sign in sign up
<<
Home , Pocket beach

Journal of Coastal Research SI 50 969 - 977 ICS2007 (Proceedings) Australia ISSN 0749.0208

Pocket response to high magnitude–low frequency floods (Elba , Italy)

E. Pranzini and V. Rosas Dipartimento di Scienze della Terra Università degli Studi di Firenze Borgo Albizi 28 50123, Firenze, Italy [email protected]

ABSTRACT

PRANZINI, E. and ROSAS, V., 2007. Pocket beach response to high magnitude – low frequency floods (Elba Island, Italy). Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 969 – 977. Gold , Australia, ISSN 0749.0208

A megaflood, with an estimated recurrence time of approximately 200 yr, affected the Elba Island in September, 2002. In several pocket , active and reactivated creeks discharged a huge volume of unsorted to the coast. Since the morphological and sedimentological conditions of one of these bays ( of Procchio) was known due to topographic and sedimentologic studies performed in 1999, the impact of this event was easily evaluated through a survey performed a few days after the flood. The main beach responses were the formation of ring deltas, the increase of the fine fraction in the nearshore sediments and the coarsening of those in the zone.

A further survey in 2004 allowed monitoring the recovery of the beach, which is still returning to the pre-event conditions, at a slow rate. Although only the widest delta among those formed is still identifiable on the shoreline, and in spite of the nearshore sediments having lost all the fines, gravel and cobbles are still present from the step to the berm crest in the sectors adjacent to the old outlets and gravel is moving alongshore. The erosion that affected some pocket beaches at Elba during the second half of the 20th century, firstly attributed to the agriculture abandonment and to the consequent forest recovering, now has a new or additional cause: the return of the to pre-flood conditions within cycles of catastrophic accretion followed by mild erosion.

ADDITIONAL INDEX WORDS: Coastal dynamics, Megafloods, Sedimentology, Human impact.

INTRODUCTION At Elba Island, in only one case beach erosion is induced by the Pocket beaches are the most attractive segments of rocky presence of coastal structures (the harbour of Marina di Campo; and are the base of the tourist activity of several small PRANZINI, 1986) and none of the main causes that are usually held (SCHWARTZ, 1982). Limited in width, they are frequently backed responsible for this process on the continent (river damming, river by bluffs and fed by small creeks. The tourist use of the coast bed quarrying, land reclamation) is present there. Beach retreat exposes these valuable areas to intense urbanisation that reduces was therefore explained by the abandonment of agriculture which the resilience of the system. occurred after World War II, when most of the population left this Although pocket beach dynamics is a classical item in traditional activity in order to migrate to the coast, attracted by the geomorphology (YASSO, 1965; SHORT, A.D., MASSELINK, G. 1999; richer tourist industry. The forest covered the ancient fields and KLEIN et al, 2002), no specific data exist on how much erosion soil erosion was reduced as observed in other areas subject to affects the pocket beaches at a worldwide scale, and few papers similar land-use changes (e.g. CALDER, 1993; PETTS, 1994; focus on this process (e.g. GAILLOT and PIÉGAY, 1999; MICALLEF, MOUNT et al., 2005). At Elba, farmers did not realise that the 2003; COOPER and PETHICK, 2005). In Italy, where 42% of the beach, which was the basis of their new welfare, was in fact being beaches are eroding, most of pocket beaches for which these data produced by themselves and that a holiday-based economy would are available are retreating (GNRAC, 2006), but since erosion at not be sustainable under these circumstances. pocket beaches does not proceed with the high rate which it The relationship between changes to land-use and beach erosion frequently has on the long continental beaches fed by large rivers, was tested on two large pocket beaches of Elba Island (Lacona the process is probably underestimated. and Procchio): in the watershed that feeds the Procchio bay we see The study of the twenty longest pocket beaches at Elba Island that from 1940 to 2000 forest cover expanded from 41% to 74% (Tuscany, Italy), ranging in length from 100 to 1300 m, showed and artificial areas from 1% to 20% whereas beach retreated that nineteen of them are eroding, although at a rate lower than 0.5 approximately 12 m in the same period. For the Lacona area, m/yr, while on mainland Tuscany, where 36% of the beaches forest coverage passed from 17% to 77% and artificial areas, suffers from the same problem, this value is frequently one order almost absent in 1940 (<1%), represented 8% in 2000; beach magnitude larger (CIPRIANI et al., 2004). retreat was 11 m from 1940 to 1997 (MANNORI and PRANZINI, 2004).

Journal of Coastal Research, Special Issue 50, 2007

970 Pranzini and Rosas

On 4th September, 2002 a megaflood, with an estimated After World War II the rush to the coast started in Italy and recurrence time of approximately 200 yr, occurred in the central soon reached Elba Island; the 1960’s represent the period of the part of Elba Island, comprising the two mentioned basins. Active final transition from agriculture to tourism in the island. and reactivated creeks transported a huge volume of unsorted This industry is based on several pocket beaches but all of them sediments to the coast, modifying the morphology and are only a few metres wide and delimited by bluffs, cliffs, roads, sedimentology of beaches. buildings or other structures. Therefore shoreline retreat cannot be Morphological and sedimentological data acquired in 1999 on compensated by the shift of the entire beach profile and the several pocket beaches of Elba Island allowed the study of the surface available for tourism is continuously reduced. modification induced by this high magnitude – low frequency event (PITTY, 1982). In the present paper, after a general MATERIALS AND METHODS description of the effects of this flood on some pocket beaches at The present study is based on a shoreline dataset derived from Elba, the response of the Procchio beach is analysed comparing the digitalisation of the following documents: 1940 (1:2.000 pre-event data with those collected on two occasions: a few days cadastral map), 1954 (1:33.000 air photo), 1968 (1:10.000 map), after the event and two years later. Finally, a new interpretation of 1981 (1:2.000 map), 1989 (1:5.000 map), 2005 (Quickbird the process active on these pocket beaches is presented. panchromatic image); in addition, direct topographic surveys were carried out in May 1999, September 2002 and February 2004. GEOGRAPHIC SETTING The last three shorelines were acquired during bathymetric Elba Island is part of the Tuscan and is located 5 surveys performed along 13 profiles extending from the upper nautical miles from the mainland (Figure 1). With a surface of beach to -7 m. In addition, 80 samples were collected only 225 km2, it has a 142-kilometre-long coastline due to the during each survey, with a Van Veen grab sampler and presence of several . automatically sieved at ½ φ intervals to retrieve Mean size (Mz) The eastern side of the island was the most important iron and Sorting (σI) (FOLK and WARD, 1957); Percentage of fines (< 4 mining and melting district for the Etruscans and for the Romans, φ) and 1st percentile size were also considered. causing massive destruction of the forest and subsequent transfer Topographic and sedimentological data were geocoded in of melting activities to the mainland. Absent from the chronicles Gauss-Boaga, datum Rome 1940. Shoreline data were processed during the Early Middle Ages, was later disputed by the marine using specific software to extract beach surface variations for republics of Pisa and Genoa. The island felt under Spanish domain selected coastal segments; elevation changes were analysed in the 16th century and was sold to the Granducato di Toscana through Surfer, release 8. under Cosimo I de’ Medici, but was then conquered by the British and then by the French. The renaissance of the island is THE 2002 MEGAFLOOD AND ITS EFFECTS consequent to Napoleon’s exile, when agriculture and iron mining ON THE BEACHES bloomed again; the present road network was also developed th under his administration. It returned to the Tuscans in 1815 and On 4 September, 2002 a short but extremely intense rainfall later became part of Italy, with the Italian Unification in 1860. affected the central part of the Elba Island, producing catastrophic Mining lasted until the 1960’s in some places and during floods in the few and limited coastal plains. All pluviographs twenty-four centuries of this activity, millions of cubic metres of collapsed in this area but data collected where rain was less material was discharged onto the coastal system and produced intense showed that in 8 hours more rain felt than what is the several of the beaches that are currently used for bathing along the monthly average for September (220 mm vs. 51 mm). Estimations based on observations (e.g. bucket filling) at the hot-spot during eastern coast (NORDSTROM et al, 2004). On the hills, forest cutting to support mining and melting activity left the land open to this rain event indicated precipitation of more than 300 mm in 4 agriculture, which was the main activity in the first half of the 20th hours. A recurrence time of 200 yr is estimated for this event (Regione Toscana, pers. com.). century (MANNORI and PRANZINI, 2004). The event happened late in the morning and nobody from the thousands of people staying in the campsites for summer holidays was injured, even if most of the tents were torn down and several caravans were transported to the sea by the fluvial . 43°00’ Photos and videos made from the helicopter of Regione Toscana gave the first insight of the disaster and of the coastal developed (Figure 2). A huge volume of sediments was carried to the sea by each active creek and many other channels, which had not been active for many years, opened their way to the sea cutting foredunes (Figure 3) and causing severe damages to bathing establishments (Figure 4). The dry beach was deeply cut Golfo di Procchio and was laid in the nearshore along with the fluvial material. Natural boulders, larger than 50 cm, were deposited at the mouth of creeks, together with pieces of artificial structures, such as Isola d’Elba concrete blocks, iron fences and guardrails. 42°45’ At the initial stage, all this material was deposited on the nearshore but in this microtidal environment low swells (Hs < 0.50 m) reshaped it in a few hours, forming semicircular bars centred at the creek outlet (Figure 5) similar to that studied by COOPER (1990) and BROWNE (2002), who describe floods that 10°15’ 10°30’ reshaped pre-existing bars (closing a , in the first case, and a in the second). Figure 1. Location map.

Journal of Coastal Research, Special Issue 50, 2007

Pocket beach response 971

Figure 5. Ring delta developed at Lacona after the flood.

A small opening remained to allow fluvial water to reach the sea but the gap was closed where creek discharge was interrupted within a few days, creating small delimited by emerged crescent bars. Figure 2. One of the submerged fan delta of the Lacona beach During the following months the bar migrated onshore, (Low-resolution frame from a video made from the helicopter of reducing the lagoon and filling it. A circular platforms Regione Toscana on the same day of the flood). composed by boulders now faces a coarse-grained salient. Reactivated creeks formed a similar morphology, although these were smaller and constituted by finer sediments. The trenches cut by them on the beach were still visible during the 2004 survey, wherever beach cleaning and/or artificial reshaping was not performed.

PROCCHIO BEACH AND ITS RESPONSE TO THE FLOOD The Gulf of Procchio is located on the northern side of the island (Figure 1) and is 790 m wide and 450 m deep, with an embayment ratio (KLEIN et al., 2002) of 2.3. Tidal range in this sector of the Mediterranean Sea is 35 cm. The bay is open to the 300°÷0° sector, where offshore significative wave height (HS0) exceeds 2.5 m in 1 ‰ of the time. From the adjacent sector centred at 270°, sheltered by the delimiting the western side of the bay, the same frequency is observed for waves having HS0 = 4.5 m. The watershed discharging into the gulf has an area of approximately 3.2 km2, with the main input coming from the Figure 3. Trench in a cut by a reactivated at Lacona. Guarlone Creek, draining some granodioritic outcrops and empting onto the eastern side of the bay. The beach of Procchio, due to the beautiful landscape and the medium-sized light-coloured sand, is one of the preferred sites in the Island and supports a very active tourism industry which is based on holiday houses, hotels and residences.

Pre-flood evolution An overview of the shoreline evolution in the Gulf of Procchio is possible by comparing different cartographic documents dating from 1940. As on most pocket beaches, the long term evolution is associated to higher frequency shoreline rotation (MASSELINK and PATTIARATCHI, 2001; NORCROSS et al., 2002) which cause all coastal segments and mostly the lateral ones, to shift between accretion to erosion phases. At Procchio this rotation is evident comparing close surveys but its value is limited to a few metres due to the high indentation ratio of the bay, which causes all waves to approach almost orthogonally to the shoreline. This “noise” is filtered considering the whole beach length and extending the observation period to several decades. From 1940 Figure 4. Reactivated channel passing through a bathing hut at to 1999 the beach eroded for more than 12 m (Figure 6). Procchio.

Journal of Coastal Research, Special Issue 50, 2007

972 Pranzini and Rosas

1940 1950 1960 1970 1980 1990 2000 0 -1 -2 -3 -4 -5 -6 -7 -8 -9 Flood -10 -11 -12 -13 -14

Figure 6. Mean shoreline displacement at Procchio since 1940.

A 0.2 m/yr erosion is extremely low, but at Procchio this is actually considered to be “severe”, due to the limited width of the beach, to the impossibility of the profile to recede and, mostly, to the high economic value of each square metre of beach (the only existing evaluation refers to 1988, when each square metre of beach was estimated to produce an economic output of 24 €/yr; AAI, 1994). In 1999, after the survey performed in May, a limited with offshore sediments was initiated but the proximity of the dredging area to the Posidonia oceanica prairie caused the interruption by the Ministry of the Environment of the work, after a 7.000 m3 filling of medium-sized sand. In 1999 beach sediments comprised coarse to medium sand (sensu KRUMBEIN, 1934) with most of them having a sorting value (σI) between 0.35 and 0.50 (well sorted according to FOLK and WARD, 1957) (Figures 7 and 8). Percentage of fines (< 4 φ) was extremely low on the sediments of both the swash zone and the nearshore, with values over 2 % in only one point (Figure 9). The only anomaly was constituted by a platform in front of the Guarlone Creek, considered by a previous study (DEL GROSSO and PRANZINI, 2003) to be a lag deposit and attesting the occurrence of some ancient flood, being detectable due to the wave diffraction pattern in the area (Figure 10 top).

Flood impact The 4th September, 2002 flood strongly modified the morphology of the bay but the accuracy of the bathymetric data does not allow an evaluation of the volume of the sediment that reached the coast. The best accuracy expected in bathymetric data in operational surveys is of 10 cm (GIBEAUT et al, 1998; VAN DER WAL and PYE, 2003); therefore, any vertical variation within 20 cm cannot be considered to be real. Over a surface of 216.500 m2, such as the one within the –7 m contour line of Procchio, a volume inaccuracy of approximately 43.000 m3 is expected (twice the results obtained in this study for volumetric variation: 21.000 m3). However, a qualitative analysis of the morphological changes induced by the flood can be performed where depth variation is larger (Figure 11). In some places, these are related to the cross- shore displacement of bars over short times but significant variations are also present in front of the mouth of creeks, where ephemeral deltas formed. At the Guarlone Creek a depocentre of more than 1.5 m is present, whereas a 1 m rise of the sea bottom was measured in front of the creek empting onto the southern part of the bay. To analyse the shoreline evolution, the coast was divided into ten 110 m long sectors, for which the variation in dry beach surface was measured in order to calculate the mean shoreline Figure 7. Nearshore sediments Mean size (Mz) during the displacement for all time intervals (Figure 12). period of study.

Journal of Coastal Research, Special Issue 50, 2007

Pocket beach response 973

Figure 8. Nearshore sediment Sorting (σI) during the period of Figure 9. Percentage of fines in the nearshore sediments during study. the period of study.

Journal of Coastal Research, Special Issue 50, 2007

974 Pranzini and Rosas

between the two surveys, in spite of the small nourishment that was performed. In addition, where the flood entered the beach trough reactivated channels, deep and wide trenches formed, determining a volume loss from the dry beach itself. The eroded material was deposited in the nearshore together with the fluvial sediments. As far as sediment texture is considered, very coarse and unsorted material reached the coast. The coarsest fraction deposited in front of the creeks (Figure 7) and formed submerged fan deltas which were reshaped in a few hours into the mentioned ring deltas, whereas clay and were dispersed offshore and settled covering the well sorted fine sand previously present in the nearshore. The proportion of fines is over 20% (in weight) in some samples (Figure 9). A reduction in Mean size (Mz) in the nearshore contrasts with the increase in dimension of the swash zone sediments. All this resulted in a strong decrease in Sorting (σI values increasing), mostly in the area directly fed by the Guarlone Creek (Figure 8).

Two years later Important changes to bathymetry were verified to happen at specific points from 2002 to 2004 (Figure 11). Quantitative analyses here, however, face the same problems as described for the 2002 data. Nearshore sediments moved to the dry beach, which had a general rise and a mean progradation of 1 m, with the largest values being verified in the sectors located near the mouths of creeks (Figure 12). The ring delta migrated onshore and erosion of the seafloor was conspicuous (over 1 m) in front of the mouth of Guarlone Creek, were a lag deposit, comprising of boulders and , increased the area of the pre-existing shore platform (Figure 7). The smallest ephemeral deltas were flattened and no morphological evidence of their presence is now observable.

The swash zone material underwent a significative increase in size due to the shoaling of the coarser grains and to the drift of gravel and pebble away from the Guarlone Creek mouth. This process is shown by the tongue of coarse material starting at the Guarlone outlet and running westward. Comparing the sediment Mean size of February, 2004 with that of May, 1999 the effect of the flood is evident, with a generalised increase in and, therefore the reduction in the quality of the beach for recreational use. A sandy beach was transformed into a mixed sand and gravel beach, as shown by the sediment sorting map for February, 2004 (Figure 8). On the nearshore, where the flood induced a significant increase in the fines fraction (< 4 phi), in 2004 we returned to the original conditions, with values below 1%, except on the most protected north-eastern side of the gulf (Figure 9).

CONCLUSIONS The September, 2002 flood strongly modified the morphology and sedimentology of the beach at Procchio. Dry beach accretion was not immediate, since most of the sediment carried by the Figure 10. The Guarlone Creek mouth in 1999 (top), 2002 (centre) creeks was deposited on the nearshore (Figure 13). In the two and in 2005 (bottom). following years this material moved ashore and determined a mean shoreline progradation of approximately 2 m. The most conspicuous morphological change is related to the ephemeral ring The survey performed a few days after the flood does not show delta, produced by the evolution of the submerged fan delta that consistent beach progradation (approximately 1 m on average) had been formed first. This coarse sediment feature changed, except where the Guarlone Creek delta formed (sector I and moving onshore to create a pebble salient and leaving a wide adjacent sectors in Figure 12). Actually, some sectors were boulder platform in front of the creek outlet. retreating if compared to the 1999 survey results; this is the effect Swash-zone and step sediments underwent a progressive of the progressive erosion which happened in the period of time coarsening as far as gravel moved longshore from the source area.

Journal of Coastal Research, Special Issue 50, 2007

Pocket beach response 975

Figure 11. Bathymetric variations (m) at Procchio from 1999 to 2002 (top) and from 2002 to 2004 (bottom).

Journal of Coastal Research, Special Issue 50, 2007

976 Pranzini and Rosas

6 0100200 m 1999 - 2002 5

4

3

2

1

m 0 AB CDE FGH I L -1 -8 H -2 -7 -3 Sectors -6 G -5 F -4 6 -3 2002 - 2004 -2 E 5 1 - 4 D 3 C B 2 A 1

m 0 ABCDEFGHI L -1 Figure 12. Shoreline evolution at Procchio in the two periods of -2 -3 Sectors study. Mean values computed on ten 110-m-long sectors (2002 bathymetric contours in the basemap).

with COOPER (2002), when he writes that “periodical inputs of fluvial sediment to the coast may control coastal behaviour for several decades”, but we must stress that, in the present case study, this is far more true for the sediment texture than for the beach morphology.

LITERATURE CITED A.A.I., 1994. Progetto Elba Promotion, 5° LIFE Program. Unpublished report. Associazione Albergatori Isola d’Elba, Portoferraio. BENEDET, L.; FINKL, C.W.; CAMPBELL, T. and KLEIN, A., 2004. Predicting the effect of beach nourishment and cross-shore Figure 13. Beach trench and small crescent delta formed in the sediment variation on beach morphodynamic assessment. southern part of the bay in front of the pipe that runs under the , 51, 839-861. village of Procchio and collects the water from a small watershed. BROWNE, G.H., 2002. A large-scale flood event in 1994 from the mid-Canterbury Plains, New Zealand and implications for A medium to coarse sandy beach was therefore transformed into ancient fluvial deposits. In: Flood and Megaflood Processes a mixed sand and gravel barrier, less attractive for the summer and Deposits: Recent and ancient examples, Spec. Publs. visitors. International Association of Sedimentologists, 32, 99-109. No forecast is possible concerning the time necessary for a full CALDER, I.R., 1993. Hydrological effects of land-use change. In: recovery of the beach but the increasing proportion of gravel MAIDMENT, D.R. (ed.), Handbook of Hydrology. New York: during the period of this study exclude the possibility of a fast McGraw-Hill, 13.1–13.50. return to the original texture. The platform in front of CIPRIANI, L.E., FERRI, S., IANNOTTA, P., MANNORI, S. and Guarlone Creek must be considered as a permanent feature of this PRANZINI, E., 2004. Evoluzione recente delle spiagge toscane. pocket beach. In: REGIONE TOSCANA, Il Piano Regionale di gestione Fines, which had been firstly deposited on the nearshore, were integrata della costa ai fini del riassetto idrogeologico. rapidly washed off and sediments in 2004 present a texture- Florence: Edifir, 75-92. similar to that they had before the flood. As observed by FAN et al. COOPER, J.A.G., 1990. Geomorphological effects of catastrophic (2004) in another area, fines are lost very quickly from the flooding on a small subtropical . Earth Surface nearshore and we think that they cannot mark the existence of past Processes and Landforms, 15, 24-41. flooding events. COOPER, J.A.G., 1993. Sedimentation in a river dominated Nevertheless, the Procchio pocket beach is now very different estuary. Sedimentology, 40, 979-1017. from what it was before the 2002 flood and the time for a full COOPER, J.A.G., 2002. The role of extreme floods in estuary- recovery seems to be very long, more for its textural coastal behaviour: contrast between river- and tide-dominated characteristics than for the morphology. Relatively large volumes microtidal . Sedimentary Geology, 150, 123-137. of sediments can enter and exit a pocket beach without inducing COOPER, N.J. and PATHICK, J.S, 2005. Sediment budget approach notable changes in its morphology but the input of coarse material to addressing problems in St. Ouen’s Bay, is extremely impacting on such low energy coasts We must agree

Journal of Coastal Research, Special Issue 50, 2007

Pocket beach response 977

Jersey, Channel Islands. Journal of Coastal Research, 21, MICALLEF, A., 2003. Monitoring beach stability on the 112-122. Mediterranean island of Malta. Proceedings of the 6th DEL GROSSO, G. and PRANZINI, E., 2003. Pocket beach erosion: International Conference on the Mediterranean Coastal Golfo di Procchio (Isola d’Elba). Proceedings of the 6th Environment - Medcoast (Ravenna, Italy), 1355-1368. International Conference on the Mediterranean Coastal MOUNT, N.J., SMITH, G.H.S. and STOTT, T.A., 2005. An Environment - Medcoast (Ravenna, Italy), 1559-1570. assessment of the impact of upland afforestation on lowland FAN, S., SWIFT, D.J.P., TRAYKOVSKI, P., BENTLEY, S., BORGELD, river reaches: the Afon Trannon, mid-Wales. J.C., REED, C.W. and NIEDORODA, A.W., 2004. River Geomorphology, 64 (3-4), 255-269. flooding, storm resuspension, and event stratigraphy on the NORCROSS, Z. M., FLETCHER, C. H. and MERRIFIELD, M., 2002. northern Carolina shelf: observations compared with Annual and interannual changes on a -fringed pocket simulations. Marine Geology, 210, 17-41. beach: Kailua Bay , Hawaii. Marine Geology, 190, 553-580. FOLK, R.L. and WARD, W.C., 1957. Brazor river bar: a study in NORDSTROM, K.F., JACKSON, N.L. and PRANZINI, E., 2004. Beach the significance of grain size parameters. Journal of sediment alteration by natural processes and human action: Sedimentary Petrolology, 27, 3–26. Elba Island, Italy. Annals of the Association of American GAILLOT, S. and PIÉGAY, H., 1999. Impact of gravel-mining on Geographers, 94 (4), 794-806. stream channel and coastal sediment supply: examples of the PETTS, G., 1994. Large-scale river regulation. In: ROBERTS, N. Calvi Bay in Corsica (France). Journal of Coastal Research, (ed.), The changing global environment. Cambridge, MA, 3, 774-788. Usa: Basil Balckwell, 262-284. GIBEAUT, J.C., GUTIERREZ, R. and KYSER, J.A., 1998. Increasing PITTY, A.F., 1982. The nature of Geomorphology. London: the accuracy and resolution of coastal bathymetric surveys. Methuen & Co., 161p. Journal of Coastal Research, 14, 1082-1098. PRANZINI, E., 1986. La dinamica dei sedimenti nel Golfo di G.N.R.A.C., 2006. Lo stato dei litorali italiani. Studi costieri, 10, Campo (Isola d'Elba). Boll. Soc. Geol. It., 105, 253-264. 3-175. SCHWARTZ, M. L., 1982. Geographic terminology. In: SCHWARTZ KLEIN, A.H.F., FILHO, L.B. and SCHUMACHER, D.H., 2002. Short M.L. (ed.), The Encyclopedia of Beaches and Coastal term beach rotation processes in distinct headland bay beach environments. Pennsylvania: Hutchinson Ross Publishing systems. Journal of Coastal Research, 18, 442-458. Co., Stroudsburg, 442-445. KRUMBEIN, W.C., 1934. Size frequency distributions of SHORT, A.D. and MASSELINK, G., 1999. Embayed and structurally sediments. Journal of Sedimentary Petrology, 4, 65 – 77. controlled beaches. In: SHORT, A.D. (ed.) Handbook of beach MANNORI, S. and PRANZINI, E., 2004. From agriculture to and shoreface morphodynamics. Wiley, 230-250. st tourism: a cause of beach erosion. Proceedings of the 1 VAN DER WAL, D. and PYE., K., 2003. The use of bathymetric International Conference on the Management of Coastal charts to assess morphological and sedimentological budget Recreational Resources (Malta), 79-85. change in estuaries. Geographical Journal, 169, 21-31. MASSELINK, G. and PATTIARATCHI, C.B., 2001. Seasonal changes YASSO, W.E., 1965. Plan geometry and headland-bay beaches. in beach morphology along the sheltered coastline of Perth, Journal of Geology, 73, 703-714. Western Australia. Marine Geology, 172, 243-263.

Journal of Coastal Research, Special Issue 50, 2007