基于GIS的滑坡地质灾害地貌因素分析

基于ArcGIS平台, 利用SRTM-DEM数据资料, 选择青藏高原东缘及四川盆地为研究区, 提取了区内地形起伏度和坡度等地貌参数, 统计了区内2319个滑坡点的高程, 初步建立了地形地貌与滑坡灾害点分布之间的对应关系。结果表明, 研究区滑坡灾害点及其高程分布具有明显的区域规律性, 滑坡灾害点发生的高程为400~800m和1400~2000m, 这两个区间占研究区所有滑坡总数的40%和28%;滑坡所对应的地形起伏度主要在300~600m, 占研究区所有滑坡总数的48.68%;滑坡灾害发生的地形坡度为10°~25°, 占研究区所有滑坡总数的44.70%。研究发现, 这些地区对应的地貌类型主要是深切的"V"型河谷和山谷地貌。此外, 从断裂活动等方面分析了滑坡形成的动力机制。 

GIS-BASED ANALYSIS OF GEOMORPHOLOGICAL FACTORS FOR LANDSLIDE HAZARDS

Based on SRTM-DEM data and using the ArcGIS platform, the authors have extracted and calculated the elevations, relief amplitudes and slopes of 2319 landslide sites on the eastern margin and the Qinghai-Tibet Plateau and in the Sichuan basin. The correlation between the geomorphological factors and landslide distribution has been preliminarily established. The landslides in the study area occur at sites with specific geomorphological factors and are mainly distributed along the active faults and fiver valleys. The elevations at which the landslides occur mostly range between 400 and 800 m and between 1400 and 2000 m. The landslides occurring in the two ranges account for 40% and 28% of the total in the study area. The relief amplitudes of the landslides are mainly in the range of 300-600m, and the landslides occurring in this relief amplitude range account for 48.68 % of the total. The topographic slopes mainly range from 10° to 25°, and the landslides occurring in this slope range accounts for 44.70% of the total. The geomorphological types at these sites are mainly deeply incised V-shaped valleys and mountainous river valleys. In addition, active faults play an important role in controlling the distribution and occurrence of the landslides.