Causes of large-scale gully debris flow and enlightenment of disaster reduction——Taking the"7·14"debris flow in Guru Gully of Heishui County as an example
Causes of large-scale gully debris flow and enlightenment of disaster reduction——Taking the"7·14"debris flow in Guru Gully of Heishui County as an example
Gully debris flow has the characteristics of steep valley slope,large relative height difference and large gully slope,which often forms large-scale debris flow disasters.At about 20:00 pm on July 14,2021,a large-scale debris flow disaster occurred in Guru Gully of Heishui County,causing a direct economic loss of 33 million yuan.To improve and perfect the prediction and early warning means and disaster reduction level of debris flow disaster,the"7·14"debris flow in Guru Gully was taken as the research object.Through field investigation,model calculation,watershed geomorphic information entropy and meteorologi-cal analysis,the characteristics of the"7·14"debris flow in Guru Gully were revealed,its causes were ana-lyzed,and its future development trend was predicted.The results show that the bulk density of the"7·14"debris flow in Guru Gully is 1.83 g/cm3,which is a viscous debris flow,the average velocity of 11.2 m/s,and the peak of debris flow reaches 991.2 m3/s.The mature and juvenile landform development stage provides sufficient dynamic potential energy conditions for the"7·14"debris flow in Guru Gully outbreak.The daily rainfall of 49.7 mm is the triggering factor for the debris flow.According to the gray catastrophe prediction model,the Guru Gully will have an outbreak of debris flow disasters in 2027,2034,and 2042.The research results help to improve the prediction and early warning of gully debris flow,and can provide reference for debris flow prevention and mitigation in other areas.
关键词
沟谷型泥石流/形成机制/预测预警/流域地貌信息熵/灰色灾变预测模型/谷汝沟泥石流
Key words
gully debris flow/formation mechanism/prediction and early warning/geomorphic information entropy of watershed/gray catastrophe prediction model/Guru Gully debris flow