Fig. 1: Water use and competition for different conditions of green (GWS), blue (BWS), and economic (EWS) water scarcity.
From: Competition for water induced by transnational land acquisitions for agriculture
Gray box: No GWS. Sufficient green water is available for rainfed farming. Yellow box: GWS with EWS and no BWS. Irrigation is needed and enough blue water is available for sustainable irrigation, but irrigation infrastructure is missing; crop-water needs can be met through the implementation of irrigation systems, channels, wells, and other irrigation infrastructure. Light and dark blue boxes: GWS with BWS; irrigation is needed but sufficient blue water is not available to satisfy irrigation needs. These conditions lead to either competition for water because of its limited availability (light blue box) or to meeting crop-water requirements at the expenses of environmental flows (“unsustainable irrigation”, dark blue box). Orange box: GWS but no BWS and no EWS (sustainable irrigation); in these conditions, crop yields can be enhanced by irrigation and both blue water and infrastructure are available to practice sustainable irrigation.
