A Grid-and-Zone Geospatial Framework for Wetland Condition Assessment and Conservation Planning of East Kolkata Wetlands

Wetland ecosystems face accelerating threats from urban expansion and land use transformation, necessitating robust, spatially explicit frameworks for evidence-based conservation planning. This study presents a comprehensive methodology integrating multi-temporal satellite remote sensing, Land Use and Land Cover (LULC) change detection, field-based ground truthing, and zone-differentiated management strategies to systematically prioritize wetland conservation interventions. Multi-temporal satellite imagery spanning 2011 to 2025 was classified into five LULC categories—wetland, agriculture, built-up, open lands and dumping ground—enabling rigorous temporal comparison of landscape-scale transformations. Accuracy of the classified maps was validated through ground truthing using high-resolution Google Earth imagery and systematic field verification, encompassing land use checks, wetland boundary delineation, and LULC accuracy assessments. Building count data, derived through automated and manual extraction procedures, were analysed as a direct proxy for quantifying urbanisation pressure on adjacent wetland patches. Two complementary conservation strategies were operationalised: a grid-based condition scoring system that classifies individual wetland cells on a five-point scale from Very Poor to Excellent, thereby generating spatially explicit priority tiers ranging from Very High to Very Low Priority; and a concentric zone-based management framework that delineates Wetland Core (Zone 1), Buffer (Zone 2), and Transition (Zone 3) areas, each prescribing land use-specific intervention measures. The integrated outputs, encompassing building count statistics, temporal change analysis, urbanization pressure indices, and priority classification maps, provide science-based recommendations to support immediate conservation action and sustainable land use governance around threatened wetland complexes.