Lancaster County, Virginia 2015 Tidal Marsh Inventory

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Metadata:

Identification_Information
Data_Quality_Information
Spatial_Data_Organization_Information
Spatial_Reference_Information
Entity_and_Attribute_Information
Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator:: Center for Coastal Resources Management, Virginia Institute of Marine Science (VIMS)
Publication_Date: 20160201
Title: Lancaster County, Virginia 2015 Tidal Marsh Inventory
Geospatial_Data_Presentation_Form: vector digital data
Other_Citation_Details:: Center for Coastal Resources Management, Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, Virginia, 23062.
Online_Linkage:: <http://ccrm.vims.edu/gis_data_maps/static_maps/gis/tmi_updated.html>

Description:

Abstract:: The Virginia Institute of Marine Science published the first Tidal marsh Inventories for Virginia in the 1970s. Using high resolution color infra-red imagery from 2013 a new Tidal Marsh Inventory has been developed for Lancaster County. Marsh boundaries were generated using heads-up digitizing techniques at a scale of 1:1,000. Each marsh polygon was classified by morphologic type: fringe, extensive, embayed, or marsh island. Marshes were ground-truthed in the field where a community type index was assigned to each marsh based on plant community make-up. Each marsh was also coded with a marsh number which corresponds to the original 1970s delineation. This will provide an opportunity to review changes that have occurred in the marshes over time.
Purpose:: To maintain and update an inventory of the distribution of tidal marshes for the Commonwealth of Virginia.
Supplemental_Information:: There are four shapefiles that are part of the 2015 Lancaster County Shoreline Inventory database:Lancaster_lubc_2015, Lancaster_sstru_2015, Lancaster_astru_2015 and Lancaster_tm_2015. Lancaster_lubc_2015 (land use and bank cover for Lancaster County) is a linear shapefile containing data about land use, tree fringe, bank height, bank cover, bank stability and beach status along the shoreline. Lancaster_sstru_2015 (Lancaster Countyshoreline structures) is a linear shapefile delineating hard structures in place at the shoreline (bulkhead, dilapidated bulkhead, riprap, wharf, unconventional, debris, marina < 50 slips, marina > 50 slips, jetty, marsh toe revetment, groinfield and breakwaters). Lancaster_astru_2015 ( Lancaster County access structures) is a point shapefile with locations of docks, dilapidated docks, boathouses, and private and public boat ramps. Lancaster County_tm_2015 (Lancaster County tidal marshes) shows the location, size, species and type of tidal marshes. The attributes of these four shapefiles are explained in the Entity and Attribute Information section below.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20150609
Ending_Date: 20150618

Currentness_Reference: ground condition

Status:

Progress: Complete
Maintenance_and_Update_Frequency: Unknown

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -76.634921
East_Bounding_Coordinate: -76.283521
North_Bounding_Coordinate: 37.834455
South_Bounding_Coordinate: 37.606436

Keywords:

Theme:

Theme_Keyword_Thesaurus: None
Theme_Keyword:: Tidal Marsh, Wetland Plant Identification, Wetland Community Type

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Categories
Theme_Keyword: biota
Theme_Keyword: boundaries
Theme_Keyword: environment

Place:

Place_Keyword_Thesaurus: None
Place_Keyword:: Lancaster Creek, Rappahannock River, Corrotoman River, Fleets Bay, Dymer Creek, Indian Creek, Rappahannock Creek, Windmill Point

Access_Constraints: None

Use_Constraints:

The Comprehensive Coastal Inventory Program (CCI) provides these data with the understanding that it is not guaranteed to be correct or complete, and conclusions drawn from the data set are the sole responsibility of the user. See full TMI disclaimer page: <http://ccrm.vims.edu/gis_data_maps/static_maps/gis/disclaimer.html>

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:: Center for Coastal Resources Management, Virginia Institute of Marine Science (VIMS)
Contact_Person: Marcia Berman

Contact_Position: Director Comprehensive Coastal Inventory Program

Contact_Address:

Address_Type: physical
Address: Virginia Institute of Marine Science, P.O. Box 1346, 1375 Greate Rd
City: Gloucester Point
State_or_Province: Virginia
Postal_Code: 23062

Contact_Voice_Telephone: (804) 684-7188

Contact_Electronic_Mail_Address: marcia@vims.edu

Native_Data_Set_Environment:

Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.3.0.4322

Data_Quality_Information:

Logical_Consistency_Report: Polygons are topologically correct. They do not self intersect or overlap.

Completeness_Report:

Tidal marshes observed in the field are the only polygons to be coded for marsh community type. Field collection of marsh data was performed primarily from a small shallow-draft vessel. Surveys extended as far upstream as depth and field conditions allowed. During surveys, marsh boundaries were verified, and wetland plant species observed within each marsh polygon were recorded along with relative cover estimates to determine marsh community types.

Lineage:

Process_Step:

Process_Description:: All processing steps for the shoreline inventory were generated using ArcGIS - ArcMap v10.2.2 while viewing conditions observed in 2015 Bing high resolution oblique imagery and 2013 imagery from the Virginia Base Mapping Program (VBMP). Using the latest VBMP 2013 imagery as a background, conditions visible on shore were used to code a digital shoreline created using VBMP 2013 imagery at a scale of 1:1000. Conditions were also verified using Bing Birds Eye, VBMP 2011, and VBMP 2009 imagery.

Process_Step:

Process_Description:: VBMP imagery, with the marsh polygon layer overlay, was printed for use in field surveys of the marshes.

Process_Step:

Process_Description:: A shoreline for Lancaster County was created using the 2013 VBMP imagery as a backdrop and using ArcGis version 10.1. Using this as a baseline the shoreline inventory was remotely generated using two sources: Google Earth 2015 imagery , and 2013 high resolution imagery available through Bing Maps and 2013 high resolution imagery available from the Virginia Base Mapping Program (VBMP).
Process_Date: 20150101

Process_Step:

Process_Description:: Tidal marshes were delineated from 2013 VBMP imagery using onscreen digitizing techniques at a scale of 1:1,000. Bing and Google Earth online imagery was used to provide additional interpretive information to improve the accuracy of marsh boundaries. Marsh polygons were coded by shape and physiographic setting based on a classification system applied in the first Lancaster County Inventory in Lancaster County (in 1973). Quality assurance and control measures were performed prior to generation of maps for fieldwork.
Process_Date: 20150202

Process_Step:

Process_Description:: Field collection of marsh data was performed primarily from a small shallow-draft vessel, navigating at slow speeds parallel to the shoreline. Surveys extended as far upstream as depth and field conditions allowed. Some additional data collection was performed by land where marshes were easily accessible from public lands. During surveys, marsh boundaries were verified, and wetland plant species observed within each marsh polygon were recorded along with relative cover estimates to determine marsh community types.
Process_Date: 20150601

Process_Step:

Process_Description:: Corrections were made to the digital data back at the lab using ArcGis Version 10.0
Process_Date: 20150701

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: 3087

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Map_Projection:

Map_Projection_Name: NAD 1983 UTM Zone 18N

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: 0.000000002220024164500956
Ordinate_Resolution: 0.000000002220024164500956

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: Lancaster_TMI_2015
Entity_Type_Definition: polygon
Entity_Type_Definition_Source: ESRI

Attribute:

Attribute_Label: FID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: Esri