SYNERGISM OF MULTISPECTRAL SATELLITE-OBSERVATIONS FOR ESTIMATING REGIONAL LAND-SURFACE EVAPORATION

The global water cycle is perhaps the most important of all the biogeochemical cycles, and land surface evaporation, which is a significant component of the water cycle, is also linked with heat and carbon cycles. Long-term, regional and global land surface evaporation have been computed using meteorological and river runoff data, although much uncertainties remain due to inadequacy of the input data. Multispectral observations could aid in estimating evaporation by providing spatially representative, multitemporal data for surface characteristics and fluxes. Estimation of evaporation using the residual method with coarse resolution multispectral satellite observations in the optical region is briefly reviewed. Then, semiempirical equations are used to relate unstressed transpiration to potential evaporation and vegetation indices, and correlations among multispectral data are discussed in the context of estimating evaporation.