Hindcast of sediment flow along the Curonian Spit under different wave climates

We analyze wave-driven longshore sediment transport along the Curonian Spit, a narrow about 98 km long sandy peninsula at the south-eastern coast of the Baltic Sea. The bulk and net longshore sediment transport in existing and in a selection of future wave climates is calculated using the CERC formula for about 3 nautical miles long sections. The calculations are based on numerically simulated long-term time series of wave properties along the beach evaluated using adjusted geostrophic winds for 1970-2007. Changes to the wave climate are simulated by means of systematic rotation of the contemporary wave approach direction clockwise and counterclockwise. The spit is in an almost perfectly equilibrium shape under the existing wave climate. Systematic rotation of the wave approach direction leads to an almost linear increase in the net transport rate from its present almost zero value whereas the bulk transport rate would insignificantly change. A rotation by more than 10° results in complete disappearance of convergence points of sediment flow along the spit and apparently to substantial coastal damage.