Measurement of In-Situ Unsaturated Hydraulic Conductivity Using Inverse Approach

Abstract

The number of inverse approaches already been used for unsaturated hydraulic conductivity  estimation. Which are mostly based on the laboratory-scale experiments and not much compatible with in-situ conditions. In this study,an inverse approached was used for in-situ estimation. The in-situ measured saturated hydraulic conductivity  and soil water content data was used in RETC computer code for parametersoptimization. The optimized parameters , , and , wereused in analytical models for  estimation and compared withthe observed . During this study an exponential functionwas alsomodified for  estimation, which performed well when compared to the observed data. The selected models were evaluated using Root Mean Squared Error (RMSE), Nash Sutcliff efficiency, and Coefficient of determination . The Van Genuchtensoil water retention and Mualempore size distribution modelperformed well having 96% model efficiency, RMSE was1.43E-04, and 0.97. The modified exponential function efficiency was 78%, and RMSE was 3.53E-04 for in-situ estimation.