ANALISIS DAN PEMETAAN TINGKAT KERAWANAN BANJIR DI KOTA TANGERANG BERBASIS SISTEM INFORMASI GEOGRAFIS

Abstract

This study aims to map the flood vulnerability levels in Tangerang City by utilizing Geographic Information Systems (GIS) technology. The analysis process was conducted using the overlay method and scoring based on weighting for six main parameters that influence flood potential, namely land elevation, rainfall distribution intensity, soil type, slope gradient, proximity to rivers (river buffer), and land use. The accuracy of the mapping results was validated using ROC (Receiver Operating Characteristic) analysis to assess the model's accuracy level. Three weighting schemes were tested using a trial-and-error approach, and the best result was obtained from the third weighting scheme, which produced an AUC value of 0.96, categorized as “perfect classification,” indicating a higher level of model accuracy compared to the other two schemes. Based on the mapping analysis results, the area of Tangerang City is generally dominated by regions with low to moderate flood vulnerability levels. Areas with low vulnerability cover 26.8 km² or 16.3% of the total area of Tangerang City, while moderately vulnerable areas cover 119.59 km² or 72.7%. Areas with very high flood vulnerability reach 18.10 km² or 11% of the city’s total area, mainly located near rivers or in regions with inadequate drainage systems. Ciledug, Karang Tengah, and Larangan Districts are identified as the locations with the most significant flood potential.