A Simulation-based Modeling Approach to Adapt Social-Ecological Green Infrastructure System for Resilient Urban Flood Management
Authors: Rahman MD Rakesur , Kim Hojun , Kwon Doyean , Lee Junga 
Published: February 2023

Floods have devastated many urban socio-ecological systems, adding to urban planners' concerns. Floods caused by typhoons and heavy rain are common in South Korea during the summer, and especially Seoul has experienced urban flooding due to unusually localized heavy rains since 2010. According to the Intergovernmental Panel on Climate Change scenarios (IPCC, 2014), flood damage in Korea is expected to increase due to summer-concentrated precipitation. As an example of what happened, record-breaking rainfall in the summer of 2022 caused severe damage in the Gangnam, a prime district in Seoul, Korea, that has been most vulnerable to flood damage due to drainage problems.Green infrastructure's socio-ecological system aspect has been recognized for its ability to improve the provision of urban ecosystem services and is increasingly being used for stormwater management. Flood resilience necessitates the ability of urban socio-ecological systems to maintain their structures and functions during and after flooding events. In terms of achieving sustainable outcomes for municipalities, green infrastructure has practical limitations, such as a limited capacity for storing and infiltrating stormwater. As an interdisciplinary approach, green infrastructure necessitates the involvement of multiple stakeholders with conflicting interests, and it is critical to identify the best measures to apply in each context for effective flood mitigation strategies. There is, however, a knowledge gap in investigating an urban water system as a social-ecological system that coevolves because of interactions between actors, institutions, and water systems.Gangnam district has quickly become the focal point for discourses on socio-economic inequality in Korea, consolidating both socio-economic segregation and political conservatism, making social-economic-ecological context critical for any urban planning to be sustainable. The aim of this research is to develop a system for selecting appropriate green infrastructure for resilient urban stormwater management in Seoul's Gangnam district using simulation-based modeling.The first step will be to identify suitable green infrastructure practices for Gangnam district&#8217;s socio-economic context based on a co-benefits analysis, which will include incorporating co-benefits and human well-being into flood management decision-making while taking stakeholders' perceptions into account using a multi-criteria decision support system. The second step involves using the "Green Values Stormwater Management" model (Jaffe et al., 2010) to assess the green infrastructure's ability to adhere to the "4R" principles of resilience: robustness, rapidity, redundancy, and resourcefulness based on simulation results.The volume of rain captured or retained by the area's green infrastructure, providing feedback on construction and maintenance costs, as well as an estimate of the percentage of the desired volume retention goal being met will be estimated by the simulation model. Additionally, co-benefits such as cost savings and increased real estate value will be calculated and presented. This research framework will assist city planners decide which green infrastructure practices to use for resilient urban flood management.ReferencesIPCC (2014). Climate Change 2014: Synthesis Report. IPCC, Geneva, Switzerland.Jaffe, M., Zellner, M., Gonzalez-Meler, M., Cotner, L. A., Massey, D., Ahmed, H., & Elberts, M. (2010). USING GREEN INFRASTRUCTURE TO MANAGE URBAN STORMWATER QUALITY: A Review of Selected Practices and State Programs.