid elevation data, the classification was processed with imagery bands only and later merged with the rest of the dataset. b) Dissolve unvegetated regions smaller than a threshold value to the surrounding vegetated regions and vice versa to clean the UVV raster. For this purpose, use the REGION(Number of neighbors=4; Zone grouping method=Within; Add Link field to output) to get the [UVV_region.tif], and TEST("Count" less than 9) to set a threshold value of 9 raster cells [UVV_test.tif]. Use RASTER CALCULATOR to toggle the value of the Link field in the region raster, where the test raster indicates regions with areas smaller than the threshold. c) RASTER TO POLYGON(Simplify polygons=False) and CLIP with the final marsh complex outline [CMU_mask_final.shp] to obtain [UVVc_filt_clip.shp]. d) REPAIR GEOMETRY and DISSOLVE(Create multipart features=False) to get filtered, clipped and dissolved unvegetated-vegetated polygons [UVVc_filt_clip_diss.shp]. e) INTERSECT the final conceptual marsh units [CMU.shp] with unvegetated-vegetated polygons [UVVc_filt_clip.shp], REPAIR GEOMETRY, and calculate the area of unvegetated and vegetated polygons in each marsh unit. To do this ADD GEOMETRY ATTRIBUTES(Geometry properties=Area_geodesic; Area unit=Square_meters) to get [UVV_poly.shp], and DISSOLVE(Input features=UVV_poly.shp; Dissolve fields=FID_CMU, gridcode; Statistics field=gridcode.MEAN, Area_geo.SUM) and REPAIR GEOMETRY to get [UVV_poly_diss.shp]. Edit the fields to have "TYP", "APGN_M2", and "ATOT_M2" fields for type of polygon indicating vegetated or unvegetated, surface area of the polygon, and total surface area of the marsh unit, respectively. f) Add field "UVVR" and calculate unvegetated to vegetated ratio based on "TYP", "APGN_M2" and "ATOT_M2" fields. If the vegetated area is zero for a marsh unit set the value of UVVR to -1. g) Calculate the mean elevation for each marsh unit with ZONAL STATISTICS AS TABLE(Raster layer=[elev_mosaic.tif]; Zone features=[CMU.shp], Zone field=FID_CMU; Statistics type=Mean; Ignore Nodata=True) and JOIN with [CMU.shp] to get [mu_elev.shp]. Source_Used_Citation_Abbreviation: NAIP Process_Date: 2020 Process_Step: Process_Description: Finalize the conceptual marsh units. a)Add field "COLORID" to cycle through integers from 0 to 9 to be used for coloring the marsh units. This field is used for display purposes only to distinguish between each marsh unit. b) Add field "FLG" to flag anomalous marsh units based on elevation, surface area, and absence of vegetation. Set FLG to -1) no vegetated area in the marsh unit; (-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 m^2; (-10000) mean tidal range of marsh unit is extrapolated; and (0) no flag. Combination of negative values indicate combination of flags. For example, -1001 indicates no vegetated area and area less than 900 m^2. c) Remove field "UVVR" and 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 [CMU_NSLI.shp]. Process_Date: 2020 Process_Step: Process_Description: Added keywords section with USGS persistent identifier as theme keyword. Process_Date: 20200806 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: VeeAnn A. Cross Contact_Position: Marine Geologist Contact_Address: Address_Type: Mailing and Physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Contact_Voice_Telephone: 508-548-8700 x2251 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: vatnipp@usgs.gov Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: G-polygon Point_and_Vector_Object_Count: 2357 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Map_Projection: Map_Projection_Name: WGS 1984 Web Mercator Auxiliary Sphere (Esri Full Name: WGS_1984_Web_Mercator_Auxiliary_Sphere) Mercator: Standard_Parallel: 0.0 Longitude_of_Central_Meridian: 0.0 False_Easting: 0.0 False_Northing: 0.0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 0.6096 Ordinate_Resolution: 0.6096 Planar_Distance_Units: Meter Geodetic_Model: Horizontal_Datum_Name: D_WGS_1984 Ellipsoid_Name: WGS_1984 Semi-major_Axis: 6378137.0 Denominator_of_Flattening_Ratio: 298.257223563 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: CMU_NSLI Entity_Type_Definition: Table containing attribute information associated with the dataset. Entity_Type_Definition_Source: U.S. Geological Survey Attribute: Attribute_Label: FID Attribute_Definition: Internal feature number. Attribute_Definition_Source: Esri Attribute_Domain_Values: Unrepresentable_Domain: Unique whole numbers that are automatically generated. Attribute: Attribute_Label: Shape Attribute_Definition: Feature geometry. Attribute_Definition_Source: Esri Attribute_Domain_Values: Unrepresentable_Domain: Coordinates defining the features. Attribute: Attribute_Label: FID_CMU Attribute_Definition: Unique whole numbers used to identify each conceptual marsh unit. These numbers are duplicated when a marsh unit has both vegetated and unvegetated sub-polygons. Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 37 Range_Domain_Maximum: 1778 Attribute_Units_of_Measure: none Attribute: Attribute_Label: TYP Attribute_Definition: Classification of the polygon features in a marsh unit as vegetated or unvegetated. Attribute_Definition_Source: USGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: unvegetated Enumerated_Domain_Value_Definition: Unvegetated part of the marsh unit. Enumerated_Domain_Value_Definition_Source: USGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: vegetated Enumerated_Domain_Value_Definition: Vegetated part of the marsh unit. Enumerated_Domain_Value_Definition_Source: USGS Attribute: Attribute_Label: APGN_M2 Attribute_Definition: Surface area of the selected polygon type (vegetated or unvegetated). Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 9.085341 Range_Domain_Maximum: 185492.964019 Attribute_Units_of_Measure: m^2 Attribute: Attribute_Label: ATOT_M2 Attribute_Definition: Total surface area of a marsh unit in m^2 Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 9.085341 Range_Domain_Maximum: 219320.976263 Attribute_Units_of_Measure: m^2 Attribute: Attribute_Label: FLG Attribute_Definition: Marsh unit flag indicating anomalous marsh units based on elevation, surface area, and absence of vegetation. 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 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 m^2; (-10000) mean tidal range of marsh unit is extrapolated; and (0) no flag. Combination of negative values indicate combination of flags. For example, -1001 indicates no vegetated area and area less than 900 m^2. Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -11201 Range_Domain_Maximum: 0 Attribute_Units_of_Measure: None Attribute: Attribute_Label: COLORID Attribute_Definition: Recycling sequential whole numbers (0-9) 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. Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0 Range_Domain_Maximum: 9 Attribute_Units_of_Measure: None Overview_Description: Entity_and_Attribute_Overview: In this dataset, the salt marsh complex in north shore Long Island has been delineated to conceptual salt marsh units to facilitate unit by unit evaluation of the response and resiliency of the 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. 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 is assumed to be 1 meter. Entity_and_Attribute_Detail_Citation: USGS Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - ScienceBase Contact_Address: Address_Type: mailing and physical address Address: Denver Federal Center, Building 810, Mail Stop 302 City: Denver State_or_Province: CO Postal_Code: 80225 Contact_Voice_Telephone: 1-888-275-8747 Contact_Electronic_Mail_Address: sciencebase@usgs.gov Resource_Description: CMU_NSLI.shp (and files associated with a shapefile), browse graphic (CMU.png), and CSDGM metadata in XML format. Distribution_Liability: 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. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: shapefile Format_Version_Number: ArcGIS 10.7.1 Format_Information_Content: This dataset contains a polygon shapefile and its components and metadata in xml format Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://doi.org/10.5066/P9UNOMM8 Network_Resource_Name: https://www.sciencebase.gov/catalog/item/5e84cfa5e4b01d50927b7147 Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/5e84cfa5e4b01d50927b7147 Access_Instructions: The first link in network resources is to the main page of the data release. The second link points to a landing page with metadata and data. The third link is to download data directly. Digital_Form: Digital_Transfer_Information: Format_Name: WMS Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalogMaps/mapping/ows/5e84cfa5e4b01d50927b7147?service=wms&request=getcapabilities&version=1.3.0 Access_Instructions: The link in network resources points to the Web Mapping Services (WMS) end point. Digital_Form: Digital_Transfer_Information: Format_Name: WFS Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalogMaps/mapping/ows/5e84cfa5e4b01d50927b7147?service=wfs&request=getcapabilities&version=1.0.0 Access_Instructions: The link in network resources points to the Web Feature Service (WFS) end point. Fees: None. No fees are applicable for obtaining the data set. Metadata_Reference_Information: Metadata_Date: 20200806 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, Northeast Region Contact_Person: Robert J Welk Contact_Position: Hydrologic Technician Contact_Address: Address_Type: mailing address Address: 2045 Route 112 City: Coram State_or_Province: NY Postal_Code: 11727 Country: US Contact_Voice_Telephone: 631-736-0783 x141 Contact_Electronic_Mail_Address: rwelk@usgs.gov Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998