Multi-Criteria GIS for Sponge City Planning with Open Data Sources in Vigo (Spain)

Abstract. Sponge cities are renowned for their efficacy against extreme weather events, reducing surface runoff, managing stormwater, and mitigating flood risks. Moreover, they present multifaceted advantages by integrating blue-green infrastructure, enhancing urban sustainability, and improving water quality. The trend of their expansion beyond China marks a significant development in climate-resilient urban planning. This study pioneers the use of open data to locate suitable sites for sponge Low Impact Development (LID) solutions, showcasing Vigo (Spain) as a viable case for mid-sized cities. Input data is obtained from administrative cartography (DTM, hydrogeology, land cover, river courses, and demographic census) and satellite imagery (impervious coverage, vegetation, and surface temperature) from Landsat 8 and MODIS calculating three spectral indices (NISI, NDVI, NDIH). A robust Geographical Information System (GIS) method is proposed weighting the multi-criteria with AHP matrix. Three main potential sites are identified for deploying specific sponge LID strategies, as green roofs, green parking, or rain gardens. Nevertheless, while the method swiftly identifies intervention sites on a municipal scale, conclusive decisions necessitate terrain insights, public sentiments, urban regulations, and funding considerations.