Spatial distribution pattern and impacting factor of mountain torrent disasters in Chongqing
ZHANG Qianzhu;LU Yang;QIN Wei;XIN Xinfu;Chongqing Branch,Changjiang River Scientific Research Institute;Chongqing Branch,Wuhan Changjiang Kechuang Technological Development Ltd.;
Revealing the spatial pattern of mountain torrent disasters in Chongqing can provide guidance for disaster prevention and control. According to a survey conducted between 2013 and 2015,the spatial distribution patterns of mountain torrent were discussed in consideration of the landform,elevation,slope,rainfall and river density. The results indicate that high frequent flood disaster areas are distributed in low altitude rolling mountainous or hilly area of slope less than 15 °,as well as the 1000 ~1300 mm rainfall areas. In these areas,as the river net gets denser,the mountain torrent disasters become more frequent. Moreover,Changjiang and its major tributary watersheds are the high frequent area; slope-river valleys in mountainous areas of Huaying mountains,Fangdou mountain,Tiefeng mountain and Qiyao mountain are the second-high frequent area; the disasters occur relatively less in the Northwest Chongqing. The development of mountain torrent disaster is subject to multiple factors including terrain,rainfall,and river net density. The Yangtze River mainstream and its tributaries are the key prevention areas of mountain torrent disasters.