Metadata: Identification_Information: Citation: Citation_Information: Originator: Joseph F. Terrano Originator: Kathryn E.L. Smith Originator: Jonathan Pitchford Originator: Michael Archer Publication_Date: 20241113 Title: Shorelines, shorepoints, and transects with rates for the Point Aux Chenes and Grand Bay Estuaries in Mississippi and Alabama from 1848 to 2023 Edition: 1.0 Geospatial_Data_Presentation_Form: vector digital data Larger_Work_Citation: Citation_Information: Originator: Joseph F. Terrano Originator: Kathryn E.L. Smith Originator: Jonathan Pitchford Originator: Robert L. Jenkins III Publication_Date: 20241113 Title: Estuarine Shoreline, Upland Boundary, and Marsh Habitat Change Analyses for the Point Aux Chenes and Grand Bay Estuary Systems, Mississippi and Alabama Series_Information: Series_Name: U.S. Geological Survey data release Issue_Identification: doi:10.5066/P1HZES2R Publication_Information: Publication_Place: St. Petersburg, FL Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.5066/P1HZES2R Description: Abstract: This dataset represents a compilation of vector shorelines, shorepoints, and transects with rates for the Point Aux Chenes and Grand Bay estuaries in Mississippi and Alabama from 1848 to 2023. Shoreline data were obtained from multiple data sources, including the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the Grand Bay National Estuarine Research Reserve (GNDNERR), and the Mississippi Office of Geology (MOG). All shoreline data types have uncertainty associated with delineating the shoreline location, particularly with vegetated coastlines. For this study, the "apparent shoreline" was mapped for all data sources. The "apparent shoreline" is defined as "where the actual shoreline is obscured by marsh, mangrove, cypress, or other type of marine vegetation, the outer edge of the vegetation is mapped (Shalowitz, 1964). In the case of aerial imagery, vegetation-water boundary was digitized (Smith and others, 2021). Field surveys identified the edge of the dominant vegetation or the eroding scarp line (Smith and others, 2021). WorldView satellite imagery was classified using the normalized difference vegetation index (NDVI) (Maglione and others, 2014; Smith and others, 2021). Regardless of the source, all shorelines were merged into a single file to generate shorepoints and transects, in order to conduct shoreline change analyses. Datasets were compiled and analyzed using the R package Analyzing Moving Boundaries Using R (AMBUR) program (Jackson, 2010). This data release contains shorelines from 1848-2023 along with transects with rates of change joined to the data table, and shorepoints. Several shorelines were specifically digitized for use with transects in this study or have limited spatial resolution and are described in the attribute table or in this metadata record. This data release is an expansion of a previously published 1848-2017 shoreline change data release (Terrano and others, 2018). Purpose: The purpose of these data is to examine the shoreline change rates for estuarine shorelines for the Point Aux Chenes and Grand Bay estuaries in Mississippi and Alabama from 1848 to 2023. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 18480101 Ending_Date: 20230131 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -88.522752 East_Bounding_Coordinate: -88.293545 North_Bounding_Coordinate: 30.425254 South_Bounding_Coordinate: 30.316464 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:5914b08f-08c0-4812-aa76-60f624ffd62f Theme: Theme_Keyword_Thesaurus: USGS Thesaurus Theme_Keyword: coastal processes Theme_Keyword: aerial photography Theme_Keyword: digitization Theme_Keyword: topographic maps Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: oceans Theme_Keyword: environment Theme_Keyword: boundaries Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: shoreline data Theme_Keyword: shoreline map Theme_Keyword: global positioning system Theme_Keyword: satellite imagery Place: Place_Keyword_Thesaurus: Common geographic areas Place_Keyword: Grand Bay National Wildlife Refuge Place_Keyword: Gulf of Mexico Place_Keyword: United States Place_Keyword: Mississippi Place_Keyword: Alabama Place: Place_Keyword_Thesaurus: None Place_Keyword: Grand Bay National Estuarine Research Reserve Place_Keyword: MS Place_Keyword: AL Place_Keyword: USA Access_Constraints: None Use_Constraints: The U.S. Geological Survey requests to be acknowledged as originator of the data in future products or derivative research. Some shoreline data were developed to calculate long and short-term shoreline change rates for specific locations and may not be suitable for studies using different transects. Aerial imagery from Earth Explorer is publicly available and free to download (Earth Explorer, 2023). WorldView imagery remains the property of Maxar Technologies and was accessed through a special use agreement with Maxar Technologies (Maxar, 2022). Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center Contact_Person: Joseph F. Terrano Contact_Position: Physical Scientist Contact_Address: Address_Type: Mailing Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Contact_Voice_Telephone: 727-502-8047 Contact_Facsimile_Telephone: 727-502-8182 Contact_Electronic_Mail_Address: jterrano@usgs.gov Data_Set_Credit: Acknowledgment of the U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, as a data source would be appreciated in products developed from these data, and such acknowledgment as is standard for citation and legal practices. Sharing of new data layers developed directly from these data would also be appreciated by the U.S. Geological Survey staff. These data are not legal documents and are not to be used as such. WorldView imagery was accessed through a special use agreement with Maxar Technologies (Maxar, 2022). Native_Data_Set_Environment: Environment as of Metadata Creation: Microsoft Windows 10 Version 22H2 (Build 19045.3448); Esri ArcMap 10.5.1.7333; XTools Pro (version 17); Esri ArcGIS Pro 3.0.3; R (version 4.0.4), Analyzing Moving Boundaries Using R (AMBUR) r package; ERDAS IMAGINE 2020 (version 16.6.0). Cross_Reference: Citation_Information: Originator: Aaron L. Shalowitz Publication_Date: 1964 Title: Shore and Sea Boundaries Edition: Volume 2 Publication_Information: Publication_Place: Washington D.C. Publisher: U.S. Government Printing Office Other_Citation_Details: Defines an "apparent shoreline" on page 177. Online_Linkage: https://nauticalcharts.noaa.gov/publications/docs/shore-and-sea-boundaries/shore-and-sea-boundaries-vol-2.pdf Cross_Reference: Citation_Information: Originator: Kathryn E.L. Smith Originator: Joseph F. Terrano Originator: Jonathan L. Pitchford Originator: Michael J. Archer Publication_Date: 2021 Title: Coastal Wetland Shoreline Change Monitoring: A Comparison of Shorelines from High-Resolution WorldView Satellite Imagery, Aerial Imagery, and Field Surveys Series_Information: Series_Name: Remote sensing Issue_Identification: Volume 13, Issue 15 (New Insights into Ecosystem Monitoring Using Geospatial Techniques) Publication_Information: Publication_Place: St. Petersburg, Florida Publisher: MDPI Other_Citation_Details: Smith and others (2021) Online_Linkage: https://doi.org/10.3390/rs13153030 Cross_Reference: Citation_Information: Originator: Jackson, C.W., Jr. Publication_Date: 2010 Title: Basic User Guide for the AMBUR package for R Edition: Version 1.0a Publication_Information: Publication_Place: Online Publisher: Chester W. Jackson Jr. Other_Citation_Details: User guide includes requirements for shorelines that are to be run through AMBUR Online_Linkage: http://ambur.r-forge.r-project.org/user/ambur%20basic%20user%20guide%201_0a.pdf Cross_Reference: Citation_Information: Originator: Hapke, C.J., Himmelstoss, E.A., Kratzmann, M.G., List, J.H., and Thieler, E.R. Publication_Date: 2011 Title: National assessment of shoreline change: Historical shoreline change along the New England and Mid-Atlantic coasts Series_Information: Series_Name: U.S. Geological Survey Open-File Report Issue_Identification: 2010-1118 Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: https://doi.org/10.3133/ofr20101118 Cross_Reference: Citation_Information: Originator: Maglione, P., Parente, C. and Vallario, A. Publication_Date: 20140204 Title: Coastline extraction using high resolution WorldView-2 satellite imagery Series_Information: Series_Name: European Journal of Remote Sensing Issue_Identification: Volume 47, Issue 1 Publication_Information: Publication_Place: London, United Kingdom Publisher: Taylor & Francis Group Online_Linkage: https://doi.org/10.5721/EuJRS20144739 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Shoreline change rates are influenced by availability and accuracy of shoreline data. Analyses of highly dynamic areas are particularly challenging, including 1) areas near inlets, where there are excessively dynamic depositional/erosional sand bars that may appear/disappear rapidly, and 2) tidal creeks, where the land/water line is hard to distinguish due to sporadic vegetation lines. Comparisons with other datasets for the same area from other time periods may be inaccurate due to inconsistencies resulting from changes in photointerpretation, mapping conventions, and digital processes over time. Logical_Consistency_Report: Vector features and attributes were checked for completeness and accuracy. Linework is generated by the "Construct transects" and "Filter transects" algorithm in the AMBUR program at a perpendicular angle to the shorelines. In areas where shorelines experience sharp bends, such as in small bays and narrow spits, the filter algorithm often created transects that were not perpendicular to the shoreline. If necessary, transects were manually edited so they crossed the shorelines in a perpendicular direction. Completeness_Report: Dataset is considered complete for the information presented. Some dated shorelines do not have complete coverage over the entire study area (for example, the 2017 shorelines were collected using global positioning system (GPS) and are only available for select study areas). This was acceptable as the analysis method accounts for the available dates only. In addition, select shoreline dates (1942, 1975, 1986, 1992, 2004, 2006, and 2014) were created using a point intersection of shoreline and transect, and are intended for use only with the transects also published in this data release. The 2022 WorldView shoreline was generalized using a 1-meter (m) filter to reduce the number of shoreline vertices. The generalization was acceptable because it only changed some shoreline positions by sub-meter distances. Islands not used in the shoreline change analysis were added back into the final published dataset because they were used to create the raster dataset also published in this data release. AMBUR produces numerous fields during the analysis, most of which are not relevant to the final dataset. Therefore, blank fields are considered acceptable because they have no impact on the final result. These blank fields were not removed to provide consistency with other published data and to provide users all the necessary information to reproduce results. Users are advised to read the rest of the metadata record carefully for additional details. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: A formal accuracy assessment of the horizontal positional information in the dataset has not been conducted. Elevation and water levels were not addressed in this study. For additional information on data collection techniques, see the source metadata. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: Several factors may influence the accuracy and uncertainty of shoreline position for vegetated shorelines, such as water level. Water level at the time of imagery collection is largely unknown for most historical imagery, therefore USGS staff cannot account for shoreline positional errors associated with water level. Published uncertainty estimates for sandy shorelines were used for all shorelines in this study, with the exception of 1993, 1995, 1999, 2001, 2010, 2012, and 2017. Shorelines in this study, with the exception of the dates above, are less conservative than errors that may account for uncertainty in digitization of vegetated shorelines from aerial imagery or satellite imagery. For additional information on data collection techniques or imagery information, please refer to the source agency or source metadata. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Terrano, J.F., Smith, K.E.L., Pichford, J., McIlwain, J., and Archer, M. Publication_Date: 20180926 Title: Shoreline Change Analysis for the Grand Bay National Estuarine Research Reserve, Mississippi Alabama: 1848 to 2017 Edition: Version 2.0 (February 2019) Geospatial_Data_Presentation_Form: vector digital data Publication_Information: Publication_Place: St. Petersburg, Florida Publisher: U.S. Geological Survey Other_Citation_Details: Provides shorelines for Grand Bay from 1848-2017. Online_Linkage: https://doi.org/10.5066/P9JMA8WK Type_of_Source_Media: digital data Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 18480101 Ending_Date: 20171017 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: Shorelines (1848-2017) Source_Contribution: Shorelines previously published within the Grand Bay region from 1848-2017. Source_Information: Source_Citation: Citation_Information: Originator: EarthExplorer Publication_Date: 2023 Title: EarthExplorer Imagery Geospatial_Data_Presentation_Form: raster digital data Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: https://earthexplorer.usgs.gov/ Type_of_Source_Media: digital data Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 1942 Ending_Date: 2014 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: EarthExplorer imagery Source_Contribution: Repository used to acquire remotely sensed imagery such as 1) modern high resolution National Agricultural Imagery Program (NAIP) or 2) historical imagery (such as 1942 black and white images). Source_Information: Source_Citation: Citation_Information: Originator: Maxar Publication_Date: 2022 Title: Global Enhanced GEOINT Delivery (G-EGD) Geospatial_Data_Presentation_Form: raster digital data Publication_Information: Publication_Place: Westminster, CO Publisher: Maxar Technologies (formerly DigitalGlobe Inc.) Online_Linkage: https://evwhs.digitalglobe.com/myDigitalGlobe/ Type_of_Source_Media: digital data Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20220511 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: WorldView 2022 imagery Source_Contribution: Commercial satellite (WorldView) imagery repository. WorldView 2 satellite imagery (image ID number WV220220511164242) was obtained through the National Aeronautics and Space Administration (NASA) Commercial Smallsat Data Acquisition (CSDA) program. For access requirements, contact Maxar Technologies. Process_Step: Process_Description: Shorelines for 1848-2017 were downloaded from the Terrano and others (2018) data release as shapefiles (.shp) that were projected into the North American Datum of 1983 Universal Transverse Mercator zone 16 North (NAD83 UTM 16N). These shorelines were already in the necessary format for the shoreline change analysis and were not modified for use in this study. Since these shorelines originated from several internet sources or were created by the USGS, please refer to Terrano and others (2018) for data sources, processing steps, and attribute accuracy reports related to these shorelines. Source_Used_Citation_Abbreviation: Terrano and others (2018) Process_Date: 2018 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Joseph F. Terrano Contact_Position: Physical Scientist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8047 Contact_Electronic_Mail_Address: jterrano@usgs.gov Process_Step: Process_Description: From 2013 to 2023, coastal managers surveyed shoreline positions using Real-time Kinematic (RTK) GPS at eleven locations in GNDNERR. Shorelines from 2013-2017 were previously published in Terrano and others (2018). Shorelines from 2018-2023 were collected as part of this study using similar methods to the 2013-2017 data. GPS data were collected using a Trimble R8 Model 3 Global Navigation Satellite System (GNSS) and TSC3 data collector from 2013 to 2018, or a Trimble R10 GNSS system and TSC3 data collector from 2018 to 2020. Each was attached onto a 2 m graphite rod with a mounted foot to obtain both horizontal and vertical shoreline position. The positional accuracy of Trimble R8 Model 3 GPS points was ± 10 millimeters (mm) + 1 parts per million (ppm) root mean square (RMS) horizontal error and ± 20 mm + 1 ppm RMS vertical error. The horizontal error of the Trimble R10 GPS points was ± 8 mm + 0.5 ppm RMS and vertical error was ± 15 mm + 0.5 ppm RMS. The points were collected roughly 5 to 10 meters apart along the vegetation-water boundary, which typically represented the top of an erosional scarp. In instances where an erosional scarp was not visible, the most suitable shoreline position based on dense shoreline vegetation was mapped. Shorelines were mapped at GNDNERR quarterly erosion sites or at USGS study sites and do not have full study area coverage. GPS points were then converted into a shapefile. The points were converted into vector shorelines using the XTools Pro (v.17) "polylines from points" tool. The location between each point was interpolated, so the specific shoreline location between each point may not represent the actual shoreline position. Source_Used_Citation_Abbreviation: Shorelines from 1848-2017 published in Terrano and others (2018) Process_Date: 2023 Source_Produced_Citation_Abbreviation: Vectorized GPS point-based shorelines for 2013-2023 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Joseph F. Terrano Contact_Position: Physical Scientist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8047 Contact_Electronic_Mail_Address: jterrano@usgs.gov Process_Step: Process_Description: WorldView 2 imagery from 20220511 (YYYYMMDD, image ID number WV220220511164242) was downloaded from Maxar’s G-EGD. The images were radiometrically and atmospherically corrected and then pansharpened using ERDAS IMAGINE 2020 (version 16.6.0) to obtain measures of ground reflectance. The output image was reprojected into the World Geodetic System of 1984 Universal Transverse Mercator zone 16 North coordinate system (WGS84 UTM zone 16N). The image was then co-registered to high-resolution aerial imagery (NAIP) using the AutoSync-workstation in ERDAS Image pixels. First, an NAIP image mosaic was created for an extent larger than the WV image coverage. Ground control points coincident on both images were used to adjust the WV image to the corresponding location on the NAIP. Control points with an error value greater than 1 were removed. A methodology similar to that described by Maglione and others (2014) was used to generate vector shorelines from WorldView (WV) images. All WV images were classified into land-water rasters using tools within ArcGIS Pro. Then, normalized difference vegetation index (NDVI) was calculated using WV band 5 in the visible red spectrum (RED) and band 7 in the near-infrared spectrum (NIR1) using the following formula: NDVI=(NIR1−RED)/(NIR1+RED). High values (above 0.2) are classified as vegetation, low values (less than -0.2) as water, and in between values (-0.2 to 0.2) as soil. A value of 0.21 provides an adequate representation of the shoreline (wetland-water boundary) and that value was used to reclassify the NDVI to a land-water raster. The land-water raster was processed to reduce isolated pixels by using expand-shrink procedure. The resulting image classified vegetated shorelines. Due to the high reflectance of beach and urban areas a second classification using band 8 (NIR2) with a threshold value of 5000 was used. Values above 5000 were considered urban or beach. The beach/urban classification was merged with the vegetated land classification to create a binomial land-water raster. In ArcMap, the classification boundaries were smoothed to remove any extraneous cells missed in the expand and shrink steps. The raster was then converted into polygons and the polygons were converted into polylines. To smooth the ridged cell edges, the lines were smoothed using the Polynomial Approximation with Exponential Kernel (PAEK) algorithm at a 2-meter smoothing filter. A final quality control was conducted and any shorelines that were not in the study area or shorelines improperly classified (such as nearshore sand shoals) were removed or manually edited. A second USGS GIS user then conducted a second quality control check and updates were made as necessary. Shorelines were projected into NAD83 UTM 16N. The shoreline was run through the Arc Pro "Generalize" tool set to a filter of 1 meter to reduce the number of shoreline vertices. Source_Used_Citation_Abbreviation: Maxar WorldView 2 satellite imagery from 2022. Process_Date: 2023 Source_Produced_Citation_Abbreviation: High resolution satellite imagery derived shorelines for 2022 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Joseph F. Terrano Contact_Position: Physical Scientist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8047 Contact_Electronic_Mail_Address: jterrano@usgs.gov Process_Step: Process_Description: The vectorized shorelines that were produced in the previous process steps were compiled in ArcMap. These vectorized shorelines were manually edited in ArcMap so that only the desired shorelines were included in the final dataset. Once shorelines were edited and checked, all dated shorelines were merged into a single shapefile for inclusion in this data release, Shorelines_1848_2023.shp. Attributes were edited to include information regarding the date and source of the original data. The compiled shorelines were processed using the Analyzing Moving Boundaries Using R (AMBUR) statistical package for R (version 4.0.4) to add required missing attributes and calculate shoreline change rates. AMBUR performs shoreline change analysis on vector digital shorelines (Jackson, 2010). All necessary attribute fields must be present in order to run various AMBUR functions. The following fields are required for boundaries: "Id", "Date_", "Accuracy", "SHORE_LOC", "CLASS_1", "CLASS_2", "CLASS_3", and "GROUP". In order to determine if all the required fields were present in the merged boundary datasets, an AMBUR sub-routine (ambur.check) was used to check all shoreline shapefiles for missing attribute fields. During the shoreline change analysis, AMBUR also creates shorepoints. A shorepoint was created at each transect and shoreline intersect point. Several transects intersected shorelines that doubled back or intersected both sides of an island. In these instances, multiple shorepoints were created for the same date on the same transect. To remove the duplicate points, the shorepoint file was then run through an R code to remove all shorepoints after the first intersection for each date. For more information about the AMBUR shoreline requirements see the AMBUR user manual (Jackson, 2010). Some fields created by AMBUR ("SHORE_LOC", "CLASS_1", "CLASS_2", "CLASS_3", and "GROUP") are required and have null values as placeholders. Several islands within the study area were not used in the shoreline change analysis as they were too far offshore but were retained in the shoreline data set. Null fields were left in the attribute table as they are required by AMBUR and are needed to replicate this study. Source_Used_Citation_Abbreviation: Terrano and others (2018) - 1848-2017 shorelines Source_Used_Citation_Abbreviation: Vectorized GPS point-based shorelines for 2013-2023 Source_Used_Citation_Abbreviation: High resolution satellite imagery derived shorelines for 2022 Process_Date: 2024 Source_Produced_Citation_Abbreviation: Shorelines_1848_2023.shp Source_Produced_Citation_Abbreviation: Shorepoints_1848_2023.shp Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Joseph F. Terrano Contact_Position: Physical Scientist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8047 Contact_Electronic_Mail_Address: jterrano@usgs.gov Process_Step: Process_Description: Transects were generated by buffering the shoreline dataset produced in the previous step to create inner (land-based) and outer (water-based) baselines. The baselines form the start and end point for shoreline-perpendicular transects. Baselines were input into the AMBUR statistical package for R (using R version 4.0.4). AMBUR has several tools, which utilize shoreline parallel baselines to generate transects that are generally perpendicular to the shoreline. Transects were constructed at a sampling distance of 50 meters. Length varied from 1000 to 3000 meters, depending on location, and was selected to cover all dated shorelines. Once transects were created, the "Filter Transects" tool was used to adjust and even out the spread of transects. Where shorelines experience sharp bends, such as in small bays and narrow spits, transects may fall at a non-perpendicular angle. Small islands located within 50 meters of the main island boundary were considered a part of the barrier island system and were included in the analyses. Final transects were checked and edited in ArcGIS Pro, if necessary, in order to improve analysis results and improve shoreline coverage. Transects were manually edited to reduce errors in the analyses. Shoreline points and final statistical analyses were completed in AMBUR to generate the shoreline change rates. The following analysis parameters were used: first intersection (if transect intersects the same shoreline more than once, then by default it selected the first intersection), confidence level 95 (confidence level for the linear regression statistics), unit label m (the units of measure for the map is for Universal Transverse Mercator and in meters), analysis type is advanced (advanced includes additional statistics for a robust linear regression), and time unit for rates is yr (utilizes years for calculating rates of shoreline change). For more information on the AMBUR program, refer to Jackson (2010). Source_Used_Citation_Abbreviation: Shorelines_1848_2023.shp Source_Used_Citation_Abbreviation: Shorepoints_1848_2023.shp Process_Date: 2024 Source_Produced_Citation_Abbreviation: Transects_with_rates_1848_2023.shp Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Joseph F. Terrano Contact_Position: Physical Scientist Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8047 Contact_Electronic_Mail_Address: jterrano@usgs.gov Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 16 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 Longitude_of_Central_Meridian: -87.0 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: Meter 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: Shorelines_1848_2023.shp, Shoreline_shorepoints_1848_2023.shp Entity_Type_Definition: Attribute table associated with the 1848 to 2023 Grand Bay MS/AL vectorized marsh shorelines and shorepoints shapefiles. This is not the complete list of attributes for these datasets. For the remaining attributes and their definitions, please refer to the accompanying data dictionary, AMBUR_Transect_Attributes.docx, included with this data download (Shoreline_change_analysis.zip). Entity_Type_Definition_Source: USGS Attribute: Attribute_Label: Region Attribute_Definition: An identifier for the general location of the vector shorepoint data. This field is only present in Shoreline_shorepoints_1848_2023.shp. Attribute_Definition_Source: USGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: Point Aux Chenes Enumerated_Domain_Value_Definition: Data is within the Point Aux Chenes area. Enumerated_Domain_Value_Definition_Source: USGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: Middle Bay Enumerated_Domain_Value_Definition: Data is within the Middle Bay area. Enumerated_Domain_Value_Definition_Source: USGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: Grand Bay Enumerated_Domain_Value_Definition: Data is within the Grand Bay area. Enumerated_Domain_Value_Definition_Source: USGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: South Rigolets Enumerated_Domain_Value_Definition: Data is within the South Rigolets area. Enumerated_Domain_Value_Definition_Source: USGS Attribute: Attribute_Label: Date_ Attribute_Definition: Date imagery or shoreline was collected using the "MM/DD/YYYY HH:MM:SS" format. Additional information can be found in the "Year" field. The HH:MM:SS was set at 3:00:00 PM for all shorelines as a general placeholder. "Date_" is the required field name used by AMBUR. Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 01/01/1848 3:00:00 PM Range_Domain_Maximum: 01/31/2023 3:00:00 PM Attribute: Attribute_Label: Year Attribute_Definition: 4-digit year in which the imagery was collected. Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1848 Range_Domain_Maximum: 2023 Attribute_Units_of_Measure: Year Attribute: Attribute_Label: Accuracy Attribute_Definition: A value representing the shoreline position uncertainty associated with the imagery type which was used in the shoreline change statistical computations reported by Hapke and others (2011). As stated previously, several factors may influence the accuracy and uncertainty of shoreline position for vegetated shorelines, such as water level. Water level at the time of imagery collection is largely unknown for most historical imagery, therefore USGS staff cannot account for shoreline positional errors associated with water level. Error values are less conservative than errors that may account for uncertainty in digitization of vegetated shorelines from aerial imagery or satellite imagery. The 2017 USGS GPS shoreline accuracy was calculated based on the average positional error of the GPS points for each line segment. The MOG and GNDNERR GPS data was assigned a 5-meter uncertainty value based on reported values in the MOG source metadata. The 2010 and 2012 uncertainty values were computed as the square root of the sum of squares of the image resolution, image uncertainty, and the maximum digitization error of 1 meter. For additional information, see the source metadata. Attribute_Definition_Source: USGS Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.0054 Range_Domain_Maximum: 10.8 Attribute_Units_of_Measure: meters Attribute: Attribute_Label: Source Attribute_Definition: An identifier for the source of the vector shoreline data. Attribute_Definition_Source: USGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: GNDNERR Enumerated_Domain_Value_Definition: Data collected by the Grand Bay National Estuarine Research Reserve. Enumerated_Domain_Value_Definition_Source: USGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: MS Office of Geology Enumerated_Domain_Value_Definition: Mississippi Office of Geology digitized shorelines. Enumerated_Domain_Value_Definition_Source: USGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: NOAA Enumerated_Domain_Value_Definition: NOAA digitized topographic sheet (t-sheet) shorelines. Enumerated_Domain_Value_Definition_Source: USGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: USGS Enumerated_Domain_Value_Definition: Data collected or digitized by the USGS Coastal and Marine Science Center- St. Petersburg, FL. Enumerated_Domain_Value_Definition_Source: USGS Attribute: Attribute_Label: Orig_Name Attribute_Definition: The original name of the downloaded file. Attribute_Definition_Source: USGS Attribute_Domain_Values: Unrepresentable_Domain: A text string describing the name of the file as it was downloaded from the original source or created by the USGS. Attribute: Attribute_Label: Download Attribute_Definition: The web link for the source of the original data. Attribute_Definition_Source: USGS Attribute_Domain_Values: Unrepresentable_Domain: A text string describing the web address for the original source of the imagery or shoreline. Attribute: Attribute_Label: Notes Attribute_Definition: Any data documentation notes. Attribute_Definition_Source: USGS Attribute_Domain_Values: Unrepresentable_Domain: A text string describing the notation. Attribute: Attribute_Label: Shape_Leng Attribute_Definition: System-generated attribute field, which was automatically created by ArcGIS (ArcMap or ArcGIS Pro) to indicate the shoreline length (shoreline file only). Attribute_Definition_Source: ESRI Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 0.013884 Range_Domain_Maximum: 129069.641286 Overview_Description: Entity_and_Attribute_Overview: Shoreline_change_analysis.zip: All remaining attribute information not presented in the above section for the shorelines (Shorelines_1848_2023.shp) and shorepoints (Shoreline_shorepoints_1848_2023.shp) and all entity and attribute information for the transects (Transects_with_rates_1848_2023.shp) were generated by AMBUR (Jackson, 2010). These attributes are defined in the accompanying data dictionary, AMBUR_Transect_Attributes.docx, included with this data download (Shoreline_change_analysis.zip). Unless otherwise noted, no data values are left blank. All distance units are in meters and time units are in years. Therefore, rates of change are presented in meters per year (m/yr). AMBUR produces numerous fields during the analysis, most of which are not relevant to the final dataset. These blank fields were not removed to provide consistency with other published data and to provide users all the necessary information to reproduce results. Transects that intersected two or fewer shorelines only calculated net shoreline movement (NSM) and end point rate (EPR) statistics. Entity_and_Attribute_Detail_Citation: The entity and attribute information were generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information. Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center Contact_Person: USGS SPCMSC Data Management Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: Saint Petersburg State_or_Province: FL Postal_Code: 33701 Country: United States Contact_Voice_Telephone: 727-502-8000 Contact_Electronic_Mail_Address: gs-g-spcmsc_data_inquiries@usgs.gov Resource_Description: Shorelines_1848_2023.shp, Shoreline_shorepoints_1848_2023.shp, and Transects_with_rates_1848_2023.shp Distribution_Liability: This digital publication was prepared by an agency of the United States Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: Shapefile Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-P1HZES2R/data/Shoreline_change_analysis_1848_2023.zip Fees: None. No fees are applicable for obtaining the dataset. Metadata_Reference_Information: Metadata_Date: 20241113 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center Contact_Person: USGS SPCMSC Data Management Contact_Address: Address_Type: mailing and physical Address: 600 4th Street South City: Saint Petersburg State_or_Province: FL Postal_Code: 33701 Country: United States Contact_Voice_Telephone: 727-502-8000 Contact_Electronic_Mail_Address: gs-g-spcmsc_data_inquiries@usgs.gov Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998