The impact of human activities on the occurrence of mountain flood hazards: lessons from the 17 August 2015 flash flood/debris flow event in Xuyong County, south-western China

摘要

Mountain flood hazards are now among the most studied hazards, given that they cause loss of life and damage to property and infrastructure throughout the world. This paper takes the 2015 Xuyong flash flood/debris flow event as a case study to examine the impacts of human activities on the occurrence and amplification of mountain flood hazards. Field investigations, the interpretation of observational data and mechanistic analyses are carried out as part of a comprehensive analysis of the processes by which mountain flood hazards develop and become amplified, the contribution of excessive sediment supplies to mountain flood hazards and the effects of human activities on mountain flood hazards. Results of this comprehensive analysis indicate that some human activities contribute to the occurrence of the initiation of mountain flood hazards. These human activities fall into two main categories: (1) deforestation and improper construction damage the natural environment and may increase the occurrence of mountain flood hazards; (2) improper choices of residences, local congestion of engineering structures and some other factors may directly amplify the losses caused by mountain flood hazards. Finally, some hazard prevention and mitigation measures for mountain flood hazards are discussed.