西藏古乡沟泥石流堰塞湖演化规律

Evolution of debris-flow dammed lake at Guxiang gully in Tibet

西藏东南地区地质灾害频发,历史上曾多次发生过泥石流阻塞河流形成堰塞湖的灾害事件。但是对西藏东南地区堰塞湖的研究多针对长时间大尺度的古堰塞湖的研究,而对短时间高分辨率的泥石流堰塞湖演化规律的研究尚显不足。古乡沟是帕隆藏布江的一条支流,泥石流规模大,爆发频率高,曾两次阻断帕隆藏布江。通过对古乡堰塞湖段的河床结构测量和沙洲钻孔取样,计算了古乡沟泥石流阻断帕隆藏布江后对泥沙淤积速率和山区河床结构的影响。

Fluvial processes of mountain river in the Southeast Tibet have been severely modified by debrisflow dams. However,most of the researches on the debris-flow dammed lake focus on the ancient dammed lake associated with the research on the long-time scale climate change. Researches on the detail fluvial process of debris-flow dammed lake from the short-time scale perspective are insufficient. In this study,we detailed the methodology to extract the sedimentation rate,and the effect of the debris-flow dammed lake on the bed structure is calculated.