喜马拉雅山中段波曲流域近期冰湖溃决危险性分析与评估  

Risk Assessment of Glacial Lake Outburst in the Poiqu River Basin of Tibet Autonomous Region

作　　者：陈晓清[1] 崔鹏[1] 杨忠[2] 齐永青[2] 

机构地区：[1]中国科学院山地灾害与地表过程重点实验室,四川成都610041 [2]中国科学院成都山地灾害与环境研究所,四川成都610041

出　　处：《冰川冻土》2007年第4期509-516,共8页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金西部重大研究计划项目(90202007);国家杰出青年科学基金项目(40025103)资助

摘　　要：西藏聂拉木县波曲流域内分布有大量的冰湖,对2000/2001年度卫星遥感数据遥感解译获取了冰湖的分布及面积;对比1987年的数据发现,经过15 a流域内冰湖数量和面积均发生了巨大的变化.通过野外考察获取了重要冰湖的溢流状态、冰碛堤稳定性、冰川影响等资料,在此基础上使用直接判别法和冰湖溃决危险性指数(Idl)进行了冰湖溃决危险性评价,所有冰湖中有9个处于高度危险状态的,3个处于较高危险的,2个处于稳定状态,其余35个处于相对稳定或趋于衰退状态.冲堆普下游、科亚普下游和主河至科亚普汇口以下为高度危险区,塔吉岭普下游、如甲普下游和章藏布下游处于较高危险,其他支沟下游及所有上游区处于冰湖溃决相对安全区.基于危险性评价结果,建议下游根据危险性大小,采取相应的应对措施以减轻冰湖溃决泥石流的危害.There are many glacial lakes in the Poiqu River basin, Nyalam County, Tibet Autonomous Region. Based on interpreting the remote sensing data of Landsat satellite, 2000/2001, the distribution and area of glacial lakes are obtained. Compared with the data of 1987, it is found that their number and area changed greatly： the area of glacial lakes increased 46% and the number of the lakes in area over 0.02 km^2 increased 11%. Especially, the Galongco and Gangxico increased 104% and 118%, respectively. Field investigation revealed the overfall conditions of some key lakes, the stability of moraine dams, and the impact of glaciers. Using direct distinguishing and risk indexes of glacial lake outburst （Idl） , respectively, two types of risk assessments have been completed.Risk assessment shows that there are nine glacial lakes at high dangerous degree, three at middle degree, and two at stable state and the other 35 at relative stable state. In this basin, there are high danger regions in the lower reaches of Chongdui gully, Keya gully and the confluence spot of Keya gully and Poiqu River, and of middle degree, the lower reaches of Tajiling gully, Rujia gully and Zhangzang gully, and safe regions in the other places. In order to mitigate harm to Nyalam and Zham port, a series of countermeasures is put forward, such as ： 1） designing mitigation programme on the base of risk assessment, 2） pre-warning and emergency programme, 3） periodical professional measure and 4） public warning and prevention system.

关 键 词：波曲流域 冰湖 溃决 危险性 

分 类 号：P343.6[天文地球—水文科学] X43[天文地球—地球物理学]