重庆市山洪灾害空间分布规律及影响因素研究

揭示重庆市山洪灾害发育规律可进一步指导山洪灾害防治工作。根据2013~2015年度重庆市山洪灾害调查成果,结合影响山洪灾害发生的地貌、高程、坡度、降雨及河网密度因素,探讨了山洪灾害空间分布规律。结果表明,200 m高程、15°坡度以下的低海拔小起伏山区与丘陵区和1 000~1 300 mm降雨区是山洪灾害高发区,随河网密度增加,山洪灾害频率增多。另外,长江干流沿线和主要支流区是山洪灾害高发区,境内华蓥山系、方斗山、铁峰山及七曜山斜坡-河谷带是山洪灾害的次高发区,渝东北等高海拔区山洪灾害低发。由此得出,重庆市山洪灾害发育受地形、降雨及河网密度等多因素叠加影响,境内长江干、支流沿线是山洪灾害重点防治区。研究成果可为重庆市灾害防治工作提供一定数据与技术支撑。

Spatial distribution pattern and impacting factor of mountain torrent disasters in Chongqing

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.