1879-2015年巴尔喀什湖水位变化及其主要影响因素分析

Analysis of Water Level Changes in Lake Balkhash and Its Main Influencing Factors during 1879-2015

近年来因气候变暖和人类活动影响,巴尔喀什湖水位下降,造成了湖泊及周边区域的生态危机,引起了国际关注。基于巴尔喀什湖流域1879—2015年的湖泊水位、河川径流、降水、气温和土地利用等数据,采用趋势分析、突变检验、周期分析和相关性分析等方法,定量解析了流域湖泊水位、气候和土地利用等变化特征,综合探讨了巴尔喀什湖水位的影响因素。结果表明:1879—2015年,巴尔喀什湖水位在340-344 m呈明显丰枯周期性的变化,变化周期为48-52年;1988—2015年,水位呈现显著上升趋势,增速约为6.91 cm/a。巴尔喀什湖流域主要河流的入湖水量均呈减少趋势,东部主要支流甚至出现断流现象,使得伊犁河入湖水量占比约80%,且不断增大;中国伊犁河流入哈萨克斯坦境内的水量呈增加趋势,但由于普恰盖水库截流蓄水,导致伊犁河下游水量急剧减少。巴尔喀什湖流域农业用地从1928年左右开始到现在经历了"增加—减少—增加—平稳"的变化过程,伊犁河中下游哈萨克斯坦的农业用地扩张和水利工程建设造成了伊犁河入湖水量减少,是巴尔喀什湖水位下降的根本原因。研究结果可为中哈跨境流域水资源合理利用、生态环境保护等提供一定参考。

In recent years,impacts of climate warming and human activities have brought irregular fluctuations of Balkhash Lake’s water level into focus as the issue draws growing attention from the public and politicians.This study uses trend and correlation analysis to quantitatively analyze the changes of lake level,river discharge,precipitation,temperature,and land cover in the Balkhash Lake Basin,and comprehensively explore the influencing factors of lake levels.Results show that the water level of Balkhash Lake exhibited obvious periodic variations between 340-344 m during 1879-2015,and the change period was between 48-52 years.A significant upward trend was detected for the water level from 1988 to 2015,with an increasing speed of about 6.91 cm/a.A decreasing trend was observed for runoff from major rivers flowing into the lake;among them,the amount of water from the Ili River accounted for about 80%with an upward trend.Also,The Ili River’s runoff flowing into Kazakhstan from China has been increasing,suggesting that the water utilization in China does not cause the decrease in the lower stream of the Ili River.The first water storage of the Kapchagay Reservoir directly lead to a sharp decrease in runoff in in the lower reaches of the Ili River,which eventually caused a significant downward trend in lake levels.During this period,the lowest level was about 340.68 m in1987,suggesting a decrease of nearly 2.3 m.Since the Soviet period,agriculture land of the Balkhash Lake Basin has undergone four periods:increasing period,decreasing period,increasing period,and stable period,and the expansion of agricultural land and water conservancy projects in the middle and lower reaches of Kazakhstan resulted in a decrease in the amount of water flowing into the lake from the Ili River.Results obtained from this study could offer a useful reference for the rational utilization of water resources and ecological environment protection in the Sino-Kazakh cross-border river basin.