Analysis of drainage efficiency under extreme precipitation events based on numerical simulation

Abstract

The recent increase in extreme climatic phenomena has gradually attracted the attention of researchers regarding urban flooding. This paper used a hydrological model combined with the Computational Fluid Dynamics software to assess the drainage efficiency, predict the hydrological processes under different precipitation intensities and establish the relationship between rainfall intensity and inundation depth under extreme rainstorm events. The study proposed several thresholds such as specific rainfall intensities (that is, RI 95% and RI 50% ), drainage efficiency, and the limited flow rate of pipes. Based on 2021 July 20, 0:00 to 24:00 precipitation monitoring data from the "7.20 Zhengzhou Rainstorm Extreme Event," the relationship between rainfall intensity and road-pipe overflow patterns was determined by analysing these thresholds for different drainpipe diameters and spacings of catchment wells. The results demonstrated the evaluation parameters varied with rainfall intensities and pipe characteristics and revealed the main limitation of drainage efficiency and flow rate of drainpipes. The simulation helped the drainage systems design for different precipitations and proposed several relative suggestions for drainage-system improvements, wherein the diameter of the branch pipes plays a dominant role in coping with extreme rainstorm events.

Analysis model of flood spatiotemporal change characteristics based on k-means clustering algorithm

“…It is shown from some facts that the spatiotemporal concentration of precipitation is closely related to serious drought and flood events. So whether the spatiotemporal concentration of precipitation will further strengthen with global warming, and whether its change will lead to more serious drought and flood disasters, and other issues have aroused widespread concern (Wang et al, 2022;Darand, 2021). Therefore, many domestic scholars have conducted indepth research on the spatiotemporal variability of precipitation in China.…”

Influence of Teleconnection Factors on Extreme Precipitation in Henan Province under Urbanization

“…Deng et al [25] pointed out that the binary typhoon Infa and Cempaka provided moist air parcels for "21.7" heavy rainfall in Henan province through numerical simulations. Wang et al [26] determined the relationship between rainfall intensity and road-pipe overflow patterns based on "21.7" precipitation monitoring data. Zhao et al [27] found that the upper-level synoptic-scale disturbance, which leads to the development of potential vorticity anomalies and its downward intrusion, played a critical role in the development of the "21.7" event.…”