基于GIS的西藏林芝地区泥石流易发与危险区分析

Analysis of Debris Flow-prone and Dangerous Area in Nyingchi of Tibet Based on GIS

西藏林芝地区是我国泥石流灾害最为严重的地区之一,特别是近年来受全球气候变化的影响,冰川融化速度加快,冰川融水型泥石流灾害频频发生,危害严重。自2011年6月中旬开始,对该地区泥石流做了系统调查,并以遥感与GIS作为数据获取与分析处理的技术手段。首先分析了地质、地貌、冰川活动、气候、地震单因子对林芝地区泥石流易发区的影响并给出了相应的易发区区划结果;其次,以主导因素分析原则对单因子进行综合叠加得到该地区泥石流易发区分区结果;最后,在易发区的基础上考虑区域内的威胁对象进行空间运算叠加得到该区域泥石流危险区,并针对性地提出了区域泥石流防灾减灾的建议。

Nyingchi is one of the most dangerous regions threatened by debris flows in China. Under the influence of globe warming, the melting rate of glacier has accelerated, leading to the frequent initiation of glac- ier-melting debris flow, which is severely hazardous. Since the middle of June, 2011, the authors had carried out systematic investigation about debris flow in Nyingchi, and took remote sensing and GIS as the technical methods for the acquisition of data. First of all, it is analyzed that the individual factors including geology, geomorphology, glacial actions, climate, and earthquake had the important influence on debris flow-prone area, and homologous result was gotten. Secondly, we obtained debris flow-prone area result of Nyingchi through superimposing individual factors according to principle-leading factor analysis. At last, we obtained dangerous area through spatial operation based on debris flow-prone area considering threat object in Nying chi, based on specific advice on disaster prevention which we proposed.