High-resolution Ensemble Climate Projections of Water Deficit in Arid Regions by the Mid-21st Century

Future changes in water deficit in Central Asia are analyzed based on the ensemble simulations with the system of the regional climate model (RCM) and atmospheric boundary layer model (ABLM) developed at the Voeikov Main Geophysical Observatory. It is shown that by the middle of the 21st century the forecasted changes over the irrigated areas are greater by 2.5-4.0 times than those inferred from the standalone RCM simulation without irrigation effects. Future water deficit is forecasted to grow across Central Asia and will lead to 10% larger irrigation water demand per hectare in order to sustain cotton productivity, depending on the conditions of its cultivation at individual farms. The results of the study can be used for the planning of the rational use of agricultural lands and for the effective management of water resources.