Spatiotemporal Dynamics of Flood Susceptibility in Rapidly Urbanizing Areas: A Multi-Criteria Analysis of Tangerang City (2017–2025)

Abstract

Flooding, a meteorological disaster, causes material and non-material losses in society. Flood events can be observed not only in confined spaces but also from previous incidents, allowing the identification of upward or downward trends. This study analyses the distribution and changes in susceptibility from 2017 to 2025. Geographic Information System (GIS) is used as the method, with a Multi-Criteria Decision Analysis (MCDA) approach, employing the Weight Sum algorithm and weighting with SMARTER, using parameters such as land use/land cover, elevation, slope, rainfall, soil types, distance to rivers, and the normalized difference vegetation index. The study results show that the low or safe classification area decreased from 5,065.32 hectares in 2017 to 3,519.68 hectares in 2025, while high and very high susceptibility classifications increased by approximately 300 hectares and 1,200 hectares, respectively. Pinang District experienced a change from high to very high classification, covering about 456.83 hectares. Along with Tangerang and Pinang, this area also saw a shift from low or safe classification to high, covering approximately 1.5 hectares. The spatial distribution of flood susceptibility exhibits a pattern where the northern part of Tangerang is very low and degrades southward to very high, including the Pinang and Ciledug districts. These findings serve as input for implementing mitigation measures and environmentally friendly land use planning.