汶川地震受灾严重区域崩塌与滑坡体空间分布研究

Spatial distribution of rockfall and landslide mass in disaster areas of Wenchuan earthquake

基于北京一号小卫星遥感影像，提取地震受灾严重区域（简称重灾区）崩塌与滑坡体的空间分布信息；以缓冲区空间分析技术，分析不同距离缓冲区段内崩塌与滑坡体的面积、个数、体积、等级大小、分布密度等指标，得出崩塌与滑坡体与4级以上余震集中带及5级以上震源之间的空间关系。结果表明：在不同距离的余震集中带缓冲区段内，崩塌与滑坡体面积在10-30 km缓冲区段内分布最多，而崩塌与滑坡体个数、体积、分布密度均以5 km缓冲区段内为最大；在不同距离的5级以上震源缓冲区内，崩塌与滑坡体面积、个数均以10-30 km缓冲区段内分布最多，而崩塌与滑坡体分布密度均以5 km缓冲区段内为最大；30 km缓冲区为崩塌与滑坡体的高发区，该区的面积仅占调查面积的10%左右，但崩塌与滑坡体面积达到崩塌与滑坡体总面积的60%，个数和体积均占总数的80%以上；不同距离缓冲区段内，崩塌与滑坡体个数多以1-5 hm^2范围内的为最多，其次为小于1 hm^2的。

Taking Beijing-1 remote sensing image as basic material, this paper distills the spatial distribution information of landslide and rockfall mass in disaster areas of Wenchuan earthquake. Utilizing buffer analysis as main technique. We analyze the indicators of landslide and rockfall mass including area, number, volume, size and distribution density in different distant buffers of the aftershock centralized belt, as well as the epicenters upwards 5^th grade, and obtain the spatial relationship between them. The result shows, among the different distance buffers of the aftershock centralized belt, the area of landslide and rockfall mass in 10 - 30 km section is the largest, while the largest number, volume and distribution density appear in 5 km buffer. Among the buffers of the epicenters upwards 5^th grade, the area and number of landslide and rockfall mass in 10 - 30 km section are the largest, while the largest distribution density appears in 5 km buffer. The 30 km buffer is the high frequency region of landslide and rockfall mass, the area of this region only occupies 10% of the research area, but landslide and rockfall mass reaches 60 % of the total area, about above 80 % of the total number and volume of landslide and rockfall mass. The number of landslide and rockfall mass whose area is from 1 hm^2 to 5 hm^2 is the most in each buffer, then is the area less than 1 hm^2.