Elevation of marsh units in Massachusetts salt marshes

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Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: Kate V. Ackerman
Originator: Zafer Defne
Originator: Neil K. Ganju
Publication_Date: 20210929
Title: Elevation of marsh units in Massachusetts salt marshes
Edition: 1.0
Geospatial_Data_Presentation_Form: Vector Digital dataset (Polygon)
Series_Information:
Series_Name: data release
Issue_Identification: DOI:10.5066/P97E086F
Publication_Information:
Publication_Place: Woods Hole Coastal and Marine Science Center, Woods Hole, MA
Publisher:
U.S. Geological Survey, Coastal and Marine Hazards and Resources Program
Online_Linkage: https://doi.org/10.5066/P97E086F
Online_Linkage:
https://www.sciencebase.gov/catalog/item/60f9932ed34e3ccd82fe3fcb
Larger_Work_Citation:
Citation_Information:
Originator: Kate V. Ackerman
Originator: Zafer Defne
Originator: Neil K. Ganju
Publication_Date: 2021
Title: Geospatial Characterization of Salt Marshes for Massachusetts
Edition: 1.0
Geospatial_Data_Presentation_Form: vector digital data
Series_Information:
Series_Name: data release
Issue_Identification: DOI:10.5066/P97E086F
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Other_Citation_Details:
Suggested citation: Ackerman, K.V., Defne, Z., and Ganju, N.K., 2021, Geospatial Characterization of Salt Marshes for Massachusetts: U.S. Geological Survey data release, https://doi.org/10.5066/P97E086F.
Online_Linkage: https://doi.org/10.5066/P97E086F
Online_Linkage:
https://www.sciencebase.gov/catalog/item/60f79c4dd34e9143a4ba4e04
Description:
Abstract:
This data release contains coastal wetland synthesis products for Massachusetts, developed in collaboration with the Massachusetts Office of Coastal Zone Management. Metrics for resiliency, including unvegetated to vegetated ratio (UVVR), marsh elevation, and tidal range, are calculated for smaller units delineated from a digital elevation model, providing the spatial variability of physical factors that influence wetland health. 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:
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 Massachusetts salt marshes is given in terms of mean elevation of conceptual marsh units. The elevation data is based primarily on the 1-meter resolution Coastal National Elevation Database (CoNED), as well as a 1-meter resolution USGS DEM, and the 1/9- arc-second resolution USGS National Elevation Dataset (NED).
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2021
Currentness_Reference: publication date
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -71.2265
East_Bounding_Coordinate: -69.9299
North_Bounding_Coordinate: 42.8719
South_Bounding_Coordinate: 41.2423
Keywords:
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: oceans
Theme_Keyword: inlandWaters
Theme_Keyword: environment
Theme_Keyword: elevation
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: elevation
Theme:
Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:60f9932ed34e3ccd82fe3fcb
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: United States
Place_Keyword: Massachusetts
Place_Keyword: Massachusetts Bay
Place_Keyword: Cape Cod Bay
Place_Keyword: Buzzards Bay
Place_Keyword: Plum Island
Place_Keyword: Cape Cod
Place_Keyword: Martha's Vineyard
Place_Keyword: Nantucket
Place_Keyword: Parker River National Wildlife Refuge
Place_Keyword: Parker River/Essex Bay Area of Critical Environmental Concern
Place_Keyword: Great Marsh Area of Critical Environmental Concern
Place_Keyword: Sandy Neck/Barnstable Area of Critical Environmental Concern
Place_Keyword: Wellfleet Harbor Area of Critical Environmental Concern
Place_Keyword: Pleasant Bay Area of Critical Environmental Concern
Place_Keyword: Cape Cod National Seashore
Place_Keyword: Essex Bay
Place_Keyword: Merrimack River
Place_Keyword: Ipswich River
Place_Keyword: Danvers River
Place_Keyword: Pines River
Place_Keyword: Neponset River
Place_Keyword: Weymouth Fore River
Place_Keyword: Weymouth Back River
Place_Keyword: Scituate Harbor
Place_Keyword: North River
Place_Keyword: South River
Place_Keyword: Duxbury Bay
Access_Constraints: None
Use_Constraints:
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.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Kate Ackerman
Contact_Organization: U.S. Geological Survey
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543
Country: US
Contact_Voice_Telephone: 508-548-8700 x2331
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: kackerman@usgs.gov
Browse_Graphic:
Browse_Graphic_File_Name:
https://www.sciencebase.gov/catalog/file/get/60f9932ed34e3ccd82fe3fcb/?name=Elev_MA_Browse.png
Browse_Graphic_File_Description:
Graphic that shows elevation of conceptual marsh units of Massachusetts salt marshes.
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 horizontal accuracy from the accuracy of the source data, the conceptual marsh units, and their vertical accuracy from the elevation datasets (USGS CoNED, USGS 1-meter DEM, and USGS NED).
Logical_Consistency_Report:
Positive elevation indicates above sea level. Marsh units with extremely low elevation (smaller than the 0.2 percentile value), extremely high elevation (larger than the 99.8 percentile value) or areas less than 900 square meters were flagged. In one area (around marsh unit 6125), there are marsh units that have straight lines for boundaries; this is due to larger areas of hydro-flattened bathymetry/elevation values that do not allow the basin analysis to identify ridge lines between basins. These marsh units have a flag that shows that the hydro-flattened area of the marsh unit is greater than 25 percent of the marsh unit area.
Completeness_Report:
The results are specific to the marsh polygons as defined within the boundaries of Massachusetts salt marshes. Sliver polygons of open salt water along the marsh edges may also be included in some instances as a result of geoprocessing. In some marsh units there are small sliver gaps due to coupling of artifacts of the NWI (e.g., NWI polygons for ditches that are classified as riverine) and geoprocessing when the marsh polygons were closer than 10 meters at a specific section that is followed by a wider distance (e.g., access roads, fringing forests, etc.). The effect of these slivers on the calculations is negligible. For example, in marsh units 5958 and 5965 the sliver gaps are a result of the geoprocessing steps that remove riverine polygons. Other examples include marsh units 165, 308, 648, 3441, 5613. A detailed on-the-ground analysis of a single site may result in a different interpretation of the wetland and marsh unit boundaries. Occasionally, marsh units are retained in this dataset even though the imagery displayed extreme change (e.g., partially or completely converted to water) from the NWI wetland delineation.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Horizontal accuracy for the polygon boundaries is inherited from the source layer, the conceptual marsh units, and is considered to be +/- 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 datasets (USGS 1m CoNED, USGS 1m DEM, and USGS 1/9 arc second NED). The vertical accuracy is inherited from the source elevation datasets; it is reported to be 0.2 meters for the 1 meter elevation datasets, and is reported as "N/A" for the USGS 1/9 arc second NED dataset. No additional accuracy assessment of the vertical accuracy has been conducted.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: Danielson, J.
Originator: Tyler, D.
Publication_Date: 20160501
Title:
Topobathymetric Model for the New England Region States of New York, Connecticut, Rhode Island and Massachusetts, 1887 to 2016
Edition: First
Geospatial_Data_Presentation_Form: Raster Digital dataset
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Online_Linkage: https://topotools.cr.usgs.gov/topobathy_viewer/
Type_of_Source_Media: Digital
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 18870103
Ending_Date: 20160201
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: USGS CoNED
Source_Contribution:
Downloaded CoNED Digital Elevation Model geodatabase. Projection was NAD 1983 UTM Zone 18N with the North American Vertical Datum of 1988 (NAVD 88). Download date was 01/29/2020.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Woolpert
Publication_Date: 20150219
Title: New England CMGP Sandy Lidar
Geospatial_Data_Presentation_Form: raster digital data
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Online_Linkage: https://apps.nationalmap.gov/downloader/#/
Type_of_Source_Media: Digital
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 20131116
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation: USGS 1m DEM
Source_Contribution:
Downloaded Digital Elevation Model. Projection was NAD 1983 UTM Zone 19N with the North American Vertical Datum of 1988 (NAVD 88). Download date was 09/11/2020.
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: 2012
Title: USGS National Elevation Dataset (NED) 1/9 arc second
Geospatial_Data_Presentation_Form: raster digital data
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Online_Linkage: https://apps.nationalmap.gov/downloader/#/
Type_of_Source_Media: Digital
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2012
Source_Currentness_Reference: publication date
Source_Citation_Abbreviation: USGS NED
Source_Contribution:
Downloaded NED tiles in geographic coordinate system (NAD83) with the North American Vertical Datum of 1988 (NAVD 88). Download date was 09/11/2020.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Ackerman, K.V., Defne, Z., and Ganju, N.K.
Publication_Date: 2021
Title: Conceptual marsh units of Massachusetts salt marshes
Geospatial_Data_Presentation_Form: Vector Digital Dataset (Polygon)
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Online_Linkage:
https://www.sciencebase.gov/catalog/item/60f992fcd34e3ccd82fe3fbf
Type_of_Source_Media: Digital
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2021
Source_Currentness_Reference: publication date
Source_Citation_Abbreviation: CMU_MA
Source_Contribution:
Used conceptual marsh units to delineate marsh unit boundaries and areas of vegetation.
Process_Step:
Process_Description:
This process step and all subsequent process steps were performed by the same person, Kate Ackerman, 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 square meters (m^2) unless otherwise stated.
a) Set the data frame coordinate system and projection to NAD 1983 UTM Zone 19N.
b) Dissolve the vegetated and unvegetated classes in each marsh unit to have only one class for each marsh unit. DISSOLVE(Input features=[CMU_MA.shp]; Dissolve field=FID_CMU; Statistics field=ATOT_M2 and FLG with Statistics type= First). PROJECT(Input coordinate system=WGS 1984 Web Mercator Auxiliary Sphere; Output coordinate system=NAD 1983 UTM Zone 19N; Geographic transformation=WGS 1984 (ITRF00) to NAD 1983) the feature dataset to obtain dissolved marsh units [mu_diss.shp].
c) Prepare elevation dataset. For the USGS NED tiles: MOSAIC TO NEW RASTER; PROJECT the new raster to NAD_1983_UTM_Zone_19N; and RESAMPLE the new raster to 1m. MOSAIC TO NEW RASTER the USGS 1m DEM tiles. PROJECT the USGS CoNED raster to NAD_1983_UTM_Zone_19N. MOSAIC TO NEW RASTER the USGS CoNED raster, USGS 1m DEM raster, and the USGS NED raster, with the order of precedence: the USGS CoNED, USGS 1m DEM raster, USGS NED raster.
d) Create a rectangular polygon that covers the domain [extent.shp]. CLIP the elevation dataset by the boundaries polygon [elev_mosaic.tif].
Source_Used_Citation_Abbreviation: USGS CoNED
Source_Used_Citation_Abbreviation: USGS 1m DEM
Source_Used_Citation_Abbreviation: USGS NED
Source_Used_Citation_Abbreviation: CMU_MA.shp
Process_Date: 2020
Source_Produced_Citation_Abbreviation: elev_mosaic.tif
Source_Produced_Citation_Abbreviation: mu_diss.shp
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Kate Ackerman
Contact_Organization: U.S. Geological Survey
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing address
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543
Country: US
Contact_Voice_Telephone: 508-548-8700 x2331
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: kackerman@usgs.gov
Process_Step:
Process_Description:
a) Remove pixels from elevation raster that are hydro-flattened. Use FOCAL STATISTICS(Input raster=[elev_mosaic.tif], Output raster=[FocalStats_3x3_range.tif], Neighborhood settings=3x3 cell, Statistics type=range) and RASTER CALCULATOR to identify (Map algebra expression: Con("%FocalStats_3x3_range.tif%" == 0,-1,1); Output raster=[elev_mosaic_One_NegOne.tif]) and remove (Map algebra expression: SetNull("%elev_mosaic_One_NegOne.tif%", "%elev_mosaic.tif%", "value = -1"); Output raster=[elev_mosaic_noHF.tif]) all hydro-flattened areas from [elev_mosaic.tif] to create [elev_mosaic_noHF.tif].
b) Calculate the mean elevation for each marsh unit with ZONAL STATISTICS AS TABLE(Feature zone data=[mu_diss.shp], Zone field=FID_CMU; Input value raster=[elev_mosaic_noHF.tif]; Statistics type=Mean; Output table=[mu]; Ignore Nodata=True). 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.
c) Export dataset as a shapefile [mu_elev.shp] and keep the "mu_MEAN" and "mu_ATOT_M2" fields from the join operation.
d) In [mu_elev.shp], add field (MU_HFAR) to calculate the percent of the marsh unit that has hydro-flattened area. If the percent hydro-flattened area is greater than 25 percent, the marsh unit elevation is set to -9999.
e) Calculate elevation of the vegetated areas only. SELECT BY ATTRIBUTES FROM [CMU_MA.shp] where "TYP"= 'vegetated.' Follow steps (b) to (d) using the selected features to export [veg_elev.shp].
Source_Used_Citation_Abbreviation: elev_mosaic.tif
Process_Date: 2020
Source_Produced_Citation_Abbreviation: mu_elev.shp
Process_Step:
Process_Description:
a) 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" for the fields with the mean elevation for the vegetated area only and mean elevation for the entire marsh unit, respectively. Name fields "AVEG_M2" and "ATOT_M2" for vegetated and total area, respectively; and "MU_HFAR" and "VG_HFAR" for the percent (in decimal form) of the marsh unit, and of the vegetated portion, that has hydro-flattened area, respectively. Set MU_ELEV to -9999 if MU_HFAR is greater than 0.25; set VG_ELEV to -9999 if there is no vegetated area in the marsh unit or if VG_HFAR is greater than 0.25. Export to a new shapefile [mu_Elev_MA.shp].
b) Run Python script (marsv5.py) in ArcPro (v.2.4.1) to calculate metrics that quantify the distribution of marsh unit elevation values. Skewness ("SKWNSS") is the measure of asymmetry 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 skewness values indicate a left-skewed distribution and clustering towards higher elevations. Lower third ("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. If VG_ELEV= -9999, set SKWNESS and LOW3RD values to -9999.
c) SELECT BY ATTRIBUTES from [CMU_MA.shp] where "TYP"= 'vegetated,’ and join field "APGN_M2" from [CMU_MA.shp] to the feature dataset [mu_Elev_MA.shp] and rename this field "AVEG_M2."
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.
Source_Used_Citation_Abbreviation: mu_elev.shp
Process_Date: 2020
Source_Produced_Citation_Abbreviation: mu_elev_MA.shp
Process_Step:
Process_Description:
a) Add field "FLG" to flag anomalous marsh units based on absence of vegetation, elevation, surface area, and tidal range extrapolation. The flags are calculated in their respective shapefile (i.e., elevation flags are calculated in the elevation shapefile). 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 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.
b) 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 19N; Output coordinate system=WGS 1984 Web Mercator Auxiliary Sphere; Geographic transformation=WGS 1984 (ITRF00) to NAD 1983) the feature dataset to obtain the final elevation dataset [mu_Elev_MA.shp].
Process_Date: 2021
Source_Produced_Citation_Abbreviation: mu_Elev_MA.shp
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: 6580
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)
Map_Projection_Parameters:
False_Easting: 0.0
False_Northing: 0.0
Latitude_of_Projection_Origin: 0.0
Longitude_of_Central_Meridian: 0.0
Standard_Parallel: 0.0
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 0.6096
Ordinate_Resolution: 0.6096
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: D_WGS_1984
Ellipsoid_Name: WGS 84
Semi-major_Axis: 6378137.0
Denominator_of_Flattening_Ratio: 298.257223563
Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: mu_Elev_MA.shp Attribute Table
Entity_Type_Definition:
Table containing attribute information associated with the dataset.
Entity_Type_Definition_Source: USGS
Attribute:
Attribute_Label: FID
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: Esri
Attribute_Domain_Values:
Unrepresentable_Domain:
Sequential 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.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 6579
Attribute_Units_of_Measure: none
Attribute:
Attribute_Label: ATOT_M2
Attribute_Definition: Total surface area of a marsh unit.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 185.979591105
Range_Domain_Maximum: 1446641.95436
Attribute_Units_of_Measure: m^2
Attribute:
Attribute_Label: AVEG_M2
Attribute_Definition: Surface area of the vegetated part of a marsh unit.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.0
Range_Domain_Maximum: 1257718.49982
Attribute_Units_of_Measure: m^2
Attribute:
Attribute_Label: MU_ELEV
Attribute_Definition:
Mean elevation of a marsh unit. Value is set to -9999 if MU_HFAR is greater than 0.25. No data value is -9999.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -1.8881
Range_Domain_Maximum: 7.4295
Attribute_Units_of_Measure: meters
Attribute:
Attribute_Label: VG_ELEV
Attribute_Definition:
Mean elevation of the vegetated area in a marsh unit. Value is set to -9999 if there is no vegetated area in the marsh unit. No data value is -9999.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -1.049032
Range_Domain_Maximum: 8.671375
Attribute_Units_of_Measure: meters
Attribute:
Attribute_Label: MU_HFAR
Attribute_Definition:
Percent (in decimal form) of the marsh unit that contains hydro-flattened bathymetric/elevation values.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 1
Attribute_Units_of_Measure: none
Attribute:
Attribute_Label: VG_HFAR
Attribute_Definition:
Percent (in decimal form) of the vegetated portion of the marsh unit that contains hydro-flattened bathymetric/elevation values. No data value is -9999.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 1
Attribute_Units_of_Measure: none
Attribute:
Attribute_Label: SKWNSS
Attribute_Definition:
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 values (left-skewed distribution) indicate clustering towards higher elevations. Values of -9999 indicate no vegetated area within the marsh unit or no elevation value for the vegetated portion. No data value is -9999.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -8.8776
Range_Domain_Maximum: 7.92619
Attribute_Units_of_Measure: none
Attribute:
Attribute_Label: LOW3RD
Attribute_Definition:
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 or no elevation value for the vegetated portion. No data value is -9999.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.009983
Range_Domain_Maximum: 99.8945
Attribute_Units_of_Measure: none
Attribute:
Attribute_Label: FLG
Attribute_Definition:
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.
Attribute_Definition_Source: USGS
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -11010
Range_Domain_Maximum: 0
Attribute_Units_of_Measure: none
Overview_Description:
Entity_and_Attribute_Overview:
In this dataset, mean elevation for each conceptual salt marsh unit in Massachusetts salt marshes has been calculated based on the 1-meter resolution CoNED, USGS 1-meter DEM and the 1-meter resampled 1/9 arc-second horizontal resolution source datasets. 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 and elevation values is assumed to be 1 meter and 0.01 meter, respectively.
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:
mu_Elev_MA.shp (and other files associated with a shapefile), browse graphic (Elev_MA_Browse.png), and CSDGM metadata in XML format.
Distribution_Liability:
Although these data have been processed successfully on a computer system at 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. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. 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, firm, or product 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://www.sciencebase.gov/catalog/file/get/60f9932ed34e3ccd82fe3fcb
Network_Resource_Name:
https://www.sciencebase.gov/catalog/item/60f9932ed34e3ccd82fe3fcb
Network_Resource_Name: https://doi.org/10.5066/P97E086F
Access_Instructions:
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.
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/60f9932ed34e3ccd82fe3fcb?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/60f9932ed34e3ccd82fe3fcb?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 dataset.
Metadata_Reference_Information:
Metadata_Date: 20210929
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Kate V. Ackerman
Contact_Organization: U.S. Geological Survey
Contact_Position: Geologist
Contact_Address:
Address_Type: mailing address
Address: 384 Woods Hole Rd
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543
Country: US
Contact_Voice_Telephone: 508-548-8700 x2331
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: kackerman@usgs.gov
Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/SB_data_release/DR_P97E086F/mu_Elev_MA.html>
Generated by mp version 2.9.50 on Fri Oct 8 17:53:53 2021