摘要
锁儿头滑坡长期处于缓慢蠕滑状态,然而对其具体活动特征,目前尚无定论。本文在野外详细调查的基础上,基于1969—2015年多源多期高分辨率历史卫星影像以及2008年和2010年两期高精度航空正射影像,采用目视对比地貌特征和同名点测量方法,从定性与定量相结合角度分析了该滑坡的活动特征。研究发现,滑坡活动的整体性不明显,但分块差异性活动突出。滑坡中部以及临江前缘活动相对强烈,其他部位活动微弱。滑坡中部地表运动并不规则,侧缘边界处活动强度明显高于滑坡区内。两期航空正射影像上的测量结果显示,滑坡中部在2008年8月—2010年8月间,平均年位移0.82~2.94 m,平均测量误差约0.75 m。现场调查及2008年以后的高分辨率影像分析发现滑坡临江前缘以小规模滑塌为主,伴随微弱深部位移。依据滑坡活动特征及其所在地段的地质背景、地形地貌和外部环境条件推测,活动断裂是控制滑坡活动的主要因素,地形、地下水和松软滑体物质可能是控制滑坡中部相对强烈活动的主要因素;滑坡前缘较强活动可能与较陡地形、白龙江水切脚侧蚀和人类工程活动有关。
The activity features of the landslide of the Suoertou landslide in Zhouqu county of Gansu were analyzed based on detailed field surveys,46 pieces of high resolution archival satellite images from multiplatforms from 1969 to 2015 and two aerial othophotos in 2008 and 2010. The results show that the landslide was moving as blocks rather than as a whole. The middle and the very frontal parts were the most intensive areas,and activities in other parts were relatively weak. The irregular surface movement in the middle mostly behaved as that the shear deformation in the upper left boundary was larger than in the right,and that the lower right boundary deformed more significantly than the left. Homologous points measurement on the aerial othophotos reveal that the average annual displacement ranges from 0. 82 to 2. 94 m from 2008 to 2010 with an average measurement error of 0. 75 m. According to the activity features,geological settings,geomorphology and external environment conditions,the active fault is thought to be the principal factor controlling the activity of the landslides. Groundwater and weak material at the depth of 20 m might be the main controlling factors in terms of the intensive activity in the middle. The frequent failures in the very front are related to the steep terrain,lateral erosion by the river water and human engineering activities.
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2016年第2期69-74,92,共7页
Hydrogeology & Engineering Geology
基金
国家自然科学基金项目资助(41372305)
关键词
锁儿头滑坡
活动特征
断裂带
遥感影像
同名点测量
Suoertou landslide
fault zone
remote sensing images
homologous points measurement
