Analysis of Fixed-Time Synchronization by Rainfall Runoff Method

Abstract

Due to climate change, the frequency and intensity of torrential rainfall in urban areas are increasing, resulting in frequent flood damage. Despite the wide usage of the dual-drainage model—which relies on minimum time-step synchronization for accurate flood analysis computational speed remains a major challenge. This study employs the Hyper-Connected Solution for Urban Floods (HC-SURF) model to conduct a sensitivity analysis of fixed time-step flow synchronization for different rainfall runoff approaches(lumped and distributed). Laboratory experiments and real-world urban watershed simulations were used to evaluate the accuracy and efficiency of each approach. While some accuracy loss may occur due to the choice of rainfall runoff method, overall performance in terms of mass balance and maximum inundation area remained excellent. These findings highlight HC-SURF’s potential for rapid and precise urban flood modeling, offering a balanced perspective on computational efficiency and model accuracy.