Green infrastructure planning criteria for flood-prone areas to restore water cycle system and improve flood resilience 

Abstract

Abstract The expansion of impervious surfaces resulting from urbanization induces alterations in the natural water cycle system, culminating in urban flooding. Persistent flood damage arises from issues such as the failure to designate flood-prone areas despite receiving flood reports or the exclusion from flood-prone zones due to complaints. Both the central government and local authorities are taking measures to designate and manage flood-prone areas, recognizing the necessity to address this issue not only from an ecological standpoint but also considering social aspects, including the real estate value of the region and the effort and cost of flood damage recovery. Furthermore, flood resilience should be a central consideration, aiming to identify existing problems through the virtuous cycle process of flood damage, both upstream and downstream, and working towards recovery or improvement to a state superior to pre-flood conditions. This study's objective is to redefine the criteria for green infrastructure planning in flood-prone zones, exploring interrelated factors influencing urban water systems and identifying synergistic solutions to enhance resilience. The application of systems thinking involves four integral stages: dynamic thinking, causal thinking, closed-loop thinking, and strategic discovery. These stages collectively establish a systematic dynamic loop. To construct this loop within the complexity of a water circulation system, initial attention must be given to discharge management. Ensuring a robust water cycle necessitates the equitable distribution of runoff across processes such as evaporation, filtration, infiltration, and groundwater recharge. Secondly, green infrastructure design should leverage technologies that harness natural mechanisms, enhancing the cyclical movement of materials within the ecosystem. This involves strategic infrastructure planning that minimizes alterations to topography, preserving the natural functions of the water cycle while allowing for flexible application tailored to ecosystem requirements. These green infrastructure characteristics, effects, and plans are summarized as variables. Thirdly, the dynamic loop is constructed with consideration of the summarized variables. The final stage of the process integrates flood risk management within a community flood resilience framework. By cycling through the stages of learning, prevention, resistance, response, and recovery, the objective is to minimize damage caused by floods and effectively respond to unexpected floods due to climate change. As a result, seven derived criteria include land use type identification, target site characteristics analysis, detailed survey, water circulation goal selection, design criteria and layout strategy, spatial suitability evaluation, and water cycle change verification. Using these criteria, the ultimate goal of this study is to identify suitable green infrastructure locations and create a monitoring map for a healthy water cycle. The study aims to contribute to flood prevention measures in flood-prone areas by analyzing the impact of green infrastructure on emissions. Acknowledgements This work was supported by Korea Environment Industry &Technology Institute (KEITI) through "Climate Change R&D Project for New Climate Regime.", funded by Korea Ministry of Environment (MOE) (2022003570003).