Rapid assessment of climate risks for irrigated agriculture in two river basins in the Aral Sea Basin

Abstract

Understanding of future climate change impacts and successful planning of adaptation measures are of vital importance for Central Asia given the region's economic vulnerability, dependence on scarce water resources, and observed above global average warming rates. This paper analyses how impacts of climate change on the hydrological regimes and temperature patterns could affect the irrigated agricultural production in two case study areas, the Aspara and Isfara river basins. The methodology applied is based on analysis of temperature indicators and current cropping calendars in target locations combined with hydrological simulations by the process-based Soil and Water Integrated Model (SWIM) of the two river basins. The selected climate change projections comprise the moderate and high emissions scenarios - RCP4.5 and RCP8.5. The results reveal that climate change will create unfavourable conditions for irrigated spring crops, due to decrease of discharge during the vegetation period. On the other hand, the projected shift of peak discharge to an earlier date offers benefits for irrigated winter cereals, providing more water for irrigation in spring. Results suggest that, there is an opportunity to adapt the irrigated agricultural production in the selected regions by fitting the cropping calendars to changing vegetation periods and to the timing of peak discharges.