Modeling tsunami-induced beach erosion
Though beachfront property may be highly desirable, it is also on the frontline of climate change. Erosion caused by tsunamis is one of the many threats facing sandy beaches, but the mechanisms behind the erosion are little understood. Field observations of this phenomenon are limited by the available sensing technology and laboratory tests are difficult to scale.
Instead, Huang and Huang used a three-phase flow numerical model to understand how solitary waves induce erosion.
“Extreme waves due to climate change and tsunamis can cause significant beach erosion in a short period,” said author Zhenhua Huang. “Numerical simulation is an important tool that can provide information difficult to obtain in lab tests or field observations and will help us understand wave-induced beach erosion.”
In their model, the authors minimized the number of required tuning parameters by including three phases: air, water, and sediment. The physical input parameters are easily measured properties that determine the rheology of the sediment phase and the drag force between the sediment and water.
It was difficult to model the rheology of the sand to account for the complex interactions between sediment grains.
“The three-phase model shows promising capacity in simulating the erosion processes of a sandy beach. It can reveal the detained hydrodynamic and sediment transport processes and capture the infiltration and exfiltration processes,” Huang said.
Understanding how single, large waves erode beaches will be crucial for coastland management. The information obtained by this tool will impact where and how communities will be built and how they prepare for potential storms and their aftermath.
Source: “Three-phase flow simulation of beach erosion induced by breaking solitary waves,” by Shijie Huang and Zhenhua Huang, Physics of Fluids (2023). The article can be accessed at https://doi.org/10.1063/5.0144791 .
This paper is part of the Physics and Modelling of Tsunamis Collection, learn more here .