Comparative Study of Beach Erosion and Shoreline Recession Using XBeach in Non-hydrostatic Mode

Erosion by wave action affects shorelines for both marine and inland water bodies, but the prediction of erosion rates needs further development. XBeach is an open-source coastal modeling software with hydrostatic and non-hydrostatic modes, primarily used to study hydrological and morphological processes. In this study, a simple 1D numerical wave tank was created in XBeach to observe the erosion and recession of a sand beach using the non-hydrostatic mode. A number of test cases were conducted on a restricted time scale to calibrate the model, after which simulations were run with regular waves of varying height, period, and duration. The resulting beach profile was then analyzed to quantify the erosion of the simulated beach over time. The erosion data was then compared with an analytical model as well as results from recent experiments carried out in a wave tank at the National Sedimentation Laboratory in Oxford, MS, which considered both cohesive and non-cohesive soils. Preliminary results indicate that the XBeach non-hydrostatic model tends to underestimate the amount of beach recession. Upon the formation of a near-vertical seaward facing berm, the rate of erosion was observed to be similar to that found in the experimental studies as well as the analytical model.