藏东南地区直白沟冰雪型地质灾害链时空演化特征  

Spatial-Temporal Evolution of Geohazard Chain Participated by Glacier and Snow in Zhibai Gully,SE Tibetan Plateau

作　　者：黄海[1,2] 龚诚 Huang Hai;Gong Cheng(Institute of Exploration Technology,Chinese Academy of Geological Sciences,Chengdu 611734,China;Technology Innovation Center or Risk Prevention and Mitigation Engineering of Geohazard,Ministry of Natural Resources,Chengdu 611734,China;Faculty of Engineering,China University of Geosciences,Wuhan 430074,China)

机构地区：[1]中国地质科学院探矿工艺研究所,四川成都611734 [2]自然资源部地质灾害风险防控工程技术创新中心,四川成都611734 [3]中国地质大学工程学院,湖北武汉430074

出　　处：《地球科学》2024年第10期3784-3798,共15页Earth Science

基　　金：中国地质调查局地质调查项目(No.DD20221741);第二次青藏高原综合科学考察研究项目(No.2019QZKK0902)。

摘　　要：冰雪型地质灾害链是藏东南地区重大工程建设中的重要风险源,分析灾害链的演化规律可为重大灾害隐患识别和风险研判提供支撑.以直白沟为对象,通过野外调查、遥感解译和灾害监测,研究了孕灾背景的演化和1950年以来的6次灾害链事件的活动特征.结果表明:直白沟冰雪型地质灾害链是由冰川活动和高位岩崩驱动的,演进模式分为相变驱动物性变化成链和多要素级联效应成链两类,灾害链的活跃程度受地震作用显著控制.孕灾条件中的冰川和冰碛物的时空演化控制了灾害链的活动特征,地震和冰川消退驱动链首灾害由冰川跃动向高位岩体转换,物源增多和冰水相变作用增加了灾害链的演进长度和规模.现状直白沟内的则隆弄冰川退缩严重,由冰川跃动启动灾害链可能性减小,而由地震及冻融循环诱发的高位岩崩启动灾害链的可能性显著增强.The glacier and snow-related geohazard chain pose a significant threat to the economic activities in the Southeast Tibetan Plateau.Analyzing the evolution law of disaster can provide support for the risk prevention and mitigation,and also for the early identification of disaster.Based on field survey,remote sensing interpretation,and hazard monitoring,in this paper it aims to analyze the evolution of disaster formation conditions and the activity characteristics of six geohazard chain events since the 1950.The results show that the geohazard chain in Zhibai Gully was driven by glacier activity and rock collapse.The evolution models of geohazard chain are summarized into two types:physical property change chain induced by ice water phase transformation,and geological cascade chain induced by coupling of multi factors.It is found that the disaster activity is significantly controlled by the earthquake,and the disaster characteristics is correlated with the temporal-spatial evolution of the formation conditions.Under the influence of the earthquake and deglacialtion,the initiation of disaster chain is transformed from glacier active to rock collapse.The increasing of soil material sources and the effect of ice water phase transformation both enhance the evolution length and scale of disaster.For the present,the Zelongnong glacier is retreating seriously,decreasing the possibility of a geohazard triggered by a glacier.Corresponding the ice/rock avalanche becomes the key to the geohazard chain.

关 键 词：灾害链 演进过程 冰川跃动 冰岩崩 泥石流 环境地质学 

分 类 号：P694[天文地球—地质学]