摘要
2008年"5·12"汶川地震时,映秀-北川断裂通过的映秀镇红椿沟流域内产生了大量的碎屑体,约为384.3×104m3,为泥石流的发生提供丰富的固体物源条件。2010-08-14,红椿沟暴发特大型泥石流,冲断公路,堵塞岷江致使江水改道,威胁映秀新区。为研究物源区演变特征,选取3期影像,并结合野外调查资料,通过ArcGis分析发现:地震前,红椿沟植被良好,未发现大规模地质灾害,流域内沟道均属于清水沟。地震后,流域内滑坡崩塌数量为68处,滑坡面积为101.12×104m2,沟道总长度5 752 m,沟道总面积11.82×104m2。受上盘效应影响,沟右岸滑坡发育强于左岸,左岸大多为小型浅层滑坡。2010年"8.14"泥石流后,受地表径流和泥石流的冲刷、侵蚀、切割作用影响,使部分滑坡"复活"或产生新的滑坡,流域内滑坡个数77处,新增9处,变化率为13.23%,滑坡面积139.80×104m2,新增38.68×104m2,变化率38.25%。沟道总长度8 851 m,新增3 099 m,沟道总面积17.48×104m2,新增5.66×104m2。泥石流暴发后,流域内仍有固体物源量约为344.6×104m3,泥石流治理工程可控制物源量约为92.8×104m3,在极端降雨条件下,仍有暴发大规模泥石流的可能。
In ＂5 · 12＂ Wenchuan earthquake,the ＂Yingxiu-Beichuan＂ fault zone across Hongchun gully of Sichuan,China,made the area produced abundant debris,estimate 384.3 × 104 m3,it provide a rich source for debris flows.On 14th August,2010,Hongchun gully occurred debris flows,it thrust in highway and jam Minjiang River diversions,threat new Yingxiu.In order to research the dynamic evolution of source,we select three times RS image and investigation data,compares the evolution characters of the gully by Arcgis.It indicates that：before ＂5 · 12＂ earthquake,the study areacover is good,it did not find geologic hazards,the basin stream all belong to clear ditch.After＂5 · 12＂earthquake,the number of landslide is 68 and the area is 101.12 × 104 m2,the total longth of stream is 5 752 m and stream area is 11.82 × 104 m2.However,because of the ＂hanging wall effect＂,the geological disaster on the right of the gully is more developing than the left,in the left,most are small and shallow landslide.After ＂8 · 14＂debris flows,affected by the surface runoff and debris flows＇ washing,cuting,it made some landslip revive and made some now landslip,the number of landslip is 77.After ＂8 · 14＂,increased 9landslip,and the area of landslip is 139.80 × 104 m2,increased 38.68 × 104 m2,the gradient is 38.25%,the total longth of stream is 8 851 m increased 3 099 m,and the area is 17.48 × 104 m2,increased 5.66 × 104 m2.After ＂8 · 14＂ debris flow,the debris capacity 344.6 × 104 m3 in the study area,and the debris flow training works can contrl 92.8 × 104 m3,so in the heavy rainstorm,it could triggered debris flow disaster again.
出处
《山地学报》
CSCD
北大核心
2014年第1期81-88,共8页
Mountain Research
基金
科技基础性工作专项项目(编号:2011FY110100)
地质灾害防治地国家重点实验室自主研究基金(SKLGP2011Z008)~~
关键词
汶川地震
泥石流
滑坡
动态演变
遥感解译
Wenchuan earthquake
debris flow
landslides
dynamic evolution
remote interpretation
作者简介
蒋志林（1987-）,男,硕士研究生,研究方向：工程地质、地质灾害、遥感与GIS应用.E—mail：652019285@qq．com
