基于投影寻踪和模糊物元组合模型的地下水水质评价

Groundwater Quality Assessment Based on Projection Pursuit and Fuzzy Matter-Element Model

针对水质评价指标的不相容性和指标多样性等特点,将投影寻踪与模糊物元相结合,构建了用于地下水水质评价的组合模型.该模型运用投影寻踪(projection pursuit,PP)方法,构建了投影指标函数,引入萤火虫算法(firefly algorithm,FA)进行优化,寻求地下水水质评价指标体系的最佳投影方向,利用最佳投影方向值确定各评价指标权重,再通过计算复合模糊物元与标准模糊物元之间的欧氏贴近度,实现了地下水水质综合评价.随机选取北京市2012年枯水期水样9例,运用该组合模型进行水质评价,与投影寻踪模型(RAGA-PP)和综合评分法(F值法)的结果进行比较,应用结果证明了该模型的可行性和有效性.

A combined model is proposed to assess the groundwater quality through combination of projection pursuit model and fuzzy matter-element model for the incompatible characteristics and diversity of the water quality evaluation index, etc. Using projection pursuit （PP） method the model constructs the projection index function, and firefly algorithm （FA） was adopted to optimize the projection index function for obtaining the best projection direction of groundwater quality index evaluation system which was applied to determine the weights of various evaluation index. By calculating the Euclid approach degree between compound fuzzy matter-element and a standard fuzzy matter element, a comprehensive evaluation of groundwater quality was achieved. Nine cases of dry season samples of Beijing （2012） were randomly selected and analyzed the water quality with the combined model. The evaluation results of the combined model were compared with one of projection pursuit models （RAGA-PP） and comprehensive scoring method （ F value method）. Results of the application example approved that the combined model is feasible and effective.