Analysis Of Debris Flow Source Areas Based On Remote Sensing Images Of Yaluzangbu River Along Linzhi-Jiacha Railway Line In Tibet

Tibet Brahmaputra (Nyingchi - Add check section), mostly along the cold mountain areas, rock crushing, the mountain poor stability, complex geological structure, seismic activity; by the monsoon climate control, study area, spatial and temporal distribution of rainfall is uneven county section, glaciers, ice Lake broad distribution; In addition, cutting the surface along a strong, strong frost weathering, soil erosion, coupled with irrational human activities, so that the frequent occurrence of debris flow area. Fieldwork in the study area are developed along the debris flow were 241, of which 188 storm debris flow, debris flow on a total of 53 glaciers, glacial debris flow accounted for 22% of the total number of debris flow.Through this study, the use of remote sensing image processing and analysis combined with the DEM, summarized the debris flow hazards unique to the region, the source surface features source and glaciers, glacial lakes interpretation of remote sensing characteristics of the information, and then analyzes the information along the debris flow source distribution, Trends for the evaluation of debris flow provide useful information, but also works for the Tibetan mountains linear linear pre-line and future projects and the renovation and expansion project with the help of a large role, this paper concluded:1. The source of the study area along the debris flow source characteristic surface features and analysis of remote sensing survey, mainly in the RapidEye high-resolution remote sensing data based on the source surface features to interpret the source is divided into four categories: one is the channel deposits, Mostly loose and ancient glacial Quaternary deposits; second is the landslide, avalanche slope plot objects to provide this type of source material side of loose debris flow volume; The third line of the forest line and between glacial Residual slope sediments, most chilling weakly weathered material; The fourth category is the residual slope above the glacial sediments, mostly frost weathered material. In addition, from RapidEye image of debris flow can be clearly identified and the debris flow fan channel topography to shape, size and other features.2. The study area along the debris flow source glaciers, glacial lakes investigation and analysis of remote sensing feature, mainly in the Landast-7 ETM + multispectral image data, based on the ratio method by spectral bands, principal component analysis, spectral angle mapping method, Unsupervised classification and supervised classification methods such as comparison of the five classical methods verify the final selection of a better way of glaciers, glacial lakes information extraction. The results showed that the glacier supervised classification of information extracted image is clear, structured, clear classification of the border, to meet the requirements of glacial landform interpretation.3. Carried out by means of this remote sensing investigation section Nyingchi to add surface features along the debris flow source of information sources and glacier hydrology study and analysis of feature extraction based on the show: check section Nyingchi to add surface features along the debris flow source with a uniform source distribution Nature, source uneven distribution of glaciers, the source of the material along the debris flow source in the glacial melt water and glacial debris flow after more development, more abundant accumulation of loose material, debris flow source to source further revival of surface features and produce a lot of new material Source, so that the increased frequency of landslides along the scale increases.