Study On Cause And Distribution Pattern Of Debris Flows Along Chengdu-Jiu Zhaigou Railway

Chengdu—Jiu Zhaigou Railway is a branch of Cheng-Lan Raiway from Chengdu to Jiu Zhaigou, and it passes through mainly mountainous areas featured with cracked rock clusters, unstable mountain, complex geographical structure, frequent earthquake occurrence. Heavily influenced by monsoon climate, the volume of rainfall is quite unevenly distributed, causing rainstorm often to happen. Besides, the earth's surface is severed destructively, leading to mass loss of water and soil. Exacerbated by human activities, debris flows now are a serious problem in this region. It has been attested that there are more than 40 debris flow putting Jiu Zhaigou railway's normal operation in jeopardy. In order to guarantee the construction and security as well as the utility from railway operation, this article will conduct a systematic and thorough investigation on 27 typical debris flows to delve into the causal effect of these natural disasters, and it is also necessary to know their distribution pattern.Through on-site research on the debris flow valley, we obtain, organized information, supported by statistical analysis, to examine the reasons and conditions to cause debris flow, based on particular geographical environment. Also, GIS technological platform supplies sophisticated analytical tools, such as GIS space analysis, graph making, and visualization, to systematically overlap items like terrain, landscape, geographic structure, lithological characters, earthquake, and water zone among all the investigated debris flows. The conclusion is made that geographical structure is the main reason to the current distribution pattern of debris flows, and human activities, earthquake and rainfall are also causal factors. Detailed empirical case studies on Sun Jiagou and Zhong Zhaogou are provided to testify the correctness of the conclusion. In summary, the article analyzes the basic characteristics and distribution pattern of debris flows along the Chengdu-Jiu Zhaigou raiway, based on the examination of its causal factors. The article also supplies fundamental materials and scientific methods to alleviate and subsequently prevent the debris flows with many underlying practical implications...