奥布公路泥石流危险性评价

作为喀喇昆仑公路的重要组成部分,奥依塔克-布伦口(简称奥布)公路受到沿线数量众多且规模较大的泥石流影响,常导致行车中断,人员和车辆安全受到威胁。在现场地质考察和走访基础上,依据ArcGIS工具对奥布公路段的15条典型泥石流沟开展了重点调查和危险性评价。首先对汇流面积、纵坡度、面积宽度比、堆积区面积和距公路距离等5个评价因子属性进行归一化处理;然后采用两层结构的层次分析法计算得到影响因子的权重,随后将属性函数与权重乘积加和,得到灾害易发性指数(DFRD);最后对泥石流危险度(DRFR)进行计算分析和危险程度分级。结果发现,高-中度危险的11条泥石流主要分布在布伦口峡谷上游、盖孜检查站和加水沟之间,构成了泥石流灾害发育较为集中且危害性较大的路段。工程上相应采用隧道、高架桥等绕避措施,取得较好成效。

Risk Evaluation of Debris Flow along Ao-Bu Section of Karakoram Highway

As an important section of the Karakoram Highway (KKH), Ao-Bu (From Aoyitake to Bulunkou) highway, large scale debris flows are concentrated and the transportation safety along the Highway is heavily threatened. Based on field survey and interview with local people,the main 15 nos. debris flow were selected for detailed exploration and risk analysis.Firstly the drainage area,longitudinal slope,the ratio of the drainage area to the width of debris outlet,the area of accumulated region, as well as the distance from debris outlet to the highway,were undertaken normalization processing from their features;Then analytic hierarchy process was adopted to calculate their weight ratio according to the interactions of factors at two different levels;After that,the weight ratio and the normalized featured parameter were multiplied and added together,one rick degree value DRFR was obtained.As a result, it was found that the 11 nos. mid-high risky debris flow were distributed at upper reach of the Bulunkou Gorge,at one part between the Water Gully to Gaizi Village,the threaten from debris flow is serous and more attentions are to be paid on dealing with them.