Wyoming Geohydrologic Setting Sensitivity Ratings at 1:500,000-Scale

Metadata:

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

Identification_Information:

Citation:

Citation_Information:

Originator: Wyoming Water Resources Center

Publication_Date: 199702

Title:

Wyoming Geohydrologic Setting Sensitivity Ratings at 1:500,000-Scale

Publication_Information:

Publication_Place: Laramie, Wyoming

Publisher: Wyoming Water Resources Center

Online_Linkage: <URL:http://www.sdvc.uwyo.edu/clearinghouse/water.html>

Description:

Abstract:

This dataset represents an aquifer sensitivity rating for the Geohydrologic Settings in the State of Wyoming. This dataset is specifically to be used within a DRASTIC-type aquifer sensitivity/vulnerability analysis.

Purpose:

This layer was developed specifically to serve as a parameter in a ground-water vulnerability to surface contamination study conducted at the Wyoming Water Resources Center. The DRASTIC-based model requires geohydrologic setting rating as one of its parameters. No other suitable uses for this data are known.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: unknown

Ending_Date: present

Currentness_Reference: Publication date of sources

Status:

Progress: complete

Maintenance_and_Update_Frequency: no plans to update

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -111.04531329

East_Bounding_Coordinate: -103.84002217

North_Bounding_Coordinate: 44.99712629

South_Bounding_Coordinate: 40.94825784

Keywords:

Theme:

Theme_Keyword: Geohydrologic Setting

Theme_Keyword: Hydrology

Theme_Keyword: Ground Water

Theme_Keyword: Aquifer

Theme_Keyword: Ground-Water Vulnerability

Theme_Keyword: Aquifer Sensitivity

Theme_Keyword: Saturated Zone

Theme:

Theme_Keyword_Thesaurus: none

Place:

Place_Keyword: Wyoming

Place:

Place_Keyword_Thesaurus: none

Access_Constraints: none

Use_Constraints:

This data should not be used for analysis at a scale larger than 1:100,000. Because updates to this dataset or the attached metadata will occur without notice, this dataset may not be redistributed or repackaged in any form without the express written consent of the University of Wyoming Spatial Data and Visualization Center. Instead it is recommended that additional users download the most current version of the data from <http://www.sdvc.uwyo.edu/clearinghouse>.

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: SDVC Technical Coordinator

Contact_Organization: Spatial Data and Visualization Center

Contact_Address:

Address_Type: mailing address

Address: Box 4008 University Station

City: Laramie

State_or_Province: Wyoming

Country: USA

Postal_Code: 82071

Contact_Voice_Telephone: 307-766-2532

Contact_Electronic_Mail_Address: itasca@uwyo.edu

Hours_of_Service: 8 AM to 5 PM MST

Browse_Graphic:

Browse_Graphic_File_Name: <URL:http://www.sdvc.uwyo.edu/images/dtw.gif>dtw.gif

Browse_Graphic_File_Description: geohydrologic setting ratings in Wyoming

Browse_Graphic_File_Type: gif

Native_Data_Set_Environment:

This dataset is a polygon layer created using ARC/INFO version 7.0.4 on a SUN Microsystems UNIX computer. The layer is ARC/INFO export file format and ARC/INFO shapefile format.

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report: see Process Steps

Quantitative_Attribute_Accuracy_Assessment:

Attribute_Accuracy_Value: n/a

Attribute_Accuracy_Explanation: n/a

Logical_Consistency_Report: All polygons are closed and each polygon has one unique label.

Completeness_Report: All polygons are fully attributed.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report: see Process Steps

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Originator: Green, G.N. and P.H. Drouillard

Publication_Date: 1994

Title: Digital Geologic Map of Wyoming in ARC/INFO Format

Type_of_Source_Media: digital map

Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 1994

Source_Currentness_Reference: 1994

Source_Citation_Abbreviation: Digital Geologic Map of Wyoming in ARC/INFO Format

Source_Contribution: source of majority of boundaries used in attributes

Source_Information:

Source_Citation:

Citation_Information:

Originator: Case, J.C., Arneson, C.S., and Hallberg, L.L.

Publication_Date: 1998

Title:

Preliminary 1:500,000-Scale Digital Surficial Geology Map of Wyoming

Type_of_Source_Media: digital map

Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 1998

Source_Currentness_Reference: 1998

Source_Citation_Abbreviation: Surficial Geology map

Source_Contribution: source of majority of boundaries used in attributes

Source_Information:

Source_Citation:

Citation_Information:

Originator: Love, J.D. and A.C. Christiansen

Publication_Date: 1985

Title: Geologic Map of Wyoming

Type_of_Source_Media: paper map

Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 1985

Source_Currentness_Reference: 1985

Source_Citation_Abbreviation: Geologic Map of Wyoming

Source_Contribution: was source for Green and Drouillard (1994) map

Process_Step:

Process_Description:

Geohydrologic Setting represents the aquifer characteristics of the uppermost aquifer. This comprehensive layer replaces both the Aquifer Media and the Saturated Hydraulic Conductivity layers that are used within the standard DRASTIC methodology. For purposes of the DRASTIC project, there was no single comprehensive analysis on the generalized hydrologic characteristics of the geological formations present in Wyoming. There were, however, a number of studies that addressed the hydrology of specific basins or regions within the state. The first step in analyzing the geohydrologic settings for all areas in Wyoming was to determine the generalized hydrologic characteristics for each geological formation present in the state by summarizing the formation-specific hydrologic characteristics published in the Water Resources Research Institute Basin Ground Water Report Series . The Water Resources Research Institute (which became the Wyoming Water Resources Center) reports provided overviews on the occurrence and characteristics of ground water in most basins in Wyoming. The project used the USGS Hydrologic Investigations Atlases to provide ground water reconnaissance for most of the state and selected USGS Water Supply Papers for information on ground water resources and geology for specific areas of the state. Using the above references for guidance, the Wyoming State Geological Survey developed a classification scheme to rank all geological formations in Wyoming by generalized hydrologic characteristics. In cases where the hydrologic characteristics were not described in the literature, the characteristics were estimated, based upon the dominant lithology of the formation. The classification scheme is as follows: 1. Aquiclude/aquitard - low to no yield 2. Aquitard with aquifer interbeds - low yield 3. Aquitard with aquifer interbeds, secondary permeability - low to moderate yield 4. Aquifer and aquitard mixed - moderate to low yield 5. Aquifer with aquitard interbeds - moderate yield 6. Aquifer with aquitard interbeds, secondary permeability - moderate to high yield 7. Aquifer - high to moderate yield 8. Aquifer - high yield The Stratigraphic Chart Showing Phanerozoic Nomenclature for the State of Wyoming (Love, Christiansen, and Ver Ploeg 1993) was used as the basis for the geological formations that were classified. Geological formations were classified within specific geographic regions of the state. Generalized hydrologic classifications assigned to the formations range from a high-yield aquifer to an aquiclude/aquitard with low to no yield. For the purposes of this study, the following definitions of yield were used: High Yield: May provide water supply for irrigation or water supplies for large communities in Wyoming. In general, such formations yield over 100 gallons per minute and may yield thousands of gallons per minute. Moderate Yield: May provide water supply for small communities or for light industrial needs. In general, such formations may yield approximately 30 gallons per minute. Low Yield: May provide a limited water supply for stock or domestic use. In general, such formations may yield up to 5 gallons per minute. The values for yield are approximate, and in localized areas any geological formation may produce significantly more or less water than indicated by the classification. The classification represents average characteristics for a formation over an entire basin. One of the key elements of the Ground Water Vulnerability Mapping Project is the final aquifer sensitivity analysis, which synthesizes data from multiple sources. The project used the 1:500,000-scale Geologic Map of Wyoming (Love and Christiansen 1985) as one of the base layers for the sensitivity assessment. The aerial extent of many geological formations are too small to be shown at a scale of 1:500,000, and some formations with similar ages but dissimilar hydrologic characteristics have been combined on the Geologic Map of Wyoming. As a result, in order to delineate geohydrologic settings many of the formations that were individually classified in regards to their hydrologic characteristics, have been combined with other formations with similar hydrogeologic characteristics, and the combination then reclassified using the scheme presented above. Individual formations may have different classifications based on what area of the state it occurs. DRASTIC (Aller et al 1987) defined a sensitivity rating for saturated aquifer media in large part based upon inferred hydrologic, geologic, and lithologic characteristics for various rock and material types. It ranged from 1 to 10, with 1 representing unfractured massive shale with a low pollution potential and 10 representing well-developed karst limestone with a high pollution potential. Because the Wyoming method uses a more comprehensive Geohydrologic Setting layer instead of individual Aquifer Media and Hydraulic Conductivity layers, the DRASTIC classification was modified to include hydraulic conductivity values from Freeze and Cherry (1979). Relative rankings from the Wyoming model were compared to the relative rankings from the eight-step aquifer characteristics model, presented above. One of the limitations of the DRASTIC model is that sensitivity rankings are largely based upon rock type, lithology, and inferred hydrologic characteristics. The comparison allowed the DRASTIC ranking to be adjusted to reflect the actual hydrologic characteristics of the geological formation or material. Process_Date 1996

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:

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Geographic:

Latitude_Resolution: .001

Longitude_Resolution: .001

Geographic_Coordinate_Units: Decimal Degrees

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983

Ellipsoid_Name: GRS1980

Semi-major_Axis: 6378206.4

Denominator_of_Flattening_Ratio: 294.98

Entity_and_Attribute_Information:

Overview_Description:

Entity_and_Attribute_Overview:

The lone attribute within this layer is called RATING containing an integer value between 1 and 10. This value is the sensitivity rating for the unit with 10 being the highest possible value.

Entity_and_Attribute_Detail_Citation: n/a

Distribution_Information:

Distributor:

Contact_Information:

Contact_Person_Primary:

Contact_Person: SDVC Technical Coordinator

Contact_Organization: Spatial Data and Visualization Center

Contact_Address:

Address_Type: mailing address

Address: Box 4008 University Station

City: Laramie

State_or_Province: Wyoming

Country: USA

Postal_Code: 82071

Contact_Voice_Telephone: 307-766-2532

Contact_Electronic_Mail_Address: n/a

Distribution_Liability:

The distributor shall not be held liable for improper or incorrect use of this data, based on the description of appropriate/inappropriate used described in this metadata document. It is strongly recommended that this data is directly acquired from the distributor described above and not indirectly through other sources which may have changed the data in some way. See the Use_Constraints section of this metadata for appropriate uses/limiations of the data. The distributor makes no claims for the data's suitability for other purposes.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: ARCE (Arc/Info export)

Format_Version_Number: 7.0.4

Format_Version_Date: 1995

File_Decompression_Technique: Export file was created using defaults, no compression

Transfer_Size: 8.9

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name: ftp.sdvc.uwyo.edu or <http://www.sdvc.uwyo.edu/clearinghouse>

Access_Instructions:

Online_Computer_and_Operating_System:

Both the ftp and WWW server which this data is available from is a Silicon Graphics Challenge server, running the IRIX 6.2 UNIX operating system.

Fees:

No fees are required for downloading the data that is on-line. Some fees may be required to cover costs of tapes if data is required on tape media.

Metadata_Reference_Information:

Metadata_Date: 19970616

Metadata_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Margo Berendsen

Contact_Address:

Address_Type: mailing address

Address: Box 3067 University Station

City: Laramie

State_or_Province: Wyoming

Postal_Code: 82071

Country: USA

Contact_Voice_Telephone: 307-766-2735

Contact_Electronic_Mail_Address: meh@uwyo.edu

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998