Influences of"23·7"heavy rainfall on the hidden danger of debris flow at Caojiafang,Beijing
To explore the influence of extremely heavy rainfall on the susceptibility of mudslides,and provide support for early warning and prevention of mudslide disasters,this paper takes Caojiafang mudslide ditch in Beijing as the study area and selects 15 factors such as sediment recharge length ratio,loose material storage along the ditch,and the average thickness of loose material in the sand-producing area.The standardized scoring method is applied in combination with remote sensing to score the suscepti-bility and make comparisons of the mudslides before and after the heavy rainfall of"23·7"in the study area.The results show that 5 factors,including the length ratio of along-channel recharge,loose material storage along the gully,the average thickness of loose material in the sand-producing area,the degree of blockage of the gully,and the recent variation of the gully,are more sus-ceptible to the influence of extreme rainfall.Under the decisive influence of the flushing effect,the susceptibility of Caojiafang mudslide gully is upgraded from"low susceptibility"to"medium susceptibility".The susceptibility of Caojiafang mudslide ditch is also upgraded from"low susceptibility"to"medium susceptibility"under the decisive influence of alluvial action.
万方数据
