Modelos de Infiltración y Funciones de Pedotransferencia aplicados a Suelos de distinta Textura

Abstract

The knowledge of the process of water infiltration in soil is important in the design of irrigation systems and in the prediction of the vulnerability to the contamination of soil and groundwater. Moreover, it is important to evaluate the efficiency of the hydrological models that predict the movement of water in soil. The objective of this study was to evaluate and to compare the goodness of fitting of Kostiakov-Lewis (K-L) and Philip (Ph) infiltration models to experimental data obtained from three soils: two of them at the Province of Buenos Aires, and the third one at the School of Agronomy’s campus of the Buenos Aires University, (Argentina). Efficiency of Saxton and Rawls (SyR) pedotransfer functions (FPT) on the determination of the Green and Ampt (GA) model input hydraulic parameters and the prediction of the soil-moisture release curve were analyzed too. K-L and Ph models fitted data with R2 coefficient greater than 0.6. Then it was concluded that these models accurately describe the infiltration process of the studied soils. The highest basic infiltration rate (fo) was 0.42 cm min-1 and corresponded to a silty clay soil with organic amendment, and for the other two soils (silt loam and clay loam) were 0.03 and 0.07 cm min-1 respectively. For two of the studied soils, GA model obtained from input parameters determined with the FPT, predicted the infiltration process with an efficiency coefficient (CE) greater than 0.8. However, at some cases, the fitting was not so good for dephts greater than 20 cm. For the silt loam soil, the FPT predicted the soil-moisture release curve with an CE close to 0.9. It might be suggested to carry out a preliminary few number of infiltration tests on any soil under study, and analyze the FPT and the GA model goodness of fit. In this way, the convenience of using these models could be evaluated.