Hydraulic Parameters Sensitivity Analysis of Porous Media at Inverse Solution of Bromide Transport

Abstract

Simulation of water and salt transfer in soil is very effective in managing optimal water and fertilizer use in the field. In this study, the HYDRUS-1D model was used to simulate the transfer of water and bromide in a laboratory column of soil with clay loam texture. Soil hydraulic parameters (including air entry point) α, (saturated hydraulic conductivity) ks, (residual moisture content) θr (saturation moisture content) θs, (pore and particle joint parameter) l (parameter of moisture curve shape) n through measurement and using Retc software was obtained Solubility transfer parameters including difiusion coefficient and actual velocity were estimated using soil hydraulic parameters and bromide concentration data by reverse modeling method. According to the target coefficients, the sensitivity analysis of the physical model was performed .The results showed that the correlation coefficient of observation and simulation bromide concentration in optimal mode was 0.84%. accordingly, the diffusion coefficient was estimated to be 4.9 cm. based on the results of the sensitivity analysis, the saturation hydraulic conductivity had the greatest effect on the variation of this parameter, so that the amount sensitivity coefficient of this parameter was 2.64 The RMSE coefficient with a value of 0.04 was the lowest and ME coefficient with the value of -0.0001 had the most parameter variations.