Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P STYLE="margin:7 0 7 0;"><SPAN><SPAN>In 2011, the Virginia General Assembly adopted a policy into law that specifies living shorelines as the preferred management practice for erosion control in Virginia waters. In accordance with the law, the Commonwealth defines a living shoreline as ... "... a shoreline management practice that provides erosion control and water quality benefits; protects, restores or enhances natural shoreline habitat; and maintains coastal processes through the strategic placement of plants, stone, sand fill, and other structural and organic materials".</SPAN></SPAN></P><P STYLE="margin:7 0 7 0;"><SPAN /><SPAN /></P><P STYLE="margin:7 0 7 0;"><SPAN><SPAN>The Center for Coastal Resources Management (CCRM) at the Virginia Institute of Marine Science (VIMS) has been developing tools for several years to guide local governments in shoreline management. In particular, they have focused on the use of ecologically preferred alternatives for erosion control and have conducted research into refining the appropriate uses for a large suite of possible treatments based on existing shoreline conditions. A series of Decision Trees were developed to determine shoreline best management practices when conducting onsite inspections. These were developed to support integrated guidance at the management and regulatory level.</SPAN></SPAN></P><P STYLE="margin:7 0 7 0;"><SPAN /><SPAN /></P><P STYLE="margin:7 0 7 0;"><SPAN><SPAN>This body of work has been expanded and re-developed as a GIS spatial model known as the Shoreline Management Model (SMM) to determine appropriate shoreline best management practices from the desk-top using available spatial data and the decision tree logic. The assessment is conducted at parcel level scale but the output represents a reach based or cumulative approach to shoreline management. The variables used in the SMM include fetch, nearshore bathymetry, bank condition, bank height, marsh presence, beach presence, tree canopy presence, and permanent structures within the riparian zone. Version 5 adds existing shoreline erosion control structures, and the presence of submerged aquatic vegetation (SAV) to enhance the models capabilities for evaluating best management practices along shorelines that have already been hardened or where erosion control practices may impact SAV.</SPAN></SPAN></P><P STYLE="margin:7 0 7 0;"><SPAN /><SPAN /></P><P STYLE="margin:7 0 7 0;"><SPAN>Most appropriate for desk-top reviews, regulatory compliance and comprehensive planning, the recommendations derived from the SMM may be altered due to lot size, shoreline length along a single parcel, proximity of primary buildings to the shoreline, type of existing erosion control structures, land use practices, and local biota. The output of the SMM is delivered to the end user in two ways: interactive map viewer, and digital shape file.</SPAN></P><P STYLE="margin:7 0 7 0;"><SPAN /></P><P STYLE="margin:7 0 7 0;"><SPAN>Mobjack Bay has been pulled out from the original SMM v5.1 run in 2019 and rerun to provide reccommendations in areas previously classified as 'Ecological Conflicts'. Original classification is still provided.</SPAN></P></DIV></DIV></DIV>
Copyright Text: Center for Coastal Resources Management (CCRM), Virginia Institute of Marine Science (VIMS),
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This layer was generated by combining the VIMS Shoreline Studies Erosion Rates from 1937-2009 (Hardaway, Jr. et al. 2020) with the NOAA Coastal Resilience water interface shoreline (\\ccrmspace\ccrm\NOAACoastalResilience\GIS\Data\Shorelines\water_interface_shl\allVA_waterinterface_line_noboundaries.shp). The shoreline layer was first dissolved into a single multipart shoreline, and then split into 10 m segments using the QGIS v3.24 "Split lines by maximum distance" tool. The erosion rate points were then joined to their nearest shoreline segment, with a maximum search distance of 500 m. Shoreline segments greater than 500 m from the nearest erosion rate point were manually assigned a rate of -0.03 m/yr based on work done by Cielomar Rodriguez for her dissertation at VIMS. The 3 cm/year loss will only be valid in small creeks, and should not be used for the Seaside Eastern Shore or any shoreline along larger bodies of water (e.g., the Pamunkey River). The field "EPR_Mtr" is the erosion rate in meters. Segments where fields "n" and "distance" == 0 are where the line segments were more than 500 m from the nearest EPR point, and were therefore assigned a value of -0.03 m/yr.</SPAN></P></DIV></DIV></DIV>
Copyright Text: Jessica Hendricks - NOAA Coastal Resilience shoreline layer
Hardaway et al. - Erosion Rates
Robert Isdell - this layer
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>Attribution for these Virginia parcels is limited to locality identification and parcel id. Tax parcel boundaries have not been edge-matched across municipal boundaries. The boundaries are intended for cartographic use and spatial analysis only, and not for use as legal descriptions or property surveys. Not all localities within the Commonwealth of Virginia have a digital record for parcel geography.</SPAN></P></DIV></DIV></DIV>
Copyright Text: Virginia Geographic Information Network (VGIN), Virginia local government GIS
Description: The Watershed Boundary Dataset (WBD) is a comprehensive aggregated collection of hydrologic unit data consistent with the national criteria for delineation and resolution. It defines the areal extent of surface water drainage to a point except in coastal or lake front areas where there could be multiple outlets as stated by the "Federal Standards and Procedures for the National Watershed Boundary Dataset (WBD)" “Standard” (http://pubs.usgs.gov/tm/11/a3/). Watershed boundaries are determined solely upon science-based hydrologic principles, not favoring any administrative boundaries or special projects, nor particular program or agency. This dataset represents the hydrologic unit boundaries to the 12-digit (6th level) for the entire United States. Some areas may also include additional subdivisions representing the 14- and 16-digit hydrologic unit (HU). At a minimum, the HUs are delineated at 1:24,000-scale in the conterminous United States, 1:25,000-scale in Hawaii, Pacific basin and the Caribbean, and 1:63,360-scale in Alaska, meeting the National Map Accuracy Standards (NMAS). Higher resolution boundaries are being developed where partners and data exist and will be incorporated back into the WBD. WBD data are delivered as a dataset of polygons and corresponding lines that define the boundary of the polygon. WBD polygon attributes include hydrologic unit codes (HUC), size (in the form of acres and square kilometers), name, downstream hydrologic unit code, type of watershed, non-contributing areas, and flow modifications. The HUC describes where the unit is in the country and the level of the unit. WBD line attributes contain the highest level of hydrologic unit for each boundary, line source information and flow modifications.
Copyright Text: Funding for the Watershed Boundary Dataset (WBD) was provided by the USDA-NRCS, USGS and EPA along with other federal, state and local agenciesies. Representatives from many agencies contributed a substantial amount of time and salary towards quality review and updating of the dataset in order to meet the WBD Standards. Acknowledgment of the originating agencies would be appreciated in products derived from these data. See dataset specific metadata for further information
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>Geospatial layers were collected for each of the four habitat suitability factors identified as important for oyster growth and survival: salinity, substrate, wave energy, and bathymetry. Each layer was clipped and projected onto 1-meter grid cell covering the Mobjack Bay study area. Each grid cell contains a score value for each layer. Scores for the salinity and substrate layers were assigned so that unsuitable sites were excluded from the analysis. Scores for wave energy and bathymetry were assigned based on threshold values that affect the type of oyster structure suitable for that location. The suitability of each 1-meter cell was calculated by multiplying the scores for each of the four suitability layers, and the resulting overall score indicates whether the location is 1) suitable and 2) what type of oyster structure would be most appropriate based on bathymetry and wave energy. Suitable cells were exported to polygons, and areas with important management considerations (SAV beds, private lease areas, and Baylor grounds) are flagged.</SPAN></P></DIV></DIV></DIV>
Copyright Text: Center for Coastal Resources Management (CCRM) at the Virginia Institute of Marine Science