易贡藏布冰川边缘地带暴雨泥石流与冰川融雪泥石流特征差异分析  

Characteristics of rainstorm and glacial snowmelt-induced debris flow in the paraglacial zone of Yigong Zangbo

作　　者：张瀛玉龙 陈宁生[2,3] 彭泰鑫 侯儒宁 李志 杜鹏 ZHANG Yingyulong;CHEN Ningsheng;PENG Taixing;HOU Runing;LI Zhi;DU Peng(College of Engineering,Tibet University,Lhasa 850000,China;Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Ministry of Water Resources,Chengdu 610041,China;Academy of Plateau Science and Sustainability,Xining 810016,China;School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]西藏大学工学院,拉萨850000 [2]中国科学院、水利部成都山地灾害与环境研究所,成都610041 [3]高原科学与可持续发展研究院,西宁810016 [4]中国科学院大学工程科学学院,北京100049

出　　处：《成都理工大学学报（自然科学版）》2024年第2期345-360,共16页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：第二次青藏高原综合科学考察项目(2019QZKK0902);国家自然基金联合基金项目(U20A20110);中国科学院加德满都科教中心资助(131C11KYSB20200033);西藏重大科技专项(XZ202101ZD0013G)。

摘　　要：本文为探究冰川边缘地带暴雨泥石流与冰川融雪泥石流的特征差异,以易贡藏布流域中下游的64条泥石流沟为研究对象,在实地考察的基础上,通过遥感解译、建立Matrix Laboratory数学模型等方法,得到了两者在形成发育条件上和下游段威胁范围的差异。结果表明:(1)在地形地貌上,冰川融雪泥石流和暴雨泥石流在相对高差、纵向剖面形状指数等地形因子上有不同或相似的峰值数量分布。(2)在物源上,冰川融雪泥石流单沟最大、最小物源储量分别为6740×10^(4)m^(3),253×10^(4)m^(3),暴雨泥石流单沟最大、最小物源储量分别为228×10^(4)m^(3),1.5×10^(4)m^(3)。(3)在流量上,冰川融雪泥石流最大、最小流量分别为1498.2 m^(3)/s,105.4 m^(3)/s,暴雨泥石流最大、最小流量分别为126.7 m^(3)/s,2.0 m^(3)/s。两者在流量上有明显差异的原因,除了汇水面积相差大,还因冰川融雪泥石流有冰川融水与积雪融水的补给。其百年一遇重现期的冰川融水峰值流量最大、最小值分别为79.7 m^(3)/s,0.6 m^(3)/s,融雪当量为32.52 mm/d。(4)冰川融雪泥石流堆积区固体松散物质冲出距离远大于暴雨泥石流,冰川融雪泥石流单沟最大冲出距离为414.3 m,暴雨泥石流单沟最大冲出距离为43.6 m。对该区域内不同泥石流之间的发育机制差异进行研究,可为类似地区的泥石流防治提供一定的参考。To investigate the distinctive characteristics of rainstorm and glacial snowmelt-induced debris flows in fringe regions of glaciers,this study focused on 64 debris flows located in the middle and lower reaches of the Yigong Zangbo Basin.We used field investigations to comprehensively analyze and inform our remote sensing-based interpretations,and established matrix laboratory-based mathematical expressions for them.The objective was to identify variations in the backgrounds of formation of the two types of debris flows as well as the extent of hazard posed by them to downstream areas of accumulation.The findings revealed the following.(1)Glacial snowmelt-and rainstorm-induced debris flows exhibited dissimilar or analogous distributions in terms of key topographical factors,including the relative differences in elevation and indices of the shapes of their longitudinal profiles.(2)The maximum and minimum material reservoirs for glacial snowmelt-induced debris flows within a single gully were 6740×10^(4) m^(3) and 253×10^(4) m^(3),respectively,while those for rainstorm-induced debris flows were 228×10^(4) m^(3) and 1.5×10^(4) m^(3),respectively.(3)Glacial snowmelt-induced debris flows had maximum and minimum peak discharges of 1498.2 m^(3)/s and 105.4 m^(3)/s,respectively,while rainstorm-induced debris flows had those of 126.7 m^(3)/s and 2.0 m^(3)/s,respectively.The noticeable disparity in flow between them arose not only due to differences in the area of the catchment,but also due to the influence of glacial meltwater and snowmelt in case of glacial snowmelt-induced debris flows.Notably,the maximum and minimum peak flows of glacial meltwater during a 100-year period of recurrence were 79.7 m^(3)/s and 0.6 m^(3)/s,respectively,with a snowmelt equivalent of 32.52 mm/d.(4)The distances over which solid loose materials were carried by glacial snowmelt-induced debris flows in the areas of accumulation were significantly greater than those carried by rainstorm-induced debris flows.For instance,the maximum washout di

关 键 词：易贡藏布 发育特征 暴雨泥石流 冰川融雪泥石流 

分 类 号：P642.22[天文地球—工程地质学]