A Simulation Model for Soil Moisture and Energy Balance of Paddy Field

The energy balance connects to water balance through the evapo transpiration term in the equation. The research utilizes soil water flow and surface energy balance models that estimates thermal environment, evapotranspiration and soil water flows. A computer program codes were developed based on the models. Energy balance model used in this study was able to calculate separately evaporation and transpiration which values were input to soil water flow. The program gives results of sensible heat energy flux, latent heat energy flux and temperatures below, at and above the canopy as well as soil water profiles. Simulation for rice field soil after irrigation is stopped shows the variation of energy fluxes and temperature, and soil water condition that still providing enough moisture for the plant even though the soil surface turns very dry.