Agricultural water demands in Central Asia under 1.5 °C and 2.0 °C global warming

Abstract

In the arid region of Central Asia, climate change leads not only to changes in water availability generated by glacier/snow melt in the alpine regions, but also to changes in water consumption. This paper evaluates agricultural water demand and water supply (represented by precipitation) for the five Central Asian countries (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan) under global warming conditions of 1.5 °C and 2.0 °C. As Central Asia is more sensitive to climate change compared to the global average, the temperature is predicted to rise by 1.7 °C and 2.6 °C and precipitation to increase by 9 % and 12 % in global warming scenarios of 1.5 °C and 2.0 °C, respectively. The average crop water requirement (CWR) is expected to increase by 13 mm and 19 mm per year, respectively, under the global warming scenarios of 1.5 °C and 2.0 °C. A widening gap between water supply and water demand is expected compared to the historical period (1976–2005) under global warming scenario of 2.0 °C. Under global warming of 2.0 °C, the anticipated water gaps between precipitation and CWR are projected to increase by 2.8 × 108 m3 and 1.5 × 108 m3 for the rainfed north Kazakhstan region and the irrigated Fergana region while the increase of precipitation could able to meet the increase in CWR under global warming of 1.5 °C. Investigating the water balance for major planting areas in water-limited Central Asia could provide a scientific basis for sustainable development of the entire region.