Green Infrastructure and Urban Flood Mitigation: Evaluating Spatial Priorities through Multi-Criteria GIS Analysis

Abstract

Urban population increases at an unprecedented rate, coupled with climatic variability and the growing urbanization of impervious surfaces, urban flood events are now a growing concern, requiring sustainable solutions to reduce the impacts of stormwater. In this study, a Geographic Information System (GIS) based Multi-Criteria Decision Analysis (MCDA) framework is used to assess green infrastructure spatial priorities. A geospatial dataset of 400 spatial units and several environmental, hydrological, land use and socio-economic variables was analysed to pinpoint areas that needed priority interventions. Historical flood depth, annual precipitation, impervious surface, drainage capacity, soil infiltration, vegetation cover, and population density were combined with spatial criteria to produce a Green Infrastructure Priority Score and to identify the suitability for implementation. Historical flood depth, rainfall, impervious surfaces, and population density were positively related to flood vulnerability while drainage capacity, vegetation cover, and soil infiltration were negatively related to flood risk. The majority of spatial units were rated low priority and a few high priority hotspots were identified for targeted intervention. The proposed GIS-MCDA framework offers a systematic and evidence-based approach to support sustainable urban planning, optimize investments in GIFs, and improve urban flood resilience. The results provide insightful recommendations for planners and policymakers aiming to improve climate adaptation efforts by using space-informed decision making and environmentally sustainable infrastructure planning.