Inverse Solution of Soil Hydraulic Conductivity and Resistance of Plant to Uptake of Water under Field Conditions using Soil Moisture Content Data and Numerical Modeling

摘要

Inverse procedures or indirect methods of estimating soil hydraulic conductivity, K_z are model-based techniques that relate primary model variables such as volumetric water content (6), soil water suction , or discharge to K_z and the soil-water characteristic curve. In this study, an inverse procedure was developed to determine K_z and plant resistance to water uptake, R under field conditions using soil moisture data and numerical modeling. The experimental data corresponding to and come from extensive field tests conducted on an 8-ha furrow irrigated tomato plot wherein the moisture content data were taken at 36 grid locations and at 3 different depths (15, 45 and 75 cm). First, response surfaces were created for each combination of K_z and Rusing a 1-D water transport model and then, an inverse solution process wasutilized to seek the optimum values of K_z and R that predict the measured values of 0 with time following irrigation with minimum error. Data from four randomly selected grid locations were used for this purpose and high correlation coefficient betweenthe model predicted and experimental 0 in all the grid locations confirms that the inverse solution procedure works reasonably well.