Assessment of the Geomorphological and Sedimentological Changes in Mamaia Sector after the Implementation of the Coastal Protection Measures

Abstract

The paper analyses the changes in the beach sector of Mamaia resort from a geomorphological and sedimentological point of view in the context of coastal protection works carried out in 2014-2015 and 2021 (measures to reduce wave energy, beach protection with structures to stabilize the sand and beach nourishment). The Mamaia sector, with a length of about 12 km, is geomorphologically constituted mainly by sandy barrier of Lake Siutghiol representing a transition unit between the northern unit (deltaic and lagoon shore) and the southern unit (small pocket rocks-beaches in front, separated by small coastal sandbars). From an economic point of view, the sector is important for coastal tourism both in terms of the number of tourists and the existing of infrastructure generating significant revenues. Since the 1950s, the sector has been severely affected by the construction of the dikes of the Midia Port in the north, which have affected the longitudinal transport of sediments and accentuated the erosion of the submerged and backshore beach. To counteract the effects of erosion, a longitudinal and transversal coastal protection system was built between 1960 and 1990, which proved to be ineffective in the long term.

The data collected in the field (topographic profiles of the backshore, shoreline, sediment samples) before and after the recent coastal protection works were processed using a dedicated software (ArcGIS 10.x and Gradistat v8) and represented in the form of maps and graphics. The spatial analysis highlighted the modification of the coastal system components, the trends of the beach evolution in longitudinal and transversal profile and the changes in the structure and distribution of sediments determined by the impact of the coastal protection works.