Predicting Shoreline Evolution on a Centennial Scale Using the Example of the Vistula (Baltic) Spit

摘要

The proposed algorithm comprises three main steps. The first step is the evaluation of the sediment transport and budget. It was shown that the root segment of the Vistula Spit is dominated by eastward longshore sediment transport (up to 50 thousand m~3/year). Over the rest of the spit, the shoreline's orientation causes westward sediment transport (more than 100 thousand m~3/year). The gradients of the longshore and cross shore sediment transport become the major contributors to the overall sediment balance. The only exception is the northeastern tip of the spit due to the appreciable imbalance of the sediment budget (13 m~3m~(-1) yr~(-1)). The second step in the prediction modeling is the estimation of the potential sea-level changes during the 21 st century. The third step involves modeling of the shoreline's behavior using the SPELT model [6, 7, 8]. In the most likely scenario, the rate of the recession is predicted to be about 0.3 m/year in 2010—2050 and will increase to 0.4 m/year in 2050—2100. The sand deficit, other than the sea-level rise, will be a key factor in the control of the shoreline's evolution at the northeastern tip of the spit, and the amount of recession will range from 160 to 200 m in 2010—2100.