Author(s): Z. Y. Li; K. M. Lam
Linked Author(s): Kit Ming Lam
Keywords: Stormwater management; Low-impact design; Bioretention
Abstract: This paper introduces a simple performance indicator to evaluate the hydrologic benefits of a bioretention system in reducing stormwater runoff in a specific region. The estimation is made using the stormwater management model (SWMM) with input from the recent 10-year (2004-2013) rainfall record of Hong Kong at 1-minute intervals. The model flowrate outputs of stormwater runoff into the bioretention system, including the catchment area being served, and stormwater overflow from the system are integrated over each year to obtain the yearly total stormwater volumes. The ratio of stormwater volume retained by bioretention to the inflow volume is used as a single-value indicator to quantify the retention capacity of the bioretention system. Performance evaluation is made for various values of infiltration rate of subsoil and area ratio between bioretention cell and drainage catchment. The use of the performance indicator in bioretention design is demonstrated.
Year: 2014