Prevention of the effects of coastal structures on shoreline change using numerical modeling

Abstract

Seas surround Turkey for three quarters, and coastal regions constitute important areas of agriculture, tourism, industry, logistics and living for Turkey. Although the economic value of coastlines is increasing day by day with the increase in population, artificial and natural factors such as incorrectly designed coastal structures (ports, fishing shelters, breakwaters, groins, etc.), climate change, tides etc., cause increased or decreased sediment transport and the coasts become more unstable. Significant changes in the shoreline separating the sea and the coast (erosion and deposition) occurs.Considering the benefit of estimating the direction of the change in the shoreline, this important research gap needed to be filled. Within the scope of this study, the effective wave direction was determined by making wind and wave climate analyses in the selected coastal area in the Karasu District of Sakarya province in Turkey and the changes in the shoreline that occurred in this area over the years. Therefore, the effects of these changes were examined in the light of field studies, satellite images and data obtained from state institutions and organisations between 2003 and 2021. This research presents a new numerical model based on the Preissmann Schema Technique and the finite difference method, which differs from the existing numerical models. This model has some advantages, such as easy adaptation to non-uniform networks, control stability using weighting factor, convergence and calculation based on all variables. The Numerical Model of Shoreline Change Based on the Preissmann Scheme Technique (COPREM-2D) has been developed to predict shoreline changes. The COPREM-2D prediction results were calibrated by comparing them with the actual shoreline positions for 2013, 2017 and 2021, the model results were consistent, and the shoreline position was estimated for 2028.