Distribution and Characteristics of Secondary Mountain Hazards Triggered by Ludian Earthquake in Yunnan(PDF)
《地球科学与环境学报》[ISSN:1672-6561/CN:61-1423/P]
- Issue:
- 2015年第04期
- Page:
- 84-93
- Research Field:
- 水资源与环境
- Publishing date:
Info
- Title:
- Distribution and Characteristics of Secondary Mountain Hazards Triggered by Ludian Earthquake in Yunnan
- Author(s):
- TAO Yuan; HU Kai-heng; TIAN Yong-zhong; GE Yong-gang; CHEN Xing-chang
- 1. School of Geographical Sciences, Southwest University, Chongqing 400715, China; 2. Key Laboratory of Mountain Hazards and Earth Surface Processes, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China; 3. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences and Ministry of Water Resources, Chengdu 610041, Sichuan, China; 4. School of Environment and Resource, Southwest University of Science and Technology, Mianyang 621010, Sichuan, China
- Keywords:
- Ludian earthquake; secondary mountain hazard; spatial distribution; GIS; center number density; area percentage; Yunnan
- PACS:
- P694
- DOI:
- -
- Abstract:
- At 16:30 on August 3rd, 2014, Ms 6.5 earthquake occurs in Ludian County of Zhaotong City, Yunnan Province, China. Ludian earthquake causes a wide spread of secondary mountain disasters including collapse, landslide, unstable slope, etc. By field investigation and interpretation of remote sensing images, there are 235 secondary mountain disasters, and the area is 8.59 km2. Based on GIS spatial analysis method, relationships between the distribution of secondary mountain disaster and earthquake were explained by secondary mountain disaster center number density and area percentage. The former is defined as the number of secondary mountain disaster central point per square kilometer; the latter is defined as the percentage of the area affected by secondary mountain disasters. The effects of topography, river and rock on spatial distribution of secondary mountain disasters were discussed with the factors including elevation, slope, aspect, lithology and distance from the river. Secondary mountain disaster center number density is about 0.2 points per square kilometer, and area percentage is about 0.79%. The results show that the arrangement of secondary mountain disaster is controlled by the main fault of Zhaotong-Ludian with NE-orientation, and 63.83% of secondary mountain disasters happen in the region with a distance of 2-8 km to the causative fault; secondary mountain disasters mainly distribute in the areas with the elevation of 1 000-1 200 m and the slope of 35°-45°; secondary mountain disaster center number density and area percentage are maximum under the slope of 20°-30°; secondary mountain disasters develop mostly in hard rock strata such as carbonate rock, while steep slope secondary mountain disasters develop mostly in soft rock strata; secondary mountain disasters approximately distribute in a line along Niulan River, and the farther away from the river, the lower the probability of occurrence is.
Last Update: 2015-07-20