Water accounting of a trans-boundary river basin using satellite observations and WA+ framework

Abstract

The estimation of total water consumptions is useful for watershed management aspect such as for the development of agricultural and environmental services in a trans-boundary river basin. The freely available open access satellite observations viz. CHIRPS and PERSIANN precipitation were evaluated with India Meteorological Department (IMD) precipitation. The satellite observations including MODIS land use/land cover dataset was used in the WA + framework for calculation of water accounting; land use map (WALU) and outcomes from WALU suggested the Rainfed crops–cereals as 40.50% (highest percent) followed by Forest plantation (13.29%) in the study area. The CHIRPS dataset is more close with the observed precipitation than PERSIANN. The value of R2, RMSE, NSE and PBIAS were 0.87, 45.22, 0.86 and −0.91%, respectively for the CHIRPS. The maximum mean water yield (2003–2019) in the basin was accounted as 125 mm/month for CHIRPS. However, for the PERSIANN, it was 40 mm/month. The total water consumptions in the basin for wet year (2018–19) and dry year (2010–11) were 110.0 and 105.3 BCM/year for the PERSIANN. Further, for the CHIRPS, the total water consumptions in the basin for 2013–14 (wet year) and 2015–16 (dry year) are 106.3 and 101.8 BCM/year. The findings from study suggested that non-beneficial component of total water consumptions in the basin was higher than beneficial part. Among the satellite observations, CHIRPS precipitation data is more suitable over the central Himalayan river basin for the study of the hydrological processes.