小流域堰塞湖对山洪泥石流的调控模式探讨

Discussion of regulation mode of torrent- debris flow by dammed lake in small river basin

通过对我国青藏高原东缘小流域堰塞湖系统调查与分析,选择金沙江一级支流巧家县的海子沟、岷江一级支流茂县的宗渠沟和岷江二级支流理县的古城沟作为典型案例,进行小流域堰塞湖对山洪泥石流的调控模式研究。研究得出,小流域堰塞湖调节作用下山洪泥石流的相互转换模式主要有3类:1淤积与再侵蚀产生泥石流模式;2淤积与清水出流模式;3侵蚀规模放大模式。基于小流域堰塞湖对山洪泥石流调控特征分析,揭示不同特征的小流域堰塞湖成灾风险,并提出针对性的处理措施。

Through the detail investigation and analysis on dammed lakes in small river basin in the east of Tibetan plateau, the first tributary Haizi gully of the Jinsha River in Qiaojia County, the first tributary Zongqu gully of the Minjiang River in Maox- Jan County, and the second tributary Gueheng gully of the Minjiang River in Lixian County are selected as typical cases to study the regulation mode of torrent - debris flow by dammed lakes in small river basin. There are three mutual transformation modes of torrent and debris flow under the regulation of dammed lakes ： the torrent - debris produced by deposit and re - erosion, the deb- ris deposited and clear water discharged, and erosion scale enlarged. Based on the regulation mode of small watershed dammed lakes on the torrent - debris flow, the disaster risks of the dammed lakes with different characteristics are revealed, and some tar- geted measures are proposed.