Hydrological simulation of bioretention: analysis of the efficiency of compensatory techniques to mitigate impacts of urbanization

Abstract

The rapid urbanization of cities has generated numerous consequences for rainwater drainage systems: increased surface runoff, worsening quality, and scarcity of groundwater, causing floods and affecting the health of the urban population. An alternative to mitigate these adverse effects is the insertion of Low Impact Development (LID) practices such as permeable pavements, green roofs, and bioretention cells. Using the HYDRUS-1D computational model a simulation of water flows in a porous medium was performed, similar to what occurs in a bioretention, with data from soil samples from an area located in João Pessoa-PB. Soil infiltration was evaluated in field trials using a modified Philip-Dunne infiltrometer (MPD). Hydrological performance parameters of a bioretention system were investigated by varying height of soil profiles (100, 120, 130, and 150 cm), surface retention depth (10, 20, and 30 cm), and duration of rainfall (20 and 60 min). The simulation results showed that better hydrological benefits were obtained with shorter rainfall, with peak flow and surface runoff reduction by 100% for retentions of 20 and 30 cm.

Keywords:
Urban drainage; Hydrological modelling; Sustainability; Green infrastructure