Beach nourishment experiment in Palanga, Lithuania

Abstract

Pupienis, D., Jarmalavičius, D., Žilinskas, G., Fedorovič , J., 2014. Beach nourishment experiment in Palanga, Lithuania. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 490–495, ISSN 0749-0208.Palanga is one of the most popular Lithuanian seaside resorts, which has previously been valued for its wide beaches composed of light yellow fine-grained quartz sand. At the turn of the 20th and 21st centuries, intensified erosion processes in recreation zones led to shoreline retreat and the volume of beach sand reduced. Increased coastal erosion resulted in diminishing recreational space. In order to rebuild the eroded beaches, a decision to implement a beach nourishment project was made. From 2006 to 2012, through several stages along a 2.5 km stretch of shoreline, over half a million m³ of sand was added to the beach, dredged from the onshore Kunigi kiai sand quarry or offshore from the Baltic Sea floor. From 2004 to 2013, along the nourished stretch, coastal monitoring was carried out once a year in the spring; the beach's condition was assessed based on 10 cross-shore profiles: cross-shore levelling was carried out and sand samples were collected. On the basis of repeated cross-shore levelling, changes in the morphometric characteristics of the beach and dune ridges and sand volume were undertaken. Sand samples allowed the identification of its granulometric composition. The results showed that the shoreline has partially stabilised after the beach reclamation; the beach has become wider and higher, thus recreational conditions have partially improved, i.e. beach recreational space has increased. However, beach nourishment has not changed the coastal dynamic patterns. The beach is relatively stable due to the additional nourished sand. It should be noted that the morphometric parameters of the beach profile depend on the nourished sand volume. Due to the increased beach width, aeolian processes have intensified, resulting in an increased sand volume carried towards the coastal backdune forest. These shore reclamation operations have changed in the prevailing sand's granulometric composition. Previously, predominantly light yellow fine sand was replaced by dark brown medium sand. The beach restoration was the reason for an increase in beach slope.