Studying rainfall characteristics affecting low-impact development runoff control measures via numerical simulation

ABSTRACT To gain a comprehensive understanding of the intricate interplay between rainfall characteristics and the effectiveness of runoff control, this study focuses on a representative urban district equipped with low-impact development (LID) features within the Xi'an New Area, China. By utilizing a diverse range of rainfall profiles and employing the GPU-Accelerated Surface Water Flow and Transport Model (GAST), a sophisticated two-dimensional hydrodynamic model was developed to simulate surface runoff dynamics. Our findings highlighted the substantial influence of rainfall intensity, duration, and peak coefficients on the efficiency of runoff control. Specifically, we observed that a rainfall event with a duration of 2 h and a peak coefficient of 0.2 resulted in a runoff control rate varying from 86.17 to 45.44%, depending on the specific rainfall conditions. Furthermore, when rainfall intensity was varied from 19.20 to 87.22 mm, while maintaining a peak coefficient of 0.5, the runoff control rate fluctuated between 82.70 and 44.97%. This investigation reveals a quantifiable framework that elucidates the intricate relationship between rainfall attributes and runoff control effectiveness, providing crucial insights into the development of informed urban flood management strategies.