GIS- and MCDA-based identification of priority areas for green infrastructure development in Dong Hoi ward, Quang Tri province

Abstract

Urban flooding, exacerbated by concretisation and extreme weather events, poses a major challenge in Dong Hoi ward, Quang Tri province, requiring a shift towards sustainable stormwater management using green infrastructure (GI). This study applies geographic information systems and multi-criteria decision analysis (GIS-MCDA) using the analytic hierarchy process (AHP) to identify priority areas for GI development. The spatial model integrates seven criteria: slope, topographic wetness index - TWI, imperviousness ratio, feasibility of site clearance, distance to transportation networks, flood risk (validated using historical data from the United Nations Satellite Centre - UNOSAT), and asset protection priorities. The findings reveal a distinct spatial differentiation between the Bao Ninh peninsula and the western area of the Nhat Le river. Distributed GI measures such as permeable pavements and roadside bioswales should be implemented in dense urban cores. Meanwhile, large-scale GI infrastructures such as detention basins and ecological parks are centrally allocated in the southern agricultural area. The findings provide a reliable quantitative spatial tool that assists urban planners in optimising land allocation and investment resources for urban drainage infrastructure.