Application of pressure–state–response approach for developing criteria and indicators of ecological health assessment of wetlands: a multi-temporal study in Ichhamati floodplains, India

Abstract Background Tropical floodplain wetlands are among the most disturbed and intensively harvested ecosystems. Their sustainable management is often hindered due to the lack of comprehensive, coherent, and standardized assessment frameworks of wetland ecological health (WEH). In this study, a set of appropriate criteria and indicators (C&I) of WEH assessment was developed and tested on seven wetlands of River Ichhamati, eastern India. Methods Based on the pressure–state–response (PSR) approach, evaluation indicators representing ecological, socio-economic, and institutional sustainability issues of floodplain wetland systems were either selected or formulated through literature survey and stakeholder consensus. Weights of indicators were assigned by the entropy weighting method and then used in the Technique for Order of Preference by Similarity to Ideal Solution model to determine the Euclidean distances of each wetland from the positive ideal solution and negative ideal solution. Subsequently, a comprehensive wetland ecological health index (CWEHI) was constructed from these distances to portray the condition of any PSR system component in a wetland under a fivefold classification scheme, namely ‘excellent health’ (CWEHI ≥ 0.81), ‘good health’ (0.61–0.80), ‘moderate health’ (0.41–0.60), ‘weak health’ (0.21–0.40), and ‘morbid’ (≤ 0.20). Results The developed C&I set contains 8 criteria and 38 indicators under pressure component, 7 criteria and 49 indicators under state component, as well as 4 criteria and 18 indicators under response component. When applied in 2016 and 2022, it was found that the Panchita and Aromdanga wetlands were continuously in weak and morbid health status, while the Madhabpur wetland always showed an excellent or good status for all components. Health of other wetlands oscillated between moderate and morbid health across assessment years and system components. Conclusions The developed C&I set was found to be a flexible, holistic, and refined framework that could be applied elsewhere in similar assessments with minor indicator-level adjustments. The present assessment inferred that agriculture-dominated wetlands were more affected by amplified environmental pressure than fishing-dominated wetlands. Absence of persistent water flow from main river channel, wide-spread jute-retting, agriculture-induced eutrophication, proliferation of aquatic weeds were identified as the major causes of rapid ecological deterioration.