| 引用本文: | 李想,张雪芹,徐晓明.近40年来贝加尔湖区气候变化及其对湖泊水位的影响.湖泊科学,2022,34(1):219-231. DOI:10.18307/2022.0118 |
| Li Xiang,Zhang Xueqin,Xu Xiaoming.Climate change and its effects on the water level of Lake Baikal region since the 1980s. J. Lake Sci.2022,34(1):219-231. DOI:10.18307/2022.0118 |
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| 摘要: |
| 气候变化对湖泊水位的影响是湖泊研究的关注热点.作为欧亚大陆最大淡水湖，贝加尔湖水位变化深受自然因素和人类活动的共同影响.在全球变暖背景下，贝加尔湖水位升降将对维系流域生态系统与社会发展至关重要.为此，基于湖区气象站、水文站和湖泊水位观测数据，采用突变检验、变异系数检验等方法，分析了过去40年贝加尔湖周边气候变化及其对水位的影响.主要结论如下：1980-2019年，贝加尔湖及其周边区域气温整体呈显著上升趋势（0.31℃/10 a），其空间分布主要受纬度和海拔影响；年际降水波动较大（变异系数达0.2左右），但变化趋势不显著，其空间分布主要影响因素为地形.过去40年，贝加尔湖平均水位为456.42 m，水位发生多次大幅波动.1980-2015年，色楞格河和安加拉河径流量总体呈先增加后减少的变化格局，是导致贝加尔湖水位先上升后下降的重要原因.而入湖、出湖径流的高低主要受控于降水的多寡.通径分析结果表明，降水是影响贝加尔湖水位变化的主要气象因素，降水通过直接补给和入湖径流补给共同影响贝加尔湖水位.本文将水位转折的原因大致划分为3类：第1类是气候变化驱动型，指1982-1983、1985-1987和2013-2015年这3个阶段的水位突变过程；第2类是气候变化与人类活动共同驱动型，以1995-1996年水位大幅下降过程为例，气候变化与流域内人类活动共同导致了水位突变；第3种类型是气候变化背景下的人为调控驱动型，这是贝加尔湖特有的水位变化驱动类型，即俄罗斯联邦政府立法通过下游水利枢纽工程人为调控湖泊水位.由于持续的暖干气候条件，贝加尔湖2015-2017年水位被严格控制在456.07 m左右的低水位.本研究将为贝加尔湖未来气候变化预估、后续水位调控以及流域灾害防控提供理论支撑. |
| 关键词: 气候变化 湖泊水位 径流 突变检验 贝加尔湖 |
| DOI：10.18307/2022.0118 |
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| 基金项目:中国科学院战略性先导科技专项子课题（XDA20030203）和第二次青藏高原综合科学考察研究项目（2019QZKK0202）联合资助. |
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| Climate change and its effects on the water level of Lake Baikal region since the 1980s |
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Li Xiang1,2, Zhang Xueqin1, Xu Xiaoming1,2
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1.Key Lab of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, P. R. China;2.University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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| Abstract: |
| The impact of climate change on lakes is one of the lake research foci. As the largest freshwater lake in Eurasia, Lake Baikal is impacted by both the natural environment and human activities. Hence, it is indispensable to discuss how Lake Baikal will change with global warming to guarantee the watershed ecological balance and regional sustainable development. We, therefore, analyzed the climate change in the Lake Baikal region and its impacts on the water surface level of Lake Baikal over the past 40 years, with the coefficient of variation test and multi-methods of abrupt change test using the observation data from meteorological stations, hydrological stations and water level of the lake surface. The main conclusions are summarized as follows. From 1980 to 2019, the annual average temperature around Lake Baikal shows a significant rising trend of 0.31℃/10 a, and its spatial distribution is mainly affected by latitude and altitude. The annual average precipitation fluctuates remarkably with a variation coefficient of about 0.2, and the overall variation trend is not significant. The main controlling factor of its spatial distribution is topography. In the past 40 years, Lake Baikal's average water level is 456.42 m, and the water level has undergone several sharp changes. The runoff in Selenga River and Angara River increases first and then decreases during 1980-2015, leading to the water level changes of Lake Baikal synchronously. The results of path analysis show that precipitation is the main meteorological factor affecting the water level of Lake Baikal. Precipitation affects the water level of Lake Baikal through both direct recharge and runoff recharge. We roughly divide the causes of water level transition into three categories. The first type is the climate change-driven type, which refers to the abrupt changes in water level during 1982-1983, 1985-1987, and 2013-2015. The second type is the combination of climate change and anthropogenic activities. Taking the dramatic decline of water level in 1995-1996 as an example, climate change and the increase of human water use in the basin led to the dramatic shift in water level. The third type is government regulation control with climate change, which is unique to Lake Baikal. That is, the government regulates the water level of the lake artificially through the downstream hydroelectric facilities. Due to the continuous warm and dry climate conditions, Lake Baikal's water level is strictly controlled at a low value of 456.07 m from 2015 to 2017. This study hopefully will provide theoretical support for the projection of climate change, water level control, and disaster prevention of Lake Baikal Basin. |
| Key words: Climate change water level of lake runoff abrupt change detect Lake Baikal |
