Metadata: Identification_Information: Citation: Citation_Information: Originator: Rachel Stevens, Great Bay National Estuarine Research Reserve, Stewardship Coordinator and Wildlife Ecologist Publication_Date: 20230301 Title: SaltMarshMetrics2022 Geospatial_Data_Presentation_Form: vector digital data Other_Citation_Details: New Hampshire Salt Marsh Plan: A Guide for Sustaining Tidal Marshes Description: Abstract: Efficient stewardship of tidal wetlands requires robust comparative assessments of different marshes to understand their resilience to stressors, particularly in the face of relative sea level rise. To address this need, NH Fish and Game and the Great Bay National Estuarine Research Reserve developed a framework based on three elements of marsh resilience: current condition, vulnerability to sea level rise, and adaptation potential. In collaboration with other agencies and academics, we identified a set of metrics that influence resilience and then calculated a score for each element of resilience as well as an overall resilience score. Purpose: NH salt marsh units with metrics of resilience comparing, across marshes, the current condition, vulnerability to sea level rise, and adaptation potential. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20221207 Ending_Date: 20230301 Currentness_Reference: NH coast Status: Progress: Complete Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -70.952570 East_Bounding_Coordinate: -70.709717 North_Bounding_Coordinate: 43.217864 South_Bounding_Coordinate: 42.861849 Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: GBNERR Access_Constraints: None Use_Constraints: Intended for general planning purposes, not for legal use. Data_Set_Credit: NH Fish and Game Department and the Great Bay National Estuarine Research Reserve. Native_Data_Set_Environment: Version 6.2 (Build 9200) ; Esri ArcGIS 10.9.1.28388 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains Point_and_Vector_Object_Count: 224 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Map_Projection: Map_Projection_Name: NAD 1983 StatePlane New Hampshire FIPS 2800 Feet Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9999666666666667 Longitude_of_Central_Meridian: -71.66666666666667 Latitude_of_Projection_Origin: 42.5 False_Easting: 984250.0 False_Northing: 0.0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 0.0003280833333333333 Ordinate_Resolution: 0.0003280833333333333 Planar_Distance_Units: foot_us Geodetic_Model: Horizontal_Datum_Name: D North American 1983 Ellipsoid_Name: GRS 1980 Semi-major_Axis: 6378137.0 Denominator_of_Flattening_Ratio: 298.257222101 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: SaltMarshMetrics2022 Attribute: Attribute_Label: OBJECTID 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: NH_Clump_ID Attribute_Definition: Unique identifier for each marsh unit Attribute_Definition_Source: NOAA (July 2019) Attribute: Attribute_Label: Marsh_Name Attribute_Definition: Name commonly used for the marsh unit Attribute_Definition_Source: GBNERR Attribute: Attribute_Label: Town Attribute_Definition: Town within which the largest portion of the marsh unit is located Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Region Attribute_Definition: Region within the NH seacoast having broadly similar tidal regime Attribute_Definition_Source: GBNERR Attribute: Attribute_Label: DES_Code Attribute_Definition: n/a Attribute_Definition_Source: NHDES Attribute: Attribute_Label: Acres Attribute_Definition: Size of the marsh unit Attribute_Definition_Source: calculated in ArcGIS Attribute: Attribute_Label: Coreedge Attribute_Definition: Computed as marsh unit area / edge length for each marsh unit. A low value represents more edge which means exposure and increased risk of loss, and is a negative. Attribute_Definition_Source: NOAA Attribute: Attribute_Label: UVVR Attribute_Definition: Computed as the Unvegetated area / Vegetated area within each marsh unit. Computed using the marsh extent layer OCM generated as part of the marsh habitat mapping project because it includes the non-vegetated classes. Polygons were derived from the raw marsh clump dataset with a 10 meter buffer to enclose/capture small pannes, pools, and creeks that were not included in the marsh polygons. A low value represents more vegetation and is a positive, while a high value indicates higher amount of unvegetated surface and is a negative. Attribute_Definition_Source: NOAA Attribute: Attribute_Label: PercImpervious Attribute_Definition: Percent impervious cover within 150 meter buffer of each marsh unit. Computed using “Impervious Surfaces in the Coastal Watershed of NH and Maine, High Resolution – 2021” (NH GRANIT). A high value represents more impervious cover and potentially polluted runoff that can negatively impact marsh habitat. Attribute_Definition_Source: NHFG Attribute: Attribute_Label: PercNatural Attribute_Definition: Percent natural cover within 150 meter buffer of each marsh unit. Computed using NOAA 2016 C-CAP BETA 10m land cover data and derived from all the natural cover classes. A high value represents more natural cover that can absorb runoff and filter pollutants and is a positive. Attribute_Definition_Source: NOAA Attribute: Attribute_Label: PercAgriculture Attribute_Definition: Percent agricultural cover within 150 meter buffer of each marsh unit. Computed using NH 2015 Land Use data and derived from the "Agricultural Land" and "Other Agricultural Land" classes. A high value can result in more potentially polluted runoff and is a negative. Attribute_Definition_Source: NOAA Attribute: Attribute_Label: TEspecies Attribute_Definition: Count number of different species of rare animals and plants within the marsh unit (occurrences provided by NH Natural Heritage Bureau, Dec. 2022). Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Nitrogen Attribute_Definition: Estimated from water quality samples. Computed by intersecting marsh units with USGS SPARROW catchments, calculated the area-weighted average of the “tn” value. Attribute_Definition_Source: NHFG Attribute: Attribute_Label: DitchDensity Attribute_Definition: Computed as a line density raster dataset (feet per acre); and the metric represents the maximum value for any portion of the marsh unit (ditch presence verified using recent orthophotos). Value increases with ditch density, and is a negative. Attribute_Definition_Source: NHFG Attribute: Attribute_Label: PercPhrag Attribute_Definition: Computed as percent area of each marsh unit, using the data layer “nh_salt_marsh_habitats_20191010_Phrag_only”. Value increases with higher potential impact from invasive plants, and is a negative. Attribute_Definition_Source: UNH Attribute: Attribute_Label: HabitatDiversity Attribute_Definition: Computed Shannon diversity index based on habitat types mapped in the data layer “nh_2013_salt_marsh_habitats_20200123” within each marsh unit. The value, Shannon index, increases as both the richness and the evenness of the community increase, and is a positive. Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Berms Attribute_Definition: Computed as the proportion of migration space immediately adjacent to marsh unit boundary that has berms present. Berms are based on TPI, derived from the LiDAR DEM using a raster calculator equation: ("tpi" > 0.1) & ("slopedeg" < 8), where tpi = elevation – focal mean of elevation in a 8x8 neighborhood. Marsh units buffered by 16m and clipped to migration space, measured amount of berm area in that resulting area. Value increases with berm presence and is a negative. Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Erodibility Attribute_Definition: Computed by averaging the "AVG_KFACT" attribute from the Area- and Depth-Weighted Averages of Selected SSURGO Variables for the Conterminous United States and District of Columbia data set across soil units contained in the MUPOLYGON feature class from the gSSURGO database. It is a unitless erodibility factor ranging from 0 to 0.64, which quantifies the susceptibility of soil particles to detachment by water. Soils resistant to detachment have low values < 0.15 and erodible soils that easily detach have values > 0.4. This metric is a Negative, higher erodibility indicates higher vulnerability and lower resilience. Attribute_Definition_Source: NOAA Attribute: Attribute_Label: TidalRange Attribute_Definition: Mean tidal range computed for each marsh unit. Units are meters. Tidal range values represent the height from Mean Lower Low Water to Mean Higher High Water as derived from NOAA's Vdatum model. Higher value indicates larger tidal range and better resilience, it is a Positive. Attribute_Definition_Source: NOAA Attribute: Attribute_Label: PercMHHW Attribute_Definition: Percent of marsh unit below Mean Higher High Water (MHHW). Computed using tidal surface generated from NOAA's Vdatum model. It is a Negative - more area below MHHW indicates higher vulnerability and lower resilience. Attribute_Definition_Source: NOAA Attribute: Attribute_Label: PercMTL Attribute_Definition: Percent of marsh unit below Mean Tide Level (MTL). Computed using tidal surface generated from NOAA's Vdatum model. It is a Negative. Attribute_Definition_Source: NOAA Attribute: Attribute_Label: PercHardShoreNH Attribute_Definition: Percent of shoreline within marsh unit that is hardened. Computed by dividing the length of New Hampshire’s shorelinestructureinventory.shp by the length NHShoreline.shp contained within a 10 meter buffered version of each marsh unit. Higher value indicates more impediment to migration, and is a negative. Attribute_Definition_Source: NOAA Attribute: Attribute_Label: MigrationSpace Attribute_Definition: Migration space represents the area into which marsh units may migrate under future sea level rise scenarios. Unioned marsh units with the 2022 SLAMM results ("salt marsh persistent" and "salt marsh potential" status for the 1.5 meter SLR by 2100 scenario which represents the high end of the range for this region). Calculated area (sq. meters) contiguous with each marsh unit. Higher value indicates marsh persistence, and is a positive. Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Connectedness Attribute_Definition: This represents the degree to which each marsh unit will be connected to adjacent marsh units under future sea level rise scenarios. This was computed by using the combined 2025, 2050, and 2075 marsh migration areas (persistent and potential) under the 2-meter SLR scenario and counting the number of connections with adjacent marsh units. The count was scaled by the total lengths of the connections for each marsh unit. Higher value indicates better connectedness and is a positive. Attribute_Definition_Source: NOAA Attribute: Attribute_Label: Sinuosity Attribute_Definition: The sinuosity of shoreline within each marsh unit. (from Anderson and Barnett, 2017: "An intricate shoreline with lots of inlets and variable physical characteristics provides diverse habitat options and harbors greater ecological diversity than a simple shoreline, and creates resilience by dividing and distributing inundation levels." Computed using NOAA's Environmental Sensitivity Index shoreline and the Sinuosity python script provided by Esri, using ESI shoreline segments intersected with 10m buffered marsh units. Since the sinuosity script generates values from 0-1, Data Notes for the New Hampshire Salt Marsh Plan, April 2023 page 6 where 1 is a straight feature, we multiplied the sinuosity index by -1 so that values closer to 0 were scored higher in the quantile index. A value closer to 0 is a more complex shoreline, and is a positive. Attribute_Definition_Source: NOAA Attribute: Attribute_Label: Score_Condition Attribute_Definition: Higher score = Good current condition, higher resilience on scale 1-100 Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Score_Vulnerability Attribute_Definition: Higher score = More vulnerable, lower resilience on scale 1-100 Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Score_Adaptation Attribute_Definition: Higher score = More adaptation potential, higher resilience on scale 1-100 Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Overall_Score Attribute_Definition: Equally weighted sum of Condition + Vulnerability(inverted) + Adaptation. High Score = high overall resilience, good condition, low vulnerability, more adaptation potential Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Condition Attribute_Definition: high/low designation indicates whether the marsh unit is in the top half or lower half of all marshes in NH based on the current condition score Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Vulnerability Attribute_Definition: high/low designation indicates whether the marsh unit is in the top half or lower half of all marshes in NH based on the vulnerability score Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Adaptation Attribute_Definition: high/low designation indicates whether the marsh unit is in the top half or lower half of all marshes in NH based on the adaptation potential score Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Feasibility Attribute: Attribute_Label: MarshMgt Attribute_Definition: concatenation of Condition-Vulnerability-Adaption Attribute_Definition_Source: NHFG Attribute: Attribute_Label: HighMarshAc Attribute_Definition: acres of high marsh habitat in the marsh unit Attribute_Definition_Source: Habitat characterizations are based on NOAA’s high resolution tidal habitat data collected in 2013 Attribute: Attribute_Label: LowMarshAc Attribute_Definition: acres of low marsh habitat in the marsh unit Attribute_Definition_Source: Habitat characterizations are based on NOAA’s high resolution tidal habitat data collected in 2013 Attribute: Attribute_Label: VegAcres Attribute_Definition: total vegetated area in the marsh unit Attribute_Definition_Source: Habitat characterizations are based on NOAA’s high resolution tidal habitat data collected in 2013 Attribute: Attribute_Label: PctHigh Attribute_Definition: Percent of the vegetated marsh area that is high marsh habitat Attribute_Definition_Source: NHFG Attribute: Attribute_Label: PctLow Attribute_Definition: Percent of the vegetated marsh area that is low marsh habitat Attribute_Definition_Source: NHFG Attribute: Attribute_Label: SQMETERS Attribute_Definition: overall size of the marsh unit in square meters Attribute_Definition_Source: calculated in ArcGIS Attribute: Attribute_Label: UVVR2100 Attribute_Definition: Computed as the Unvegetated area / Vegetated area within each marsh unit estimated for the year 2100 at intermediate sea level rise. Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Quantile_Condition Attribute: Attribute_Label: Shape_Length Attribute_Definition: Length of feature in internal units. Attribute_Definition_Source: Esri Attribute_Domain_Values: Unrepresentable_Domain: Positive real numbers that are automatically generated. Attribute: Attribute_Label: Shape_Area Attribute_Definition: Area of feature in internal units squared. Attribute_Definition_Source: Esri Attribute_Domain_Values: Unrepresentable_Domain: Positive real numbers that are automatically generated. Attribute: Attribute_Label: Quantile_Vulnerability Attribute_Definition: For each metric, NH Fish and Game calculated decile breaks to create 10 equal bins within the raw data, and then assigned a rank score to each marsh unit based on the corresponding bin: 1-10. We multiplied metrics with a negative impact by negative 1, so that scores within an element (Condition, Vulnerability or Adaptation) are on a consistent scale, e.g., from poor condition to good condition. For example, a high percentage of phragmites was transformed to a low decile score so that it would correspond with poor condition and low resilience. Quantile scores are available within the attribute table accessible through Data Viewer to enable users to learn more about an individual marsh and see how it compares to other marshes in NH. Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Quantile_Adaptation Attribute_Definition: For each metric, NH Fish and Game calculated decile breaks to create 10 equal bins within the raw data, and then assigned a rank score to each marsh unit based on the corresponding bin: 1-10. We multiplied metrics with a negative impact by negative 1, so that scores within an element (Condition, Vulnerability or Adaptation) are on a consistent scale, e.g., from poor condition to good condition. For example, a high percentage of phragmites was transformed to a low decile score so that it would correspond with poor condition and low resilience. Quantile scores are available within the attribute table accessible through Data Viewer to enable users to learn more about an individual marsh and see how it compares to other marshes in NH. Attribute_Definition_Source: NHFG Attribute: Attribute_Label: Quantile_Overall Attribute: Attribute_Label: QUANTILE_coreedge Attribute: Attribute_Label: QUANTILE_uvvr Attribute: Attribute_Label: QUANTILE_uvvr2100 Attribute: Attribute_Label: QUANTILE_pctimp Attribute: Attribute_Label: QUANTILE_pctnat Attribute: Attribute_Label: QUANTILE_pctag Attribute: Attribute_Label: QUANTILE_tespecies Attribute: Attribute_Label: QUANTILE_nitrogen Attribute: Attribute_Label: QUANTILE_ditches Attribute: Attribute_Label: QUANTILE_pctphrag Attribute: Attribute_Label: QUANTILE_habdiv Attribute: Attribute_Label: QUANTILE_berms Attribute: Attribute_Label: QUANTILE_erod Attribute: Attribute_Label: QUANTILE_tidalrange Attribute: Attribute_Label: QUANTILE_mhhw Attribute: Attribute_Label: QUANTILE_mtl Attribute: Attribute_Label: QUANTILE_hardshore Attribute: Attribute_Label: QUANTILE_migspace Attribute: Attribute_Label: QUANTILE_connected Attribute: Attribute_Label: QUANTILE_sinu Metadata_Reference_Information: Metadata_Date: 20230530 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: NH Fish and Game Department Contact_Person: Catherine Callahan Contact_Position: GIS Coordinator Contact_Address: Address_Type: mailing and physical Address: 11 Hazen Dr City: Concord State_or_Province: NH Postal_Code: 03301 Country: US Contact_Voice_Telephone: 603-271-3014 Contact_Electronic_Mail_Address: Catherine.B.Callahan@doit.nh.gov Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Time_Convention: local time