Geospatial Analysis-Based Tidal Flood Vulnerability Mapping in the Coastal Area of Sungai Kakap District, Kubu Raya Regency

Abstract

Tidal flooding has become an increasingly significant environmental hazard in coastal areas. This study aims to: (1) identify the spatial characteristics of tidal flooding in the coastal area, (2) analyze the spatial factors influencing tidal flood vulnerability; (3) assess the level of tidal flood vulnerability using geospatial analysis; and (4) propose adaptation strategies based on the resulting vulnerability patterns. The analysis includes eight key variables: slope gradient, elevation, distance to the coastline, distance to the river, Topographic Moisture Index (TWI), soil type, rainfall, and land use. The spatial datasets were processed in a Geographic Information System (GIS) environment and integrated using a multi-criteria spatial analysis approach to generate a tidal flood vulnerability map. The results showed that vulnerability to tidal flooding was strongly associated with low elevation, gentle slopes, proximity to the coastline and river network, high TWI values, poorly drained alluvial soils, high rainfall intensity, and land use dominated by settlements, fish farming ponds, and agricultural land. The vulnerability assessment classified the study area into five categories: very high (5,717 ha; 12.62%), high (7,919 ha; 17.47%), moderate (5,515 ha; 12.17%), low (2,404 ha; 5.30%), and very low (23,762 ha; 52.44%). Areas with high and very high vulnerability were concentrated in lowland coastal zones and riverine environments. Adaptation strategies include strengthening coastal protection, improving drainage infrastructure, implementing ecosystem-based coastal management, regulating land use in vulnerable areas, and enhancing community-based disaster preparedness. This study demonstrates the effectiveness of geospatial analysis to support tidal flood risk reduction and sustainable coastal planning.