Effect of Matching Point Moisture Content on the Predictability of Unsaturated Hydraulic Conductivity for Different Qualities of Water and Soil Texture

A comparison was made between the calculated (Green and Corey's equation based on pore-size distribution) and observed (obtained from soil water diffusivity, D [θ], and moisture retention curves) values of unsaturated hydraulic conductivity [K(θ)]. For calculating K(θ), three matching moisture contents, namely low, medium and high were considered. The results on K (θ) were obtained in relation to water quality (good, saline and sodic) and soil texture (sandy loam and clay loam). The agreement between the values of K(θ) as obtained by these two procedures was in the order: normal water > saline water > sodic water. Matching at mid moisture content recorded the highest agreement followed by those at high and low moisture levels. Both the soils behaved almost similarly.