摘要
全球气候变暖背景下,青藏高原的石冰川活动性增强,产生灾变的趋势上升。采用遥感影像分析、现场调查及气象和径流监测等方法,获取了藏东南地区乌连沟石冰川的特征数据,分析其灾变形成泥石流的诱发因素及过程。结果显示,乌连沟石冰川2010—2017年平均运动速度为1~3 m·a^(-1),且前缘整体运动速度显著高于中后部。石冰川前缘向前运动进而失稳,可持续为沟道输送松散物源,2013年及2014年约有5600~9000 m^(3)石冰川输送的松散物质被启动。形成泥石流除需要充沛的物源外,还需要足够的水源启动。区内降雨量有限,乌连沟最大径流出现在5—6月,主要由高温引发冰雪消融贡献。分析2013年及2014年两次泥石流事件发现,其主要诱发因素是高温,灾变机制为气温快速升高导致表层冰雪快速消融,融水在石冰川表面凹陷处积聚形成湖塘,湖水泄流启动了石冰川前缘积累的松散物质形成泥石流。未来随着气候变暖加剧,石冰川的活动性进一步增强,在急剧升温或强降雨影响下,形成泥石流的规模及频率可能会增加,需防范石冰川灾变形成泥石流的致灾风险。
Against the backdrop of global climate warming,the activity of rock glaciers in the Qinghai-Xizang Plateau has been enhanced,leading to an increasing trend of disasters.By using methods such as remote sensing image analysis,field investigation,meteorological and runoff monitoring,characteristic data of the Wulian rock glacier in southeastern Qinghai-Xizang Plateau were obtained,and the triggering factors and processes of the formation of debris flows were analyzed.The findings indicate that the Wulian rock glacier’s mean velocity ranged from 1~3 m·a^(-1) between 2010 and 2017,with the frontal velocity being substantially higher than that of the middle and rear.This advancement and associated instability of the rock glacier front can be attributed to the channel transportation of loose material sources.Notably,the rock glacier transported approximately 5600~9000 m^(3) of loose material,which triggered debris flow events in 2013 and 2014.The generation of such flows requires not only abundant loose sources but also sufficient water to initiate.In this study,the maximum runoff occurred during May and June,primarily driven by the melting of ice and snow resulting from elevated temperatures.By examining the two debris flow events,it was discovered that high temperature was the primary contributing factor,and the disaster mechanism involved the rapid melting of surface ice and snow due to elevated temperatures,causing the accumulation of meltwater in depressions on the rock glacier surface,resulting in a pond that,when discharged,caused loose material in front of the rock Glacier to form debris flow.As climate warming exacerbates in the future,rock glacier activity is anticipated to increase.Additionally,under the influence of rapid warming or heavy rainfall,the scale and frequency of debris flows may increase.Therefore,it is imperative to mitigate the risk of rock glacier disaster formation through debris flow prevention measures.
作者
李元灵
余斌
黄海
陈龙
杨东旭
张佳佳
高波
田尤
李洪梁
罗伦
LI Yuanling;YU Bin;HUANG Hai;CHEN Long;YANG Dongxu;ZHANG Jiajia;GAO Bo;TIAN You;LI Hongliang;LUO Lun(College of Environment and Civil Engineering,Chengdu University of Technology,Chengdu 610059,China;Institute of Exploration Technology,Chinese Academy of Geological Sciences,Chengdu 611734,China;Technology Innovation Center for Risk Prevention and Mitigation of Geohazard,Ministry of Natural Resources,Chengdu 611734,China;Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China;Research Center of Applied Geology of China Geological Survey,Chengdu 610036,China)
出处
《冰川冻土》
CSCD
2024年第2期406-416,共11页
Journal of Glaciology and Geocryology
基金
中国地质调查局项目(DD20190644,DD20221741)
第二次青藏高原综合科学考察研究项目(2019QZKK0902)
国家自然科学基金项目(41807300)资助。
关键词
石冰川
泥石流
青藏高原
气候变化
rock glacier
debris flow
Qinghai-Xizang Plateau
climate change
作者简介
李元灵,博士研究生,主要从事山地灾害研究.E-mail:lyuanling@mail.cgs.gov.cn。
