摘要
结合野外资料,利用GIS技术,提取了绵远河流域的坡度、地形起伏度等地貌参数,对绵远河流域的构造地貌进行了分析;以汶川地震重灾区绵远河流域的文家沟滑坡、泥石流为例,对该区汶川地震驱动的构造抬升与滑坡、泥石流的表面侵蚀过程进行研究。研究表明,文家沟地处汶川地震震中区,映秀-北川断裂带(主断裂带)在其北西侧约3.6 km的地方切过,为引发滑坡提供了构造条件;地震之前,文家沟近百年内未发生过滑坡、崩塌;地震之后,触发了体积约为2 750×104m3的初始滑坡体,最终滑坡体堆积物多达5 000×104m3,是汶川地震中的第二大滑坡;从2008年9月至2010年10月,文家沟先后发生了5次规模较大的泥石流灾害,累积泥石流量达557×104m3,表明约有11%的震后滑坡转化为泥石流;汶川地震造成了文家沟约1 952.5×104m3的同震抬升量,而震后滑坡体堆积量约为5 000×104m3,说明震后的滑坡量远大于同震抬升量,山体平均海拔被降低。
Combine with GIS spatial analysis technology and on the base full use of field survey data,tectonic geomorphologic characteristics of the Mianyuan river basin are studied by slope analysis,amplitude of landforms.Take landslides and debris-flow of the Wenjia gully of Mianyuan river for example,which are used to conducted quantitative analyses of the tectonic uplift driven by the Wenchuan earthquake and landslide and debris-flow erosion processes,along with their effects on the geomorphic growth of Longmenshan. The results show that： Wenjia Gully located at the epicenter area of Wenchuan earthquake,the triggering seismic fault（ Yingxiu-Beichuan fault）through the gully at the northwest about 3. 6 km,which provide the geological condition. Before the earthquake,the gully nearly never happened landslide and debris-flows,however,the Wenchuan earthquake trigged the second largest landslide. From Sept. 2008 to Octo. 2010,there were happened 5 times debris-flow,the total debrisflow volume reached 557 × 104m3,which shown that about 11% of the amount earthquake landslide transform into debris flow. The volume of coseismic landslides of Wenjia gully of Mianyuan River（5 000 × 10^4m3） was larger than the volume of coseismic uplift（1 405. 8 × 10^4m3）,which show the average elevation of mountain was cut down.
出处
《东华理工大学学报（自然科学版）》
CAS
2015年第1期75-80,共6页
Journal of East China University of Technology(Natural Science)
基金
国家自然科学基金项目(41340005
41372114
41172162)
关键词
汶川地震
构造抬升
同震滑坡
绵远河
文家沟
Wenchuan earthquake tectonic uplift coseismic landslides Mianyuan river Wenjia gully
