Interpolating water-table altitudes in west-central Kansas using kriging techniques

Kriging is a regionalization technique that incorporates the autocorrelation between known data values in its estimation of values at unmeasured sites. This technique is reproducible, accepts irregularly spaced data, uses only measured values closely surrounding points at which values are estimated, is an exact interpolator at measured data points, and calculates an error of estimate.

Kriging was used to interpolate water-table altitudes for 1978 and an average 1978-80 for the Ogallala aquifer in the Western Kansas Groundwater Management District No. 1. An altitude and an error of estimate were provided at the center of each one-mile section of the district. The data were related to altitudes of the bedrock and the 1950 water table. A digital-contouring procedure was used to construct maps of the water table for 1978 and for the average 1978-80, the errors of estimate, the saturated thickness of the aquifer for 1978 and for the average 1978-80, and the percentage changes in saturated thickness since 1950. Maps made by kriging compared favorably with maps contoured manually by the point-intersection method.