Improvement of rainfall boundary treatment based on the diffusion wave approximation equation

Authors

Xu WANG, Research Center of Coastal and Urban Geotechnical Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, ChinaFollow
Mei DONG, Research Center of Coastal and Urban Geotechnical Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, China
Meng-yue KONG, Hangzhou Archaeological Ruins of Liangzhu City World Heritage Monitoring and Management Center, Hangzhou, Zhejiang 311113, China
Yun-peng DENG, Research Center of Coastal and Urban Geotechnical Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, China
Ri-qing XU, Hangzhou Archaeological Ruins of Liangzhu City World Heritage Monitoring and Management Center, Hangzhou, Zhejiang 311113, China
Xiao-nan GONG, Research Center of Coastal and Urban Geotechnical Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, China

Abstract

During the simulation of rainwater infiltration, the conventional rainfall boundary cannot accurately reflect the influence of the variation of ponding water depth on the calculation of actual rainwater infiltration rate. To address this issue, the conventional rainfall boundary is improved by incorporating the diffusion wave approximation equation, allowing for the coupling of ponding water depth variations with actual infiltration rate during heavy rainfall events. Additionally, the accuracy of the improved boundary is validated through two classical experimental cases. The improved boundary is subsequently applied to the simulation of an actual engineering scenario. The findings indicate that the improved rainfall boundary is capable of achieving real-time dynamic transition between flux and pressure head boundaries. When the rainfall boundary functions as the pressure head boundary, the theoretical maximum ponding water depth calculated by the improved boundary is located at the slope toe. Conversely, when the rainfall boundary serves as the flux boundary during the final stage of rainfall, the ponding water depth becomes negligible, and the theoretical maximum ponding water depth is located at the intersection of the flat and steep slope surface.

Graphic Abstract

Recommended Citation

WANG, Xu; DONG, Mei; KONG, Meng-yue; DENG, Yun-peng; XU, Ri-qing; and GONG, Xiao-nan (2023) "Improvement of rainfall boundary treatment based on the diffusion wave approximation equation," Rock and Soil Mechanics: Vol. 44: Iss. 6, Article 5.
DOI: 10.16285/j.rsm.2022.6104
Available at: https://rocksoilmech.researchcommons.org/journal/vol44/iss6/5