山区镇域山洪灾害危险性分区研究——以跳石镇为例

Hazard zoning of flash flood in mountainous administrative region of town: a case study on Tiaoshi Town

山洪对山区人们的生命和财产安全构成了严重的威胁,近年来的一系列山洪灾害造成了重大的人员伤亡和财产损失,严重制约了山区社会经济的可持续发展。以重庆市巴南区跳石镇为研究范围,针对山区镇域山洪灾害的形成特点,构建了由微地貌类型、地形坡位、汇流累积量和植被覆盖度等组成的山区镇域山洪危险分区指标体系,并在Arc GIS平台支持下,通过相应方法获取研究区危险分区指标数据,利用建立的镇域山洪危险分区模型计算得到各评价网格单元山洪危险综合指数并据此进行了综合分区。研究结果表明:跳石镇山洪灾害以低危险和中危险等级为主,分别占总面积的40.12%和34.23%,而中危险区和高危险区共占总面积的47.37%;居民房屋位于中危险和高危险区范围内的面积达846427.9 m2,占房屋总面积的45.40%;在汛期,跳石镇防治山洪的任务较繁重。研究成果可为跳石镇的山洪灾害防灾减灾提供决策依据,同时也可为山区镇域山洪灾害危险分区提供理论参考。

Flash flood is a serious threat to people's life and property security. In recent years,a series of flash flood disasters leaded to a series number of casualties and property losses,which seriously hampered the sustainable development of the socio- economic in mountain areas. With Tiaoshi Town in Chongqing Banan District as a research scope,according to the characteristics of the formation of flash flood disasters in mountain areas,this paper establishes a flash flood hazard zoning index system based on the micro landforms,topography and slope position,flow accumulation and vegetation coverage,and under the Arc GIS platform support,gets the index data of study area by the appropriate methods,calculates the flash flood hazard comprehensive index of every cell by using the flash flood hazard zoning model,after that gets the results of comprehensive partition. The results show that: most of the flash flood disasters in Tiaoshi Town take low and medium risks as dominant grade and they account for,40. 12% and34. 23% respectively,and the medium and high risk area accounts for 47. 37% of the total area,the houses of residents which located in the medium hazard zone and high hazard zone are 846 427. 9 m2,accounting for 45. 40% ofthe total housing area,in the flood season,the flood prevention tasks of Tiaoshi Town are more heavy. The results of flash flood disasters research can provide a decision- making basis to Tiaoshi Town for preventing and mitigating the flash flood disasters,meanwhile also can provide some theory reference to the hazard zoning of flash flood disasters in mountain areas.