MODELING AND VALIDATING WATER AND ENERGY TRANSFER IN SOIL VEGETATION ATMOSPHERE SYSTEM

A one-dimensional soil-vegetation-atmosphere transfer model including groundwater (GSVAT) is constructed. The model consists of two parts, i. e. soil surface-canopy-atmosphere submodel and sat urated-unsaturated soil submodel. A winter wheat field experimentis conducted to validate the model. Surface energy balance, soil moisture budget and other micromet eorological measurements are measured through jointing to mature period, of 1992 in North China Plain. The simulation of energy balance and soil moisture agree well with the observed. The sensitivity analysis show that the influence of leaf area index (L AI) to evapot ranspiration(ET) is obvious, however it is becoming indisting uishable with a higher LAI; While the minimum stomatal resistance is smaller, it is more sensitive to ET; The response of ET to groundwater table is apparent while water table is between 1.5～1.75 m depth. When the water table is less than 1.5 m, ET decreases due to less intensity of soil evaporation, whereas canopy transpiration is a little bit enhance.