[Application and verification of distributed model in simulating watershed evapotranspiration].

Based on the conventional observed meteorological data during 1989 approximately 2000, a distributed model was employed to simulate the temporal and spatial distribution of the potential and actual evapotranspiration in the upper Zagunao watershed of Sichuan Province. Grids of 500 m and step of 1 d were used to describe the spatial and temporal heterogeneity and variability in the study area. The potential evapotranspiration was simulated by a deformation form of Penman-Monteith Equation, and a method for calculating actual evapotranspiration was proposed, with the underlying conditions considered. The results showed that the relative error of the normal annual evapotranspiration in the 12 years between the simulation and the calculation was 3.47%, with a reasonable temporal and spatial distribution. The research results provided an effective method for the distributed rainfall-runoff model in simulating actual evapotranspiration.