The impact of urbanization on urban flood risk of Nakhon Ratchasima, Thailand

Urban flooding is a hazardous consequence of urbanization, climate change, and spatial factors. It occurs when people gather in specific areas, disrupting natural and built environments. Despite its importance, the manner in which urbanization transforms land use patterns and overall land topography, contributing to the uncertainty of urban flooding, remains unclear. This study presents a comprehensive spatiotemporal assessment of the impact of urbanization on urban flood risk based on the Urban Flood Risk Triangle Index (UFRTI) of Nakhon Ratchasima, Thailand, in 2000, 2010, and 2020. The study developed this assessment framework through spatial analysis using Bivariate Local Indicators of Spatial Association and K-means clustering analysis. The revised parameters for urban flood hazard, exposure, and vulnerability constitute the UFRTI, illustrating how urbanization influences the degree and characteristics of urban flood risk. This study highlights the potential of using BiLISA and K-means clustering in GIS-based spatial analysis that reveals flood risk characteristics are shifting towards the city's periphery, requiring land use regulations and efficient flood risk management to confront urban growth.