%0 Journal Article
%T Characteristics and Prevention of the Debris Flows following Wenchuan Earthquake in Jushui River Basin, An County, China
%A Yonggang Ge
%A Jianqiang Zhang
%A Xiaojun Guo
%J Journal of Earthquakes
%D 2014
%R 10.1155/2014/519865
%X After analysing the catastrophic debris flows on August 18, 2012, and on July 9, 2013, in Jushui River basin, An County, the Wenchuan Earthquake seriously striken areas, it was found that they were characterized by the clay soil content of 0.1~1.2%, the density of 1.68~2.03£¿t/m3, the discharges of 62.2£¿m3/s to 552.5£¿m3/s, and the sediment delivery modulus of 1.0~9.4 ¡Á 104£¿m3/km2. Due to intense rainstorm, many large debris flows produced hazard chain, involved in flash flood, debris flow, dammed lake, and outburst flood, and rose Jushui River channel about 1~4£¿m as well as amplified flood. The hazards and losses mainly originated from the burying and scouring of debris flows, flood inundating, and river channel rise. The prevention of debris flows is facing the intractable problems including potential hazard identification, overstandard debris flow control, control constructions destructing, and river channel rapid rise. Therefore, the prevention measures for the basin, including hazard identification and risk assessment, inhabitants relocating, monitoring and alarming network establishing, emergency plans founding, and river channel renovating, and the integrated control mode for watershed based on regulating the process of debris flow discharge, were recommended for mitigation. 1. Introduction Debris flow, an abrupt earth surface phenomenon, extensively and frequently occurs at mountain areas with steep terrain, quantity of unconsolidated soil, and abundant surface runoff. It is often exasperated by extreme rainstorms, intensive exploitation activities, and intensive earthquakes. Due to quantity of loose soil accumulation, the debris flow following intense earthquake generally expresses different characteristics to those before the earthquake. The debris flows following Wenchuan Earthquake are characterized by lower triggering rainfall threshold, high density, higher velocity, larger discharge, bigger magnitude, and intensive impact and impose the heaviest-dangerous hazards on local living and reconstructions at the seriously stricken areas [1, 2]. The noticed catastrophic debris flows, including the ones on September 24, 2008, at Beichuan County [3], on August 13 and 14, 2010, at Wenchuan, Dujiangyan, and Mianzhu [4], on July 3, 2011, at Wenhuan Chuan [5], on August 18, 2012, at Pengzhou [6] and An County, and the ones on July 9-10, 2013, at the whole earthquake areas, not only made huge properties losses and casualties but also produced new challenges and requirements for measures and technologies of mitigation due to the breaches of most control
%U http://www.hindawi.com/journals/jearth/2014/519865/