摘要
冰川终碛湖溃决引发的大规模山洪泥石流灾害,常给下游沿河一带造成重大人员伤亡和财产损失,受到社会广泛关注。冰川终碛湖一次溃决常未到底,其部分溃决后,残留湖因源头冰川进退、冰舌持续消融致后期湖面面积增大,湖水量增加,作者将这种现象定义为冰川终碛湖溃决-再生现象。以西藏波密米堆沟光谢错和聂拉木章藏布次仁玛错冰湖为研究对象,基于前人研究成果,利用遥感解译方法,分析了光谢错和次仁玛错冰湖面积的变化和冰川末端进退变化的特征。研究表明:光谢错、次仁玛错呈现出冰湖面积增大→溃决缩小→面积再增大的过程,光谢错在1988年溃决后面积已恢复至溃决前的63.6%,次仁玛错在1981年溃决后面积已基本恢复至溃决前的大小;从1980年代末至现在,贡扎冰川、阿玛次仁冰川末端处于退缩状态,终碛湖面积呈扩张状态。结合波密、聂拉木两气象站多年年降水量和年平均气温观测资料进行同步对比分析,初步探讨了冰川终碛湖再生现象的机理:1.冰川末端的前进与后退是冰湖面积变化的主导者,冰舌前进推动湖盆底冰碛物和溃口两侧岸坡垮塌导致堵塞泄流通道,冰川末端的退缩提供了空间条件;2.持续高温与强降雨的耦合作用是冰湖溃决的直接激发条件,持续高温累积是冰川消融冰湖面积增大的主要因素。
Large-scale mudslides disaster causing by outburst of glacier lakes has attracted broad attention for causing heavy casualties and property losses frequently to the downstream. Many glacier lakes show a phenomenon of larger area and increasing reservoir water after outburst,which was known as glacier lake outburst-regeneration phenomenon. Two typical glacier lakes： the Guangxiecuo Lake in Midui Gully and the Cirenmacuo Lake in Zhangzangbu,Tibet Autonomous Region of China are taken for the study. Characteristics of glacial lake area variation and glacier retreat and advance were analyzed basing on remote sensing interpretation method. Studies have shown that：the two lakes show a process of glacial lake area increase→ area reduction after outburst → area increase again.Area of the Guangxiecuo Lake has been restored to 63. 6% since it outburst in 1988,and area of the Cirenmacuo Lake has been restored to the size before outburst in 1981. The Gongzha glacier and the Armagh Tsering glacier have been in a state of retreat from the late 1980 s and early 1990 s to the present,and glacier lake area show a expansion state at the same time. Combining with years of annual precipitation and annual mean temperature data from Bomi station and Nyalam station,the glacier lake outburst-regeneration mechanism was discussed： 1） The advance and retreat of the end of glaciers is a major influencer to glacial lake regeneration,because glacier advance pushing moraine and loose matter on both sides of the breach collapse cause discharge channel blocked,and glacier retreat provides space conditions. 2） The coupling effect of high temperature and heavy rainfall becomes a direct excitation condition for glacial lake outburst,and the temperature rise is a major factor leading to glacial lake area increase.
出处
《山地学报》
CSCD
北大核心
2015年第6期703-712,共10页
Mountain Research
基金
中国交通建设股份有限公司科技研发项目"堰塞湖风险评估与减灾关键技术研究"
水利部公益性行业科研专项经费项目"藏东南水灾害危险性评估及减灾对策研究"(201301037)
国家国际科技合作专项项目"中巴喀喇昆仑公路地质灾害综合减灾与环境保护合作研究"(2012DFA20980)资助~~
关键词
冰川终碛湖
光谢错
次仁玛错
溃决-再生
西藏
Glacier lake
Guangxiecuo glacier lake
Cirenmacuo glacier lake
outburst-regeneration
Tibet
