Estimation of Water Deficit under Climate Change and Irrigation Conditions in the Fergana Valley of Central Asia

Abstract

We evaluated changes in the deficit of irrigation water in the Fergana Valley of Central Asia under different scenarios of climate change and water management. The Fergana Valley is located within the Syr Darya River basin and is shared by Uzbekistan, Kyrgyzstan, and Tajikistan. We estimated the climate-related changes in irrigational water demand in the Fergana Valley in the 2020s, the 2050s, and 2080s. Considerably higher temperatures and a moderate change in precipitation lead to increasing potential evapotranspiration (PET), which nearly doubles the irrigation water demand by the 2080s. This is driving the request for a scientifically substantiated scheme of irrigation that takes into account the quality of soils and the ground water table, correction of the water consumption norms for different crops, and changes in the crop composition in favor of winter horticulture plantations and cereals.