藏东南地区冰川泥石流形成条件初步分析——以天摩沟冰川泥石流为例  

Preliminary analysis on formation conditions of glacier debris flow in Southeast Tibet——a case of glacial debris flow in Tianmo Gully

作　　者：屈永平 肖进[1] 潘义为 QU Yongping;XIAO Jin;PAN Yiwei(Sichuan College of Architectural Technology,Deyang618000,Sichuan,China;China Water Northeastern Investigation,Design and Research Co.,Ltd.,Changchun130061,Jilin,China)

机构地区：[1]四川建筑职业技术学院,四川德阳618000 [2]中水东北勘测设计研究有限责任公司,吉林长春130061

出　　处：《水利水电技术》2018年第12期177-184,共8页Water Resources and Hydropower Engineering

基　　金：四川省教育厅重点项目(18ZA0326);德阳市应用技术研究与开发项目(2017zz063);德阳重点科学技术研究项目(2015zz035);四川建筑职业技术学院科研项目(2017KJ21)

摘　　要：针对融雪、降雨融雪等条件诱发的冰川泥石流形成过程,为了更好的认识藏东南地区冰川泥石流形成条件,选取藏东南地区天摩沟为研究对象,根据研究区流域特征、冰川覆盖面积以及气温等条件,在热化学、土力学以及流体力学等理论基础上,分析得到藏东南地区冰川泥石流在融雪条件下的起动流深阀值。结果表明:由于藏东南地区冰川泥石流沟分布高程影响,使得冰川泥石流沟所处的大气压为41. 0×103～54. 0×103kPa,使得雪线位置的冰川熔点上升至0. 352～0. 45℃;天摩沟冰川泥石流沟道冰碛物表层有效粒径(d10=10 mm)起动的临界流深为0. 04 m;天摩沟冰川泥石流沟道冰碛物发生冲蚀剪切破坏时的临界地表流深为其侵蚀厚度的3. 17倍;当天摩沟的降雨强度大于10. 22mm/h时可诱发冰川泥石流过程。研究成果为藏东南地区冰川泥石流的防治提供一定的参考。In order to better understand the formation condition of glacier debris flow in the Southeast Tibet,Tianmo Gully in the region of the Southeast Tibet is selected as the case for the study on the formation process of glacier debris flow induced by the conditions of snow melting,rainfall-snowmelt,etc.,and then the threshold of the starting flow depth of the glacial debris flow under the snow melting condition in the region is analyzed herein based on the theories of thermochemistry,soil mechanics,Fluid Mechanics,etc.in accordance with the conditions of the watershed characteristics,glacier covering area and air temperature of the study area.The result shows that the atmospheric pressure is 41.0×10 3~54.0×10 3 kPa and the glacier melting point at the snow line rises up to 0.352~0.45℃at the location of the glacier debris flow gully due to the effects of the elevation distribution of the glacier debris flow gullies located in the Southeast Tibet,while the starting critical flow depth of the effective particle size(d 10=10 mm)of the surface glacial till of the glacial debris flow in Tianmo Gully is 0.04 m.Meanwhile,the critical surface flow depth when erosion-shearing failure of the glacial till of the glacial debris flow channel in Tianmo Gully occurs is 3.17 times of its erosion thickness.When the precipitation intensity is large the 10.22 mm/h within a day,the formation process of glacial debris flow can be induced.The study result can provide a certain reference for prevention and control of glacial debris flow in the Southeast Tibet.

关 键 词：西藏 天摩沟 冰川泥石流 流深阀值 寒旱区 青藏高原 地质灾害防治 管涌型破坏模式 

分 类 号：P642.23[天文地球—工程地质学]