Study On The Impacts Of Climate Change And Human Activities On Runoff In The Amu Darya River,Central Asia

Central Asia is characterized by arid climate and fragile ecology,and water resources are extremely sensitive to climate change and human activities.As the largest inland river in Central Asia,the Amu Darya is one of the two main water sources of the Aral Sea.Based on meteorological data,runoff data,irrigation water consumption,and irrigation area,trend analysis and mutation test were used to analyze the changes trends of hydrometeorological elements and clarify the water use of the Amu Darya River basin and the affect on the ecological and environmental changes in the Aral Sea,analysis quantitatively the impact of climate change and human activities in the Amu Darya River on the hydrological processes of the Amu Darya and the withdrawal of the Aral Sea.The results of the study are of great importance to understand the changes trends in water resources in the Amu Darya River basin and to make rational use of water resources across rivers.The detailed research progress is listed as follows:(1)The precipitation in the Amu River Basin showed a decreasing trend: from1950 to the beginning of 1970,the precipitation showed a downward trend;from the early 1970 s to the end of the 1990 s,it showed a slight increase;after 2000,it began to decline.The trend of temperrature after the 1990 s is significant,and the trend of warming is: downstream > midstream > upstream.The sudden changes in temperature and precipitation occurred after the 1990 s,but the time between the two mutations differed by nearly a decade.(2)Under the influence of climate change and human activities,the runoff of the Kelif hydrological station in the upper reaches of the Amu river basin showed an increasing trend,while the overall runoff in the middle and lower reaches showed a decreasing trend.The sudden drop in runoff in the middle and lower reaches of the Amu Darya(Kerki hydrological station to the Aral Sea)occured mainly around 1960 s,the water loss in the middle and lower reaches of the Amu Darya River was severe,which caused by the large-scale development and utilization of land resources by humans in the early 1960 s.The water consumption in the middle and lower reaches of the Amu Darya River increased rapidly until the beginning of 2000,but there wereseveral years of drought in the middle,resulting in the availability of water in the downstream.Water consumption of the Amu Darya River mainly occurs in the middle and lower reaches of the river,and the water consumption in the middle reaches(between the kerki hydrological station and the tuyamuyum hydrological station)and downstream(below the kiziljar hydrological station)are almost the same.(3)Since the 1960 s,human activities,including land use/land cover change,agricultural irrigation,industrial water use,construction of large-scale water conservancy facilities,and water management have had a significant impact on the runoff in the Amu Darya.Above all,the proportion of agricultural water use accout for over 87% of total water amount.Therefore,the increase in agricultural water use,especially in irrigated agriculture,is the main factor leading to the withdrawal of the Aral Sea.