Metadata: Identification_Information: Citation: Citation_Information: Originator: Neil K. Ganju Originator: Kate V. Ackerman Originator: Zafer Defne Publication_Date: 20250924 Title: Projections of vegetated area and vegetated plain elevation in Chesapeake Bay salt marsh units Edition: 1.0 Geospatial_Data_Presentation_Form: comma separated text files (.csv) Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P1ASOF7N 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 Other_Citation_Details: Suggested citation: Ganju, N.K., Ackerman, K.V., and Defne, Z., 2025, Projections of vegetated area and vegetated plain elevation in Chesapeake Bay salt marsh units: U.S. Geological Survey data release, https://doi.org/10.5066/P1ASOF7N. Online_Linkage: https://doi.org/10.5066/P1ASOF7N Online_Linkage: https://www.sciencebase.gov/catalog/item/67ea9dc8d34ed02007f8335b Description: Abstract: Projections of vegetated area and vegetated plain elevation for salt marsh units within the Chesapeake Bay (CB) salt marsh complex are calculated using geospatial information for conceptual marsh units defined by Ackerman and others (2022) and Defne and others (2023). The projections are based on the UBMorph model, described in Ganju and others (2025), which estimates changes in areal cover and elevation due to open-water expansion and sea-level rise (SLR). Sea-level rise rate predictions are implemented at constant rates of 3, 5, 7, and 10 mm/y, beginning in 2010, along with two time-varying cases corresponding to a linear decadal increase in rate from 3 to 12 mm/y and an “upper end of likely range limit” scenario described by Ganju and others (2025). 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, including the Chesapeake Bay salt marshes, 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. References: Ackerman, K.V., Defne, Z., and Ganju, N.K., 2022, Geospatial characterization of salt marshes in Chesapeake Bay: U.S. Geological Survey data release, https://doi.org/10.5066/P997EJYB. Defne, Z., Ganju, N.K., and Ackerman, K.V., 2023, Lifespan of Chesapeake Bay salt marsh units: U.S. Geological Survey data release, https://doi.org/10.5066/P9FSPWSF. Ganju, N.K., Ackerman, K.V., Defne, Z., Mariotti, G., Curson, D., Posnik, Z., Carr, J.A., and Grand, J., 2025, A Simple Predictive Model for Salt Marsh Internal Deterioration Under Sea-Level Rise and Sediment Deficits: Application to Chesapeake Bay: Estuaries and Coasts 48, 178, https://doi.org/10.1007/s12237-025-01618-w. Purpose: The purpose of this set of tables is to present projections of vegetated area and vegetated plain elevation for each marsh unit in the Chesapeake Bay. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2025 Currentness_Reference: publication date Status: Progress: Complete Maintenance_and_Update_Frequency: None Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -77.3747 East_Bounding_Coordinate: -75.5934 North_Bounding_Coordinate: 39.5898 South_Bounding_Coordinate: 36.3744 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_Keyword: sea-level change Theme_Keyword: sediment transport Theme_Keyword: estuarine processes Theme_Keyword: vegetation Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: salt marsh Theme_Keyword: marsh health Theme_Keyword: lifespan Theme_Keyword: estuary Theme_Keyword: Long-Term Ecological Research Theme_Keyword: LTER Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:67ea9dc8d34ed02007f8335b Place: Place_Keyword_Thesaurus: Common geographic areas Place_Keyword: Atlantic Place_Keyword: United States Place_Keyword: Maryland Place_Keyword: Virginia Place_Keyword: Chesapeake Access_Constraints: No access constraints. Please see 'Distribution Information' for details. Use_Constraints: These data are marked with a Creative Commons CC0 1.0 Universal License. These data are in the public domain and do not have any use constraints. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. The area and elevation projections for each marsh unit 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_Person_Primary: Contact_Person: Neil Ganju Contact_Organization: U.S. Geological Survey Contact_Position: Research Oceanographer 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 x2252 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: nganju@usgs.gov Browse_Graphic: Browse_Graphic_File_Name: https://www.sciencebase.gov/catalog/file/get/67ea9dc8d34ed02007f8335b/?name=CB_SaltMarsh_Browse.png&allowOpen=true Browse_Graphic_File_Description: Graphic that shows salt marshes of Chesapeake Bay. Browse_Graphic_File_Type: PNG Native_Data_Set_Environment: Environment of Metadata Creation: Microsoft Windows 10 Version 22H2 (Build 19045); Matlab 2018b Cross_Reference: Citation_Information: Originator: Kate V. Ackerman Originator: Zafer Defne Originator: Neil K. Ganju Publication_Date: 2023 Title: Geospatial characterization of salt marshes in Chesapeake Bay Edition: 1.0 Geospatial_Data_Presentation_Form: Vector Digital Data Set (Polygon) Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P997EJYB Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.5066/P997EJYB Online_Linkage: https://www.sciencebase.gov/catalog/item/630f73acd34e36012efa0842 Cross_Reference: Citation_Information: Originator: Zafer Defne Originator: Neil K. Ganju Originator: Kate V. Ackerman Publication_Date: 2023 Title: Lifespan of Chesapeake Bay salt marsh units Edition: 1.0 Geospatial_Data_Presentation_Form: Vector Digital Data Set (Polygon) Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P9FSPWSF Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.5066/P9FSPWSF Online_Linkage: https://www.sciencebase.gov/catalog/item/63a32f2bd34e176674f520ee Cross_Reference: Citation_Information: Originator: Neil K. Ganju Originator: Kate V. Ackerman Originator: Zafer Defne Originator: Giulio Mariotti Originator: David Curson Originator: Zachary Posnik Originator: Joel A. Carr Originator: Joanna Grand Publication_Date: 2025 Title: A simple predictive model for salt marsh internal deterioration under sea-level rise and sediment deficits: application to Chesapeake Bay Edition: 1.0 Series_Information: Series_Name: Estuaries and Coasts Issue_Identification: 48 Online_Linkage: https://doi.org/10.1007/s12237-025-01618-w Cross_Reference: Citation_Information: Originator: Neil K. Ganju Originator: Zafer Defne Originator: Matthew L. Kirwan Originator: Sergio Fagherazzi Originator: Andrea D'Alpaos Originator: Luca Carniello Publication_Date: 2017 Title: Spatially integrative metrics reveal hidden vulnerability of microtidal salt marshes Edition: 1.0 Series_Information: Series_Name: Nature Communications Issue_Identification: 8:14156 Online_Linkage: https://doi.org/10.1038/ncomms14156 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Marsh units, and water and land boundaries inherit their accuracy from accuracy of the source data, Chesapeake Bay marsh units. The vertical accuracy of the marsh unit elevation is inherited from the 1-meter resolution U.S. Geological Survey Coastal National Elevation Database (USGS CoNED) data from 1859 to 2015 and the NOAA North Carolina DEM dataset. The uncertainty in the area and elevation projections is large because of the nature of the empirical equations used and the uncertainty in the source data. For example, a 20% variation in each of the unvegetated to vegetated marsh ratio (UVVR), elevation, bulk density and sea-level rise variables, when all in favor of increasing sediment export and decreasing lifespan, may result in accelerated marsh loss by 50%. Logical_Consistency_Report: For area and elevation calculations, no calculations were performed if the marsh unit had a flagged UVVR value of -1 or elevation value of -9999 in the original datasets. Completeness_Report: The results are specific to the marsh polygons definition within the boundaries of the Chesapeake Bay salt marsh complex. A detailed on-the-ground analysis of a single site may result in a different interpretation of the wetland and marsh unit boundaries. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Horizontal accuracy is inherited from the source dataset that delineates the marsh units and can be considered to be +/-6 meters. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Because the elevation values are averaged over delineated polygons, vertical accuracy of marsh unit elevation depends on both the horizontal accuracy of NWI dataset and the vertical accuracy of source elevation data. CoNED vertical elevation accuracy is 0.2 meters. NOAA North Carolina DEM dataset resolution is 0.06 meters. Additionally, the transformation between the vertical datums is based on the VDatum model which had a vertical uncertainty of 0.1 meters for the transformation points with the domain. Therefore, when all combined the maximum uncertainty could be in excess of 0.36 meters. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Zafer Defne Originator: Neil K. Ganju Originator: Kate V. Ackerman Publication_Date: 2023 Title: Lifespan of Chesapeake Bay salt marsh units Geospatial_Data_Presentation_Form: Vector Digital Data Set (Polygon) Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P9FSPWSF Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: https://www.sciencebase.gov/catalog/item/63a32f2bd34e176674f520ee Online_Linkage: https://doi.org/10.5066/P9FSPWSF Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2023 Source_Currentness_Reference: publication date Source_Citation_Abbreviation: mu_lifespan_CB.shp Source_Contribution: Used the vegetated fraction elevation relative to mean tidal level (VG_ELEVMTL), total marsh unit area (ATOT_M2), and UnVegetated-Vegetated Ratio (UVVR) as inputs. Process_Step: Process_Description: The process step uses the initial conditions for vegetated area and elevation, along with the empirical equations presented by Ganju and others (2025), to project future changes in response to sea-level rise scenarios. 1) Import the following variables from mu_lifespan_CB.shp into Matlab (v. 2018b): marsh unit ID (FID_CMU), total marsh unit area in square meters (m2) (ATOT_M2), vegetated plain elevation relative to mean tidal level in meters (m) (VG_ELEVMTL), and the dimensionless UnVegetated-Vegetated Ratio (UVVR). 2) To eliminate spurious calculations in marsh units with flags for the UVVR, replace UVVR values less than 0 (fill values) with NaNs. 3) For each marsh unit (FID_CMU), extract the UVVR and VG_ELEVMTL, and set the two main parameters (surface accretion rate, loss partition coefficient) to surface accretion rate (sar)=0.9, and loss partition coefficient (w)=0.8. These two parameters and their selection are described by Ganju and others (2025). Set substrate density (rho_sub)=373 kg/m3 and depositional density (rho_dep)=159 kg/m3. 4) Specify time-varying sea-level rise rate (slr, meters/year (m/y)) at annual interval. Rates are either constant values of 3, 5, 7, or 10 millimeters/year (mm/y), variable rates corresponding to a linear decadal increase from 3 to 12 mm/y, or variable rates corresponding to the “upper limit of likely range” from Ganju and others (2025). Specify background sea-level rise rate (slr_bgrnd (m/y)) as 0.003 m/y. Specify maximum time step, t, as 100 years. 5) This step initializes model variables. Calculate the initial vegetated area as area_veg(t=0) = ATOT_M2/(1+UVVR). Calculate the initial unvegetated area as area_unveg(t=0) = ATOT_M2 - area_veg (t=0) Calculate the initial sediment mass as sed_mass(t=0)=area_veg(t=0) x VG_ELEVMTL x rho_sub Calculate the initial sediment budget as sed_bud(t=0)=(-0.416 x log(UVVR)-1.0749) x ATOT_M2-(slr(t=0)-slr_bgrnd) x rho_dep x ATOT_M2, following Ganju and others (2017). If more than zero, indicating sediment import, set to zero. Calculate initial elevation loss as elev_loss(t=0)=(sed_bud(t=0) x w)/(rho_sub x area_veg(t=0)) Calculate initial areal loss as area_veg_loss(t=0)=((1-w) x sed_bud(t=0))/(rho_sub x VG_ELEVMTL) If VG_ELEVMTL is equal to zero the calculation is terminated. 6) This step begins forward time-stepping, t=t+1, and updates UVVR and VG_ELEVMTL at each time step. If area or elevation drop below 0, stop computation. Calculate vegetated elevation at next time step, VG_ELEVMTL(t+1)=VG_ELEVMTL(t)+elev_loss(t)-slr(t+1)+[slr(t+1) x sar] Calculate vegetated area at next time step, area_veg(t+1)=area_veg(t)+area_veg_loss(t) Calculate sediment mass at next time step, sed_mass(t+1)=area_veg(t+1) x VG_ELEVMTL(t+1) x rho_sub Calculate unvegetated area at next time step, area_unveg(t+1)=ATOT_M2-area_veg(t+1) Calculate UVVR at next time step, UVVR(t+1)=area_unveg(t+1)/area_veg(t+1) Calculate sediment budget at next time step, sed_bud(t+1)=(-0.416 x log(UVVR(t+1))-1.0749) x ATOT_M2-(slr(t+1)-slr_bgrnd) x rho_dep x ATOT_M2. If more than zero, indicating sediment import, set to zero. Calculate elevation loss at next time step, elev_loss(t+1)=(sed_bud(t+1) x w)/(rho_sub x area_veg(t+1)) Calculate areal loss at next time step area_veg_loss(t+1)=((1-w) x sed_bud(t+1))/(rho_sub x VG_ELEVMTL(t+1)) Repeat process step 6 until area or elevation drop below 0, or maximum time step is reached. If maximum time step is reached for all units, stop computation. 7) This step exports the projections for vegetated plain elevation and vegetated area (VG_ELEVMTL and AREA_VEG) for all timesteps and marsh units to CSV using Matlab csvwrite command. For each sea-level rise case, export the AREA_VEG and VG_ELEVMTL matrices to separate CSV files. Append FID_CMU to the first column, and the year, truncated variable name, and truncated sea-level rise scenario identifier (e.g., “2010_e3” for the year 2010, elevation variable, and 3 mm/y scenario) to the first row. These CSV files can be joined to shapefile mu_lifespan_CB.shp (Join Field= FID_CMU) to be examined spatially. Source_Used_Citation_Abbreviation: mu_lifespan_CB.shp Process_Date: 2025 Source_Produced_Citation_Abbreviation: area_veg_3mmy.csv Source_Produced_Citation_Abbreviation: area_veg_5mmy.csv Source_Produced_Citation_Abbreviation: area_veg_7mmy.csv Source_Produced_Citation_Abbreviation: area_veg_10mmy.csv Source_Produced_Citation_Abbreviation: area_veg_3to12mmy.csv Source_Produced_Citation_Abbreviation: area_veg_upperlimitoflikely.csv Source_Produced_Citation_Abbreviation: elev_veg_3mmy.csv Source_Produced_Citation_Abbreviation: elev_veg_5mmy.csv Source_Produced_Citation_Abbreviation: elev_veg_7mmy.csv Source_Produced_Citation_Abbreviation: elev_veg_10mmy.csv Source_Produced_Citation_Abbreviation: elev_veg_3to12mmy.csv Source_Produced_Citation_Abbreviation: elev_veg_upperlimitoflikely.csv Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Neil K. Ganju Contact_Organization: U.S. Geological Survey Contact_Position: Research Oceanographer Contact_Address: Address_Type: mailing and physical address Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543 Contact_Voice_Telephone: 508-548-8700 x2252 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: nganju@usgs.gov Spatial_Reference_Information: Vertical_Coordinate_System_Definition: Depth_System_Definition: Depth_Datum_Name: Mean Tidal Level Depth_Resolution: 0.1 Depth_Distance_Units: meters Depth_Encoding_Method: Attribute values Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: elev_veg_3mmy.csv Entity_Type_Definition: A CSV file that contains predictions of marsh vegetated plain elevation (in meters, relative to mean tidal level (MTL)) under a 3 mm/y of sea-level rise scenario as produced by the UBMorph model and the process steps above, for the conceptual marsh units of Chesapeake Bay salt marsh complex (identified by FID_CMU) for 100 years from 2010 to 2109. The field names are formatted to identify the year that the prediction is for, an “e” denoting the elevation dataset, and the value of the sea-level rise (SLR) scenario: 2010_e3 is the 2010 elevation prediction under a 3 mm/y SLR scenario. Elevations are relative to mean tidal level (MTL). The special value -9999 signifies no calculation was performed due to unavailable elevation data; values of 0 signify termination of the computation for either area or elevation, indicating conversion of the marsh unit to completely unvegetated. Entity_Type_Definition_Source: USGS Detailed_Description: Entity_Type: Entity_Type_Label: area_veg_3mmy.csv Entity_Type_Definition: A CSV file that contains predictions of marsh vegetated plain area (in square meters) under a 3 mm/y of sea-level rise scenario as produced by the UBMorph model and the process steps above, for the conceptual marsh units of Chesapeake Bay salt marsh complex (identified by FID_CMU) for 100 years from 2010 to 2109. The field names are formatted to identify the year that the prediction is for, an “a” denoting the area dataset, and the value of the sea-level rise scenario: 2010_a3 is the 2010 area prediction under a 3 mm/y SLR scenario. The special value -9999 signifies no calculation was performed due to unavailable elevation data; values of 0 signify termination of the computation for either area or elevation, indicating conversion of the marsh unit to completely unvegetated. Entity_Type_Definition_Source: USGS Detailed_Description: Entity_Type: Entity_Type_Label: elev_veg_5mmy.csv Entity_Type_Definition: A CSV file that contains predictions of marsh vegetated plain elevation (in meters, relative to mean tidal level (MTL)) under a 5 mm/y of sea-level rise scenario as produced by the UBMorph model and the process steps above, for the conceptual marsh units of Chesapeake Bay salt marsh complex (identified by FID_CMU) for 100 years from 2010 to 2109. The field names are formatted to identify the year that the prediction is for, an “e” denoting the elevation dataset, and the value of the sea-level rise scenario: 2010_e5 is the 2010 elevation prediction under a 5 mm/y SLR scenario. Elevations are relative to mean tidal level (MTL). The special value -9999 signifies no calculation was performed due to unavailable elevation data; values of 0 signify termination of the computation for either area or elevation, indicating conversion of the marsh unit to completely unvegetated. Entity_Type_Definition_Source: USGS Detailed_Description: Entity_Type: Entity_Type_Label: area_veg_5mmy.csv Entity_Type_Definition: A CSV file that contains predictions of marsh vegetated plain area (in square meters) under a 5 mm/y of sea-level rise scenario as produced by the UBMorph model and the process steps above, for the conceptual marsh units of Chesapeake Bay salt marsh complex (identified by FID_CMU) for 100 years from 2010 to 2109. The field names are formatted to identify the year that the prediction is for, an “a” denoting the area dataset, and the value of the sea-level rise scenario: 2010_a5 is the 2010 area prediction under a 5 mm/y SLR scenario. The special value -9999 signifies no calculation was performed due to unavailable elevation data; values of 0 signify termination of the computation for either area or elevation, indicating conversion of the marsh unit to completely unvegetated. Entity_Type_Definition_Source: USGS Detailed_Description: Entity_Type: Entity_Type_Label: elev_veg_7mmy.csv Entity_Type_Definition: A CSV file that contains predictions of marsh vegetated plain elevation (in meters, relative to mean tidal level (MTL)) under a 7 mm/y of sea-level rise scenario as produced by the UBMorph model and the process steps above, for the conceptual marsh units of Chesapeake Bay salt marsh complex (identified by FID_CMU) for 100 years from 2010 to 2109. The field names are formatted to identify the year that the prediction is for, an “e” denoting the elevation dataset, and the value of the sea-level rise scenario: 2010_e7 is the 2010 elevation prediction under a 7 mm/y SLR scenario. Elevations are relative to mean tidal level (MTL). The special value -9999 signifies no calculation was performed due to unavailable elevation data; values of 0 signify termination of the computation for either area or elevation, indicating conversion of the marsh unit to completely unvegetated. Entity_Type_Definition_Source: USGS Detailed_Description: Entity_Type: Entity_Type_Label: area_veg_7mmy.csv Entity_Type_Definition: A CSV file that contains predictions of marsh vegetated plain area (in square meters) under a 7 mm/y of sea-level rise scenario as produced by the UBMorph model and the process steps above, for the conceptual marsh units of Chesapeake Bay salt marsh complex (identified by FID_CMU) for 100 years from 2010 to 2109. The field names are formatted to identify the year that the prediction is for, an “a” denoting the area dataset, and the value of the sea-level rise scenario: 2010_a7 is the 2010 area prediction under a 7 mm/y SLR scenario. The special value -9999 signifies no calculation was performed due to unavailable elevation data; values of 0 signify termination of the computation for either area or elevation, indicating conversion of the marsh unit to completely unvegetated. Entity_Type_Definition_Source: USGS Detailed_Description: Entity_Type: Entity_Type_Label: elev_veg_10mmy.csv Entity_Type_Definition: A CSV file that contains predictions of marsh vegetated plain elevation (in meters, relative to mean tidal level (MTL)) under a 10 mm/y of sea-level rise scenario as produced by the UBMorph model and the process steps above, for the conceptual marsh units of Chesapeake Bay salt marsh complex (identified by FID_CMU) for 100 years from 2010 to 2109. The field names are formatted to identify the year that the prediction is for, an “e” denoting the elevation dataset, and the value of the sea-level rise scenario: 2010_e10 is the 2010 elevation prediction under a 10 mm/y SLR scenario. Elevations are relative to mean tidal level (MTL). The special value -9999 signifies no calculation was performed due to unavailable elevation data; values of 0 signify termination of the computation for either area or elevation, indicating conversion of the marsh unit to completely unvegetated. Entity_Type_Definition_Source: USGS Detailed_Description: Entity_Type: Entity_Type_Label: area_veg_10mmy.csv Entity_Type_Definition: A CSV file that contains predictions of marsh vegetated plain area (in square meters) under a 10 mm/y of sea-level rise scenario as produced by the UBMorph model and the process steps above, for the conceptual marsh units of Chesapeake Bay salt marsh complex (identified by FID_CMU) for 100 years from 2010 to 2109. The field names are formatted to identify the year that the prediction is for, an “a” denoting the area dataset, and the value of the sea-level rise scenario: 2010_a10 is the 2010 area prediction under a 10 mm/y SLR scenario. The special value -9999 signifies no calculation was performed due to unavailable elevation data; values of 0 signify termination of the computation for either area or elevation, indicating conversion of the marsh unit to completely unvegetated. Entity_Type_Definition_Source: USGS Detailed_Description: Entity_Type: Entity_Type_Label: elev_veg_3to12mmy.csv Entity_Type_Definition: A CSV file that contains predictions of marsh vegetated plain elevation (in meters, relative to mean tidal level (MTL)) under a 3 to 12 mm/y linear decadal increase of sea-level rise scenario as produced by the UBMorph model and the process steps above, for the conceptual marsh units of Chesapeake Bay salt marsh complex (identified by FID_CMU) for 100 years from 2010 to 2109. The field names are formatted to identify the year that the prediction is for, an “e” denoting the elevation dataset, and the value of the sea-level rise scenario: 2010_e3_12 is the 2010 elevation prediction under a 3 to 12 mm/y linear decadal increase of SLR scenario. Elevations are relative to mean tidal level (MTL). The special value -9999 signifies no calculation was performed due to unavailable elevation data; values of 0 signify termination of the computation for either area or elevation, indicating conversion of the marsh unit to completely unvegetated. The special value -9999 signifies no calculation was performed due to unavailable elevation data; values of 0 signify termination of the computation for either area or elevation, indicating conversion of the marsh unit to completely unvegetated. Entity_Type_Definition_Source: USGS Detailed_Description: Entity_Type: Entity_Type_Label: area_veg_3to12mmy.csv Entity_Type_Definition: A CSV file that contains predictions of marsh vegetated plain area (in square meters) under a 3 to 12 mm/y linear decadal increase of sea-level rise scenario as produced by the UBMorph model and the process steps above, for the conceptual marsh units of Chesapeake Bay salt marsh complex (identified by FID_CMU) for 100 years from 2010 to 2109. The field names are formatted to identify the year that the prediction is for, an “a” denoting the area dataset, and the value of the sea-level rise scenario: 2010_a3_12 is the 2010 area prediction under a 3 to 12 mm/y linear decadal increase of SLR scenario. The special value -9999 signifies no calculation was performed due to unavailable elevation data; values of 0 signify termination of the computation for either area or elevation, indicating conversion of the marsh unit to completely unvegetated. Entity_Type_Definition_Source: USGS Detailed_Description: Entity_Type: Entity_Type_Label: elev_veg_upperlimitoflikely.csv Entity_Type_Definition: A CSV file that contains predictions of marsh vegetated plain elevation (in meters, relative to mean tidal level (MTL)) under an “Upper Limit of Likely Range” sea-level rise scenario as produced by the UBMorph model and the process steps above, for the conceptual marsh units of Chesapeake Bay salt marsh complex (identified by FID_CMU) for 100 years from 2010 to 2109. The field names are formatted to identify the year that the prediction is for, an “e” denoting the elevation dataset, and the value of the sea-level rise scenario: 2010_eUPP is the 2010 elevation prediction under an “Upper Limit of Likely Range” SLR scenario. Elevations are relative to mean tidal level (MTL). The special value -9999 signifies no calculation was performed due to unavailable elevation data; values of 0 signify termination of the computation for either area or elevation, indicating conversion of the marsh unit to completely unvegetated. Entity_Type_Definition_Source: USGS Detailed_Description: Entity_Type: Entity_Type_Label: area_veg_upperlimitoflikely.csv Entity_Type_Definition: A CSV file that contains predictions of marsh vegetated plain area (in square meters) under an “Upper Limit of Likely Range” sea-level rise scenario as produced by the UBMorph model and the process steps above, for the conceptual marsh units of Chesapeake Bay salt marsh complex (identified by FID_CMU) for 100 years from 2010 to 2109. The field names are formatted to identify the year that the prediction is for, an “a” denoting the area dataset, and the value of the sea-level rise scenario: 2010_aUPP is the 2010 area prediction under an “Upper Limit of Likely Range” SLR scenario. The special value -9999 signifies no calculation was performed due to unavailable elevation data; values of 0 signify termination of the computation for either area or elevation, indicating conversion of the marsh unit to completely unvegetated. Entity_Type_Definition_Source: USGS Overview_Description: Entity_and_Attribute_Overview: In this dataset, area and elevation estimates for each conceptual salt marsh unit in the Chesapeake Bay salt marsh complex under several sea-level rise scenarios have been calculated based on the UBMorph model. Decimal values represent the precision necessary to reproduce the model output accurately. 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: The file Veg_Area_Elev_Change_CB.zip contains the 12 CSV files (area_veg_3mmy.csv, area_veg_5mmy.csv, area_veg_7mmy.csv, area_veg_10mmy.csv, area_veg_3to12mmy.csv, area_veg_upperlimitoflikely.csv, elev_veg_3mmy.csv, elev_veg_5mmy.csv, elev_veg_7mmy.csv, elev_veg_10mmy.csv, elev_veg_3to12mmy.csv,elev_veg_upperlimitoflikely.csv) and the FGDC CSDGM metadata in .xml format. Distribution_Liability: 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. 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. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: CSV Format_Information_Content: The zipped file contains the 12 CSV files and associated metadata. Transfer_Size: 109 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/67ea9dc8d34ed02007f8335b Network_Resource_Name: https://doi.org/10.5066/P1ASOF7N Access_Instructions: The first link in network resources is to download data directly in a single zip file. The second link points to a landing page with metadata and data where the individual CSV files can be downloaded. Fees: None. No fees are applicable for obtaining the data set. Metadata_Reference_Information: Metadata_Date: 20250924 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Neil Ganju Contact_Position: Research Oceanographer Contact_Address: Address_Type: mailing and physical address Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543 Contact_Voice_Telephone: 508-548-8700 x2252 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: whsc_data_contact@usgs.gov Contact_Instructions: The metadata contact email address is a generic address in the event the person is no longer with USGS. Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998