摘要
综合采用现场调查、测量及室内理论分析等方法,以金沙江干流寨子村巨型滑坡群和金沙江支流海口大型滑坡为例,对滑坡堵江的地貌效应进行了初步探讨。寨子村古滑坡群的滑坡坝及堰塞湖沉积均有残留,后者沿江分布长度55km,面积约120km^2。堵江段的金沙江平面弯曲、纵断面比降小、横断面宽而浅,具有平原区河流特征,与非堵江段差异显著。堰塞湖沉积分布区地形开阔,发育有土塬、冲沟及土梁等地貌单元,有时还会发生沙尘暴。海口滑坡的滑坡坝和堰塞湖沉积均保存完整:前者顺河水平投影长约1000m、最大厚度135m,后者沿河长3km、面积8km^2;两者分别使海口河河床比降增大、减小了11‰和95‰。滑坡堵江的地貌效应显著,它可以抑制高山峡谷区的河流底蚀,使之成为"走两步退一步"的自我调节过程,而营造开阔空间的堰塞湖沉积大多都可开垦为农田,在长期影响所在区域地貌演化的同时,也为人类在复杂山区创造了若干宜居场所。
Taking Zhaizicun giant landslides and Haikou large-scale landslide in Jinsha River and its tributary as examples, the geomorphological effects of landslide damming were preliminarily discussed by field surveying, measuring and indoor theoretical analysis. Zhaizicun giant ancient landslides possess residual landslide dams and deposits of landslide-dammed lake with a length of 55km and area of about 120km2 along Jinsha River. Severely compare to other river section, the characteristics of landslide damming section is plane bending, small gradient ratio of profile as well as wide and shallow cross-section,which manifest plain area river features. The distribution area of the deposits of landslide-dammed lake is broad,in which the geomorphic units such as table lands, gullies and earth beams develop and sometimes sandstorms occur. Both the landslide dam and deposit of landslide-dammed lake of Haikou large-scale landslide exist now. The former is about 1000m horizontal projection length and the maximum thickness is 135m. The latter possess a length of 3km and area of 8km2 along Haikou River. Because of them, the longitudinal gradient ratio of Haikou River is increased by 11%o and decreased by 95%0, respectively. Meanwhile, the latter induced the increase of the valley floor width from tens of meters to hundreds of meters. The geomorphological effects of landslide damming is extraordinary. It can restrain river base-erosion action in the Alpine-Gorge areas, which formed the self-regulated process of two-step forward and one-step backward. Moreover, The wide deposit areas of landslide-dammed lake can be opened up for farming. At the same time of long-term influence on landform evolution, deposits of landslide-dammed lakes have created many livable places in complicated mountain areas.
出处
《第四纪研究》
CAS
CSCD
北大核心
2013年第3期490-500,共11页
Quaternary Sciences
基金
国家自然科学基金-云南联合基金重点项目(批准号:U1033601)
地质灾害防治与地质环境保护国家重点实验室开放基金项目(批准号:GZ2009-10)共同资助
关键词
滑坡
滑坡堵江
堰塞湖沉积
地貌
地质环境
Key wordsenvironmentlandslide
landslide damming
deposits of landslide-dammed lake
landform
geological
