Assessing water footprints and virtual water flows in Gomti river basin of India

Abstract

This article analyses the blue, green and grey water footprints and virtual water flows within the Gomti river basin (GRB) in India. Assessments were made at spatial resolution of agricultural production units (APUs). An APU is a homogeneous spatial unit delineated on the basis of soil type, agro-ecological region and district boundaries. Water footprints of crop production and consumption were compared to arrive at virtual water balance within the GRB. Results show that water footprint of GRB was 12,773 million m3 year–1. Crop production was the largest water consumer accounting for 95.5% of water footprint within the basin. The higher proportion of blue water footprint (47.3%) indicates the dependence of GRB on irrigated agriculture. Contribution of rainfed agriculture to total water footprint was about 11.2%. Considerable portion of blue water is used in the production of low value water-intensive crops. The GRB was assessed as a net virtual water importer, indicating its dependence on the water resources of other river basins; it imports 2945 million m3 virtual water annually. This scenario can be changed if the area allocated to different water-intensive crops is optimized and limited to the extent that meets the consumption needs within the basin, leading to reduction in production surplus of these crops.