IQA FAL - Fuzzy water quality index for lotic environments

ABSTRACT The dissemination of information on water quality for a non-specialist audience is essential to support political and institutional actions for the management of aquatic environments. Therefore, water quality indices have been proposed since they are able to synthesize into a single value or category information, usually described from an extensive set of water quality variables. This research proposes a new water quality index, based on fuzzy logic, aimed at lotic environments, developed through the collaboration of experts in water quality of the Rio de Janeiro Environmental Agency (Instituto Estadual do Ambiente - INEA). The proposed index was applied to water quality data from the Paraíba do Sul River, obtained by INEA, in the years 2002 to 2009. The results of IQAFAL showed that the index was able to synthesize the water quality of this stretch of the Paraíba do Sul, satisfactorily matching the assessments of the water quality assessments contained in the reports available. It was also noticed that with this methodology it was possible to avoid the attenuation of the influence of a variable in critical condition was attenuated by the influence of other variables in favorable conditions, producing an inaccurate result in the final index.

摘要：面向非专业受众的水质信息传播，对于支撑水生环境管理的政治与制度举措至关重要。有鉴于此，水质指数应运而生，其可将通常由大量水质变量表征的信息整合为单一数值或类别。本研究提出一种基于模糊逻辑（fuzzy logic）的新型水质指数，针对流水环境开发，由里约热内卢州环境局（Instituto Estadual do Ambiente - INEA）的水质专家协作完成。本研究将所提出的指数应用于INEA于2002年至2009年间获取的帕拉伊巴杜苏河（Paraíba do Sul River）水质数据。IQAFAL指数的结果表明，该指数可有效整合帕拉伊巴杜苏河该河段的水质状况，与现有报告中的水质评估结果高度吻合。同时本研究发现，该方法可避免出现以下情况：某一处于临界状态的变量的影响，被其他处于有利状态的变量的影响所削弱，进而导致最终指数结果失真。