Simulation study on dynamic response of rain and flood process in urban renewal: A case study of Yinchuan City

During the process of urban development and renewal, the transformation of local areas can significantly affect both surface runoff and underground drainage processes. In this paper, the numerical model of coupling hydrological and hydrodynamic processes is applied, and the southern Xixia District and the northern Jinfeng District of Yinchuan City are taken as the renewal areas of the old city and the new city, respectively. The results showed that renovating the rainwater and sewage systems in the old urban area significantly reduced surface inundation and prevented pipe blockages. Different renovation schemes (Area 1, Area 2, and Area 3) resulted in a reduction of surface waterlogging ranging from 25.06% to 49.63% compared to the pre-renovation period. The percentage of time that pipes were filled with water after peak flow and 3 hours of recession was reduced by 1.51 to 2.39 and 1.32 to 2.66 times(1 ≤ P ≤ 5) compared to before the renovation. In the new urban area, the expansion of residential areas(0.56%, 0.30%, and 0.19%) had a greater impact on surface inundation and rainfall runoff control as the rainfall recurrence interval increased. However, when P = 20, the percentage of increased internal inundation after renovation was higher than before, but the rate of increase slowed down. The longer the rainfall return period, the greater the parabolic constant value. Therefore, the study emphasizes the importance of considering the impact of local changes on the overall rain and flood process in the region, achieve that effect of nip in the bud. © 2023 China Water Power Press. All rights reserved.