基于GIS技术的内蒙古地区暴雨洪涝灾害风险区划及评估研究

基于内蒙古地区87个旗县气象站1961～2008年的逐日降水量、暴雨洪涝灾情普查数据、1:25万数据高程和水系以及相关社会经济等基础资料,利用灾害学原理、风险度指数及GIS等技术方法,分析了内蒙古地区暴雨洪涝灾害形成的主要影响因子,提出了洪灾风险评价指标体系,确立了各因子在洪灾风险评估中的重要性-权重系数。在此基础上,利用GIS技术,从致灾因子危险性、孕灾环境敏感性、承灾体易损性和防灾抗灾能力等方面,综合分析区划及评估了内蒙古地区暴雨洪涝灾害的风险性。结果表明:呼伦贝尔市岭东、兴安盟南部、通辽市南部、鄂尔多斯市东部以及呼和浩特市和包头市城区是发生洪涝灾害风险最大区域;其它地区由于暴雨出现几率低、地形平坦、人口密度低、远离河网水系,发生洪涝灾害的风险性较低。

Risk zonation and evaluation of rainstorm and flood disasters in Inner Mongolia based on GIS

The main factors of disasters caused by rainstorms and floods in Inner Mongolia were analysed based on daily precipitation data at 87 weather stations from 1961 to 2008,general survey of rainstorms and floods,1 : 250,000 GIS and hydrological data,and relative social economic information.A complex technical methodology which involves disaster theory,risk assessment indicators and GIS analysis was used here.An indicator system of floods risk assessment was provided and the significance of each indicator in floods risk assessment was established by weight coefficient analysis in this paper.Rainstorm and flood disasters risk in Inner Mongolia was assessed and regionalised by the indicators related to the amount and intensity of rainstorms,sensitivity of environment to floods,prevention and resistance to disasters.The results showed that the regions including east of Da Hinggan Mountains of Hulunbeir,south of Xing’anmeng,south of Tongliao,east of Erduosi,Huhehaote and Baotou,were more vulnerable to rainstorms and floods,due to their high rainstorms frequency,small regional altitude difference,intensive river networks,concentrated farmlands,and large population,compared to other regions in Inner Mongolia.