|Type of Entry:||Case Study|
The coast is characterised by sand-beaches covering muddy-clayey materials derived from more ancient swampy and alluvial deposits. This area is the result of the interaction between river-delta and marine coastal processes.
The seawater level rising in the North Adriatic Sea is also due to an intense wind action coming from south-east, the Sirocco wind, associates to depressional fields, which move towards the East. The prevailing sea is from the SE (influenced by Sirocco wind) close to the shoreline, and from the NE (influenced by Bora wind) where water depth is higher than 3 m. During the last century, the entire coastline has been strongly influenced by two main factors: the building and progressive extending of Ravenna Port jetties (whose present length is about 2800 m) and the lack of sediment supply, formerly coming from the river consider all the negative effects caused by subsidence and the high anthropic impact due to beach-tourism management.
The coast have experienced a subsidence grater than 1 m in the last 40-50 years; natural rates of 2-3 mm/y of magnitude have been in fact greatly accelerated in the last half century by fluid (water and gas) extractions from the underground. At present, along the coastal areas, the subsiding rates are, on average, 5- 6 mm/y, with peaks of 9- 10 mm/y. The coastline experienced a huge erosion rate in the southern part (from the Fiumi Uniti river mouth to about Punta Marina) and a significant accretion in the northern part (close to the jetty).
In Marina di Ravenna the emerged beach shows a marked accretion (about 140-150 m in the last 50 years) while, where water depth exceeds 3-4m, a slight negative altimetric budget can be observed. The major function of the coastal area is tourism and recreation. More than 100 bathhouses are located on the 10.5 km of beaches. These structures damaged and destroyed the dune bar and, because of an uncontrolled use of the beach, they caused heavy and continuous impacts on the existing residual dune bars and on the pinewood.
The actual beach management strategy, according to the present knowledge, began in 1997, with the design of a new coastal semi- submerged protection structures required because the previous submerged breakwater and groins made of sand bags resulted ineffective.
|Keywords:||Beach nourishment, Beach protection, Coastal defence, Tools and techniques for beach management|
|Contact:||Prof. Giovanni GABBIANELLI
Environmental Science, University of Bologna
Telephone: +39 054 448 47 58 / +39 054 448 47 12 / +39 054 448 47 58
|Coastal databases provided and maintained|
by EUCC - The Coastal Union Germany