气候变化对可可西里盐湖流域湖泊水量变化的影响分析

湖泊是气候变化的敏感指示器。为了研究气候变化对湖泊水量的影响,以盐湖流域为研究区,应用统计方法对1989—2018年降雨、气温、蒸发进行线性趋势和突变分析,采用多源卫星遥感技术对湖泊面积等水文要素进行监测,分析湖泊面积与气象要素、湖泊面积与湖泊水量之间的相关性。利用VIC模型模拟径流并结合计算的冰川水量得到盐湖径流组成,定量探讨气象要素对湖泊水量变化的影响,综合分析2011年前后气象要素影响流域湖泊水量的差异。结合统计分析与水文模型定量计算可知:年降雨量、年平均气温显著升高,年蒸发量呈下降趋势,且与湖泊面积有较好的相关性。湖泊面积与湖泊水量间相关性较高,可间接体现气象要素对湖泊水量变化的影响。2011年前卓乃湖和盐湖水量变化主要受降雨量影响,库赛湖和海丁诺尔湖水量变化主要受气温影响;2011—2014年4个湖泊水量变化主要受降雨量影响;2015—2018年4个湖泊水量变化中降雨增加量、冻土释水和地下水补给增加量、冰川融水量对湖泊扩张的贡献约为34.48%、57.66%、7.86%,气温变化成为影响湖泊水量变化的主要因素,降雨量影响次之。

Impact of Climate Change on the Change of Lake Water Volume in the Hoh Xil Salt Lake Basin

Lakes are sensitive indicators of climate change.In the aim of studying the impact of climate change on lake water volume,statistical methods were applied to examine the linear trend and abrupt changes of rainfall,temperature,and evaporation from 1989 to 2018 in the Hoh Xil Salt Lake Basin.Hydrological elements such as lake area were monitored by using multi-source satellite remote sensing technology,and the correlation between lake area and meteorological elements,lake area and lake water volume changes were analyzed.Moreover,the impact of meteorological elements on the changes in lake water volume was quantified by obtaining the composition of the Salt Lake runoff in association with VIC model-simulated runoff and calculated glacier water volume.The differences in the impact of meteorological elements on lake water volume in the basin before and after 2011 were also comprehensively scrutinized.The statistical analysis and quantitative calculation of hydrological models manifest that the annual rainfall and annual average temperature in the Hoh Xil Salt Lake Basin have increased significantly,while annual evaporation has presented a downward trend,all in good correlation with lake area.Lake area is highly correlated with lake water volume,which indirectly reflects the impact of meteorological elements on lake water volume changes.Before 2011,the changes in the water volume of Zhuonai Lake and Salt Lake were mainly affected by rainfall,and the water volume changes in Kusai Lake and Hading Knoll were mainly affected by temperature;from 2011 to 2014,changes in the water volume of the four lakes were mainly affected by rainfall;from 2015 to 2018,the increase in rainfall,the release of water from frozen soil and the increase in groundwater recharge,and the amount of glacial melting water contributed about 34.48%,57.66%,and 7.86%,respevtively,to the expansion of the four lakes.Temperature changes have become the major factor,followed by rainfall,affecting the changes in lake water volume.