Cercetări şi contribuţii privind dinamica curenţilor costieri în zona litoralului românesc al Mării Negre

Abstract

Considering the current economic and population growth it is logical to anticipate that in the near future the global demand for energy will increase substantially, which will lead to a severe degradation of the environment if we consider the fact that a large amount of the current energy is being obtained by burning fossil fuels. Although this issue can be considered a serious threat for the future, it is possible to consider new strategies in order to consolidate a sustainable energy portfolio by using the natural resources from the marine areas. These are important sources of energy since they are characterized by large water surfaces, various resources (ex: wind, wave or currents) which are more consistent and more stable than the one reported in the onshore areas. The waves represent one of the most important resources from this environment which can transport a large amount of energy from the offshore areas (generation area) throughout the coastal regions where finally the wave energy will be dissipated. The coastal areas are very dynamic systems which constantly change under the action of the natural factors, the balance between the erosion and the accretion processes indicating the configuration of the shoreline over various time intervals. The waves from the shallow water sectors are directly involved in the erosion process throughout the mechanical abrasion effect which is acting onto the surf and beach areas, by dislocating sediment particles and transporting them into the offshore regions. Another important event in the coastal areas is the occurrence of the longhsore currents which carry sediments along the shoreline, modifying in this way the profile of the various beach sectors. During storms or extreme events a significant amount of sediments is washed by the waves or is being brought into suspension stage, which mean that the on the beach areas the degradation process will be more intense. On a global level, the Romanian coast is one of the most affected areas by the erosion processes, which present specific features for the two main units (north and south). Previous studies indicate that the north sector (located in the vicinity of the Danube Delta) is in a critical stage, while the southern sector (with more economic facilities) is more stable. This situation is determined by natural factors and also by some anthropogenic factors such as: major port developments, consolidation of the navigation channels and dam constructions on the Danube which break or reduce the volume of sediments.