The Study of Water and Energy Balance on a Paddy Field

Abstract

Water and energy balance estimation plays significant role in the prediction of water availability, consumption and the planning of water supply for food production land. The energy balance connects to water balance through the evapotranspiration term in the equation. The research utilizes models and programs that estimates thermal environment, evapotranspiration, ground and soil water flows. New computer program codes were developed based on the models for some case, and using available scientific softwares for other case. Energy balance model used in this study was able to calculate separately evaporation and transpiration which values were input to soil water flow and groundwater flow model. The shallow groundwater was relatively stable and provided moisture for upper layer soil. The paddy soil surface turned to be very dry in the absent of irrigation and rainfall, but keep sufficient moisture in the deeper layer around the rooting zone.