Usually the energy balance equation is used to estimate evapotranspiration. To calculating the potential evapotranspiration for long periods of time (more than a day), soil heat flux is assumed equal to zero. But in a catchment, the energy balance equation should be in terms of actual evapotranspiration is less than the potential. In this state, the amount of soil heat flux is not equal to zero...

A distributed model for simulating the land surface hydrological processes in the Heihe river basin was developed and validated on the basis of considering the physical mechanism of hydrological cycle and the artificial system of water utilization in the basin. Modeling approach of every component process was introduced from 2 aspects, i.e., water cycle and energy cycle. The hydrological proces...

Salati and Nobre (1990), in a review of the basinscale water vapor budget of the Amazon Basin analyzed by previous studies, pointed out that evapotranspiration accounts for more than 50% of precipitation. This estimate was later confirmed by Nobre et al. (1991) using the water vapor budget of several studies with various horizontal scales within the Amazon Basin. Note that total evapotranspirat...

abstract evapotranspiration (et) is one of the most important components of the water balance, it is also one of the most difficult to measure. despite the importance of et, methods to obtain values of et are still limited. conventional methods are very local, ranging from point to field scale. estimates of the et over the entire area, especially for irrigated areas, are essential, as these can...

in this study, climatic parameters are used to evaluate the sensitivity of reference evapotranspiration in isfahan and rasht with two semi-arid and moderate climates using two intelligent methods during 1970-2010. in this research, multi-layer precpetron e (mlp) and gene expression programming (gep) intelligent models are used in order to analyze the sensitivity of reference evapotranspiration ...