DETERMINATION OF SOIL HYDROLOGIC PROPERTIES UNDER SIMULATED RAINFALL CONDITION

Two important soil hydrologic properties viz. soil water retention (h- theta relationship) and unsaturated hydraulic conductivity (K-theta re lationship), were determined under simulated rainfall conditions. The h-theta relationship was determined using a rainfall simulator infiltr ometer (RSr). The resulting h-theta relation was then used as input to the Van Genuchten's model (VGM) for determining the K-theta relations hip. In order to validate the results obtained through RSI-VGM combina tion, the commonly adopted instantaneous profile method (IPM) was also applied to develop the K-theta relationship independently. Functional sensitivity analysis, conducted to simulate the soil wafer storage us ing the model Soil Water Actual Transpiration Rate (SWATR), showed tha t the simulated results obtained through RSI-VGM combination were in a greement with those from IPM.