Long term and short term coastal line changes of the Eastern Gulf of Finland. Problems of coastal erosion

Traditionally the coastal zone of the easternmost (Russian) part of the Gulf of Finland has not been considered as an area of active litho- and morphodynamics, but a recent study has shown that the easternmost part of the coastal zone suffers from erosion. Within some coastal segments the shoreline recession rate reaches 2 ?C 2.5?m/year. As well as determining the hydrodynamic reasons for recent erosion acceleration, important geological and geomorphic features of coastal zone which influenced the lithodynamics were established. The Kurortny District of St.Petersburg is located along the northern coast of the Gulf of Finland to the west of the St. Petersburg Flood Protection Facility. It has special importance as a unique recreation zone of the North-West of Russia. Coastal erosion is one of the most serious problems of the area. The analysis of historical materials, archive aerial photographs and modern high-resolution satellite images have shown that advancing parts of coast are almost non-existant with most sections of the coast being eroded and further retreating. Field monitoring between 2004 and 2007 showed intense damage to sandy beaches during autumn and winter storms and progressive erosion of the dunes system. Among the most important natural reasons for the erosion processes are that the coastline is open to storm waves induced by westerly and south-westerly winds, the geological structure of coastal area (easily eroded Quaternary deposits) and a sediment deficit. In some areas sediment loss was the result of the submarine coastal slope morphology (a steep slope of a narrow submarine terrace within the area of sediment drift discharge), with erosion of an alongshore submarine sandy terrace and erosion runnels at the depth 8?C12?m. The situation becomes worse due to anthropogenic impact. The southern coastal zone dynamics are also very active. According to an aerial and satellite photos analysis from 1975?C1976 to 1989?C1990, sandy beaches to the west of Lebyazhye village were eroded up to 30?m, and near Bolshaya Izora village up to 70?m. The comparison of coastine GPSsurvey with old nautical and topographic charts published in the 1980s shows the considerable change.     

Integrating GIS and high resolution orthophoto images for the development of a geomorphic shoreline classification and risk assessment—a case study of cliff/bluff erosion along the Bulgarian coast

This paper demonstrates the effectiveness of integrating GIS and modern spatial data for the development of a detailed geomorphic classification of the Bulgarian Black Sea coast. This classification is important for the precise measurement of various natural and technogenous (engineered) coastline types and serves as a basis for identification of the areas with high exposure to different coastal hazards. To illustrate potential uses of this simple methodology, a map of the potential coastal erosion/cliff retreat hazard for the Bulgarian coast was produced from this GIS database. Several types of data were used: high resolution orthophoto, topographical maps in 1:5,000 scale and geological maps. Geomorphic classification utilized both geomorphological and engineering criteria. A total of 867 segments were delineated along the coast. Four hundred sixty five were classified as natural landforms (cliffs, beaches, river mouths) with a total length of 362,62 km and 402 were indicated as technogenous segments (port and coast-protection structures, artificial beaches) with a total length of 70 km. Based on the geologic materials present at each segment and cliff height, the cliffed portions of the Bulgarian coast were classified for expected erosion rates, and therefore, hazard vulnerability: low hazard (volcanic type cliff); moderate hazard (limestone type cliff) and high hazard (loess and clayey types cliff). This “predictive model” was then compared to a previously published field study of coastal erosion rates to validate the model. As a result, a new high quality, but qualitative data for Bulgarian coastal bluff/cliff erosion were obtained, incorporated and analyzed in GIS.     

Vegetation cover influence on the morphology and migration patterns of river mouths

The present study focuses on the effects of vegetation cover changes on the dynamic morphology of seven southeastern Mediterranean river mouths. The methodology used comprised monitoring and mapping by GIS techniques, with data derived from historic aerial photographs, which were applied in the investigation of the morphological spatial and temporal migration patterns of the mouths, and subsequent analysis of the vegetation cover changes influencing them. Vegetation cover adjacent to river mouths influences river mouth morphology through five primary mechanisms: a) bank vegetation; b) dune advancement toward the shoreline; c) changes in the beach??s micro-topography; as well as d) long-term continuous channel migration through permanent vegetation patches; and e) channel switching through permanent vegetation patches. The five mechanisms are part of a system of interactions between channel water flow and fluvial processes; coastal sediment transport and coastal processes; and the evolution of plant communities. In the interplay between these factors they all affect and are being affected by one another. In many river mouths artificial channel diversion is often needed due to uncontrolled channel migration. It is demonstrated that vegetation cover can serve as a mean of ??soft?? channel regulation. Therefore, a better understanding of the five influencing mechanisms may aid in controlling and managing river mouth migration patterns. The study contributes to the knowledge about bank vegetation as a tool of ??soft?? channel regulation and thus can contribute to the improvement of coastal zone management.     

Shoreline morphological changes and the human factor. Case study of Accra Ghana

The interface between the sea and land is a very dynamic system that is always migrating landward or seaward. The landward migration results in the shoreline threatening coastal infrastructure and destroying the coastal environment. Coastal erosion has resulted in both social and economic problems. Coastal cities have also experienced increasing infrastructure development and population growth. This has resulted in a land “squeeze situation” in which both the shoreline and the “humanline” are competing for space along the coast. This struggle for space could result in serious environmental disaster as a result of the dynamics of the oceanic system, which could impact the immediate environs severely. The aim of this study was to determine if the rate of human encroachment of coastal lands for development exceed the rate at which the shoreline is moving inland as part of its natural cyclic behaviour. This study used 1985 aerial photographs and 2005 orthophoto map of the Accra western coast. Major land cover was identified, classified and overlayed in GIS environment. This enabled changes to be estimated. The shorelines were also digitised and the rate of change computed using the DSAS software. The results indicate that the estimated total area of land lost by human encroachment on the coastal land within the period under study is about 242,139.7 m2. However, the rate of land lost to human development is about 8,349.64 m2/year, which is relatively high. The historic rate of erosion computed for the period under study is about 1.92 m/year. Comparing the two rates indicates that human activities are moving closer to the shoreline as compared to the rate at which the shoreline is moving inland. This study recommends that setback lines should be put in place to protect lands for the shoreline’s cyclic activities.     

Human influence over 150 years of coastal evolution in the Volturno delta system (southern Italy)

This paper focused on the past shoreline change rates along the coastal plain of the Volturno River, in southern Italy, western Mediterranean. A wide database comprising historical maps, aerial photographs, topographic sheets, bathymetric data was used to extract the spatial and temporal information of the coastlines at seven time points. Coastline displacement was calculated for two successive time points and relative surface variation (accretion and erosion) was estimated as well as minimum and maximum accretion/erosion linear values and rates. The surface variation analysis has revealed that the studied coast can be considered homogeneous since the 1970s, whereas it exhibits a variety of shoreline evolutionary trends after that time period. Timing and causes of trends and rates of variation were detected. Based on the estimated shoreline change rates, an appropriate morhodynamic one-line model was applied to predict evolutionary scenarios also in presence of port and defence works. The results obtained strongly emphasize that a successful coastal management requires a constant monitoring of the human-induced changes to account for the variability of rates over time.     

The practice of coastal zone management in Portugal

The practice of coastal zone management in Portugal is very recent. Key issues and considerations about natural shoreline dynamics, main policy instruments, and lessons learned from the EU Demonstration Programmes on Integrated Coastal Zone Management in Portugal will be outlined in this paper in an attempt to understand how the practice of ICZM and its prospects are. Coastal zone management problems and their associated side effects, as well as national and international evolution patterns will be drawn. Some means of achieving better coastal zone management practices and ways of addressing some of its forefront issues are also identified. Special attention will go to erosion problems. The pressure induced by urban development and economic activities on coastal areas is increasing. Poor sediment availability combined with years of neglected management and over-exploitation of resources have had a negative impact, and there are many areas showing evidence of coastal erosion. There is a need to improve policies and instruments of coastal planning and management. Coastal zone management plans are being developed for the nine sectors of the continental Portuguese coast, providing a full analysis of coastal systems and a delimitation of uses in relation to the carrying capacity of the shoreline.     

National assessment of coastal vulnerability to sea-level rise for the Chinese coast

Sea-level rise as a result of climate change increases inundation and erosion, which are affected by a complex interplay of physical environmental parameters at the coast. China’s coast is vulnerable to accelerated sea-level rise and associated coastal flooding because of physical and socio-economical factors such as its low topography, highly developed economy, and highly dense population. To identify vulnerable sections of the coast, this paper presents a national assessment of the vulnerability of the Chinese coast using 8 physical variables: sea-level rise, coastal geomorphology, elevation, slope, shoreline erosion, land use, mean tide range, and mean wave height. A coastal vulnerability index was calculated by integrating the differentially weighted rank values of the 8 variables, based on which the coastline is segmented into 4 classes. The results show that 3% of the 18,000-km-long Chinese coast is very highly vulnerable, 29% is highly vulnerable, 58% is moderately vulnerable, and 10% is in the low-vulnerable class. Findings further reveal that large amounts of land and population will be vulnerable to inundation by coastal flooding from sea level rise and storm surge. Finally, some suggestions are presented for decision makers and other concerned stakeholders to develop appropriate coastal zone management and mitigation measures.     

An application of GIS and coastal geomorphology for large scale assessment of coastal erosion and management: a case study of Ghana

Coastal erosion poses serious threat to life and properties along Ghana??s coast. This is because major industries, urban settlements, recreational facilities, heritage and conservation sites are located few metres from the coast. In spite of this threat, management strategies, both past and present, remain an ??ad hoc?? and site specific. Limited attention has been given to large scale assessment and investigation to detect the rate of coastal recession and the size of land lost to the sea to inform integrated management plan and to formulate sustainable management strategies to deal with the problem. This paper provides large scale assessment of coastal recession in Ghana through field investigation, applied coastal geomorphology and GIS techniques to selected case study areas. The assessment covered 203?km out of the 540?km coastline of Ghana. Results of the assessment indicate that coastal erosion is very substantial and wide spread along the coast, but the rate of recession varies across the entire coastline. Significant amounts of losses of settlements have been experienced in some localities in the eastern coast (Keta and Ada) and the central coast (Accra, Shama and Sekondi-Takoradi). In some areas, coastal defences have been built to reduce the impacts, yet many areas are still very vulnerable. Interestingly, the paper identified that the high rates of retreat recorded in many areas have yet to cause major risks in some local communities because of the presence of a buffer of largely undeveloped land that has existed historically between the shoreline and the developments. However, recent increase in coastal tourism in Ghana has led to ??scramble?? for purchase of these buffer lands for development, which increase the risk. Ghana has the opportunity to use education and land use planning to keep the coastline clear of major developments and avoid the temptation of engaging in costly cycle of development-risk-defence experienced in many countries including the UK and the Netherlands. The paper recommends that Ghana should adopt the UK SMP, which has progressively moved away from the traditional re-active and parochial approaches of providing localised hard-engineered coastal defence work to solve what was perceived to be a local problem, to a more pro-active and holistic approach that take full account of coastal dynamics, interrelationships of coastal systems, knock-on effects, environment concerns and developments at the backshore.     

Determination of set-back lines on eroding coasts. Example of the beaches of the Gulf of Lions (French Mediterranean Coast)

The study presented here describes a method for defining set-back lines along eroding coasts. The method (a mathematical model) combines the long-term shoreline retreat trend with short-term shoreline erosion (during storms). Simulations are carried out for 2030 and compared with the beach width to determine whether the shoreline is likely to shift onshore. The mathematical model is applied to the Frontignan and Carnon beaches (south of France). Both sites possess hard engineering coastal structures and downdrift erosion on the natural beaches. The set-back lines indicate that beaches with groynes are generally wide enough to resist shoreline retreat, while the downdrift “natural” beaches are not. We discuss the possible utilisation of set-back line estimations.     

The Coastal Environmental Characteristics of Taiwan

Abstract

There are three major factors affecting the coastal environment in Taiwan: tidal current, long-shore current and land subsidence. in Taiwan, most industrial areas are located on the southwestern coast. Most of the pollutants from the factories are discharged directly to the ocean, harbours or rivers. the pollutants in harbours or rivers will eventually be delivered to coastal waters. There, the tidal current is the major force dispersing the pollutants nearshore. the polluted water extends to an area about 5 km on both sides from the discharge source, and within about 3–4 km off-shore. in this study, Hsien-Da Harbour in southwestern Taiwan is cited to explain the effects of tidal current on the coastal environment. the long-shore current induced by breaking waves is the major force shaping the coastal morphology. Along the western coast of Taiwan, the long-shore current mainly flows northward along the southern section, and southward along the northern section. in the last one hundred years, in general, the coast has been eroded along the northern and southern sections of western coast, and some reclaimed lands were formed in the middle section. Recently, erosion in some coastal zones is quite serious because of excess groundwater extraction, especially along the southwestern coast. Groundwater extraction might also induce land subsidence. There are some areas near the coast which suffer serious land subsidence problems.     

Assessing vulnerability to sea-level rise using a coastal sensitivity index: a case study from southeast Australia

Many of the world’s coasts appear vulnerable to the impacts of climate change and sea-level rise. This paper assesses the application of a coastal sensitivity index (CSI) to the Illawarra coast, a relatively well-studied shoreline in southeast Australia. Nine variables, namely (a) rock type, (b) coastal slope (c) geomorphology (d) barrier type (e) shoreline exposure (f) shoreline change (g) relative sea-level rise (h) mean wave height and (j) mean tide range, were adopted in calculation of the CSI (the square root of the product of the ranked variables divided by the number of variables). Two new variables, shoreline exposure and barrier type, were trialled in this analysis and the extent to which these increased the discriminatory power of the index was assessed. Four iterations of the CSI were undertaken using different combinations of ranked variables for each of 105 cells in a grid template, and the index values derived were displayed based on quartiles, indicating sections of coast with very high, high, moderate and low sensitivity. Increasing the number of variables increased the discriminatory power of the index, but the broad pattern and the rank order were very similar for each of the iterations. Rocky and cliffed sections of coast are least sensitive whereas sandy beaches backed by low plains or dunes record the highest sensitivity. It is difficult to determine shoreline change on this coast, because individual storms result in substantial erosion of beaches, but there are prolonged subsequent periods of accretion and foredune rebuilding. Consequently this variable is not a good indicator of shoreline sensitivity and the index is unlikely to provide a clear basis for forecasting future recession of beaches. The results of this study provide a framework for coastal managers and planners to prioritize efforts to enhance the resilience or consider adaptation measures in the coastal zone within a study region. Sensitivity of the coast if considered in conjunction with other social factors may be an input into broader assessments of the overall vulnerability of coasts and their communities.     

The Coastal Environmental Characteristics of Taiwan

There are three major factors affecting the coastal environment in Taiwan: tidal current, long-shore current and land subsidence. in Taiwan, most industrial areas are located on the southwestern coast. Most of the pollutants from the factories are discharged directly to the ocean, harbours or rivers. the pollutants in harbours or rivers will eventually be delivered to coastal waters. There, the tidal current is the major force dispersing the pollutants nearshore. the polluted water extends to an area about 5 km on both sides from the discharge source, and within about 3-4 km off-shore. in this study, Hsien-Da Harbour in southwestern Taiwan is cited to explain the effects of tidal current on the coastal environment. the long-shore current induced by breaking waves is the major force shaping the coastal morphology. Along the western coast of Taiwan, the long-shore current mainly flows northward along the southern section, and southward along the northern section. in the last one hundred years, in general, the coast has been eroded along the northern and southern sections of western coast, and some reclaimed lands were formed in the middle section. Recently, erosion in some coastal zones is quite serious because of excess groundwater extraction, especially along the southwestern coast. Groundwater extraction might also induce land subsidence. There are some areas near the coast which suffer serious land subsidence problems.     

Changing morphology of Ghana’s Accra coast

Coastal features in Ghana's Accra coast reflect both past and present processes that have been undergoing changes. These changes are influenced by a range of morphogenic factors such as geology and climatic conditions. These regimes have shaped the coastal geomorphic features through weathering processes that decompose and disintegrate the coastal rock. Sea level rise due to climate change is expected to increase coastal erosion and thus result in rapid changes in shoreline positions. Historic rate of sea level rise in Accra coast is about 2 mm/yr (Ibe & Quelennec, 1989) which is predicted to reach approximately 6 mm/yr in the next century since it conforms to the global change (Armah et al., 2005). This will result in flooding of vulnerable areas and enable waves to break closer inland. The effectiveness of the erosion process is aided considerably by the type of geology. Accra coastal zone has three types of rock in three identified geomorphic regions. They include unconsolidated and poorly consolidated rock along the western region, the Accraian series occupying the central region and the Dahomeyan series in the eastern region. The geology has thus influenced the extent to which the coastal features have changed and the type of cliff that is formed as a result of erosion within the regions. Generally, soft rock coastal features decay more rapidly than those of hard rock and tend to act as sediment sources. Human activities such as dam construction over the Densu River, engineering interventions to check the spread of erosion and sand mining has created sediment deficit which has exacerbated coastal erosion in Accra. Anthropogenic factors are estimated to account for 70-90% of coastal erosion problems in Accra.     

Rates of shoreline change along the coast of Bangladesh

Bangladesh, at the confluence of the sediment-laden Ganges and Brahmaputra Rivers, supports an enormous and rapidly growing population (>140 million in 2011), across low-lying alluvial and delta plains that have accumulated over the past few thousand years. It has been identified as one of the most vulnerable places in the world to the impacts of climate change and sea-level rise. Although abundant sediment supply has resulted in accretion on some parts of the coast of Bangladesh, others are experiencing rapid erosion. We report a systematic assessment of rates of shoreline change over a 20-year period from 1989 to 2009, using Landsat satellite images with pixel resolution of 30 m on the ground. A Band ratio approach, using Band-5 divided by Band-2, discriminated the water line on images that were largely cloud-free, adequately registered, and at comparable tidal stages. Rates of shoreline change were calculated for >16,000 transects generated at 50 m intervals along the entire mainland coastline (>1,100 km) and major islands, using the End Point Rate (EPR) method in the Digital Shoreline Analysis System (DSAS) extension in ArcGIS®. Erosion characterises most of the seaward margin of the Sundarbans in western Bangladesh. Retreat rates of up to 20 m/yr are typical, with little evidence that local devastation of the mangrove fringe by Cyclone Sidr in November 2007 had resulted in uncharacteristic long-term rates of retreat where it made landfall. Erosion exceeded accretion in the Barguna Patuakhali coastal zone, most of which eroded at up to 20 m/yr, but with truncation of the southern tip of the Patharghata Upazila at up to 100 m/yr. In Bhola, erosion at rates of up to 120 m/yr were observed along much of the coast, but in the Noakhali Feni coastal zone, similar rates of erosion were balanced by rapid accretion of the main promontory by more than 600 m/yr. Rates of change were more subdued in the Chittagong and Cox’s Bazar coastal zones of southeast Bangladesh. Islands in the Meghna estuary were especially dynamic; Hatiya Island accreted along some of its shoreline by 50 km² between 1989 and 2009, but lost 65 km² through erosion elsewhere, resulting in the island moving south. Similar trends were observed on adjacent islands. The overall area changed relatively little across the entire coastline over the 20-year period with accretion of up to 315 km², countered by erosion of about 307 km².     

Historical maps and satellite images as tools for shoreline variations and territorial changes assessment: the case study of Volturno Coastal Plain (Southern Italy)

Anthropic pressure has caused severe variations of Mediterranean coastal areas currently hosting about 480 million people. The replacement of natural land covers with crops and urban environment coupled with the reduction of sediment supply to the coast, subsidence, Relative Sea Level Rise and the high frequency of storm events, have caused severe shoreline erosion. In this paper, we stress the key role of historical maps, topographic maps and free satellite images to forecast the rates of coastline changes and to recognize the main features of past landscapes as tools for risk reduction. This data was recorded into a Geographical Information System dedicated to coastal management that allows to compare different coastal zones and elaborate maps. The analysis was applied to the case study of Volturno Coastal Plain (VCP), extending from the town of Mondragone to Patria Lake (Campania Region, Southern Italy). Indeed, the intense territorial modification that occurred between the seventies and eighties, coupled with the exposure to coastal erosion, make the VCP a good test area. The spatial analysis algorithms allowed to outline the main features of past landscapes and how they changed from roman times to present while the coastal evolution (erosion, accretion) and possible future coastal trend was assessed with the Digital Shoreline Analysis System (DSAS) software. Starting from the Bourbon domain, the reclamation caused the first great territorial change (e.g. wetlands were transformed into agricultural lands, regimentation of surperficial water) but the negative effects of antrophic pressure, as the intense urbanization of the coastal belt, emerged in the seventies of the last century. The shoreline position was defined for 9 time intervals (from 1817 to 2012) as the ratio of the distance between two shorelines and the relative elapsed time. Moreover, for the 1957–1998 and 1998–2012 time windows, the shoreline trends were calculated with the weighted linear regression method. The first trend pointed out an intensive erosional phase (mean value: 5 m/yr) for a wide sector close to the Volturno River mouth, the eroded sediment nourished the beaches of other coastal sectors. This phase was related to the reduction of River sediment supply mainly due to the construction of the Ponte Annibale dam on the Volturno River. The second (1998–2012) showed an alternation of erosion and accretion sectors due to a sediment starved condition to deltaic zone and to a sequence of 52 sea protection works in the Gaeta Gulf. Furthermore, the regression values of more recent time interval, was assumed as a scenario to draw the probable shoreline position in 2022. The overlay of this shoreline on the Technical Maps of Campania Region at 1:5000 scale highlighted the urban area that could be exposed to damages.     

Seaward coastal defence: limitations and possibilities

In The Netherlands shoreline retreat is actively counteracted, mostly by means of beach nourishment in which some allowance is made for natural fluctuations. For some parts of the coast, however, a more active socalled ‘seaward coastal defence strategy’ might be more profitable. This applies to coasts with a small dune ridge subject to severe erosion. According to this strategy the morphological system is influenced in such a way that erosion is prevented, which will result in a stable or even an accretion coastline. The effectiveness of the seaward coastal defence strategy has to be compared with maintenance by beach nourishment. The effects on the morphological system, the environment and other interests must also be analysed. Several seaward solutions are possible. In order to gain more insight into the behaviour of these solutions, comparative pilot studies have been executed for the most vulnerable locations. This paper gives an overview of the main conclusions of the pilot studies in comparison with sand nourishment, the main coastal defence measure.     

The status of beaches and shoreline development options on the French Riviera: a perspective and a prognosis

Beach conservation and management on the high-value French Riviera in southeastern France have had mixed fortunes in shoreline economic development strategies over the past half century. Prior to 1965, socio-economic growth related to immigration and tourism resulted in considerable pressure on the coastal zone, leading in particular to beach erosion and degradation of beach environmental quality. Between 1965 and 1980, over 20% of the 132 km-long French Riviera was permanently altered through the implantation of yachting harbours and reclamation fill structures, while beach-based recreation had a rather low ranking as a development choice, except in the two major resorts of Cannes and Nice which exhibit a densely urbanized seafront. On this preponderantly boldrocky coast, the mediocre recreational value inherited by many of the beaches from the regional geologic setting, and from development pressures and earlier errors in coastal management, left them vulnerable to appropriation and so-called ‘valorization’ by yachting harbour and estate developers. Over the last decade, artificial shoreline development has virtually ceased, in response to several more or less interrelated factors. These include relative stagnation of socio-economic growth, increasing development and maintenance costs of yachting harbours, saturation of the yachting harbour market as a result of the burgeoning of new, often cheaper, resorts and of reconversion of commercial and shipbuilding ports to leisure ports in the Mediterranean, more stringent legislation, since 1986, on the implantation of residential and major engineering structures on the coastline, pressure for conservation of the cultural and environmental heritage, and greater demand for beach recreational space. This situation has forced a diversification of shore-based activities, as it has been realised that better managed beaches may balance economic aspirations while contributing to enhanced environmental quality and sensible shoreline conservation. This change in strategy has entailed considerable efforts and money on the improvement of coastal water quality, the provision of amenities for beach-goers, and especially the nourishment of eroding beaches and the creation of several artificial beaches. The extent to which beaches will continue to play a role in the sustainable development of French Riviera resorts will depend largely on the capacity of local authorities to maintain environmental quality in the face of inherited and persistent handicaps such as beach erosion.     

The status of beaches and shoreline development options on the French Riviera: a perspective and a prognosis

Beach conservation and management on the high-value French Riviera in southeastern France have had mixed fortunes in shoreline economic development strategies over the past half century. Prior to 1965, socio-economic growth related to immigration and tourism resulted in considerable pressure on the coastal zone, leading in particular to beach erosion and degradation of beach environmental quality. Between 1965 and 1980, over 20% of the 132 km-long French Riviera was permanently altered through the implantation of yachting harbours and reclamation fill structures, while beach-based recreation had a rather low ranking as a development choice, except in the two major resorts of Cannes and Nice which exhibit a densely urbanized seafront. On this preponderantly bold rocky coast, the mediocre recreational value inherited by many of the beaches from the regional geologic setting, and from development pressures and earlier errors in coastal management, left them vulnerable to appropriation and so-called ‘valorization’ by yachting harbour and estate developers. Over the last decade, artificial shoreline development has virtually ceased, in response to several more or less interrelated factors. These include relative stagnation of socio-economic growth, increasing development and maintenance costs of yachting harbours, saturation of the yachting harbour market as a result of the burgeoning of new, often cheaper, resorts and of reconversion of commercial and shipbuilding ports to leisure ports in the Mediterranean, more stringent legislation, since 1986, on the implantation of residential and major engineering structures on the coastline, pressure for conservation of the cultural and environmental heritage, and greater demand for beach recreational space. This situation has forced a diversification of shore-based activities, as it has been realised that better managed beaches may balance economic aspirations while contributing to enhanced environmental quality and sensible shoreline conservation. This change in strategy has entailed considerable efforts and money on the improvement of coastal water quality, the provision of amenities for beach-goers, and especially the nourishment of eroding beaches and the creation of several artificial beaches. The extent to which beaches will continue to play a role in the sustainable development of French Riviera resorts will depend largely on the capacity of local authorities to maintain environmental quality in the face of inherited and persistent handicaps such as beach erosion.     

Erosion risk levels at the NW Portuguese coast: the Douro mouth—Cape Mondego stretch

The entire northwestern coast of Portugal is undergoing severe erosion and there are several areas at high risk of erosion. Commonly considered as a problem—because it jeopardizes human development along the coast—erosion is indeed a natural process of sediment redistribution. This paper presents a brief analysis of erosion driving forces and the subsequent state of vulnerability that coastal segments between the mouth of the River Douro and Cape Mondego are facing. The paper also discusses erosion risk levels, low or high, and the subsequent questions whether there are populations, economical assets or natural habitats at risk and/or areas prone to coastal flooding. Main challenges and future trends along the study area are identified in the light of understanding the underlying causes of conflicts and what realistically can be achieved given the morphodynamics and hydrodynamic processes, human development established along this coastal segment and the existing policies.     

Anthropic vs. natural shoreline changes along the northern Campania coast,Italy

Analysis of historical cartography, wind direction data, orientation of Volturno River mouth and shoreline changes through time point out a series of morphological changes due both to natural and man-induced processes, which occurred along the Domitia coast (Litorale Domitio) since the second half of the 50s. Meteorological time series analysis showed evidence of a change in wind frequency and direction before and after the second half of the 70s, with almost complete disappearance of wind calm periods. Particularly, after 1975, the angle of wave attack had changed and intensity and frequency increased, thus accelerating coastal erosion in some areas. The morphological response to these environmental changes, likely due to global warming and short climatic crises interacting with anthropic modifications of landscape, resulted in different orientation of the Volturno River mouth which rotated from NW (between the 50s and 70s) to SW (from the mid-70s until the present). Moreover, the NW-SE littoral drift caused a clockwise rotation of the entire coastal segment with fulcrum pole close to the river mouth, since the 50s. These findings may allow the assessment of land-use scenarios tuned with evolution trends in order to properly address planning of these reactive and dynamic landscapes.