Analyzing risk factors for shrinkage and transformation of East Kolkata Wetland, India

Abstract

The East Kolkata Wetland, called the ‘kidney’ of city Kolkata has now become a significant issue for its gradual loss and modification of anthropogenic activities. A socioeconomic elucidation had been used in this article through the analysis using GIS and field observation. Changes of wetland area have been determined from 1991 to 2017 with Landsat images and accuracy assessment through ground truth verification. It is seen that loss of wetland from 1991 to 2001 was 23.55% where it was 7.34% in 2011 to 2017, mainly due to the result of land transformation for aquaculture activity. Hence, three phases of degradation have been observed in this study, these are: the phase of rapid degradation, the phase of controlled degradation and phase of transforming degraded. At the same time, it’s highlighted the loophole of management actions. A multi-criteria analysis technique with the analytic hierarchy process has been applied to determine the risk factors of wetland degradation and it is seen that expansion of built-up area, encroachment of cropland, the transformation of wetland into fishing ponds are responsible for wetland degradation. In the conclusion, it highlights the approaches of land developers and real estate agents in their wetland hunting process and emergence consequences on the environment as well as conserving approaches for sustainable management.