Investigation of Semi-Empirical Model of Unsaturated Hydraulic Conductivity Based on Some Measurable Physical Soil Properties, Case Study: Baghin Plain, Kerman

Unsaturated hydraulic conductivity is one of the basic properties of soil that governs the water movement in the field. As application of any of the various available methods in the field deemed impracticable due to its difficulty of implication and high costs، we resorted to a laboratory method and modeling to develop a method، which may be easily used in determining this important parameter. Saturated hydraulic conductivity was determined by the falling head method. Hydrometry method was used for grain size distribution; pH، EC، and contents of mineral carbonate and gypsum were also determined using the approved methods. Unsaturated hydraulic conductivity (Ku) was estimated using the discharge equation in a unit area، the Darcy''s law، neural network، and the RETC، SPSS، Curve Expert، and Excel software. It was observed that the Power subroutine of the SPSS، with the maximum coefficient of determination and the highest correlation coefficient، and the minimum RMSE presents the best model.