Continuidade espacial da condutividade hidráulica saturada do solo na bacia hidrográfica do Alto Rio Grande, MG

Abstract

Spatial distribution of the saturated hydraulic conductivity (k0) is essential in the study of soil erosion and surface runoff. The purpose of this study was to investigate the spatial continuity of the soil hydrologic characteristic k0 in the watershed Alto Rio Grande, state of Minas Gerais, and to map k0 based on geostatistical procedures, using data without and with logarithmic transformation. Exponential and spherical semi-variogram models were fitted to the experimental semi-variograms in two approaches: ordinary minimum square (MQO) and weighted minimum square (MQP). Cross validation and predictive validation were both applied to choose the best model. The results showed that the use of log (k0) improved the geostatistical applicability due to a reduction in the number of outliers and anisotropy; however, the spatial dependency degree was highest for k0 data without log-transformation. The spherical model fitted by MQO preformed best in the spatial continuity modeling of k0. The spatial distribution in the basin, indicated by the maps developed from data without and with log transformation was not the same; the map developed on the basis of log-transformed data showed a more detailed spatial distribution.