摘要
云南澜沧江上游里底水电站地处滇西北山区,地势陡峻、沟谷深切、降雨丰富,是泥石流活动相对频繁的地段。对坝库区泥石流沟的调查研究表明,泥石流物源类型丰富,有坍塌、崩塌、滑坡及人工破坏等多种成因类型,广泛分布于泥石流沟各区段,其中以坍塌型和崩塌型最为普遍。泥石流沟谷发育特征与其发育程度有关,其中“V”型沟谷多处于泥石流发育早-中期,规模不大但发生频率相对较高;“U”型谷多处于泥石流发育的中-晚期,规模较大,发生频率相对较低。此外,泥石流沟口堆积扇的形态特征在一定程度上也可以反映泥石流的活动性强弱程度;外凸型扇缘多出现在发育期泥石流沟沟口;内凹型扇缘多见于衰退期泥石流沟沟口;“S”型扇缘则多见于成熟期泥石流沟沟口。该研究为从形态特征方面对泥石流的发育程度进行宏观判断提供了素材和依据。
With abrupt relief, deep-cutting valley and rich rainfall, the northwest mountian area of Yunnan, where the Lidi hydroelectric power stantion and reservoir are located, is a relatively active region of debris flow. The research on debric flow around the reservoir makes known that the material sources of debric flow are relatively rich in this region. Four types of the source materials have been founded： collapse-type, cave-in type, landslide-type and human detroying-type. All of them appear in every segments of the debric flow gully. It is the collapse-type and cave-in type that have the high occurrence frequency. The debric flow valley＇s development characteristic is related to its development stages, the V-type valley is in an initial-medium stage with small-scale and higher frequency of the debris flow, the U-type valley is in a medium-terminal stage with relatively large-scale and lower frequency of the debris flow. Furthermore, the debris flow fan at valley mouth can indicate the degree of debric flow＇ s actvity in a certain extent. It is the developing debric flow valley that commonly has the out-protruding type fan fringe, it is the decaying debric flow valley that commonly has the concave-type fan fringe, and it is the the maturating debric flow valley that commonly has the S-type fan fringe. So some materials and evidences have been offered to make a macroscopical estimation on the development degree of debric flow according to their shape characteristics.
出处
《中国地质灾害与防治学报》
CSCD
2006年第2期11-14,共4页
The Chinese Journal of Geological Hazard and Control
基金
国家自然科学基金资助项目(40372127)
关键词
泥石流
澜沧江
物源类型
成因机制
沟口堆积扇
debris flow
hydroelectric power station in Lancang River
types of source materials
forming mechanism
debris flow deposited fan
