Wave, Tide and Topographical Controls on Headland Sand Bypassing

Embayed beaches separated by irregular rocky headlands represent 50% of global shorelines. Quantification inputs and outflows via headland bypassing is necessary for evaluating long-term coastal change. Bypassing rates are predictable idealized morphologies; however, it remains to test the predictability realistic morphologies, quantify influence variable morphology, sediment availability, tides waves-tide interactions. Here we show that can be predicted wave-dominated conditions, depend upon cross-shore length normalised surf zone width, toe depth spatial coverage. Numerically modeled quantified 29 under wave, tide conditions along 75 km macrotidal, embayed coast. predominantly wave-driven nearly ubiquitous energetic waves. Tidal elevations modulate rates, with greatest impact at lower wave energies. currents mainly through wave-current interactions, which dominate in median conditions. Limited sand availability off apex reduce an order magnitude. minimal when >5 widths. Headland important secondary control, moderating impacts apex. Parameterisations were tested against new terms proposed include Wave-forced mean absolute error a factor 4.6. This work demonstrates amenable parameterization highlights extent occurs implications coasts worldwide.