Spatio-temporal Mapping of Climate Variability and Community Perceptions: A GIS and PGIS-based Study in Coastal Bengal, India

This chapter investigates climate change and variability in the coastal region of Bengal by integrating Geographic Information Systems (GIS) with participatory GIS (PGIS) approaches. The primary objectives are to examine the spatio-temporal patterns of climate variability over the past 122 years (1901–2022) and to assess local community perceptions of these changes. The study draws upon long-term climatic datasets from the climatic research unit (CRU), alongside primary data collected through 200 household surveys and focus group discussions conducted in December 2024 in the study area. The spatio-temporal analysis reveals a distinct warming signal, with average and maximum temperatures rising steadily since the early 20th century. Rainfall demonstrates marked variability, peaking in the mid-20th century before declining to historically low levels by 2022. This reduction in rainfall, coupled with fewer wet days and heightened atmospheric moisture, points to an increasingly erratic and unstable climatic regime. Such changes intensify risks of heat stress, water scarcity, and extreme weather events. Community perceptions, analysed using the Garrett ranking technique, broadly corroborate these findings. Respondents identified rising air temperature, increased cyclone frequency, and rainfall variability (RF) as the most critical indicators of climate change, reflecting reliance on direct, lived experiences. By contrast, less visible parameters, such as sea surface salinity (SSS) and sea surface temperature (SST), received comparatively lower recognition despite their ecological importance. Overall, the convergence of scientific evidence and community perspectives underscores the urgent need for integrated, community-driven adaptation strategies to enhance resilience in this climate-sensitive coastal zone.