EVOLVING FUZZY INFERENCE-BASED DECISION SUPPORT METHODOLOGY FOR RISK MAPPING OF WASTEWATER-FED AQUACULTURE SYSTEM

摘要

Wetlands also serve as wastewater-fed aquaculture system for augmentation and recycling of municipal wastewater. These systems are not only the place for safe disposal of huge quantity of urban sewage, but also provider of food and employment. Anthropogenic interference with commercial interest and process of urbanization has made the system dynamic and vulnerable towards exploitation. Wetlands are often misunderstood as wastelands, and as a result easy victims of the development process. Fortunately water policies do exists in India that supports and accepts the wastewater reuse. For efficient utilization and conservation of these wetland ecosystems, proper assessment and mapping is essential. In this regard, there exists a huge gap. Selection of mapping and modeling techniques for wastewater-fed aquaculture system requires the understanding of the complex components related to social, economic, technical, and environmental processes; possible trade-off variables; and its related social and economic costs. All these related datasets are sometimes incomplete and vague, which are difficult to be captured by traditional threshold-based models. Such uncertainties can be addressed by fuzzy logic, whereby fuzzy set theory provides a unifying framework for vague and fuzzy information processing. This paper presents a conceptual framework of Fuzzy Inference System (FIS) for wetland risk mapping and assessment. The framework integrates multiple risk factors and quantification of uncertainties within a system to generate consistent outcome. Remote sensing and GIS plays an integral part in generating the base layers for the system. FIS-based wetland risk assessment includes: definition of membership functions, determination of linguistic variable, construction of fuzzy rules, determination of model properties, and defuzzyfication. The fuzzy inference-based decision support system for wetland risk mapping presented here can be a useful tool for decision makers involved in the planning and management of the ecosystem.