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Precipitation estimation in mountainous terrain using multivariate geostatistics. Part I: structural analysis

Journal of Applied Meteorology

By:
, , and
DOI: 10.1175/1520-0450(1992)031<0661:PEIMTU>2.0.CO;2

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Abstract

Values of average annual precipitation (AAP) are desired for hydrologic studies within a watershed containing Yucca Mountain, Nevada, a potential site for a high-level nuclear-waste repository. Reliable values of AAP are not yet available for most areas within this watershed because of a sparsity of precipitation measurements and the need to obtain measurements over a sufficient length of time. To estimate AAP over the entire watershed, historical precipitation data and station elevations were obtained from a network of 62 stations in southern Nevada and southeastern California. Multivariate geostatistics (cokriging) was selected as an estimation method because of a significant (p = 0.05) correlation of r = .75 between the natural log of AAP and station elevation. A sample direct variogram for the transformed variable, TAAP = ln [(AAP) 1000], was fitted with an isotropic, spherical model defined by a small nugget value of 5000, a range of 190 000 ft, and a sill value equal to the sample variance of 163 151. Elevations for 1531 additional locations were obtained from topographic maps to improve the accuracy of cokriged estimates. A sample direct variogram for elevation was fitted with an isotropic model consisting of a nugget value of 5500 and three nested transition structures: a Gaussian structure with a range of 61 000 ft, a spherical structure with a range of 70 000 ft, and a quasi-stationary, linear structure. The use of an isotropic, stationary model for elevation was considered valid within a sliding-neighborhood radius of 120 000 ft. The problem of fitting a positive-definite, nonlinear model of coregionalization to an inconsistent sample cross variogram for TAAP and elevation was solved by a modified use of the Cauchy-Schwarz inequality. A selected cross-variogram model consisted of two nested structures: a Gaussian structure with a range of 61 000 ft and a spherical structure with a range of 190 000 ft. Cross validation was used for model selection and for comparing the geostatistical model with six alternate estimation methods. Multivariate geostatistics provided the best cross-validation results.

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Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Precipitation estimation in mountainous terrain using multivariate geostatistics. Part I: structural analysis
Series title:
Journal of Applied Meteorology
DOI:
10.1175/1520-0450(1992)031<0661:PEIMTU>2.0.CO;2
Volume
31
Issue:
7
Year Published:
1992
Language:
English
Publisher:
American Meteorological Society
Publisher location:
Boston, MA
Description:
16 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Applied Meteorology
First page:
661
Last page:
676
Country:
United States
State:
Nevada
Other Geospatial:
Yucca Mountain