南水北调西线一期工程泥石流研究及其他山地灾害现状

RESEARCH ON DEBRIS FLOW AND OTHER MOUNTAINOUS HAZARDS IN WEST ROUTE OF SOUTH-TO-NORTH WATER TRANSFER PROJECT

南水北调西线一期工程区地处青藏高原东部,特殊的地质、地貌、土壤、植被、气象、水文等自然条件决定了该区属山地灾害易发区。受自然因素控制和人类活动影响,崩塌、滑坡、泥石流等山地灾害较为发育。主要山地灾害有滑坡、崩塌、泥石流、危险边坡及大型堆积体;其次为山洪、水土流失、冻融土流、路基塌陷等。通过实地考察、现场灾害填图、GPS定点、室内航片判读和TM,SPOT卫星图像解译,探讨了南水北调西线一期工程区泥石流的分布特征、规律及其他山地灾害的现状,初步分析预测了泥石流的发生规模(峰值流量、一次泥石流流出总量),尝试性地探讨了泥石流堵塞主河(堵河高度、回水范围)及其可能发生的二次灾害的定量分析方法,在此基础之上初步探讨了山地灾害对工程可能造成的影响与危害。

The west route of South-to-North Water Transfer Project China lies in the east of Qinghai-Tibet Plateau. This area belongs to mountain-hazard-prone area due to the natural conditions of the special geology, landform, soil, vegetation, weather, hydrology and so on. Collapse, landslide, debris flow and other mountainous hazards are well developed, which are influenced and controlled by the natural factors and human activities. The main mountainous hazards are landslide, collapse, debris flow, dangerous slope, large-scale deposit. The secondary hazards are mountain torrents, water loss and soil erosion, freezing and thawing solifluction, road foundation collapse and so on. The distribution characteristics, rules and the status of other mountainous hazards are found out in west route of South-to-North Water Transfer Project through field survey, topography map implement, GPS fixed-point, aerial photos and TM, SPOT satellite image interpretation. The bursting scales of debris flow （the maximal flow, the total amount of a debris flow） are analyzed and predicted. The blockage of the river by debris flow （possible height, backwater length） and the quantitative analysis methods of the second possible hazards derived from debris flow are discussed. On the basis of the analysis, the possible influence of the mountainous hazards on the west route of South-to-North Water Transfer Project is considered; and the probable dangers are presented.