York County Shoreline Access Structures (yorkco_astru_13)

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator:

Comprehensive Coastal Inventory, Virginia Institute of Marine Science

Publication_Date: 2013

Title: York County Shoreline Access Structures (yorkco_astru_13)

Geospatial_Data_Presentation_Form: vector digital data

Online_Linkage:

<http://ccrm.vims.edu//gis_data_maps/shoreline_inventories/index.html>

Description:

Abstract:

Shoreline Situation Reports (SSR) were first generated by VIMS in the 1970's to report the condition and status of the shore lands. The SSR series were published in hardcopy on a county by county basis for each Tidewater Virginia localities. The reports were intended to assist planners, managers, and regulators in decisions pertaining to management of coastal areas and natural resources therein. This Shoreline Inventory report continues a process which updates and expands the earlier reports. Data collected reports conditions surveyed in the immediate riparian zone, the bank, and along the shoreline.

Purpose: To inventory Virginia's tidal shoreline conditions.

Supplemental_Information:

There are four shapefiles that are part of the 2013 York County Shoreline Inventory database: yorkco_lubc_13, yorkco_astru_13, yorkco_sstru and yorkco_tm_2013. Yorkco_lubc_13 (land use and bank cover for York County) is a linear shapefile containing data about land use, tree fringe, bank height, bank cover, erosion, and beach status along the shoreline. Yorkco_sstru _13 (York County shoreline structures) is a linear shapefile delineating hard structures in place at the shoreline (bulkhead, breakwater,debris, dilapidated bulkhead, riprap, jetty, marina, marsh toe revetment, wharf, unconventional, groinfields). Yorkco_astru _13 (York County access structures) is a point shapefile with locations of docks, public and private ramps, dilapidated docks, and boathouses.Yorkco_tm_2013 is a polygon shapefile delineating tidal marshes in York County The attributes of these four shapefiles are explained in the Entity and Attribute Information section below.

Time_Period_of_Content:

Time_Period_Information:

Currentness_Reference:

With the exception of the tidal marsh inventory, the currentness of this product is coincident with the year(s) of the images used in the data development phase. Tidal marshes also used comparable image year classes but

Status:

Progress: Complete

Maintenance_and_Update_Frequency: None planned

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -76.701109

East_Bounding_Coordinate: -76.389040

North_Bounding_Coordinate: 37.369812

South_Bounding_Coordinate: 37.089040

Keywords:

Theme:

Theme_Keyword_Thesaurus: none

Theme_Keyword: Erosion control structures

Theme_Keyword: Access structures

Theme_Keyword: Shoreline conditions

Theme_Keyword: Shoreline Inventory

Place:

Place_Keyword_Thesaurus: none

Place_Keyword: Virginia

Place_Keyword: Chesapeake Bay

Place_Keyword: York County

Place_Keyword: Back River

Place_Keyword: Bay Tree Creek

Place_Keyword: Carter Creek

Place_Keyword: Chisman Creek

Place_Keyword: Felgates Creek

Place_Keyword: Goodwin Islands

Place_Keyword: Indian Creek

Place_Keyword: King Creek

Place_Keyword: Poquoson River

Place_Keyword: Queen Creek

Place_Keyword: Skimino Creek

Place_Keyword: Wormley Creek

Place_Keyword: York River

Place_Keyword: Back Creek

Access_Constraints: none

Use_Constraints:

These data should not be used for jurisdictional permit determinations beyond providing general shoreline condition or status information. These data have not been surveyed to property boundaries.

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Marcia Berman

Contact_Organization: Virginia Institute of Marine Science (VIMS)

Contact_Position: Direstor of Comprehensive Coastal Inventory (CCI)

Contact_Address:

Address_Type: mailing address

Address: P.O.Box 1346

City: Gloucester Point

State_or_Province: Virginia

Postal_Code: 23062

Country: USA

Contact_Voice_Telephone: 804-684-7188

Contact_Facsimile_Telephone: 804-684-7179

Contact_Electronic_Mail_Address: marcia@vims.edu

Native_Data_Set_Environment:

Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.3000

Data_Quality_Information:

Logical_Consistency_Report:

Chain-node topology present. Linear coverages were built for lines and point coverages were built for points.

Completeness_Report:

All shoreline for York County that has a minimum depth of 2 feet at mean low water was surveyed. Some shorelines are coded remotely if access was restricted due to depth at time of survey. Upper reaches of creeks were often coded remotely as was Back River.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

The York County shoreline inventory published in 2009, recorded shoreline attributes with a GPS unit as the boat moved along the shoreline with a horizontal accuracy of +/- 5 meters. Data was transferred from the GPS boat track to an existing digital shoreline coverage by projecting data to the shoreline at a 90 degree angle from the boat track. Rectified imagery were used as a background coverage to aid in data positioning. Land use features were placed along the shore so changes in land use were coincident with changes illustrated in the imagery. Positional accuracy for data that has been corrected with imagery which has a resolution of 2 meters or better. Accuracy limits of the field collected data, however, are set at 5 meters due to the short occupancy of GPS units. In many cases the image correction yields a final positional accuracy much closer to 2 meters or less, depending on image resolution. For the York County 2013 Shoreline Inventory the shoreline was coded remotely using recent high resolution color infra-red and natural color imagery with a resolution of 1 meter or better along with Bing oblique imagery to identify and code the shoreline for shoreline attributes.

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Originator:

Commonwealth of Virginia, through the Virginia Geographic Information Network (VGIN) of the Virginia Information Technology Agency (VITA)

Title: Virginia Base Mapping Program (VBMP)

Publication_Information:

Publication_Place: Richmond, Virginia

Publisher: Virginia Geographic Information Network

Process_Step:

Process_Description:

The original 2009 York County Shoreline Inventory was developed using these techniques: data was collected by a two-person field crew (one person collecting land use and bank condition data and one boat operator also collecting shoreline features) using two hand-held Trimble GeoExplorers GPS Units, while navigating along the shoreline. A data dictionary designed for the inventory was installed on each GPS Unit. One data collector records natural features including land use, bank height, presence of marsh or beach, and shoreline stability. A second person collects data on the hardened structures: riprap, bulkheads, docks, boatramps, etc. Point features (docks, boathouses, ramps) were surveyed with a six second observation recorded at 1 reading/second. Linear features were surveyed kinematically at a rate of one observation every 3 seconds.

Process_Date: 2009

Process_Step:

Process_Description:

Data from the GPS units were postprocessed on a PC with Trimble Pathfinder Office software. Postprocessing includes differential correction using base station data collected at the VIMS laboratory. Corrected data is converted to shapefiles for further processing.

Process_Date: 2009

Process_Step:

Process_Description:

In the ArcMap environment, boat-track arcs were manually shifted to the base shoreline (VBMP). Arcs were split and moved to locations on the shoreline perpendicular to the original locations on the boat-track. Shoreline arc segments were coded, and the shapefiles were visually checked for attribute accuracy between coded shoreline and boat-track data.

Process_Date: 2009

Process_Step:

Process_Description:

In ArcMap, boat-track points were manually shifted to the base shoreline (VBMP). Points were moved to locations on the shoreline perpendicular to the original locations on the boat-track. Points were coded and the access structure (astru) was visually checked for attribute accuracy between coded shoreline and boat-track data.

Process_Date: 2009

Process_Step:

Process_Description:

Land use, dock, and boathouse locations were digitally checked and repositioned if necessary with VBMP imagery displayed as a background coverage. This was done using ArcMap capabilities. Areas inaccessible by boat due to low tide were coded based on features observed on the imagery. The "remote" coded areas were given the item REMOTE = "yes" to distinquish them from GPS collected data.

Process_Date: 2009

Process_Step:

Process_Description:

The 2009 York County Shoreline Inventory was updated for the 2013 York County Shoreline Inventory using on-screen, digitizing techniques in ArcMap ArcGis 10. The 1998, 2005 and 2007 data served as the baseline for the updates. These data were updated with any observable changes identified from the updated imagery. High resolution oblique imagery available through Bing and VBMP 2011 imagery provided the source data that allowed the inventory to be updated without additional field work. Bing imagery provides an excellent platform to assess changes in land use, presence of erosion control structures, and the location of private/public docks, boathouses, marinas, and boat ramps. The imagery is less suited to accurately assess changes in bank height or bank condition. By and large, these characteristics are relatively stable over time; the exception being areas with extreme exposure that may have been subject to intense storms since the original survey.

Process_Date: 2013

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Vector

Point_and_Vector_Object_Information:

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair

Coordinate_Representation:

Abscissa_Resolution: 0.000000

Ordinate_Resolution: 0.000000

Planar_Distance_Units: meters

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983

Ellipsoid_Name: Geodetic Reference System 80

Semi-major_Axis: 6378137.000000

Denominator_of_Flattening_Ratio: 298.257222

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: yorkco_astru_13

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: pntstruc

Attribute_Definition:

access structures: boathouse, dock, dilapidated dock, private boat ramp and public boat ramp

Attribute:

Attribute_Label: Inv_update

Attribute_Definition: Dates of imagery used

Distribution_Information:

Resource_Description: Downloadable Data

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: Shapefile

Transfer_Size: 0.029

Metadata_Reference_Information:

Metadata_Date: 20131203

Metadata_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Sharon Killeen

Contact_Organization:

Comprehensive Coastal Inventory, Virginia Institute of Marine Science

Contact_Position: GIS Programmer/Analyst

Contact_Address:

Address_Type: mailing address

Address: P.O.Box 1346

City: Gloucester Point

State_or_Province: Virginia

Postal_Code: 23062

Country: USA

Contact_Voice_Telephone: 804-684-7534

Contact_Facsimile_Telephone: 804-684-7179

Contact_Electronic_Mail_Address: sharon@vims.edu

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time