The 24th IAHR-APD Congress (24th IAHR-APD Congress)

471 / 2024-04-09 15:21:01

Investigation and development of key technologies for climate-resilient sponge cities using ecological biotechnology and smart strategies

climate change resilience,low impact development,Nature-based Solutions,sponge cities

Subtheme 5: Climate Change: Adaptation, Mitigation and Resilience > Topic 1: Hydrology and Water Resources response to climate change

Several studies in the past, through utilizing the Clausius-Clapeyron relationship, indicated that the intensity of extreme precipitation increases with global warming. In South Korea, a significant increase in the cumulative summer precipitation amount was observed over the last 50 years. The annual precipitation has also significantly increased in the country from 976.6 mm in 1973 to 1597.8 mm in 2023. As a response to the increasing negative impacts of both climate change and urbanization, Nature-based Solutions (NbS), particularly low impact development (LID) has continuously emerged as a technology of interest due to its contributing mechanisms to water circulation and sponge cities. Numerous research endeavors previously confirmed the capability of LID to increase stormwater runoff infiltration and improve runoff quality in urban areas. However, the optimal design of LID remains context- and site-specific. In this study, the functions and current status of LID inside and outside South Korea were investigated through a combination of extensive literature review, on-site monitoring, and laboratory experiments. In addition, a procedure for designing LID for water circulation and sponge cities was proposed considering ecological functions, extreme weather, and carbon neutrality. The results of the study revealed that identifying land use and land use changes (LULUC), as well as the changes of stormwater runoff quantitatively and qualitatively in the implementation site, is critical to selecting hydrologic and environmental mechanisms for the LID. The volume of target stormwater runoff, size of particulate matters, and type of sedimentation were also identified as crucial LID design considerations. It was also found that particular soil characteristics (sandy, loam, clay, etc.) were suitable for specific LID types. Low-permeability soil types, with infiltration rates ranging from 0 to 1.26 mm/hr were learned to be appropriate for surface flow constructed wetlands and reservoir ponds, while high permeability soils with infiltration rates ranging from 7.63 to 11.43 mm/hr were identified to be suitable for infiltration trenches and permeable pavements. Methods on utilizing sensors and artificial intelligence (AI) were also proposed. The results of this study are seen as beneficial in developing LID for water circulation and sponge cities in Korea, China, and other countries with similar climate types.