Social vulnerability to riverbank erosion in Bangladesh: Comparative insights across stages of household exposure

Riverbank erosion displaces people, interrupts livelihoods, and increases vulnerability in riverine settlements. This long-term risk needs a thorough vulnerability analysis for disaster risk reduction and sustainable planning. Existing literature has focused on static vulnerability assessments and has often omitted the dynamics of vulnerability. This research applies a modified Social Vulnerability Index (SoVI) to 420 households in erosion-prone Sariakandi and Harirampur Upazilas in Bangladesh to calculate vulnerability scores at the household level for three exposure groups (not yet affected, faced recently, and faced in the past). We developed SoVI that incorporates 29 core and context-specific variables relevant to erosion-prone communities. We find significant variation (ANOVA, p < 0.05) in vulnerability across the sites and exposure groups. Recently exposed households were the most vulnerable (mean SoVI ≈0.48–0.50), while those impacted in the past are the least vulnerable in Sariakandi where 82.8% of the households belonged to low or very low vulnerability groups. Random Forest regression indicates that poor sanitation and low household income were core factors contributing to vulnerability in both sites. Proximity to river was a contextual factor that increased vulnerability in both sites, but more in Sariakandi. Household-head illiteracy, ownership status, and dependency on farming and wage labour increased vulnerability in both sites. These results underscore the interaction between erosion, flooding, and climatic hazards in influencing vulnerability in rural settlements. They highlight the need for interventions and strategies for promoting adaptation and disaster risk reduction in erosion-prone areas.