Analysis of urban runoff with Low Impact Development (LID) applications: Focus on green roofs and permeable pavement

Background/Question/Methods

Population influx due to industrialization is continued, the city becomes greater than the capacity. In this situation, climate change is accelerating and increasing of the impervious surfaces in urban watershed is causing the water circulation system changing and sewer overflows. Faced with these problems by urbanization and climate change, Low Impact Development (LID) is recommended and applied to reduce these impacts as a sustainable solution of storm water management in urban for adapting climate change.

Therefore, this study focused on the precipitation of the wet season and evaluates the impact of applying two types of LID techniques.

The site of this study is Guwol residence zone in Incheon city and 840,907m. This study illustrates potential effectiveness of LID practices, specifically with decreased impervious cover, under changing precipitation. Green roofs and permeable paver are selected for LID practices that various advanced researches have been progressed. We use SWMM(Storm Water Management Model) of U.S. EPA for the assessment, widely used model in urban. Continuous daily runoff volume during the wet season in 2011 and 2099 are calculated for outputs. Land use is considered comparing ‘post-developed’ and ‘simple LID designs applied’ in this study. Simulation results in 2099 are suggested by using precipitation data from RCP8.5 climate change scenario, which was made by Korea meteorological administration.

Results/Conclusions

The results showed that post-applied site compared to the pre-applied site would provide about 10% reduction of total runoff and 40% reduction on peak day in 2011 and 2099. LID practices gives more effectiveness when precipitation value is higher.

LID is desirable strategy to the land use in urban site for uncertain climate condition in the future. The result can be reflected to land use planning of urban redevelopment area. This research does not verify modelling results and some of input data is from software. In further research, verifying process and more detailed and specific designing for site are needed to sustainable storm water management.