Spatial Estimation of Actual Evapotranspiration for Different Land Use Land Cover using MODIS Data

Abstract

Accurate estimation of evapotranspiration (ET) is very essential for water resources management. In the same climatic and meteorological conditions, actual evapotranspiration (AET) may exhibit remarkable spatial variability across different vegetation covers, agricultural land uses etc. The present study was undertaken to check the feasibility of using MODerate resolution Imaging Spectroradiometer (MODIS) AET data for determining the annual and seasonal AET in Andhra Pradesh and Telangana States. Also, the spatial and temporal variation of actual evapotranspiration (AET) for different land use and land covers was also determined. The mean annual AET showed a significant spatial variation, ranged from 505 mm/year in zaid crop area to 1982 mm/year in waste land. The mean AET for the selected region was 1234 mm/year (excluding build up and water bodies). For almost all the land use land cover (LULC), the value of mean monthly AET started to rise rapidly in July, reached its peak in October, and then declined. In general, all types of LULC show similar seasonal dynamic trends for AET. Among different districts of Andhra Pradesh and Telangana, higher AET was noted from districts with more water bodies such as Krishna, East Godavari and Nellore and lower AET from Chittoor, Ananthapur, Prakasam and Vizianagaram districts. MODIS AET was found suitable for estimating the AET from different land use and land covers except build up and water bodies.