A Comprehensive Study on Flood Mitigation Strategies of Low-Impact Development in Yeongdeungpo-gu, Seoul†,‡

This study evaluates the effectiveness of different Low-Impact Development (LID) scenarios in mitigating urban flooding in Yeongdeungpo-gu, Seoul, using the Storm Water Management Model (SWMM). Two key areas, an industrial zone, and a mixed residential-commercial zone, were chosen to explore how different LID implementations impact runoff. The study considers six types of LIDs, including green roofs and rain barrels for building-based scenarios; and permeable pavements, infiltration trenches, vegetative swales, and rain gardens for open space-based scenarios. The drainage network map and historical rainfall data from previous flooding events were applied in SWMM for simulation modeling using different LID scenarios: building-based, open space-based, and combined LID methods. Results show that the combined LID approach is the most effective method, reducing runoff by 26.8% and 21.1% and lowering peak runoff volumes by 7.5% and 12.6% for Block I and Block II, respectively. These scenarios demonstrate that Scenario II has a more significant impact compared to Scenario I, despite the amount of coverage area. In general, building-based LID measures alone show the least reduction in both surface runoff and peak runoff volumes. The proposed approach offers a robust solution that can shape a resilient and livable urban future.