Closed-contour depressions (polygons)

Metadata:

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

Identification_Information:

Description:

Abstract:

This layer shows the horizontal extent of closed-contour depressions on Guam. The data source is Taboroši, D. (2002), Karst features of Guam [MSc thesis], University of Guam, Mangilao, 324 pp. The contours were derived from a topographic 10-foot contour file for the entire island of Guam by manual editing in which all features except closed contours were removed. This was followed by their conversion and merging into maximum size polygons so that surface extent information is preserved but topographic information is omitted. Note that the outline of the polygon may not delineate the actual outline of the depression.The depressions shown on the map include depressions of a variety of origins: karst sinkholes, low-lying areas in the primary depositional surface, quarried areas, and other types.

Purpose: To inventory karst features of Guam.

Citation:

Citation_Information:

Originator: Danko Taboroši

Publication_Date: 2002

Title: Closed-contour depressions (polygons)

Geospatial_Data_Presentation_Form: vector digital data

Online_Linkage:

<http://www.weriguam.org/reports/item/karst-features-of-guam-mariana-islands.html>

Status:

Progress: Complete

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: 145.375177

East_Bounding_Coordinate: 146.471031

North_Bounding_Coordinate: 15.082883

South_Bounding_Coordinate: 13.875193

Use_Constraints:

Data set is not for use in litigation. The Water & Environmental Research Institute (WERI) cannot assume liability for any damages or misrepresentations caused by any inaccuracies in the data or as a result of the data to be in a particular system. WERI should be given credit for the work involved in creating the dataset.

Data_Set_Credit:

Danko Taboroši, 1998-2000 Graduate Student, University of Guam (WERI)

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Danko Taboroši

Contact_Electronic_Mail_Address: taborosi@islandresearch.org

Keywords:

Theme:

Theme_Keyword: sinkholes

Theme_Keyword: closed-contour depression

Theme_Keyword: quarries

Theme_Keyword: contours

Theme_Keyword: contour lines

Theme_Keyword: polygon

Theme_Keyword: area

Theme_Keyword: karst

Place:

Place_Keyword: Guam

Place_Keyword: U.S. Territory

Place_Keyword: Mariana Islands

Place_Keyword: Micronesia

Place_Keyword: Western Pacific

Place_Keyword: Northwest Pacific

Place_Keyword: Pacific

Place_Keyword: Pacific Islands

Metadata_Reference_Information:

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: local time

Metadata_Contact:

Contact_Information:

Contact_Address:

Address_Type:

REQUIRED: The mailing and/or physical address for the organization or individual.

City: REQUIRED: The city of the address.

State_or_Province: REQUIRED: The state or province of the address.

Postal_Code: REQUIRED: The ZIP or other postal code of the address.

Contact_Person_Primary:

Contact_Person: Maria Kottermair

Contact_Organization: Water & Environmental Research Institute, University of Guam

Contact_Position: Research Assistant III

Contact_Electronic_Mail_Address: mariakottermair@uguamlive.uog.edu

Metadata_Date: 20131010

Distribution_Information:

Resource_Description: Downloadable Data.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Transfer_Size: 3.165

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Vector

Point_and_Vector_Object_Information:

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: sinkholes_polygons

Entity_Type_Definition: Polygons derived from contour lines

Attribute:

Attribute_Label: OBJECTID

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: Id

Attribute:

Attribute_Label: Area_m2

Attribute:

Attribute_Label: Area_ha

Attribute:

Attribute_Label: Area_ac

Attribute:

Attribute_Label: Shape_Length

Attribute_Definition: Length of feature in internal units.

Attribute_Definition_Source: Esri

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Attribute:

Attribute_Label: Shape_Area

Attribute_Definition: Area of feature in internal units squared.

Attribute_Definition_Source: Esri

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair

Planar_Distance_Units: meters

Coordinate_Representation:

Abscissa_Resolution: 0.000000

Ordinate_Resolution: 0.000000

Geodetic_Model:

Horizontal_Datum_Name: D_WGS_1984

Ellipsoid_Name: WGS_1984

Data_Quality_Information:

Lineage:

Process_Step:

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Danko Taboroši

Contact_Electronic_Mail_Address: taborosi@islandresearch.org

Process_Description:

The file was created by editing an existing USGS topographic coverage and removing all lines but the closed-contour depressions and associated tick marks. For that reason, not every single feature is actually karst. Some of it could be primary depositional or man-made features.

Process_Date: 2002

Process_Step:

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Maria Kottermair

Contact_Organization: Water & Environmental Research Institute, University of Guam

Contact_Position: Research Assistant III

Contact_Electronic_Mail_Address: mariakottermair@uguamlive.uog.edu

Process_Description:

Fix topology of major sinkholes (only) by moving parts of a contour line that were obviously shifted to connect to the other parts seamlessly. Topology was not tested using topology funtions in a geodatabase.

Process_Date: 20130914

Process_Step:

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Maria Kottermair

Contact_Organization: Water & Environmental Research Institute, University of Guam

Contact_Position: Research Assistant III

Contact_Electronic_Mail_Address: mariakottermair@uguamlive.uog.edu

Process_Description:

Select only yhe contours (not tick marks and crosses) -> convert 'Feature to Polygon' -> merge all features -> explode -> add geometry field -> calculate geometry.

Process_Date: 20130915

Attribute_Accuracy:

Attribute_Accuracy_Report: Has not been assessed.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

Has not been assessed but visual comparison with the high-accuracy LiDAR-derived contour-lines shows general agreement of location.

Logical_Consistency_Report:

Few contour lines that were not continuous and above the xy tolerance (here 2 meters) were not converted to polygon. Because of the xy tolderance, some polygon outline may differ from the contour lines but not more than 2 meters.

Completeness_Report:

This dataset is believed to be complete based on the source data set.

Lineage: