怒江干流（云南段）滑坡灾害危险性分析

滑坡是怒江流域主要的地质灾害，对流域内人民生命财产和生态系统安全带来了极大的危害，因此本研究针对研究区内滑坡灾害主要诱发因子进行判识。利用1991～2006年云南省减灾年鉴、长系列流域内相关站点的年平均降雨量、2006年云南省1：5万的TM影像数据等，以GIS技术为平台对其相关因子关联性进行统计与分析。研究发现：沿怒江干流发生的滑坡灾害主要受到坡度、植被盖度、降雨强度及公路建设等因子的影响，分析灾害点的分布与相关因子间的相关性，发现相关性比较密切的是坡度〉25。的地带；植被盖度为30％～70％的地带；年降水量达到1250—1500mm的地带，以及公路沿线的地带，并以相关性作为灾害发生风险度评价的权重，建立了基于GIS的滑坡灾害危险性评价模型，实现了对怒江干流区域滑坡灾害危险性区划。

LANDSLIDE RISK ASSESSMENT IN THE NU RIVER MAIN WATERSHED(IN YUNNAN PROVENCE)

Landslide hazards are an inherent but dangerous and costly element of mountain environment in the Nu River watershed. Conventional hazard map provide useful inventories of hazardous sites but provide little insight into the potential area of the hazards. In the paper, based on the spatial analysis of driving and triggering factors promoting the occurrence and development of landslides in the Nu River watershed a correlation of the occurrence of landslides with slope gradient vegetation cover and precipitation presented for providing multivariate statistical data available for assessing risk of the landslide in the area. Using ArcGIS grid module the data including con- tour, vegetation cover and precipitation were transformed into TM data and DEM and further into raster gradient vegetation and precipitation were with a raster of 100 m ×100 m. The classification of gradient vegetation and precipitation were with five ranks, in agreement with five risk ranks of landslides of the highest, high, moderate, less and none are implemented on platform, indicating that the index selected and methods are rational and credible. The result will be base for controlling the landslide disasters and promoting sustainable eco-environment development in the area.