GLOBAL LAND SURFACE EVAPOTRANSPIRATION ESTIMATION FROM MERRA DATASET AND MODIS PRODUCT USING THE SUPPORT VECTOR MACHINE

Linking the terrestrial water cycles, carbon cycles and energy exchange, evapotranspiration (ET), which combines the surface evaporation and plant transpiration, is a key land surface parameter in water and heat balance of land, lake or river surface, and is central to earth system science. In this study, based on the MERRA reanalysis dataset and MODIS NDVI and LAI product, a support vector machine was used to estimate the land surface ET at sites and global scales. The results showed that, the support vector machine model probably could explain 60%-80% of the land surface ET change at 242 global FLUXnet sites when ten indicators while 56%-79% when five indicators were used to drive the model. For different vegetable cover sites, compared with EC observations, the results of evergreen broadleaf forest was worse than others.