Irrigation-induced land water depletion aggravated by climate change
Yi Yao, Wim Thiery, Agnès Ducharne, Benjamin I. Cook, Anxin Ding, Steven De Hertog, Petra Sieber, Kjetil Schanke, Pedro F. Arboleda-Obando, Jeanne Colin, Maya Costantini, Bertrand Decharme, David M. Lawrence, Peter Lawrence, L. Ruby Leung, Min‐Hui Lo, N. Devaraju, Ren-Jie Wu, Tian Zhou, Jonas Jägermeyr, Sonali McDermid, Yadu Pokhrel, Yusuke Satoh, Tokuta Yokohata, Lukas Gudmundsson, Sonia I. Seneviratne
Abstract
Abstract Agricultural irrigation has experienced rapid expansion, and its growing freshwater consumption is potentially exacerbating water scarcity issues. Previous studies predominantly relied on observations or land-only simulations, often neglecting land–atmosphere interactions or failing to capture long-term evolution. We therefore analyse the effects of historical irrigation expansion on water fluxes and resources using seven Earth system models. Here we show that irrigation expansion in many regions substantially decreases the net water influx from the atmosphere to land, further aggravating the existing drying trends caused by climate change. For example, irrigation expansion changed the trend of this net influx from −0.664 ( ± 0.283) to −1.461 ( ± 0.261) mm yr −2 in South Asia after 1960. Consequently, the local terrestrial water storage depletion rate is substantially enlarged by irrigation expansion (for example, from −2.559 ( ± 0.094) to −16.008 ( ± 0.557) mm yr −1 ). Our results attribute the land water loss to irrigation expansion and climate change, calling for immediate solutions to tackle the negative trends.