Wyoming Water Resources Center, 199702, Wyoming Vadose Zone Sensitivity Ratings at 1:100,000-Scale: Univ. of Wyoming, Spatial Data and Visualization Center, Laramie, Wyoming.Online Links:
This is a Vector data set. It contains the following vector data types (SDTS terminology):
Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest .001. Longitudes are given to the nearest .001. Latitude and longitude values are specified in Decimal Degrees.
The horizontal datum used is North American Datum of 1983.
The ellipsoid used is GRS1980.
The semi-major axis of the ellipsoid used is 6378206.4.
The flattening of the ellipsoid used is 1/294.98.
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.
SDVC Technical Coordinator
Spatial Data and Visualization Center
Box 4008 University Station
Laramie, Wyoming 82071
USA
307-766-2532 (voice)
itasca@uwyo.edu
- Hours_of_Service: 8 AM to 5 PM MST
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 vadose zone rating as one of its parameters. No other suitable uses for this data are known.
Green, G.N. and P.H. Drouillard, 1994, Digital Geologic Map of Wyoming at 1:500,000-scale <URL:http://www.sdvc.uwyo.edu/clearinghouse/metadata/bedgeol.html>.
Case, J.C., Arneson, C.S., and Hallberg, L., 1998, Preliminary 1:500,000-Scale Digital Surficial Geology Map of Wyoming <URL:http://www.sdvc.uwyo.edu/clearinghouse/metadata/bedgeol.html>.
Love, J.D. and A.C. Christiansen, 1985, Geologic Map of Wyoming.
DRASTIC (Aller et al, 1987) defined a sensitivity ranking for vadose zone media, with the vadose zone defined as the unsaturated zone above the water table and below the soil horizon. The EPA ranking ranged from 1 to 10, with rank 1 representing a confining layer with minimal potential for contaminants to migrate to the saturated zone, and rank 10 representing highly fractured and jointed basalt or karst limestone with a high potential for contaminants to migrate to the saturated zone.
The Wyoming State Geological Survey modified the sensitivity ranking for vadose zone media to reflect media present in Wyoming. WSGS added eolian silt (rank 5 to 7), coal sequences (rank 3 to 8), eolian sand (rank 7 to 9), volcaniclastics (rank 3 to 9), and clinker (rank 8 to 10).
The vadose zone in Wyoming is composed of bedrock, surficial materials, or a combination of the two. As a result, a vadose zone rating was assigned to the representative composition of each geological formation or combinations of geological formations present on the Geologic Map of Wyoming. The surficial units present on each geological formation were then defined and assigned a vadose zone rank that reflected the possible influence of the underlying bedrock on the composition and properties of the surficial unit. In many cases, the vadose zone includes both bedrock and the overlying surficial materials, requiring a composite rank that reflects both the bedrock rank and the surficial materials rank. A series of formulas were developed to allow for the generation of the composite rankings. The formulas used for generating a total vadose ranking are presented below where TV = Total Vadose (composite) Rank, BV = Bedrock Vadose Rank, and SV = Surficial Materials Vadose Rank.
Formula Used Surficial Units
TV = SV Ai, aR, ti, tre, fi, ei, gi, li, pea, ki, ai,
oai, Mi, Ki, xi, Ti
TV = 10 glacier, LAKE
TV = BV Ri
TV = 50%BV + 50%SV Ai, aR, ti, tre, li, ki, bi, mi
TV = 75%BV + 25%SV fi, pea, bdi, tdi, fdi, sci, ri, ui
TV = 25%BV + 75%SV ei, gi
see Process Steps
see Process Steps
All polygons are fully attributed.
All polygons are closed and each polygon has one unique label.
Are there legal restrictions on access or use of the data?
- 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>.
SDVC Technical Coordinator
Spatial Data and Visualization Center
Box 4008 University Station
Laramie, Wyoming 82071
USA
307-766-2532 (voice)
n/a
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.
| Data format: | ARCE (Arc/Info export) (version 7.0.4) |
|---|---|
| Network links: |
ftp.sdvc.uwyo.edu or <http://www.sdvc.uwyo.edu/clearinghouse> |
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.
Margo Berendsen
Box 4008 University Station
Laramie, Wyoming 82071
USA
307-766-2751 (voice)
meh@uwyo.edu