CLIMATE CHANGE AND BEACHES DESTRUCTION

It is possible to predict that the beach erosion affecting the Mediterranean coasts, prevalently caused by the cyclical climate variation, will be active for 150 years at least.

Our research has permitted to evaluate, in a three-dimensional way, the sediments with lithologic characteristics similar to those presents on the beaches, outcropping along the coastal areas, that could represent potential layers to use for the lasting beach nourishment.

With the purpose to verify the possibility to effect interventions of geoenvironmental restauration of meaningful beaches and of abandoned quaries, a study has been effected along the vesuvian coast between the communes of Vico Equense and Portici in the Gulf of Naples. Particularly has been valued the possibility to effect a geoenvironmental restauration of the abandoned coastal quarries of calcareous rock of Pozzano and of other quarries of volcanic rocks along the borders of the Somma-Vesuvius with the purpose to draw an environment restored and usable for various activities and to get necessary sediments for the construction of a new water front.

The restauration of the coastal Vesuvian zone, also, has a notable importance to sensitively improve the safety conditions of the area in relationship to the volcanic risk. The study has recorded that the urban water fronts of the coastal vesuvian area from Torre Annunziata to Portici is degraded, often real "hostages" of strategic interventions realized in the second halve of the XIX century, as for instance the railway line Naples-Salerno built along the uninhabited coast.

It deals with a series of coastal inhabited centers, practically without access to the sea; of a sea without beaches.

The coastal area of Pozzano, to the beginning of the Sorrento coast, is defaced by a secular quarry activity. As it is known in such area has been realized only the recovery of the old factory ov cement, currently turned to hotel activity. The study has been tense to appraise an intervention of restauration of the calcareous slopes through terraces. The rocky sediments obtained would be available for realizing, besides the restoration of the local beach, extremely limited in ampleness and characterized by gravelly sediments, also other environmental restaurations of the beaches present along the coast from Vico Equense to Portici.

The geoenvironmental restauration of the slopes consists of realizing in first place some terraces to stabilize the rocky slopes of the areas, affected by the past extraction of calcareous material, with the purpose to eliminate the danger of rock fall.

The terraces would reproduce the typical setups of the slopes of the Amalfi-Sorrento peninsula. It is evident that the new sediments would develop the double role to guarantee the support for the enjoyable bathing surface and of defense of the coastal area.

With the geoenvironmental restauration of the Pozzano quarry could be obtained about 5,6 million m³ of calcareous gravel; a part of the sediments could be elaborate reducing the fragments of rock to rounded pebbles necessary to be used for the strategic nourishment of the underlying shore, to get a new and ample beach. From the effected calculations they would serve around 400.000 m³ of gravel for the nourishment of the Pozzano coast. The terracing and restauration of the slopes would make available a new surface of 90.000 mqs.

The geoenvironmental restauration of the shore for a linear length of around 3000 m-4000 m, would involve the recovery of a new coastal surface, having elevated environmental value and of great economic importance, of around 270.000 mqs that would represent a protection for the anthropised environment and the occasion to environmentally redraw the water front on sustainable bases, for tourist-bathing activity, recreational and for other uses.

The search has put in evidence that along the coast between Castellammare di Stabia and Portici should be performed the restauration of the beach, as proposed for Pozzano, using partly sediments coming from the restauration of the calcareous front and partly sediments of volcanic rock available from the restauration of the abandoned caves at the base of the Somma-Vesuvius.

The investigations have underlined that similar interventions could permit to restore the Roman line of shore. Such intervention would allow to draw a new coastal band of around 260 hectares; such new coastal area would represent a qualified territory in which to realize equipped spaces, infrastructures and various equipments. Considered the elevated profitability that would characterize such coastal area, a real "Vesuvian Riviera", rich of cultural heritage and natural monument, it is realized that the intervention of restauration could also attract the necessary private capitals that would allow to perform the intervention in brief times.

The studies have been wide to the whole coastal band of Campania and have underlined that the restauration of the abandoned quarries, within a prudent and modern regional territorial planning, could include, also, the quarries of alluvial sediments. Other layers of usable sediments for the beach nourishment could be constituted by the fossil alluvial sediments that characterize the valleys of various rivers.

The investigation effected in the coastal band of the Cilento, inclusive in the National Natural Park homonym, has revealed interesting solutions of coastal restauration that, combined to interventions in the hinterland, could restore many chilometers of beach of great environmental and economic importance, currently affected by increasing erosion and destruction.

CONCLUSIONS

The study has underlined that the coastal area between Castellammare di Stabia and Portici, in the Gulf of Naples, can be valorized redrawing the water front, or better restoring a line of ancient shore.

The study has appraised the possibility to restore the beaches with selected sediments that guarantee a duration of many tens of years to the intervention, inspiring to the natural nourishment happened in a few hours to Vietri sul Mare between 25 and October 26 th 1954.

The morphology of the new restored surfaces would simulate the natural morphology of the alluvial coastal areas, characterized by the beach and by a back-beach zone, vegetated and with typical dune morphology.

Such morphology would allow to realize equipped areas and to entertain a new covered emergency street of escape that would allow a rapid connection of the zone, to greater volcanic risk, with the surrounding areas to north west and to south east; such solution would assure a street of sure evacuation, that would not have put out of use from the accumulation of pyroclastic sediments in case of vesuvian eruption.

It must be underlined that the beaches need lasting and immediate interventions to program in the regional territory on the base of the environmental priorities.

The only way of intervening is represented by the nourishment of the shores with sediments of such granulometry that could not be eroded from the beaches.

Such method of rapids realization, allows to conjugate the lasting geoenvironmental restauration and the lasting sustainable social and economic development. Considering that the erosion of the shores will increase for at least 150 years, it must be adopted seriously the objective to protect, to preserve and to valorize the shores privileging the actions to realize lasting interventions, in the respect of the natural beauties and, contemporarily, allowing to get other environmental benefits.

In a careful program of exploitation of the environmental resources and of economic development of the territory, the environmental restauration of the shore would allow the restauration of numerous abandoned quarries.

It must be considered the possibility to start, in brief times, suitable legislative interventions and experimental beach restauration in meaningful and representative areas.

The administrators of the public institutions have to become themselves account that the coastal band is an autochtonous environmental good of inestimable value that must be protected and adequately planned.

Taking in examination the Vesuvian Riviera, it could be restored in two times.

The first intervention would be tense to reconstitute a line of shore similar to the Roman one and to adjust the harbors, also for a strategic function of "Sea Street of Escape" in case of volcanic emergency.

The second intervention could concern the complete restauration of the water front whose fruition currently is mined also by infrastructures such as the coastal railway line.

The restauration of the beaches, in accord with the competent Institutions, could be improved using the sediments gotten by the restauration of the various rocky quarries of volcanic rocks at the base of the Somma-Vesuvius.

The calcareous sediments that would constitute the foundations of the nourished beaches could be transported by Pozzano by sea and directly accumulated along the coast.

Such new coastal area would represent a qualified territory in which to realize equipped spaces, infrastructures and various equipments.

Considered the elevated profitability that would characterize such coastal area, a real "Vesuvian Riviera", rich of cultural heritages (Pompei, Oplonti, Herculaneum) and natural monuments (Vesuvius), it is evident that the intervention of restauration could also attract the necessary private capitals that would allow to perform the intervention in brief times.

The economy connected to the shore of Pozzano underlines that, currently, in the three summer months the middle billing for square meter of shore is of around 70 Euro; then during the bathing season the beach produce a general billing of 2.100.000 Euro (70 Euro X 30.000 m² of the actual beach).

Such billing would increase notably if the surface of the beach is considered after the artificial nourishment; in fact with the 110.000 m² of the restored beach the total billing would be of around 7.700.000 Euro/year.

To build a new coastal emerged area 90 m width and long about 18 km from Torre Annunziata to Portici it would need around 3.000.000 of meters cubes of calcareous sediments transportable by sea from Pozzano and around 1,5 million meters cubes of sediments of volcanic rock that would guarantee the finishing touch of the visible part of the restored beach (figure 1).

The intervention would allow to have available a new emerged area of around 160 hectares.

Around 80 hectares would be constituted from the beach and around 80 hectares from the back beach area.

The cost esteemed for such restauration is valued around 70 million of Euro.

Considering the actual annual billing for square meter of beach appraised for Pozzano (70 Euro), after the restauration and equipping of the back beach area, the annual billing, induced by the 800.000 square meters of new beach, could be estimated around 56 million of Euro.

It is evident that the coastal resource can adequately be restored and valorized with a modern ability of government that makes possible transparent interventions, of great benefit for a lasting development.

The new coastal surface should be object of an unitary planning, democratically based on the demands of the communes and the whole surrounding territory, so that to create evident benefits to the citizens of the coastal communes and to guarantee a lasting social and economic development.