近60 a伊塞克湖水量平衡变化及影响因素分析

Based on the satellite data, the water level and area information of Lake Issyk-Kul was extracted, and the water volume was reconstruct; combined with CRU meteorological data from 1960-2020, the temperature and precipitation observation data from 1960- 2000 at the Cholpon- Ata meteorological station and the water volume observation data into the lake, the lake water balance model was established to analyze the changing characteristics of each element of the water balance and to explore its influencing factors. The results indicated that: (1) Since 1960, the water volume of Issyk-Kul Lake has undergone a process of continuous decrease and fluctuating increase, with 1998 being the inflection point of the change; from the 1960s to the mid-1980s, the water volume into the lake decreased continuously mainly due to the influence of irrigation diversions, and then turned to an increasing trend after 1986 with the decrease of irrigation water and the increase of precipitation and glacial meltwater; precipitation in the lake area increased at a rate of 9.1 mm·(10a)-1 , and the evapotranspiration tends to increase significantly with increasing temperature and lake area. (2) Before the mid-1980s, Issyk-Kul had a negative water balance in most years, and groundwater continued to recharge the lake; since 1986, the water balance deficit of the lake gradually decreased, and since 1998, the positive balance has been dominated. (3) The interaction of water balance components such as runoff, precipitation and evaporation determines the changes in lake water volume, while climate change in the flow-producing areas and irrigation diversions in irrigation areas indirectly drive the changes in lake water volume by changing runoff; from 1960 to 1986, human activities, mainly irrigation diversions, were the dominant factor driving the changes in Issyk- Kul water volume, with a contribution of 71.6%, and since 1987 the cumulative contribution of climate change factors to changes in lake water volume exceeds 80%.