COMPARISON OF SEBAL-BASED EVAPOTRANSPIRATION WITH LYSIMETERIC DATA

摘要

There are several algorithms for estimation of crop evapotranspiration such as SEBAL (Surface Energy Balance Algorithm for Land). In this study, SEBAL was used for estimation and evaluation of agricultural crop evapotranspiration by using of MODIS, NOAA, and ASTER imaginary and meteorological data of Kerman province and consequently results were compared with lysimeteric data. Due to hot and dry climate of the study area, optimum value of L (soil adjustment factor) had to be determined. Results show that increasing of L causes increasing of estimated evapotranspiration and minimum errors occurred when L equals to 1. In this case, RMSE was 0.29 and 0.76 by the use of MOSIS and NOAA imaginary respectively. Relative error of evapotranspiration estimation by SEBAL from MODIS, NOAA and ASTER images are 10%, 13% and 3.57% respectively. Errors are introduced by the difference in time of irrigation and different characteristics of cultivated plant in lysimeter data, adjacent farms, around area and interpolation of hourly meteorological data.