Description: 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". The Center for Coastal Resources Management (CCRM) at the Virginia Institute of Marine Science (VIMS) has been developing tools for many 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 (BMPs) when conducting onsite inspections. These were developed to support integrated guidance at the management and regulatory level. 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 BMPs 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. In 2023, CCRM began an update of the SMM. Version 6.0 continues to use fetch, nearshore bathymetry, bank height, marsh presence, beach presence, presence of submerged aquatic vegetation (SAV), roads and permanent structures within the riparian zone, and existing shoreline erosion control structures. To enhance the model’s capabilities for evaluating best management practices and determining where erosion control practices may impact ecologically sensitive areas, version 6.0 adds federal navigation channels, presence of RTE species via predicted suitable habitat, bank slope, and narrow creeks. 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 ArcGIS file geodatabase.
Copyright Text: This project has been funded wholly or in part by The Virginia Department of Environmental Quality, Virginia Coastal Zone Management Program Grant # NA24NOSX419C0026.
Description: The Virginia Shoreline Inventory is a series of reports and data that describe the condition of tidal shorelines for individual localities in the Commonwealth of Virginia. This inventory series started with historic reports produced in the 1970’s. It also includes contemporary digital inventory updates generated from 1998 to the present using a combination of Geographic Information Systems (GIS), Global Positioning System (GPS), and remote sensing technology.One of the conditions described in the inventories is the distribution of structures that are used for recreational activities (i.e., Private Boat Ramps, public Boat Ramps, Community Docks, Docks/Piers, Dilapidated Docks/Piers, Jetty, Marinas greater/less than 50 slips, and Wharfs. In addition to this, the spatial extent of marinas, wharfs and jetties is also described in this inventory.
Copyright Text: This project has been funded wholly or in part by The Virginia Department of Environmental Quality, Virginia Coastal Zone Management Program Grant # NA24NOSX419C0026.
Description: The Virginia Shoreline Inventory is a series of reports and data that describe the condition of tidal shorelines for individual localities in the Commonwealth of Virginia. This inventory series started with historic reports produced in the 1970’s. It also includes contemporary digital inventory updates generated from 1998 to the present using a combination of Geographic Information Systems (GIS), Global Positioning System (GPS), and remote sensing technology.One of the conditions described in the inventories is the distribution of beaches and dunes.
Copyright Text: This project has been funded wholly or in part by The Virginia Department of Environmental Quality, Virginia Coastal Zone Management Program Grant # NA23NOS4190255.
Description: The Virginia Shoreline Inventory is a series of reports and data that describe the condition of tidal shorelines for individual localities in the Commonwealth of Virginia. This inventory series started with historic reports produced in the 1970’s. It also includes contemporary digital inventory updates generated from 1998 to the present using a combination of Geographic Information Systems (GIS), Global Positioning System (GPS), and remote sensing technology. One of the conditions described in the inventories is the spatial extent and distribution of hardened shoreline structures that are used for erosion control (i.e., revetment, sills, bulkheads, breakwaters, groins, unconventional, oyster structures, and dilapidated bulkheads), as well as living shoreline treatments (breakwater with beach nourishment, marsh with sill, marsh with oyster structures [oyster bags, manufactured, natural materials], constructed oyster reefs, and coir logs).
Copyright Text: This project has been funded wholly or in part by The Virginia Department of Environmental Quality, Virginia Coastal Zone Management Program Grant # NA24NOSX419C0026.
Description: The boundary between the water and upland. Where there is marsh, it is the boundary between the marsh and water, if there is beach it is between beach and water (high tideline).
Copyright Text: This project has been funded wholly or in part by The Virginia Department of Environmental Quality, Virginia Coastal Zone Management Program Grant # NA23NOS4190255.
Description: Upland Shoreline is the boundary between the water and upland. Where marshes exist, it is the upland edge of the tidal marsh, or where beaches exist, the upland edge of the beach. Also referred to as the baseline shoreline, it is not a tidally referenced or surveyed demarcation. It is the baseline on which the land use and bank condition is coded.
Copyright Text: This project has been funded wholly or in part by The Virginia Department of Environmental Quality, Virginia Coastal Zone Management Program Grant # NA23NOS4190255.
Description: The Virginia Institute of Marine Science published the first Tidal Marsh Inventories in Virginia using data collected in the early 1970's. In 2010, a new iteration of the Virginia Tidal Marsh Inventory began using high-resolution color imagery from the Virginia Base Map Program (VBMP) (2009, 2011, 2013, and 2017). Marsh boundaries were generated using heads-up digitizing techniques at a scale of 1:1,000. From 2010 through 2014 marsh polygons were classified by morphologic type: fringe, extensive, embayed, or marsh island. Beginning in 2015, morphologic classification was discontinued. Marshes were ground-truthed in the field where a community type index was assigned to each marsh based on plant community make-up.In 2023, a third iteration of the Virginia Tidal Marsh Inventory began in conjunction with the shoreline inventory update. This latest phase employs advanced remote sensing techniques, utilizing the most recent VBMP imagery and ESRI ArcGIS Pro software to map marsh boundaries (updated marsh extent and distribution). While historical plant community data was retained for existing marshes, newly identified marshes were initially classified as having an "undetermined" plant community type. This classification was only updated if high-resolution aerial imagery or drone-based photography provided conclusive evidence of the specific plant communities present.
Copyright Text: This project has been funded wholly or in part by The Virginia Department of Environmental Quality, Virginia Coastal Zone Management Program Grant # NA23NOS4190255.
Description: The Virginia Shoreline Inventory is a series of reports and data that describe the condition of tidal shorelines for individual localities in the Commonwealth of Virginia. This inventory series started with historic reports produced in the 1970’s. It also includes contemporary digital inventory updates generated from 1998 to the present using a combination of Geographic Information Systems (GIS), Global Positioning System (GPS), and remote sensing technology.
Copyright Text: This project has been funded wholly or in part by The Virginia Department of Environmental Quality, Virginia Coastal Zone Management Program Grants # NA23NOS4190255 and # NA24NOSX419C0026.
Description: The Virginia Shoreline Inventory is a series of reports and data that describe the condition of tidal shorelines for individual localities in the Commonwealth of Virginia. This inventory series started with historic reports produced in the 1970’s. It also includes contemporary digital inventory updates generated from 1998 to the present using a combination of Geographic Information Systems (GIS), Global Positioning System (GPS), and remote sensing technology. One of the conditions described in the inventories is the spatial extent and distribution of hardened shoreline structures that are used for erosion control (i.e., revetment, sills, bulkheads, breakwaters, groins, unconventional, oyster structures, and dilapidated bulkheads), as well as living shoreline treatments (breakwater with beach nourishment, marsh with sill, marsh with oyster structures [oyster bags, manufactured, natural materials], constructed oyster reefs, and coir logs).
Copyright Text: This project has been funded wholly or in part by The Virginia Department of Environmental Quality, Virginia Coastal Zone Management Program Grant # NA24NOSX419C0026.
Description: There are four marsh migration models incorporated into this layer. NOAA generated raster data layers using three models (SLAMM, InVEST, NOAA). This raster showed where marsh migration was predicted to occur for a water level rise of two feet according to each of these three models. The Evolution of Tidal Marsh (ETM) marsh migration model which VIMS produced was then overlaid on top of this. The ETM rasters represent successive tidal ranges of two feet of elevation, incremented by 0.5 feet, i.e. 0-2 ft, 0.5-2.5 ft, 1-3 ft, etc.). From the ETM analysis, the tidal range layer was used which had a 2 foot water rise as a midpoint in the tidal range. The raster from ETM was overlaid on the raster from the NOAA analysis. Raster cells were classified by the number of models overlaid on a given cell. Cells overlaid by all four models were given a score of 4, cells overlaid by three models were given a score of 3, cells overlaid by two models were given a score of 2, and cells overlaid by one model were given a score of 1. This data layer was then clipped to locality boundarys. In this analysis, developed lands (Developed, Medium Intensity and Developed, High Intensity categories from the National Land Cover Dataset) were considered to be unsuitable for future marsh migration and were excluded from the final output.A series of post-processing steps were taken to eliminate stray isolated raster cells and the raster was converted to polygons. Only marsh clusters which intersected tidal marsh (CCRM Tidal Marsh Inventory) and nontidal wetlands adjacent to it were extracted for the final output. The polygons were processed through the Smooth Polygon tool in ArcGIS Pro to improve appearance while retaining spatial integrity.
Copyright Text: Marsh Migration Corridor Envelope for Maryland and Virginia (https://hub.arcgis.com/documents/ChesBay::marsh-migration-corridor-envelope-for-maryland-and-virginia/about, October 2023) Migration of the Tidal Marsh Range Under Sea Level Rise for Coastal Virginia, with Land Cover Data (https://scholarworks.wm.edu/data/444/, Mitchell and Herman, July 2021)
https://www.vims.edu/ccrm/research/inventory/
https://www.fws.gov/program/national-wetlands-inventory
Description: There are four marsh migration models incorporated into this layer. NOAA generated raster data layers using three models (SLAMM, InVEST, NOAA). This raster showed where marsh migration was predicted to occur for a water level rise of four feet according to each of these three models. The Evolution of Tidal Marsh (ETM) marsh migration model which VIMS produced was then overlaid on top of this. The ETM rasters represent successive tidal ranges of two feet of elevation, incremented by 0.5 feet, i.e. 0-2 ft, 0.5-2.5 ft, 1-3 ft, etc.). From the ETM analysis, the tidal range layer was used which had a 4 foot water rise as a midpoint in the tidal range. The raster from ETM was overlaid on the raster from the NOAA analysis. Raster cells were classified by the number of models overlaid on a given cell. Cells overlaid by all four models were given a score of 4, cells overlaid by three models were given a score of 3, cells overlaid by two models were given a score of 2, and cells overlaid by one model were given a score of 1. This data layer was then clipped to locality boundarys. In this analysis, developed lands (Developed, Medium Intensity and Developed, High Intensity categories from the National Land Cover Dataset) were considered to be unsuitable for future marsh migration and were excluded from the final output.A series of post-processing steps were taken to eliminate stray isolated raster cells and the raster was converted to polygons. Only projected marsh migration polygons which intersected tidal marsh (CCRM Tidal Marsh Inventory) and nontidal wetlands (National Wetlands Inventory) adjacent to it were extracted for the final output. The polygons were processed through the Smooth Polygon tool in ArcGIS Pro to improve appearance while retaining spatial integrity.
Copyright Text: Marsh Migration Corridor Envelope for Maryland and Virginia (https://hub.arcgis.com/documents/ChesBay::marsh-migration-corridor-envelope-for-maryland-and-virginia/about, October 2023) Migration of the Tidal Marsh Range Under Sea Level Rise for Coastal Virginia, with Land Cover Data (https://scholarworks.wm.edu/data/444/, Mitchell and Herman, July 2021)
https://www.vims.edu/ccrm/research/inventory/
https://www.fws.gov/program/national-wetlands-inventory