Application of GIS as a Sustainable Urban Planning Tool for Flood Management: A Case Study of Gampaha District, Sri Lanka

This research explores the application of Geographic Information Systems (GIS) as a sustainable urban planning tool for flood management in the Gampaha District of Sri Lanka. It addresses the challenges posed by rapid urbanisation and increased flood vulnerability, where traditional approaches have proven inadequate in the face of complex urban development patterns and climate change impacts. While previous research has established GIS's potential in flood risk assessment and management, its application for sustainable urban planning and flood management in Gampaha District remains underexplored. This study aims to fill this gap by demonstrating GIS's effectiveness in enhancing flood management practices in the area. The research employs a mixed methods approach within a case study strategy, combining qualitative and quantitative approaches. Data collection relies on secondary sources. Analysis methods include thematic, content, and GIS-based spatial analysis using ArcGIS Pro software. Key findings reveal a strong correlation between urbanisation patterns and increased flood events in Gampaha District. The study identifies specific flood management challenges, including inadequate drainage infrastructure, encroachment on flood plains, and geographical and environmental vulnerabilities. GIS analysis provides detailed flood risk mapping with a model and identifies optimal locations for sustainable infrastructure development using the multi-criteria decision analysis (MCDA) method. The research contributes to the existing body of knowledge by offering a model that integrates GIS tools for mapping, risk assessment, and strategic planning to mitigate flood risks in rapidly urbanising areas. It provides evidence-based recommendations for enhancing flood resilience through sustainable urban planning practices such as wetland restoration, permeable pavements, rain gardens, urban forests, and floodwater pumping stations. Future work involves longitudinal studies and real-time data integration for more dynamic flood management strategies with system thinking approaches.

Key Words: Urbanisation, Flood Management, GIS, Urban Planning, and Sustainability