| 川藏交通廊道林波段冰川泥石流发育动态演化分析及监测预警方案 |
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| 引用本文： | 李尧,崔一飞,李振洪,傅旭东.川藏交通廊道林波段冰川泥石流发育动态演化分析及监测预警方案[J].地球科学,2022,47(6):1969-1984. |
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| 作者姓名： | 李尧 崔一飞 李振洪 傅旭东 |
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| 作者单位： | 1.中国科学院水利部成都山地灾害与环境研究所山地灾害与地表过程重点实验室, 四川成都 610041 |
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| 基金项目： | 国家自然科学基金项目(No.41941019)； |
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| 摘 要： | 川藏交通廊道沿线山高谷深，地层岩性多变，新构造运动活跃，气候恶劣复杂，导致滑坡、崩塌、泥石流、冰湖溃决洪水等灾害极其发育，对铁路施工及运营带来严重影响.林芝-波密段就是典型地质灾害高发区域，常年受到冰川泥石流的影响，是川藏交通廊道重大灾害防治的难点区段.虽然目前在单沟尺度上对冰川泥石流的形成条件、影响因素、物源性质取得了一定的认识，但对于川藏交通廊道沿线不同类型的冰川泥石流诱发因素、区域发展演化规律及灾变指标的研究还较为初步，尚未构建完善的监测预警体系.借助多源长时序遥感影像、气象监测数据，结合野外实地验证和历史数据分析发现:川藏交通廊道周边区域冰川泥石流沟谷共99条，主要分布于恰青冰川-易贡乡、加拉贝垒-南迦巴瓦峰和古乡沟-嘎隆寺冰川一带；过去40年冰川经历了复杂的流动速度变化，表现为较小高海拔悬冰川活动性增强，大型沟谷冰川活动性减弱；自1973年以来，研究区冰川泥石流呈现频率增高、规模增大的特征.此外，从冰川泥石流发育沟道比降来看，发生高陡地形的滑坡、冰-岩崩诱发的泥石流频率增加.未来，冰川持续退缩，促使冰川源区冰瀑消失，发育更大规模的悬冰川，会增加这类冰川泥石流的风险；冰川泥石流形成及演化过程具有明显的灾变指标，如悬冰川裂隙密度增加、冰川速度增强、冰湖面积快速增加等.因此，基于以上认识，建议针对不同类型的冰川泥石流地建立完善的监测预警指标，并提出了融合卫星、航空遥感平台，气象、水文地面监测平台，地震动监测平台的冰川泥石流“空-天-地”立体监测框架，针对不同类型冰川泥石流进行灾变信息监测与预警判识，为川藏交通廊道安全施工运营提供技术参考.
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| 关 键 词： | 冰川泥石流 气候变化 冰川活动性 演化规律 灾害监测预警体系 工程地质 |
| 收稿时间： | 2021-09-29 |
Evolution of Glacier Debris Flow and Its Monitoring System along Sichuan-Tibet Traffic Corridor |
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| Abstract: | The Sichuan-Tibet traffic corridor is an important transportation strategy in China that plays a key role in the economic prosperity, long-term stability, and the "Belt and Road" strategy in western China. However, the complex terrain, climate environment and active geological tectonic movements along the Sichuan-Tibet traffic corridor lead to extremely developed geo-hazards, such as debris flows, landslides, glacial lake outbreak floods (GLOF), which have serious impacts on railway construction and operation. As a representative section, the Linzhi-Bomi is frequently affected by glacier debris flows, and deemed as the most difficult section for disaster mitigation. Although some conclusions about influencing factors and material properties of glacial debris flows have been achieved at the single-valley scale, there is lacking solid research on predisposing factors, evolution laws and catastrophe indicators of different types of glacial debris flows along the Sichuan-Tibet traffic corridor, making it impossible to build an effective monitoring and early warning system. In this paper, multi-source long-term remote sensing images and meteorological monitoring data, combined with field data, are applied to conduct an inductive analysis of the glacial debris flow along the Sichuan-Tibet traffic corridor. Four conclusions can be drawn. (1) 99 glacial debris flow valleys were identified in the study area, that mainly distributed in the Chaqing glacier-Yigong township, Jialabelei-Nangabawa peak, and Guxiang gully-Galongsi glacier. (2) Climate environment change has led to complex responses in glacier activities, characterised by increased activity of smaller glaciers (high-altitude hanging glaciers) and weakened activity of glaciers in large valleys in the past 40 years; (3) Based on the historic inventory, it can be found that the glacial debris flow has shown the characteristics of increasing frequency and scale since 1973. And (4) the frequency of the debris flows induced by landslides and ice-rock avalanches in steep terrain has increased. In the future, the continuous retreat of glaciers will promote the disappearance of ice waterfalls and the development of larger-scale hanging glaciers, which will increase the risk of glacial debris flows. The evolution process of glacial debris flows has obvious catastrophic indicators, such as: the increasing crevice density, the change in glacier velocities, and the rapid increase of glacial lake areas. Finally, it proposes a monitoring and early warning framework that contains satellites, aerial remote sensing platforms, meteorological and hydrological ground monitoring platforms, and ground motion monitoring platforms, which can provide catastrophic information for different types of glacial debris flows. |
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