Catastrophic Flood Mapping: A Geospatial Analysis for Strategic Urban Planning

Abstract

In Malaysia, Floods frequently occur, particularly during the monsoon season when heavy rainfall overwhelms drainage systems, resulting in flash floods. Rapid urbanisation, inadequate drainage, and limited flood management infrastructure exacerbate the situation, and Kuala Lumpur frequently experiencing flash floods that cause significant property damage and economic losses. Despite these challenges, the lack of detailed flood susceptibility maps hinders sustainable urban planning and proactive flood management. This study developed a flood vulnerability map for Kuala Lumpur to address this gap. Thematic maps were used to categorise the area into five susceptibility zones: very low, low, moderate, high, and very high. The map, created using a weighted overlay method, was integrated into GIS technology. Four primary flood risk factors were analysed: river proximity, rainfall distribution, slope, and elevation. The results classified 29.26% of the area in the moderate susceptibility, while 24.98% and 23.64% in the high and very high zones, respectively. The remaining areas are classified as low (16.25%) and very low (5.78%) susceptibility. These flood susceptibility maps provide essential insights for targeted flood mitigation and improved urban planning in Kuala Lumpur. These maps support targeted measures to mitigate flood impacts, helping to strengthen the city's resilience and ensure more sustainable urban development.