Estimation of Spatial Distribution of Evapotanspiration at a Bare Field and an Irrigated Paddy Field

Abstract

Spatial variation of surface heat and water fluxes should be reasonably integrated. In this paper, spatial distribution of evapotranspiration at a bare field and an irrigated paddy field a re estimated. Based on a set of micro meteorological observations at the surface boundary lay er on the fields, bulk transfer coefficients are estimated first. By using the data of field observation, distributions of soil moisture and surface temperature, and the estimated bulk transfer coefficients, evaporation from soil surface and evapotranspiration from paddy field are calculated. The results show that information of the distributed hydro-meteorological conditions is needed for more exact evaluation of the regional average evapotranspiration.