Resumen
The thermal pollution of stormwater runoff is an important factor in the degradation of the urban water environment. Bioretention is an effective way to control the thermal pollution of stormwater runoff. To understand the influence of different rainfall conditions on the reduction of thermal pollution load of rainwater runoff from bioretention facilities and the correlation between the parameters, an experimental study was carried out by using the Beijing P&C rainfall pattern to change the rainfall parameters. By proposing innovative evaluation index parameters and analysis methods, the correlation between different parameters was quantified. The results showed that the heat pollution load reduction rate (HR) had a strong negative correlation with rainfall inflow volume (IV), rainfall duration (RD), and the service area ratio of bioretention facilities (CAR), and the correlation coefficients were -0.95, -0.73, and -0.73, respectively. HR was weakly correlated with rainfall return period (RP), rainfall temperature (RT), and air temperature (At) during the experiment, and the correlation coefficients were -0.29, 0.20, and 0.20, respectively. The delay between the peak value of heat output from the bioretention and the peak value of heat input from rainfall was about 10 min. Through the research on the change of rainwater heat entering and exiting the facility, we can master some rules of heat reduction in bioretention facilities, which will provide a reference for subsequent research on the difference between the internal heat change and bioretention temperature change.