Место издания:Shaheed Bhagat Singh College, Delhi University Delhi
Первая страница:TS-12
Последняя страница:TS-12
Аннотация:The change in agricultural water deficit is evaluated under scenarios of change in climate and irrigation conditions in the Fergana valley, Central Asia. The Fergana valley is located within the Syrdarya river basin and is shared between Uzbekistan, Kyrgyzstan and Tajikistan. The main driver of economic activity in the valley is cotton farming which consumes large volumes of water. Growing population drives irrigation water demand with plans to modernize the irrigation system increasing the irrigated areas by 10 – 15 % underway. However, climate change may alter projected water demand increase in the valley. We estimated the climate-related changes in irrigational water demand in the Fergana valley in 2020s, 2050s, and 2080s using future weather patterns generated by five global circulation models (GCMs) run under the A1FI, A2 and B1 SRES scenarios. Considerably higher temperatures and a moderate change in precipitation lead to increasing potential evapotranspiration (PET), which in turn almost double irrigation water demand by the 2080s – from 10.8 to 20.8 cubic km. Using the geographical information system (GIS) “Distribution of water to the agricultural lands of the Fergana valley”, we found the area under persistent water deficit increasing to 14% by 2020s, 24% by 2050s, and to 36% by 2080s from just 12% currently. Adaptation capacity of the Fergana valley depends on implementation of scientifically substantiated scheme of irrigation according to quality of soils and ground water table, correction of norms of water consumption for different crops, and change of crop composition in favor of the winter horticulture plantations and winter cereals. Our calculation shows effectiveness of this strategy for short and middle terms as the share of lands with water deficit will not exceed the current one. However, by 2080s radical modernization of the irrigation system will be needed to cope with climate change in the Fergana valley.