Chloride Vulnerability Assessment using Multi-Criteria Decision-Making Analysis of Coastal India

Abstract

The marine environment is a vital resource that supports diverse ecosystems and sustains millions of people living along coastal zones. However, these regions are increasingly vulnerable to corrosion hazards in coastal infrastructure due to chloride intrusion from seawater, exacerbated by tidal effects, rising sea levels, excessive groundwater extraction and saline encroachment. This study presents a GIS-based multi-criteria analysis of chloride hazard vulnerability along India’s coastal regions. Five key geographical parameters were used to assess the study area's vulnerability: chloride concentration, elevation, slope, land use/land cover (LULC) and population density. To evaluate objectively the influence of each factor, the Analytic Hierarchy Process (AHP) was used to assign weights. Spatial analysis of groundwater chloride levels reveals a strong correlation between proximity to the coast and soil chloride concentration. These zones are more likely to experience substructural degradation from chloride-driven corrosion in reinforced concrete and other infrastructure materials. The GIS-based hazard assessment provides a crucial tool for regional planning and long-term infrastructure resilience. The chloride hazard mapping is expected to serve as a foundational step in coastal protection, infrastructure planning and maintenance programs, ensuring the sustainability and durability of India’s vulnerable coastal infrastructure.