Metadata: Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 2015 Title: Assateague Island Sand Areas Extracted from Orthoimagery, 1989 - 2013 Geospatial_Data_Presentation_Form: vector digital data Series_Information: Series_Name: U.S. Geological Survey Data Series Issue_Identification: 928 Publication_Information: Publication_Place: St. Petersburg, Fla. Publisher: U.S. Geological Survey Online_Linkage: https://pubs.usgs.gov/ds/0928/downloads/sand_area_polygons.zip Description: Abstract: Assessing the physical change to shorelines and wetlands is critical in determining the resiliency of wetland systems that protect adjacent habitat and communities. The wetland and back-barrier shorelines of Assateague Island, located in Maryland and Virginia, changed as a result of wave action and storm surge that occurred during Hurricane Sandy, which made landfall on October 29, 2012. The impact of Hurricane Sandy will be assessed and placed in its historical context to understand the future vulnerability of wetland systems. Making these assessments will rely on data extracted from current and historical resources such as maps, aerial photographs, satellite imagery, and lidar elevation data, which document physical changes over time. This USGS Data Series publication includes several open-ocean shorelines, back-island shorelines, back-island shoreline points, sand area polygons, and sand lines for Assateague Island that were extracted from orthoimagery (ortho aerial photography) dated from April 12, 1989 to September 5, 2013. This dataset consists of polygons that represent the sand areas found in orthoimagery taken on the date specified in the filename and in the Date_ field in the feature attribute table. Orthoimagery of Assateague Island were acquired in digital format from U.S. Department of Agriculture (USDA), U.S. Geological Survey (USGS) and Virginia Geographic Information Network (VGIN) courtesy of the Commonwealth of Virginia. Prior to processing, the images were trimmed to the Assateague Island area. Using ERDAS Imagine 9.3, the images were classified into 10-40 classes that were coded either sand or not sand. Using ArcGIS 10.1, the resulting coded raster datasets were converted to polygons and edited. The following list provides additional details about the orthoimagery used. The sand areas for each date is in a separate dataset (shapefile) named asis_sand_po_*.shp where the date, in YYYYMMDD format, replaces the asterisk. The orthoimage date for each polygon is also included in the shapefile attribute table Date_ field. Date State Type Source Resolution 198904129(1) MD DOQQ USGS 1 meter (m) 19940320 VA DOQQ USGS 1 m 20041105 VA NAIP USDA 2 m 20050608 VA NAIP USDA 2 m 20050615 MD NAIP USDA 1 m 20060528 VA NAIP USDA 2 m 20060701 MD NAIP USDA 2 m 20070622 MD NAIP USDA 1 m 20080525 VA NAIP USDA 1 m 20090626 MD NAIP USDA 1 m 20090726 VA NAIP USDA 1 m 20090807 VA NAIP USDA 1 m 20110530 VA NAIP USDA 1 m 20110602 MD NAIP USDA 1 m 20120512 VA NAIP USDA 1 m 20130315 VA VBMP VGIN(2) 1 m(3) 20130905 MD NAIP USDA 1 m DOQQ Digital Orthophoto Quarter Quads NAIP National Agriculture Imagery Program VBMP Virginia Base Mapping Program (1)Color Infrared orthoimagery; all others are natural color. (2)Imagery courtesy of the Commonwealth of Virginia. (3)Resampled from 1-foot resolution imagery. Purpose: These data were extracted from orthoimagery to document the changes to sand areas on Assateague Island due to Hurricane Sandy and over time since 1989. These data will aid in developing an assessment of the physical change in wetlands due to wave action and storm surge from Hurricane Sandy and in determining the resiliency of wetland systems that protect adjacent habitat and communities. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19890412 Ending_Date: 20130905 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -75.413621 East_Bounding_Coordinate: -75.089520 North_Bounding_Coordinate: 38.325818 South_Bounding_Coordinate: 37.850461 Keywords: Theme: Theme_Keyword_Thesaurus: USGS Metadata Identifier Theme_Keyword: USGS:9a335e6e-64b6-4f96-a466-b832f862b74c Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: aerial photography Theme_Keyword: remote sensing Theme_Keyword: orthoimagery Theme_Keyword: orthophotography Theme_Keyword: sand Theme_Keyword: overwash Theme_Keyword: erosion Theme_Keyword: beach Theme: Theme_Keyword_Thesaurus: Global Change Master Directory (GCMD) Theme_Keyword: LAND SURFACE > LAND USE/LAND COVER > LAND COVER Theme_Keyword: OCEAN > COASTAL PROCESSES > BARRIER ISLANDS Theme_Keyword: COASTAL PROCESSES > BEACHES Theme_Keyword: DOI/USGS/CMG > COASTAL AND MARINE GEOLOGY, U.S. GEOLOGICAL SURVEY, U.S. DEPARTMENT OF INTERIOR Place: Place_Keyword_Thesaurus: None Place_Keyword: Assateague Island Place_Keyword: Maryland Place_Keyword: Virginia Place_Keyword: United States Place_Keyword: National Seashore Place_Keyword: Worcester Place_Keyword: Accomack Temporal: Temporal_Keyword_Thesaurus: General Temporal_Keyword: 1989 Temporal_Keyword: 1994 Temporal_Keyword: 2004 Temporal_Keyword: 2005 Temporal_Keyword: 2006 Temporal_Keyword: 2007 Temporal_Keyword: 2008 Temporal_Keyword: 2009 Temporal_Keyword: 2011 Temporal_Keyword: 2012 Temporal_Keyword: 2013 Access_Constraints: None. Use_Constraints: None. However, variability in image quality from one date to another, from one image to another on the same date, and from one part of a single image to another part of the same image, exists due to many factors including variation in sun angle, atmospheric conditions, season, reflectivity of the earth surface, camera angle, camera lens, camera settings, film sensitivity, water turbidity, water depth, tide level, waves, and error in image rectification. No adjustments were made to account for tide level. Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center Coastal and Marine Geology Program as the originator of these data in future products or derivative research. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Person: Kristy Guy Contact_Address: Address_Type: mailing and physical Address: 600 4th St. S. City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8000 Contact_Facsimile_Telephone: 727-502-8181 Contact_Electronic_Mail_Address: kguy@usgs.gov Hours_of_Service: Monday through Friday 9:00 AM to 5:00 PM (Eastern Time) Data_Set_Credit: Acknowledgment of the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center Coastal and Marine Geology Program 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. Users should be aware that 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. These data are not legal documents and are not to be used as such. Native_Data_Set_Environment: Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.2.2.3552. Data_Quality_Information: Logical_Consistency_Report: Assateague Island was divided into five sections and data were extracted by sections and later put together. This resulted in small gaps between sections. More than one unsupervised classification scheme may have been used on a single image due to quality variations within the image. None of the orthoimagery datasets covered the entire island. No adjustments were made for varying tide levels. Completeness_Report: There are void areas due to processing the imagery in sections and incomplete image coverage. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The horizontal accuracy of the data are unknown. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: USGS Publication_Date: 2014 Title: USGS DOQQ Orthoimagery Geospatial_Data_Presentation_Form: orthophotography Publication_Information: Publication_Place: http://earthexplorer.usgs.gov/ Publisher: USGS Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19890412 Ending_Date: 19940320 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: USGS Orthoimagery Source_Contribution: This data source was used to identify sand areas. Source_Information: Source_Citation: Citation_Information: Originator: U.S. Department of Agriculture (USDA) Publication_Date: 2014 Title: USDA NAIP Orthoimagery Geospatial_Data_Presentation_Form: orthophotography Publication_Information: Publication_Place: http://datagateway.nrcs.usda.gov/GDGOrder.aspx Publisher: USDA Type_of_Source_Media: online Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20050608 Ending_Date: 20130905 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: USDA Orthoimagery Source_Contribution: This data source was used to identify sand areas. Source_Information: Source_Citation: Citation_Information: Originator: Virginia Geographic Information Network (VGIN) Publication_Date: 2013 Title: VGIN Orthoimagery Geospatial_Data_Presentation_Form: orthophotography Publication_Information: Publication_Place: Richmond, VA Publisher: VGIN Type_of_Source_Media: digital hard drive Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20130315 Ending_Date: 20130315 Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: VGIN Orthoimagery Source_Contribution: This data source was used to identify sand areas. Process_Step: Process_Description: The orthoimagery was subset to the Assateague Island area. Using ERDAS Imagine 9.3, 10-40 classes were generated by using the unsupervised classification method set to principal axis initializing, 1 standard deviation, 10 iterations maximum, 0.95 convergence threshold, skip factor of 1 for both x and y (no skipping), and zeroes not classified. The resulting classes were examined and coded as either sand or not sand. Source_Used_Citation_Abbreviation: USGS Orthoimagery Source_Used_Citation_Abbreviation: USDA Orthoimagery Source_Used_Citation_Abbreviation: VGIN Orthoimagery Process_Date: 2014 Source_Produced_Citation_Abbreviation: Classified Imagery Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS Contact_Address: Address_Type: mailing and physical Address: 600 4th St. S. City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8000 Contact_Facsimile_Telephone: 727-502-8181 Hours_of_Service: Monday through Friday 8:00 AM to 5:00 PM (Eastern Time) Contact_Instructions: If unable to reach the contact by telephone, please leave a voice message. Process_Step: Process_Description: Using ArcGIS 10.1, the sand coded raster datasets were converted to polygons. Polygons outside the island were deleted. Polygons with areas less than 100 meters2 were deleted. The open-ocean shoreline edge of the polygons were trimmed and filled to a hand-digitized water line (the same-date open-ocean shoreline found within asis_sshrln_1989_2013.shp which is included in this Data Series publication) to simplify the irregular and misclassified areas caused by wet sand and waves. Source_Used_Citation_Abbreviation: Classified Imagery Process_Date: 2014 Source_Produced_Citation_Abbreviation: Sand Polygons Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS Contact_Address: Address_Type: mailing and physical Address: 600 4th St. S. City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8000 Contact_Facsimile_Telephone: 727-502-8181 Hours_of_Service: Monday through Friday 8:00 AM to 5:00 PM (Eastern Time) Contact_Instructions: If unable to reach the contact by telephone, please leave a voice message. Process_Step: Process_Description: Added keywords section with USGS persistent identifier as theme keyword. Process_Date: 20201013 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: GT-polygon composed of chains Point_and_Vector_Object_Count: 2793 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: meter Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Geodetic Reference System 1980 Semi-major_Axis: 6378137.0 Denominator_of_Flattening_Ratio: 298.257222101 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: asis_sand_po_*.shp Entity_Type_Definition: Polygons representing sand areas on Assateague Island extracted from orthoimagery. Entity_Type_Definition_Source: USGS 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: Date_ Attribute_Definition: Date of orthoimage source. Attribute_Definition_Source: USGS Attribute_Domain_Values: Unrepresentable_Domain: Date in month, day, year formatted as text. Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Kristy Guy Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, St. Petersburg, Fla. Contact_Position: GIS/RS Analyst Contact_Address: Address_Type: mailing and physical address Address: 600 4th Street South City: St. Petersburg State_or_Province: FL Postal_Code: 33701 Country: USA Contact_Voice_Telephone: 727-502-8000 Hours_of_Service: Monday-Friday, 9:00-5:00 Eastern Time Resource_Description: DS 928 Distribution_Liability: Although these data were processed successfully on a computer system at the 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. The USGS shall not be held liable for improper or incorrect use of the data described and/or contained herein. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ArcGIS shapefile Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://pubs.usgs.gov/ds/0928/downloads/sand_area_polygons.zip Fees: None if obtained online; otherwise prices vary. Ordering_Instructions: Publications are available from USGS Information Services, Box 25286, Federal Center, Denver, CO 80225-0046 (telephone: 1-888-ASK-USGS, e-mail: infoservices@usgs.gov). Metadata_Reference_Information: Metadata_Date: 20201013 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: USGS Contact_Person: Kristy Guy 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: 727-502-8000 Contact_Facsimile_Telephone: 727-502-8181 Contact_Electronic_Mail_Address: kguy@usgs.gov Hours_of_Service: Monday through Friday 9:00 AM to 5:00 PM (Eastern Time) Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Access_Constraints: None. Metadata_Use_Constraints: None. Metadata_Security_Information: Metadata_Security_Classification_System: None. Metadata_Security_Classification: Unclassified Metadata_Security_Handling_Description: NONE