水科学进展2016，Vol.27Issue(4)：542-550,9.DOI:10.14042/j.cnki.32.1309.2016.04.008
浅层滑坡诱发沟谷泥石流的地形和降雨条件
Research on the topographical and rainfall factors of debris flows caused by shallow landslides
摘要
Abstract
The large number of debris flow events in the Dayi area, Guizhou, China, due to a large rainfall event in June 2011 provided a good opportunity to study the influence of topographical factors and rainfall factors on the trigge⁃ring of debris flows by shallow landslides. The triggering mechanism for these debris flows is the transport of sediment provided by shallow landslides into the channel. During the heavy rainfall event in 2011, 37 gully type debris flows caused by shallow landslides were triggered. In some catchments no such debris flows were triggered even though these catchments were in the vicinity of gullies with debris flows. We isolated and analyzed the influence of the topography on the formation of debris flows in gullies with almost identical hydrological and geological conditions and propose a new T⁃factor as a topographical indicator which is a combination of the catchment surface area, the percentage of the catchment area with a slope of 25—45 degree, and the average gradient of the drainage channel in the catchment. Ad⁃ditionally a new R⁃factor is proposed as a rainfall indicator which is a combination of the rainfall in 1⁃hour before the debris flow was triggered, the cumulative rainfall before the debris flow was triggered, and the annual rainfall. The re⁃lationship of the T factor and the R factor gives a primary threshold P for this kind of debris flow. The primary proba⁃bility factor P is the combination of T and R, which gives an indication of the probability of debris flow formation.关键词
地形因子/降雨因子/泥石流/浅层滑坡Key words
topographical factor/rainfall factor/gully type debris flow/shallow landslide分类
天文与地球科学引用本文复制引用
余斌,王涛,朱渊..浅层滑坡诱发沟谷泥石流的地形和降雨条件[J].水科学进展,2016,27(4):542-550,9.基金项目
国家自然科学基金资助项目（41372366） The study is financially supported by the National Natural Science Foundation of China （ No．41372366）． （）
