Response of urban floods to two coupling modes of surface and pipe flow models

Urban floods/inundation disasters are becoming a prominent problem affecting urban public security due to the impact of global climate change and rapid urbanization. Therefore, research on urban flooding via numerical modelling has important practical significance. According to hydrological and hydrodynamic theories and methods, based on the Storm Water Management Model and the self-developed Graphics Processing Unit (GPU) Accelerated Surface Water Flow and Associated Transport (GAST) model, we explore the best coupling mode, and take Xiaozhai block in Xi'an, China, as the research object to study, through the selected mode, the impact of the change of local land use type on surface inundation and pipe network. The results show that the hydrology-hydrodynamic coupling model (G-S) is more realistic, and its simulation results are more in line with the actual urban flood processes. The results are expected to provide help to other experts and scholars in future model coupling research.