Defining Spatial Heterogeneity of Hillslope Infiltration Characteristics Using Geostatistics, Error Modeling, and Autocorrelation Analysis

Abstract

AbstractProcedures that can characterize spatial correlation and interpolate values at unknown locations can be valuable in capturing spatial trends, may increase sampling accuracy, and reduce error. This study sought to compare three common methods of measuring infiltration, the double ring (DR), sprinkler (SPR), and frame (FRM) methods, on a hillslope to characterize the spatial structure of the infiltration measurements. All infiltration method measurements were log normally distributed; therefore, universal kriging estimators were developed in conjunction with semivariogram analysis and an error model to interpolate infiltration rates under wet and dry antecedent soil conditions. Variability in measured infiltration rates were greatest from the DR and SPR methods, coefficients of variation (CV) ranged from 42–53%, whereas the CV of the FRM method was 27%. This, however, is not unexpected, as the DR and SPR methods had highly significant directional trends and captured a much larger range in infiltrati...