Hydrologic performance of bioretention in an expressway service area

Abstract

Bioretention can be an effective measure for stormwater treatment. However, there is a lack of systematic analysis of the impact of bioretention design parameters on hydrologic performance.Herein, SWMM and RECARGA models were applied to generate the typical annual rainfall runoff and simulate the water balance of the bioretention system in an expressway service area. The purpose of the investigation was to identify key design parameters for the bioretention system and delineate the priorities in developing the design. Results showed that the average groundwater recharge ratios for bioretention basins with and without an underdrain were 58.29% and 92.27%, respectively, the average overflow ratios were 4.13% and 4.19%, the average evapotranspiration ratios were 4.48% and 4.47%, and the average outflow ratio for bioretention with an underdrain was 33.94%. The ratio of the bioretention area to drainage area, and the saturated infiltration rates of planting soil and native soil were the main factors influencing water balance, while the underdrain diameter and gravel layer depth exerted little effect. Based on the impact analysis, multivariate nonlinear regression models of runoff reduction rate for two types of bioretention basin were established, which both exhibited high determination coefficients and acceptable Nash-Sutcliffe coefficients.

Temporal Downscaling of IDF Curves Applied to Future Performance of Local Stormwater Measures

“…The bioretention media depth was set to 75 cm [53,54] with an infiltration rate of 10 cm/h (Inf1) which is a minimum recommended value for cold climates based on investigations carried out by Paus et al [55]. A drainage pipe was placed in the upper part of a drainage layer.…”

Evapotranspiration from Green Infrastructure: Benefit, Measurement, and Simulation

“…Potential evapotranspiration represents the ET rate limited only by energy supply instead of water supply. In current practices such as stormwater management, it is common to use PET or pan evaporation to represent ET a [100,104,[113][114][115][116] and calculate other unknowns in the water balance [62]. However, without the adjustment for the substrate moisture content, ET a will be overestimated for unsaturated conditions [89,117].…”

SWMM Sensitivity to LID Siting and Routing Parameters: Implications for Stormwater Regulatory Compliance

“…Several studies recognize the sensitivity of LID modeling to LID scale and distribution (Wolfand et al 2018; Wang et al 2019), to rainfall event size and duration (Qin et al 2013; Fry and Maxwell 2017; Mao et al 2017), and to physical LID parameters such as hydraulic conductivity or soil thickness (Gülbaz and Kazezyılmaz‐Alhan 2017; Gao et al 2018). However, model sensitivity to other siting and routing parameters such as outflow routed from LID, LID placement with adjusted imperviousness, and the percent of impervious area runoff treated by LID is not well studied.…”

“…The subsequent routing of outflow volume to either pervious areas or a subcatchment outlet is a model parameter that can be overlooked. Gao et al (2018) found that changes in bioretention (BR) design parameters, such as hydraulic conductivity, most significantly influence the proportion of flow that is outflow compared to infiltration, overflow, and evaporation. This indicates that outflow is a sensitive parameter to BR design, and the amount of outflow has the potential to fluctuate.…”

“…This indicates that outflow is a sensitive parameter to BR design, and the amount of outflow has the potential to fluctuate. However, Gao et al (2018) do not discuss subsequent routing of BR outflow in the model. LID Placement. Kaykhosravi et al (2018) reviewed eleven LID models and note the advantages and disadvantages of modeling LID as either new subcatchments or by placing LID within a parent subcatchment, but do not comment on the impacts of placement location or model adjustments that must be made with LID placement.…”