基于证据理论和可变模糊集的成都市洪灾风险评估  

Risk evaluation of Chengdu's flood hazard based on evidence theory and variable fuzzy sets theory

作　　者：任玉峰[1] 刘国东[1,2] 周理[1] 张春敏[1] 

机构地区：[1]四川大学水利水电学院,成都610065 [2]四川大学水力学与山区河流开发保护国家重点实验室,成都610065

出　　处：《农业工程学报》2014年第21期147-156,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金青年基金项目(51209152)

摘　　要：洪灾系统的高维性和不确定性,给灾害风险评估带来较多困难,为了提高评估的准确性和合理性,实现科学灾害管理,该文将Dempster_Shafer证据理论应用到洪水灾害风险评估中,同时利用可变模糊集理论来构造证据理论基本信任分配,实现了客观合理的证据建模,最后利用经典组合原理进行证据组合。以成都市区2012年风险等级的计算为例,风险为高等级时的信任区间为[0,0.52],似然区间为[0,0.54],不确定大小为0.019,根据判断规则,确定市区2012年的洪灾风险等级为高。基于此方法采用相同处理,对研究区成都市风险等级的时空分布进行了计算分析。结果表明该方法能够较好地融合洪水灾害系统各方面信息以及处理风险评估中的不确定性,实现了洪灾风险的准确评估。Under the background of global climate change, the sustainable development of a society is extraordinarily endangered by the growing frequent and severe flood in China. Flood hazard is a highly uncertain and high-dimensional system. Thus, more difficulties emerge when carrying out flood risk evaluation. In this paper, the Dempster-Shafer （DS） evidence theory was applied to evaluate the flood hazard risk due to its ability in multisource information fusing and information uncertainty processing. The establishment of basic belief assignment （BBA） called evidence model is the nodus and hotspot in DS evidence theory research. In order to solve this problem, BBA was established and combined with comprehensive relative membership degree of index by using variable fuzzy sets theory （VFS）. More specifically, the value of BBA was assigned by relatively comprehensive membership degree of VFS theory during the calculation process. BBA of hazard-formative environment, disaster-inducing factors and hazard bearing body were seen as the three pieces of evidence, and these evidences were combined by the classical evidence combination principle. Then, the decisions of flood disaster risk assessment were made by comparing quality function, belief function, relief function and uncertainty of each risk degree. So far, the objective and reasonable evidence model was established in this way while the conflict evidence was greatly reduced. Through evidence combination and the calculation of confidence, likelihood and uncertain interval of different risk degrees based on the classic evidence combination principle, the flood hazard risk was accurately assessed. The DS_VFS model was applied to evaluate the flood hazard risk in Cheng Du where flood disaster has been serious since ancient times. The study area was divided into 12 partitions and each subarea’s hazard risk degree was calculated respectively by using DS_VFS model. The results indicated that the risk degree of Cheng Du was high, especially in the northwest, northe

关 键 词：洪水灾害 风险评估 模糊集 DEMPSTER-SHAFER证据理论 可变模糊集 不确定性 

分 类 号：X43[环境科学与工程—灾害防治]