青藏高原可可西里卓乃湖溃堤成因及其影响分析
作者:段水强%LIANG Tiangang%DU Yue%LIU Baokang%侯扶江%杜玉娥%HOU Fujiang%LI Lin%任继周%REN Jizhou%DUAN Shuiqiang%刘宝康%梁天刚%李林
单位:甘肃省科学院自然能源研究所%兰州大学草地农业科技学院%青海省气象科学研究所%青海省水文水资源勘测局
In recent years,there is a warm and wet tendency over the Tibetan Plateau,as a result,the lake lev-els extensively rise up and dike burst happens occasionally. In this study,the TM(ETM+)history document da-ta and environmental mitigation satellite(HJ-1A/B)CCD data in the Zonag Lakes(including Kusai Lake,He-din Noel Lake and Yanhu Lake),combined with the air temperature,precipitation data from Wudaoliang Meteo-rological Station,were used to analyze the variation of lake surface area. The results showed that from 1961 to 2012,precipitation had increased in Hoh Xil,which was the basis of the Zonag Lake outburst. Two strong pre-cipitation processes occurred before August 22,2011 and then followed by a continuous precipitation,which led to a substantial leakage of the lakes,and finally led to outburst. There were two earthquake events before the dike burst,which may have a certain influence on the basin structure of the lakes,accelerating the dike burst pro-cess. Outburst of the lake led to shoreline retreat and land desertification,which deteriorated the Tibetan ante-lope farrowing environment and resulted in adverse impact on the surrounding grassland ecology environ-ment and major engineering projects.%受青藏高原暖湿化趋势的影响,近年来高原湖泊水位普遍上涨,湖泊溃堤时有发生。利用青藏高原可可西里卓乃湖、库赛湖、海丁诺尔湖和盐湖所在区域的TM(ETM+)等历史文献数据和环境减灾卫星(HJ1A/B)CCD数据,结合五道梁气象站气温、降水资料,分析了卓乃湖周边湖泊面积变化情况。结果表明:1961-2014年近54 a来,可可西里地区持续增加的降水是卓乃湖溃堤的基础,2011年8月22日之前的两次强降水过程和之后的持续降水是导致卓乃湖湖水大量外泄,并最终溃堤的主要原因;溃堤前的两次地震可能对卓乃湖的湖盆结构产生了一定的影响,从而加速了溃堤过程。溃堤导致湖岸线退缩,并产生大片的沙化土地,恶化了藏羚羊的产仔环境,对周边草地生态环境和重大工程设施产生了不利影响。