Estimation of evapotranspiration distribution by using NDVI

Abstract

The purpose of this paper is to develop a model for estimating the distribution of evapotranspiration over a wide area covered by forest Vegetation index closely relates to evapotranspiration. Therefore the distribution of NDVI (Normalized Differences Vegetation Index) calculated from NOAA-AVHRR data is compared with the total evapotranspiration evaluated by the conventional method (Thornthwaite method). Correlation between evapotranspiration and NDVI is derived from multiple regression analysis in three basins. It is confirmed that evapotranspiration in a forest is propotional to NDVI. The distribution of evapotranspiration in the basin can be estimated from the correlation.