浙西南山区乡镇坡面型泥石流成灾模式研究方法探讨

Discussion on Disaster Model Research Methods of Slope Debris Flow in Mountainous Areas of Southwest Zhejiang

浙西南山区乡镇汛期泥石流频发,对人民的生命与财产造成重大损失,从流域形态上分为沟谷型、坡面型两大类,目前国内外关于沟谷型泥石流机理研究较为成熟,坡面型泥石流预测评价是难点。浙西南山区乡镇梅汛期暴雨诱发坡面型泥石流与浙江沿海地区台风降雨诱发型成灾模式略有差异,本文基于莲都区老竹镇高精度地质灾害风险调查评价项目,尝试从地质条件、地形地貌条件、降雨条件等方面,探索暴雨诱发坡面型泥石流成灾模式研究方法,引入短历时雨强指数概念,提出该区坡面泥石流发生临界降雨量,为地方防灾减灾和预警预报工作提供参考。

In the mountainous areas of southwest Zhejiang,there are frequent debris flows during the flood season,causing heavy losses to people’s lives and property.From the watershed morphology,they are divided into valley-type and slopetype.At present,domestic and foreign research on the mechanism of valley-type debris flow is relatively mature.The prediction and evaluation of slope debris flow is a difficult point.There is a slight difference between the torrential rain-induced slope debris flow and the typhoon rainfall-induced disaster pattern in the coastal areas of Zhejiang Province during the plum flood season in the mountain towns of southwest Zhejiang.This article is based on the highprecision geological hazard risk survey and evaluation project in Laozhu Town of Liandu District,try to explore the research method of the disaster model of slope debris flow induced by heavy rain from the aspects of geological conditions,topography and landform conditions,rainfall conditions,etc.This paper introduces the concept of shorttime rainfall intensity index and proposes the critical rainfall for slope debris flow,which provides reference for local disaster prevention and mitigation and early warning and forecasting.