Investigating the hydrological effects of smart technologies in urban rain garden design: a case study

This paper applies smart technologies to urban rain garden design and analyzes the hydrological effects based on urban smart rain garden technologies.The SWMM model is used to simulate runoff water quantity and quality under the environment of long-term and continuous rainfall events in urban areas.Building area A is selected as the case study object of this paper, and its geographic location and precipitation data are analyzed to preliminarily explain the hydrological conditions of the case study area.Based on the SWMM model, the model pipe network generalization and other operations are carried out to establish the SWMM model of the study area.The SWMM model is calibrated in terms of the calibration of the model's parameters and the feasibility of the structured network SWMM model to verify the validity of the SWMM model of the study area and its catchment delineation method.Based on the urban smart rain garden technology, the LID module is added to the SWMM model of the study area and the hydrological effects under different scenarios such as combined LID are analyzed.Each LID measure can have a certain reduction effect on the combined runoff coef icient and total runoff.The combined LID measures in this paper have the best reduction effect, with the reduction rate of the integrated runoff coef icient over 35% and the total runoff over 50% in the 2h rainfall event.The combined LID scheme has the best reduction effect on the lood peak, and the reduction rate can reach more than 40% in both 2h rainfall events.