Abstract: This study, conducted at the Yanqi Lake Campus of the University of Chinese Academy of Sciences, is crucial for restoring urban natural hydrological processes through LID facility configuration. It utilizes simulations based on five rainfall recurrence intervals to analyze peak surface runoff and TSS loads across various sub-catchments. A comprehensive stormwater condition index was created to prioritize sub-catchments for LID facility configuration. Based on the specific requirements for LID facilities and local geographic conditions, optimal types and area proportions of LID facilities were determined, leading to a strategic LID configuration plan. The plan included different spatial configurations of green roofs, rain gardens, vegetated swales, and permeable pavements, and their impact on reducing local and overall runoff and TSS was assessed. The results indicated that implementing this strategy could reduce total surface runoff and TSS loads by 16%-24% across the study area, showing the most significant reduction compared to other strategies. The effectiveness of rain gardens, permeable pavements, and vegetated swales in reducing runoff and pollution increased with their area proportion and remained stable under different rainfall recurrences. Green roofs showed increased pollution reduction with greater area coverage, though their runoff reduction effectiveness was greatly influenced by surface land cover, improving with increased green space. However, under heavy rainfall, the effectiveness of all types of LID facilities, as well as the overall strategy, was reduced, indicating the need for integrated management with the urban underground drainage network and water systems. These findings provide a crucial reference for the redevelopment and construction of the study area to better manage potential flooding and pollution disasters from extreme rainfall events.

Key words: stormwater condition, stormwater management model, surface runoff, total suspended solids, reduction rate