Metadata: Identification_Information: Citation: Citation_Information: Originator: Grace D. Molino Originator: Zafer Defne Originator: Neil K. Ganju Originator: Joel A. Carr Originator: Glenn R. Guntenspergen Originator: David C. Walters Publication_Date: 20200602 Title: Slope Values Across Marsh-Forest Boundary in Chesapeake Bay Region, USA Edition: 1.0 Geospatial_Data_Presentation_Form: vector digital data Series_Information: Series_Name: data release Issue_Identification: DOI:10.5066/P9EJ6PGT 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: Molino, G.D., Defne, Z., Ganju, N.K., Carr, J.A., Guntenspergen, G.R., and Walters, D.C., 2020, Slope values across marsh-forest boundary in Chesapeake Bay region, USA: U.S. Geological Survey data release, https://doi.org/10.5066/P9EJ6PGT. Online_Linkage: https://doi.org/10.5066/P9EJ6PGT Description: Abstract: The marsh-forest boundary in the Chesapeake Bay was determined by geoprocessing high-resolution (1 square meter) land use and land cover data sets. Perpendicular transects were cast at standard intervals (30 meters) along the boundary within a GIS by repurposing the Digital Shoreline Analysis System (DSAS) Version 5.0, an ArcGIS extension developed by the U.S. Geological Survey. Average and maximum slope values were assigned to each transect from surface elevation data. The same values were also provided as points at the center of the transect where it crossed over the boundary. The slope values across the marsh-forest transition zone and at the boundary itself provide comprehensive data layers for local, state, and Federal managers to improve understanding of salt marsh migration. This additionally aids the U.S. Geological Survey in its effort to assess the coastal vulnerability and response of salt marsh ecosystems, including the Chesapeake Bay region. Purpose: The slope was determined at 30-meter resolution across the marsh-forest boundary in the Chesapeake Bay region to better understand the factors influencing the process of salt marsh ecosystems migrating into coastal forests. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2020 Currentness_Reference: publication date Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -77.4894 East_Bounding_Coordinate: -75.0574 North_Bounding_Coordinate: 39.5759 South_Bounding_Coordinate: 36.5300 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:5e95cbd082ce172707f2528c Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: biota Theme_Keyword: geoscientificInformation 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: remote sensing Theme_Keyword: salt marsh Theme_Keyword: coastal forest Theme_Keyword: ghost forest Theme_Keyword: Digital Shoreline Analysis System (DSAS) Place: Place_Keyword_Thesaurus: None Place_Keyword: Chesapeake Bay Place_Keyword: Blackwater National Wildlife Refuge Place_Keyword: Maryland Place_Keyword: Virginia Place_Keyword: Delmarva Peninsula Access_Constraints: None. Please see 'Distribution Info' for details. Use_Constraints: None. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Zafer Defne Contact_Organization: U.S. Geological Survey, Northeast Region 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 x2254 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: zdefne@usgs.gov Browse_Graphic: Browse_Graphic_File_Name: https://www.sciencebase.gov/catalog/file/get/5e95cbd082ce172707f2528c?name=SlopeTransectsandPoints.png Browse_Graphic_File_Description: Graphic shows slope transects and points overlaying Esri basemap. Browse_Graphic_File_Type: PNG Native_Data_Set_Environment: Environment of Metadata Creation: Microsoft Windows 10 Enterprise Version 1809 (Build 17763.1098); Esri ArcGIS 10.6.1 Service Pack N/A (Build N/A) Cross_Reference: Citation_Information: Originator: Grace D. Molino Originator: Zafer Defne Originator: Alfredo L. Aretxabaleta Originator: Neil K. Ganju Originator: Joel A. Carr Publication_Date: 2021 Title: Quantifying Slopes as a Driver of Forest to Marsh Conversion Using Geospatial Techniques: Application to Chesapeake Bay Coastal-Plain, United States Series_Information: Series_Name: Frontiers in Environmental Science Issue_Identification: vol. 9 Publication_Information: Publication_Place: Switzerland Publisher: Frontiers Media SA Online_Linkage: https://doi.org/10.3389/fenvs.2021.616319 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Overall, the accuracy of this dataset is inherited from the accuracy of the underlying U.S. Geological Survey Coastal National Elevation Database (CoNED) topobathy, National Wetlands Inventory wetlands data files, and Chesapeake Conservancy High-Resolution Land-Use and Land-Cover source datasets. Three tests were performed on two sample forest patches, one on the Eastern Shore and one on the western side of the Chesapeake Bay to determine how changing the parameters which determined where transects were cast alters the calculated slope values. First, the transects were cast every 30m with a random starting point. We shifted them laterally 15m and recalculated the average slope values. Second, we cast the transects every 20m instead of 30m to determine the effect of changing the resolution. Third, we did not smooth the forest-marsh boundary at all and then smoothed it 30m. To compare the effect of these tests on the transect slope values, we found the average slope value of all the transects in each test situation and then calculated the percent change of this averaged value between the two scenarios for each test. For all 6 tests (three tests x two sites), the percent change in average slope value was less than 3%, with 4 out of the 6 tests had percent change below 1.5% change. Additionally, a limited dataset of field measurements was available for three locations representing areas with low, medium, and high slope at the marsh-forest boundary. The start and end points of the low slope transect are (-75.8094, 38.2146) and (-75.80922, 38.21458), the medium transect start and end points are (-75.98234, 38.40398) and (-75.98226, 38.4040385), and the high transect start and end points are (-76.90067, 37.94665) to (-76.90087, 37.94657). The average percent rise calculated in ArcGIS corresponded well with those taken in the field, ie. the boundary with the highest slope in the field measurements was also the boundary with the highest calculated slope. We do not claim that this method is more accurate than taking measurements by hand. In fact, this method is only as accurate as the input datasets. However, it provides a reasonable estimate of slopes across an area too extensive for field work to cover. Logical_Consistency_Report: There are a few small patches within the CoNED elevation dataset where there are cells with "-1.0" value. This represents an area that was artificially hydroflattened; transects that overlaid this area were removed from the final product because it results in an artificial value of 0 for the slope. Additionally, there are other areas where the original source data puts a single negative value for creeks and other channels which often includes marsh units; this impacts about 9% of the transects. We left these transects in the dataset as we have no way to determine if the single value is an accurate representation of the elevation of the creek or channel. Additionally, future users of the metadata may have updated elevation files that they can use to address this inconsistency. Completeness_Report: Only NWI category Estuarine Intertidal Emergent (E2EM) wetlands were considered for the marsh extent. Geographic area consisted of the Maryland and Virginia portions of Chesapeake Bay. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: JEFFREY DANIELSON Originator: DEAN TYLER Publication_Date: 20160501 Title: Topobathymetric Model for Chesapeake Bay Region - District of Columbia, States of Delaware, Maryland, Pennsylvania, and Virginia, 1859 to 2015 Edition: First Geospatial_Data_Presentation_Form: raster digital data Series_Information: Series_Name: Topobathymetric Model, 1859 to 2015 Issue_Identification: 0.1 Online_Linkage: https://topotools.cr.usgs.gov/topobathy_viewer/dwndata.htm Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 18590101 Ending_Date: 20150131 Source_Currentness_Reference: time period of data Source_Citation_Abbreviation: CoNED Chesapeake Bay Topobathy Source_Contribution: Average and maximum slope values assigned to each transect were determined from the CoNED Chesapeake Bay topobathy. Projection was NAD NAD 1983 UTM Zone 18N. Downloaded geodatabase January 29, 2020. Source_Information: Source_Citation: Citation_Information: Originator: National Wetlands Inventory Publication_Date: 20171001 Title: National Wetlands Inventory for the State of Maryland Geospatial_Data_Presentation_Form: vector digital data Online_Linkage: https://www.fws.gov/wetlands/Data/State-Downloads.html Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 197704 Ending_Date: 2015 Source_Currentness_Reference: time period of data Source_Citation_Abbreviation: MD NWI Source_Contribution: This file was combined with the Virginia wetland datasets to obtain continuous Chesapeake Bay wetland file. The resulting file was used to determine the marsh-forest boundaries. Projection is in NAD 1983 Albers. Downloaded geodatabase September 20, 2019. Source_Information: Source_Citation: Citation_Information: Originator: National Wetlands Inventory Publication_Date: 20171001 Title: National Wetlands Inventory for the State of Virginia Geospatial_Data_Presentation_Form: vector digital data Online_Linkage: https://www.fws.gov/wetlands/Data/State-Downloads.html Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 197711 Ending_Date: 2015 Source_Currentness_Reference: time period of data Source_Citation_Abbreviation: VA NWI Source_Contribution: This file was combined with the Maryland wetland datasets to obtain continuous Chesapeake Bay wetland file. The resulting file was used to determine the marsh-forest boundaries. Projection is in NAD 1983 Albers. Downloaded geodatabase September 20, 2019. Source_Information: Source_Citation: Citation_Information: Originator: USGS Originator: Chesapeake Bay Program Originator: Chesapeake Bay Program Land Use Workgroup Originator: Chesapeake Conservancy Originator: Conservation Innovation Center Publication_Date: 20181109 Title: Chesapeake Conservancy High-Resolution Land-Use Dataset for the Chesapeake Bay 2013/2014 Geospatial_Data_Presentation_Form: raster digital data Online_Linkage: https://chesapeakeconservancy.org/conservation-innovation-center-2/high-resolution-data/land-use-data-project/ Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2013 Ending_Date: 2014 Source_Currentness_Reference: aerial imagery source date Source_Citation_Abbreviation: CC Chesapeake Bay Land-Use Dataset Source_Contribution: Source was used to obtain spatial extent of forests in the Chesapeake Bay region. Projection was in USA Contiguous Albers Equal Area Conic USGS version. Downloaded file for Chesapeake Bay on September 6, 2019. Source_Information: Source_Citation: Citation_Information: Originator: USGS Publication_Date: 20180215 Title: Chesapeake Conservancy High-Resolution Land-Cover Dataset for the Chesapeake Bay 2013/2014 Geospatial_Data_Presentation_Form: raster digital data Online_Linkage: https://chesapeakeconservancy.org/conservation-innovation-center-2/high-resolution-data/land-cover-data-project/ Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2013 Ending_Date: 2014 Source_Currentness_Reference: aerial imagery source date Source_Citation_Abbreviation: CC Chesapeake Bay Land-Cover Dataset Source_Contribution: Source was used to obtain spatial extent of forests in the Chesapeake Bay region. The 6-class Chesapeake Bay file was used. Projection was in USA Contiguous Albers Equal Area Conic USGS version. Downloaded September 5, 2019. Process_Step: Process_Description: This process step and all subsequent process steps were performed by the same person, Grace Molino, in ArcMap (ver. 10.6.2) 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 (m2) unless otherwise stated Create subdomain tiles.The individual datasets are too large for analysis as a whole so all analyses are completed within subdomains (subregions 0-11) created in this processing step. a) CREATE FISHNET (Template Extent=Chesapeake_Bay_Topobathy_DEM_1m_v2.tif; Number of Rows=6; Number of Columns=2; Geometry Type=polygon) To define tiles used in the analysis [BayWide_fishnet.shp]. b) PROJECT [BayWide_fishnet.shp] from NAD 1983 UTM Zone 18N to USA Contiguous Albers Equal Area Conic USGS version [BayWide_fishnet_Albers.shp]. Source_Used_Citation_Abbreviation: CoNED Chesapeake Bay Topobathy Process_Date: 2020 Process_Step: Process_Description: Process Maryland and Virginia National Wetland Inventory datasets to obtain the desired wetland category for this study and then combine them for a complete file of estuarine emergent wetlands in the Chesapeake Bay region. a) EXPORT features from NWI datasets after SELECT ("ATTRIBUTE" LIKE 'E2%EM%' OR "ATTRIBUTE" LIKE 'E2EM%' OR "ATTRIBUTE" LIKE 'E2AB3%' OR "ATTRIBUTE" LIKE 'E2SS%' OR "ATTRIBUTE" LIKE 'E2US4%') to select estuarine intertidal areas of 1) Emergent, 2) Scrub-shrub, 3) Rooted vascular aquatic bed, 4) Organic unconsolidated shore classes [MD_NWI_E2wetlands.shp and VA_NWI_E2wetlands.shp]. b) MERGE the state wetland files [MD_NWI_E2wetlands.shp and VA_NWI_E2wetlands.shp] to create [MDVA_NWI_E2wetlands.shp]. This will be used to erase any overlap with the forest features from Land Use and Land Cover datasets. c) EXPORT features from NWI datasets after SELECT ("ATTRIBUTE" LIKE 'E2EM%') to select estuarine intertidal emergent areas [MDVA_NWI_E2EMwetlands.shp]. This is a subset of features in step (a) and will be used to establish the marsh-forest boundary. d) PROJECT [MDVA_NWI_E2wetlands.shp] and [MDVA_NWI_E2EMwetlands.shp] from NAD 1983 Albers to NAD 1983 UTM Zone 18N [MDVA_NWI_E2wetlandsUTM.shp] and [MDVA_NWI_E2EMwetlandsUTM.shp]. Source_Used_Citation_Abbreviation: MD NWI Source_Used_Citation_Abbreviation: VA NWI Process_Date: 2020 Process_Step: Process_Description: Prepare Chesapeake Conservancy BayWide Land-Use dataset. The Land-Use dataset is a raster file with 19 different land use categories. We are only interested in the "forest" category and need the corresponding forest extent as polygons to analyze alongside the salt marsh polygons. The following process was undertaken for each of the twelve subregions in the [BayWide_fishnet_Albers.shp]. This example is written for subregion 3 which means the process steps are for the Land-Use file created in step a) for region 3 [BayWide_1m_LU3.tif]. These are the same steps taken for all the subregions. a) SPLIT (Input=BayWide_1m_LU.tif; Split Features=BayWide_fishnet.shp; Split Field=Zone) into twelve subregions. One example of the result which is used in the following process steps: [BayWide_1m_LU3.tif]. b) For each region, EXTRACT BY ATTRIBUTES (Input raster=BayWide_1m_LU3.tif; Where Clause=“Value”=8) to create [BayWide_1m_LU3_forest.tif]. Value 8 is forest. c) Convert RASTER TO POLYGON (Input=BayWide_1m_LU3_forest.tif; Field=Value; Simplify polygons=checked) [BayWide_1m_LU3_forestpoly.shp]. d) PROJECT from USA Contiguous Albers Equal Area Conic USGS version to NAD 1983 UTM Zone 18N [BayWide_1m_LU3_forestpolyUTM.shp]. Then REPAIR GEOMETRY. Source_Used_Citation_Abbreviation: CC Chesapeake Bay Land-Use Dataset Process_Date: 2020 Process_Step: Process_Description: Prepare Chesapeake Conservancy BayWide Land-Cover dataset. The Land-Cover dataset is a raster file with 6 different land use categories. We are only interested in the "Forest Canopy and Shrubland" category and need the corresponding forest extent as polygons to analyze alongside the salt marsh polygons. The following process was undertaken for each of the twelve subregions in the [BayWide_fishnet_Albers.shp]. This example is written for subregion 3 which means the process steps are for the Land-Cover file created in step a) for region 3 [Baywide_1m_LC3.tif]. These are the same steps taken for all the subregions. a) SPLIT (Input=Baywide_LandCover_UVM_CC_WorldView.tif; Split Features=BayWide_fishnet_Albers.shp; Split Field=Zone) into twelve subregions. One example of the result which is used in the following process steps:[BayWide_1m_LC3.tif]. b) For each region, EXTRACT BY ATTRIBUTES (Input raster= Baywide_LandCover_UVM_CC_WorldView_3.tif; Where Clause=“Value”=2) to create [BayWide_1m_LC3_forestandshrubs.tif]. Value 2 is "Tree Canopy and Shrubland". c) Convert RASTER TO POLYGON (Input=[BayWide_1m_LC3_forestandshrubs.tif]; Field=Value; Simplify polygons=checked) to [BayWide_1m_LC3_forestpoly.shp]. d) PROJECT from USA Contiguous Albers Equal Area Conic USGS version to NAD 1983 UTM Zone 18N [BayWide_1m_LC3_forestpolyUTM.shp]. Then REPAIR GEOMETRY. Source_Used_Citation_Abbreviation: CC Chesapeake Bay Land-Cover Dataset Process_Date: 2020 Process_Step: Process_Description: Obtain forest polygons which border marsh. a) MERGE [BayWide_1m_LC3_forestpolyUTM.shp] and [BayWide_1m_LU3_forestpolyUTM.shp] datasets [LULC3_forest.shp]. b) DISSOLVE (Input=LULC3_forest.shp; Create multipart features=unchecked) to combine overlapping features [LULC3_forest_diss.shp]. Then REPAIR GEOMETRY. c) ELIMINATE POLYGON PARTS (Input= [LULC3_forest_diss.shp]; Condition=percent; Part area percent=99; Part option=contained only) to remove any interior holes in the forest polygons [LULC3_forest_d_nh.shp]. d) ERASE any overlap with [MDVA_NWI_E2wetlands.shp] which will remove any area considered generally to be wetlands [LULC3_forest_dnh_erase.shp]. Then DISSOLVE (Create multipart features=unchecked) again to itemize any small forest patches created in the previous step [LULC3_forest_raw.shp]. e) Remove any polygons that are too small (smaller than 900 square meters) for target resolution. ADD FIELD to [LULC3_forest_raw.shp] attribute table called “Area” and then CALCULATE GEOMETRY of each polygon from within attribute table. EXPORT forest polygons from [LULC3_forest_raw.shp] which are over 900m2 [LULC3_forest900m.shp]. f) SELECT BY LOCATION forest polygons from [LULC3_forest900m.shp] which are within 10m search radius of [MDVA_NWI_E2EMwetlands.shp] marsh polygons [LULC3_forest900m_w10m.shp]. These are the forest polygons which border salt marsh. Process_Date: 2020 Process_Step: Process_Description: Prepare forest polygons. The following processing steps are needed to simplify the forest polygon edges and eliminate odd geometries which resulted from preceding processing steps such as the conversion of the forest files from raster to polygon. a) ELIMINATE POLYGON PARTS (Condition=percent; Part area percent=99; Part option=contained only) [LULC3_forest900m_w10m.shp] to remove any interior holes in the forest polygons [LULC3_forest900m_nh.shp]. b) BUFFER (Input=[LULC3_forest900m_nh.shp], Linear unit=5m) to create [LULC3_forest900m_out5m.shp] and then again BUFFER (Input=[LULC3_forest900m_out5m.shp], Linear unit= -5m) to remove unwanted edge features created during previous merge [LULC3_forest900m_in5m.shp]. c) SMOOTH POLYGON (Smoothing algorithm=PAEK; Smoothing tolerance=30 meters) to get the smoothed forest polygons [LULC3_forest900m_sm30m.shp]. d) BUFFER (Input=[LULC3_forest900m_sm30m.shp], Linear unit=-10m, Dissolve type=NONE) to create [LULC3_forest900m_in10m.shp]. Then SMOOTH POLYGON (Smoothing algorithm=PAEK; Smoothing tolerance=20 meters) to remove sharp edges which complicate analysis [LULC3_forest900m_sm20m.shp]. e) Then DISSOLVE (Create multipart features=unchecked) again to separate any small forest patches created in the previous steps [LULC3_forest900m_sm20m_diss.shp]. f) ADD FIELD to [LULC3_forest900m_sm20m_diss.shp] attribute table called “Area” and then CALCULATE GEOMETRY of remaining polygon from within attribute table. EXPORT forest polygons from [LULC3_forest900m_sm20m_diss.shp] which are over 900m2 [LULC3_forestnew900m.shp]. g) SIMPLIFY POLYGON (Simplification algorithm=point remove; Tolerance=0.5m) to reduce file size [LULC3_forestnew900m_simp.shp]. h) ELIMINATE POLYGON PARTS (Condition=percent; Part area percent=99; Part option=contained only) to remove any interior holes in the forest polygons [LULC3_forestnew900m_s_nh.shp]. Process_Date: 2020 Process_Step: Process_Description: Create input files for Digital Shoreline Analysis System (DSAS). DSAS was designed to estimate shoreline change over time by casting transects to a stable baseline. We repurposed this tool to cast transects 30 meters apart and perpendicular to the marsh-forest boundary by creating artificial shoreline and baseline files which are based on the forest polygons within 10m of salt marshes.The shoreline and baseline files do not represent the actual extent of the marsh or forest, they are only intended as an approximation of the marsh-forest transition zone so we may estimate the slope across this area. They are 20m apart which provides a buffer for us to capture the boundary if the marsh and/or forest extent is inaccurate. As DSAS was not created with this purpose in mind, there are several limitations that we established work arounds for in the following steps. For example, DSAS crashes if the number of transects in the output file exceeds approximately 66,000 transects. If the estimated number of features (polygon perimeter divided by the transect interval) is larger than this number, the subregion you are working in needs to be broken into smaller zones. This calculation needs to be done before step a). Additionally, DSAS errors often occur if the tool tries to cast transects when there are multiple segmented shorelines and baselines within the same files. To reduce the complexity of the baseline and shoreline files, we have the baselines and shorelines extend around the entire forest polygon which we use as an approximation for the location of the marsh-forest boundary, so DSAS treats them as islands, and later remove the transects not cast where forest borders marsh. a) If [LULC3_forestnew900m_s_nh.shp] needs to be split, CREATE FISHNET (Input=[LULC3_forestnew900m_s_nh.shp]). The number of columns and rows is dependent on the shape and distribution of forest polygons in the input file. SPLIT [LULC3_forestnew900m_s_nh.shp] into zones, such as Zone A, [LULC3_ZoneA.shp]. b) BUFFER (Input=[LULC3_ZoneA.shp], Linear unit=20m, Dissolve type=NONE) to create [LULC3_ZoneA_out20m.shp]. c) ELIMINATE POLYGON PARTS (Condition=percent; Part area percent=99; Part option=contained only) to remove any interior holes in the forest polygons [LULC3_ZoneA_b_nh.shp]. d) BUFFER (Input=[LULC3_ZoneA_b_nh.shp], Linear unit=-20m, Dissolve type=NONE) to create [LULC3_ZoneA_in20m.shp]. e) FEATURE TO LINE (Input=[LULC3_ZoneA_in20m.shp]) to create baseline [LULC3_ZoneA_line.shp]. Then DISSOLVE (Create multipart feature) to create a single baseline [LULC3_ZoneA_baseline.shp]. f) FEATURE TO LINE (Input=[LULC3_ZoneA_b_nh.shp]) to create shorelines [[LULC3_ZoneA_bdnh_line.shp]. Then DISSOLVE (Create multipart feature) to create a single shoreline [LULC3_ZoneA_shoreline.shp]. Process_Date: 2020 Process_Step: Process_Description: Cast transects across the marsh-forest boundary using Digital Shoreline Analysis Systems (DSAS) Version 5.0. FOr questions not covered by the information here, see the DSAS User Guide available online. Slope data is then added to these transects from the CoNED topobathy. Note that slope value of -9999 represents a slope crossing an area of the topobathy with a NaN value. Slope values of 0 flag transects which cross over areas where the originators of the dataset used artificial fill values such as -1 so there is artificially no change in slope. These are removed in step i). a) IMPORT [LULC3_ZoneA_baseline.shp] and [LULC3_ZoneA_shoreline.shp] to a personal geodatabase to create feature class files [LULC3_ZoneA_baseline.mdb] and [LULC3_ZoneA_shoreline.mdb]. b) Change attributes to meet DSAS requirements: ADD FIELD [LULC3_ZoneA_shoreline.mdb] for DATE (Text, Length=10) and UNCERTAIN (Short integer) and delete Id field. For [LULC3_ZoneA_baseline.mdb] set Id equal to Object ID and make last column. c) Import files into DSAS. Set output file to same personal geodatabase as input files [Transects_LULC3_ZA.mdb]. d) Set the following parameters in DSAS Set Default Parameters. Baseline tab: Right-hand baseline orientation, Baseline placement onshore; Shoreline tab: Landward intersection. Set the following parameters in DSAS Cast Transects. Maximum search distance: 25m, Transect spacing: 30m, Smoothing distance: 0m, Clip transects to shoreline extent. e) SELECT BY LOCATION transects from the resulting transect file [Transects_LULC3_ZA.mdb] which are within 10m of [MDVA_NWI_E2EMwetlandsUTM.shp] to create shapefile with transects only across the marsh-forest boundary [Transects_LULC3_ZA_mfb.shp]. Save file outside of personal geodatabase. f) Examine transects cast along artificial edges created by fishnets, both the exterior and interior fishnets. Remove transects which were cast along these artificial edges. g) MERGE transects from all zones in region [TRANSECTS_LULC3_mfb.shp]. h) ADD SURFACE INFORMATION (Input surface= Chesapeake_Bay_Topobathy_DEM_1m_v2.tif; Output property=Maximum slope, Average slope). i) Remove all transects where Maximum and/or Average slope equals -9999 or 0 as this reflects artificial evaluation values in the topobathy file. j) MERGE all regions to create one file of transects for Chesapeake Bay (TRANSECTS_CBslope.shp). Process_Date: 2020 Process_Step: Process_Description: Create points at marsh-forest boundary with the average slope across the transect. The shoreline and baseline files were created 10m on either side of the approximated marsh-forest boundary, so the mid-point of the transects is considered to be the approximate location of the boundary. However, this step does not calculate the slope at the boundary, the value of the point is still the average of the slope across the entire transect. The intent is to provide a visualization of the boundary for users and a file for users to create a boundary line file if they choose. a) GENERATE POINTS ALONG LINES (Input features= TRANSECTS_CBslope.shp; Point placement=percentage; Percentage=50) to create points along the marsh forest boundary with the average and maximum slope values associated with the underlying transect [POINTS_CBslope.shp]. Process_Date: 2020 Process_Step: Process_Description: Added keywords section with USGS persistent identifier as theme keyword (20200807). Added the cross-reference to a primary related publication (20230901). Process_Date: 20230901 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: VeeAnn A. Cross Contact_Position: Marine Geologist Contact_Address: Address_Type: Mailing and Physical Address: 384 Woods Hole Road City: Woods Hole State_or_Province: MA Postal_Code: 02543-1598 Contact_Voice_Telephone: 508-548-8700 x2251 Contact_Facsimile_Telephone: 508-457-2310 Contact_Electronic_Mail_Address: vatnipp@usgs.gov Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: String Point_and_Vector_Object_Count: 217200 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 18 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 Longitude_of_Central_Meridian: -75.0 Latitude_of_Projection_Origin: 0.0 False_Easting: 500000.0 False_Northing: 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: North_American_Datum_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: TRANSECTS_CBslope.shp Attribute Table Entity_Type_Definition: Table containing attribute information associated with the dataset. Entity_Type_Definition_Source: Producer Defined 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: Azimuth Attribute_Definition: Degree from north at which the transect was cast. Added by DSAS. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.0 Range_Domain_Maximum: 360.0 Attribute_Units_of_Measure: Degrees Attribute: Attribute_Label: SHAPE_Leng Attribute_Definition: Length of transect. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 19.866282557 Range_Domain_Maximum: 25.0002340392 Attribute_Units_of_Measure: Meters Attribute: Attribute_Label: Max_Slope Attribute_Definition: Maximum slope of underlying DEM raster cells that the transect crosses. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2.72274851207e-06 Range_Domain_Maximum: 2521.44328217 Attribute_Units_of_Measure: Percent rise Attribute: Attribute_Label: Avg_Slope Attribute_Definition: Average slope of underlying DEM raster cells that the transect crosses. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 5.96046091471e-07 Range_Domain_Maximum: 1434.64672589 Attribute_Units_of_Measure: Percent rise Detailed_Description: Entity_Type: Entity_Type_Label: POINTS_CBslope.shp Attribute Table Entity_Type_Definition: Table containing attribute information associated with the dataset. Entity_Type_Definition_Source: Producer Defined 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: Max_Slope Attribute_Definition: Maximum slope of underlying DEM raster cells that the transect crosses. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 2.72274851207e-06 Range_Domain_Maximum: 2521.44328217 Attribute_Units_of_Measure: Percent rise Attribute: Attribute_Label: Avg_Slope Attribute_Definition: Average slope of underlying DEM raster cells that the transect crosses. Attribute_Definition_Source: Producer Defined Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 5.96046091471e-07 Range_Domain_Maximum: 1434.64672589 Attribute_Units_of_Measure: Percent rise Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - ScienceBase Contact_Address: Address_Type: mailing address Address: Denver Federal Center, Building 810, Mail Stop 302 City: Denver State_or_Province: CO Postal_Code: 80225 Country: United States Contact_Voice_Telephone: 1-888-275-8747 Contact_Electronic_Mail_Address: sciencebase@usgs.gov Resource_Description: TRANSECTS_CBslope, POINTS_CBslope 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 on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: Shapefile Format_Version_Number: ArcGIS 10.6.1 Format_Information_Content: This dataset contains a point shapefile and its components, a plyline shapefile and its components, metadata in xml format, and a browse image. Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://www.sciencebase.gov/catalog/file/get/5e95cbd082ce172707f2528c Network_Resource_Name: https://www.sciencebase.gov/catalog/item/5e95cbd082ce172707f2528c Network_Resource_Name: https://doi.org/10.5066/P9EJ6PGT Access_Instructions: The first link in the network resources is to download data directly. The second link points to a landing page with metadata and data as does the third. Fees: None. No fees are applicable for obtaining the data set. Metadata_Reference_Information: Metadata_Date: 20230901 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Grace D Molino Contact_Organization: U.S. Geological Survey, NORTHEAST REGION Contact_Position: Associate 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 Contact_Electronic_Mail_Address: whsc_data_contact@usgs.gov Contact_Instructions: The metadata contact email address is a generic address in the event the metadata contact is no longer with the USGS or the email is otherwise invalid. Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998