一种Gamma-云的富营养化评价方法及其应用

基于富营养化评价中隶属分布的非对称性和"单侧受限"假设,引入云模型理论提出了一种基于Gamma-云模型的富营养化评价方法。由既定指标区间计算各等级的Gamma-云模型参数,通过云发生器生成各指标下相应于各等级的Gamma-云模型;由层次分析法确定指标权重。将实测水质数据代入Gamma-云模型,并通过指标权重计算得到水体对各富营养化等级的确定度,由确定度最值对应的等级作为评价结果。以我国12个代表性湖库为例验证了Gamma-云评价方法的适用性,并将该方法与单一指标法,模糊可变集法和正态云法进行对比。实例表明,基于Gamma-云模型的富营养化评价方法可行有效,为水体富营养化评价工作提供了新思路。

Gamma-Cloud Model for Eutrophication Evaluation

An eutrophication evaluation method of Gamma-Cloud model was proposed based on the theory of cloud model, with the assumption of asymmetry and unilateral constraint in membership distribution. Numeric characteristics of Gamma-Cloud model belonging to each eutrophication level were determined according to the established indicators; and the weight was calculated by analytic hierarchy process to generate Gamma-Cloud models of all indicators. Distribution of the certainty degrees belong to each level were determined after weight calculation; and the eutrophication level corresponding to the maximum certainty degree is the final evaluation. 12 lakes and reservoirs were evaluated with this model. Comparative researches with the methods of single index, variable fuzzy sets and normal cloud model shows that Gamma-Cloud model is effective and provides a new way of eutrophication evaluation.