Urban expansion induced vulnerability assessment of East Kolkata Wetland using Fuzzy MCDM method

Abstract

Wetlands provide multi-dimensional services to the society and environment but recent anthropogenic interference becomes a threat for the conservation of existing wetlands. Wetlands adjacent to megacities of South Asian countries are mostly affected by numerous adverse environmental impact of rapid urban development. The East Kolkata Wetland located adjacent to the Kolkata megacity is also struggling for its existence as the Kolkata megacity is growing rapidly by converting its surrounding areas to urban landscapes. Encroachment of settlements identified through land use change analysis that makes EKW more vulnerable. Vulnerability assessment is an essential part of formulating any conservation strategies. This study tries to identify the wetland conversion vulnerable areas within the East Kolkata Wetland. Well established Fuzzy multi-criteria decision-making approach is applied by incorporating different wetland conversion influencing factors and knowledge-based approach and the result shows near about 60% areas are lying in high to very high-vulnerable zones. This high vulnerability condition demands immediate plan formulation for protecting this ecologically rich wetland. The wetland areas which are adjacent to already develop urban built-up belongs to high and very high vulnerable zones. Validation of the result is required for understanding the applicability of Fuzzy MCDM method and for formulating an appropriate plan. In this study Receiver Operating Characteristics (ROC) is used to evaluate the result, where, Area Under Curve (AUC) accounts for 93.7% which indicates a high reliability and accuracy of the Fuzzy MCDM. The outcome of the study demands immediate attention of the local authority for conserving this wetland.