Spatial Suitability Mapping for Nature-Based Solutions (NbS) to Enhance Urban Flood Resilience : A Case Study of the Hanumante Watershed, Kathmandu Valley, with a Complementary Case Study in Naples. Vaasa 2026
Pysyvä osoite
Kuvaus
Opinnäytetyö kokotekstinä PDF-muodossa.
Rapid urbanisation, increasing impervious surfaces, and pressure on natural drainage systems are intensifying urban flood risk. Nature-Based Solutions (NbS) offer a complementary approach to con-ventional drainage, but their effectiveness depends on local hydrological, spatial, and socio-environ-mental conditions. This dissertation develops a context-specific GIS-based Multi-Criteria Decision Analysis (GIS-MCDA) framework to identify and prioritise suitable NbS, using the Hanumante Water-shed in Kathmandu Valley as the primary case study and Naples as a complementary dense-urban case.
The framework links flood processes with spatial suitability, implementation feasibility, and indige-nous knowledge. Land use, terrain, hydrology, drainage, and flood-related criteria to assess opportu-nities for infiltration, retention, detention, conveyance, and hillslope runoff-management measures. Prioritisation then distinguished broadly suitable areas from locations with greater flood-manage-ment relevance.
Results indicate substantial NbS potential across the Hanumante Watershed, although priority areas are considerably more limited. Detention showed the widest spatial applicability, while retention and infiltration were more dependent on local conditions. The analysis also identified opportunities to integrate existing landscape features and indigenous water-management practices. In Naples, urban density, groundwater conditions, and sinkhole susceptibility shifted priorities towards controlled in-filtration, attenuation, conveyance, and distributed multifunctional interventions.
The study concludes that effective NbS planning requires a context-sensitive, landscape-wide ap-proach linking flood processes, spatial suitability, implementation priorities, and local knowledge. The proposed GIS-MCDA framework provides a transferable planning-level method adaptable to dif-ferent urban contexts. Future work should integrate hydrological modelling, field validation, and stakeholder assessment to evaluate performance and support implementation.