Actual evapotranspiration (ETa) monitoring has important implications on global and regional climate modelling. It is important for the hydrological cycle and assessment of environmental stress that affects ecosystems. Accurate measurement and estimation of ETa is a basic input used to compute water balances and to estimate water availability and requirements. Most methods for ETa computation can only provide point estimates of ETa for a specific location and fails to provide ETa on a spatial scale and makes it inadequate for proper water resource management. In this book, SEBAL model is used to estimate surface albedo, NDVI, surface temperature and ETa for different land use/cover types (closed woodlands, gallery forests, open woodlands, farmlands, water bodies, barelands, rocky areas and built-up areas) for the Atankwidi and Afram catchments in the Volta basin of Ghana.