基于多因子指数集成的流域面源污染风险研究

Risk Assessment and Safety Evaluation Using System Normative Indexes Integration Method for Non-point Source Pollution on Watershed Scale

为掌握流域面源污染风险的整体趋势,基于风险评价时,单个因子对系统某种风险的贡献率可能大于1且因子对系统风险贡献呈一定结构性的问题,定义了风险标准值的概念和算法,建立了系统风险多因子集成评价方法,并在地理信息系统支持下对泸沽湖流域进行了案例研究.结果表明,泸沽湖流域面源污染流失风险处于较高的水平;系统风险多因子集成评价法在对多个同类系统间进行比较时,具有较大的优势;该方法可以与其他多种方法相结合对系统属性进行全面综合评价.

Decision-makers take non-point source pollution under control as well as possible results from enough information of risk trend of non- point source pollution on watershed scale. System normative indexes integration evaluation method about system risk trend was developed when focusing on that the probability values of some elements attributing to some trend of the system were more than one, and that the system evaluation needed a formula from the system structure. On the basis of analysis on aspects and characteristics of the system risk normalization, a new valuation method, the relationship between the normalization values of the system and the factors was established. The Lugu Lake Watershed in Southwest China was selected as study area to assess the risk of non-point source loss to surface water using this method. The results indicate that （1） the wholly risk of non-point source loss to surface water in this watershed is in a high level; （2） the system indexes integration evaluation method is an universal method to evaluate a quality or a trend of any system and shows a great power in comparing several systems; （3） the method is helpful to attain an effective and integrated assessment on a system when it is combined with other methods.