Alik Banerjee, Viral Dave and Ranendu Ghosh
Abstract
Evapo-transpiration (ET) accounts for significant water loss measure in arid and semiarid regions. Moreover, estimating ET in dry and semiarid locations is highly challenging because of the spatial heterogeneity and temporal variability. However, a systematic understanding of ET helps to assess water loss in the system and identifies remedies for it. This study utilized the Surface Energy Balance algorithm (SEBAL) to map ET coefficients for different land use / land covers (LULCs) using experimental data. Estimated ET coefficient values were found to be inconsistent. Therefore, the SEBAL ET values were compared with the ET estimated from standard CROPWAT model. The result validates that the temporal ET values in the CROPWAT model are consistently higher because of ignoring the soil data in the SEBAL model. These differences in the ET values are being balanced through estimation of evaporation from the soil. Once it was found that the estimated ET values were consistent for Ranchi, the SEBAL application was extended to diverse topographies, like Purulia and Dhanbad, to estimate the green water footprint (WFgreen). While Purulia reports the highest temporal mean value of WFgreen (231.3 M3 (*103) per km2), Ranchi illustrates the lowest (185.3 M3 (*103) per km2). Moreover, this study has also analyzed the impacts of WFgreen on water sustainability and the effective utilization of green water by the community.