Assessment of coastal erosion susceptibility at the national scale: The Italian case

To improve the present national and local sustainable planning capability for the coastal zone a GI application for the Italian Coastal Susceptibility Assessment was planned within an institutional agreement between ENEA and the Land Defence Service of the Italian Ministry of Environment. Taking into account previous European actions a suitable methodology to assess, in a quantitative way, the susceptibility of beaches to be eroded has been set up. The methodology balances the coastline trend as evaluated for a defined time period with the present coastal areas morphology and land use, this in order to derive a value that expresses the evolutionary process in terms of probability of the loss of goods within the ‘Homogeneous Coastal Tracts’. The trend in the movement of the sea-land line has been used asgeo-indicator of a complex dynamic balance that refers both to marine and inland systems, and a vector GI application was built and locally applied in southern Italian coastal areas. The present shoreline position and some other information describing the intrinsic beach morphologies, and having significance for the coastal erosion hazard assessment, have been derived from the national 1∶10.000 ortho-images of the National Cartographic Reference System provided by the Italian Ministry of Environment. The illustrated GI application— CoSTAT—keeps the nominal scale of all data collected or produced. In this analysis the coastal dune presence is analysed as factor limiting coastal erosion susceptibility. Applying a matrix calculation a quantitative evaluation of erosion susceptibility degree was achieved and plans were made to develop new information for a suitable use of Italian coastal areas. The work describes the methodology, the conceptual frame-work and the results of a local application.     

Portuguese coastal zones and the new coastal management plans

Coastal zones in Portugal, as interface areas between land and sea, have problems related to the growing human pressure in terms of changes in land use associated with urban and industrial occupation, new accessibility (ports, motorways) and traffic flows, intensification of recreational use (beaches, water sports) and excessive fishing. Impacts include deterioration of water quality and sediments; alteration and degradation of natural habitats; new hydrodynamic situations; major landscape changes: and rapid changes in habits and way of life of the local populations and increased exposure of populations and assets to natural and induced risks (storms, accidents, spills, explosions). Plans for the Management of the Coastal Zone (POOC) have been developed and seven of them have been approved, while two similar plans are at a final stage of preparation. Together they cover the entire coast of Portugal. Their implementation and assessment could be a first step towards an integrated management of the Portuguese coastal zones. River Basin Management Plans (PBH) have been concluded and recently approved for the whole country. However, these plans do not consider estuarine systems and some other issues related to coastal systems. The National Water Plan (PNA) is under public presentation and discussion. Several ‘key messages’ are presented in this paper as a contribution for assessment of the proposals of this plan on issues related with coastal waters.     

Integrated shoreline management and tourism development on the cross-border World Heritage Site: A case study from the Curonian spit (Lithuania/Russia)

The varied and very dynamic landscape with a high biological diversity is a distinctive feature of the Curonian spit at the regional scale. Throughout the 20th century the main morphodynamic trend in the littoral of the Curonian spit was shoreline grading on the lagoon side, whereas on the marine side the increasing erosion at the foot of the spit, and increasing accretion at the head of the spit prevailed. The results of a discriminant analysis (Wilkes’ λ = 0.001626 and F = 29.267 when p < 0.001) show that sites with prevailing erosion, accretion and sediment input from the drifting dunes form regular inter-related spatial structures in the littoral with distinctive resulting discontinuities of the sediment drift along the lagoon coast. Dune littoral cells are characterized by Aeolian sediment input and distribution ‘down-drift’, (usually northwards) from the source. The most likely changes in the current development trends of the lagoon shore zone of the Curonian spit are related to expected climate changes and further slowing down of the dune drift. The probability of storms and ice-drift events, and their impact on coasts is expected to increase as a result of climate change. The dune advance will gradually slow down, and with it, the sand input to the coastal zone will decline. In this paper, we define integrated shoreline management as a system of long-term shoreline management measures, which is based on a littoral cell approach and aimed at harmonizing human activity in the coastal zone with the natural development of the shoreline. We propose an integrated management program for the lagoon shoreline of the Curonian spit, which is site-specific for each littoral cell as a coastal management unit. Drifting dunes and seaside beaches are the natural amenities, which are best known and best appreciated on the Curonian spit by 49% of the respondents representing the total Lithuanian population. A responsible tourism development should be considered as the key means for proper appreciation of the drifting dunes and natural coasts by society, which means to acknowledge and cherish the aesthetic and conservation values of dune and coastal landscapes of the Curonian spit as a World Heritage Site. There are at least two pre-conditions for this: (1) to provide visitors with sufficient information about diverse values and functions of the Curonian dunes and coasts within a broader regional and global heritage conservation context; (2) to enable tourists to enjoy the most impressive dune and coastal landscapes at close range. In this paper we propose to encourage active dune tourism, to reintroduce grazing into the Curonian dune areas, to restore and to preserve the most impressive landscapes of the highest white drifting dunes by bringing the blown out sand from the leeward foot of the dunes back to the crest artificially.     

Management of the belgian coast: Opinions and solutions

Since the beginning of the 20th century the Belgian coast has undergone important changes of which an overview is presented here. To determine the view of the Belgian public on the Belgian coast and in order to obtain their opinions and solutions to the problems along the Belgian coast, a questionnaire survey was conducted with a total of 100 respondents divided into five groups, all active in the coastal zone. The five groups included (1) politicians on various levels of authority, (2) coastal entrepreneurs and business people, (3) naturalists and scientists, (4) coastal residents and (5) tourists. Coastal zone problems, as perceived by the different groups, and their solutions are discussed. Former municipalities, in particular, were held responsible for the current coastal problems. Most respondents were skeptic about the application of recent juridical instruments (e.g. the Dune Decree), the structural plans and their power to protect the remaining natural areas. The root of the problems seems to lie in lack of coordination and communication between different authorities responsible for the coastal zone.     

Towards a common Mediterranean framework for beach nourishment projects

Integrated Coastal Zone Management as a strategy for achieving conservation and sustainable multiple use of the coastal zone includes various types of management initiatives. Due to natural phenomena such as tides and winds and to social and economic activities, coastal areas undergo transformation. Coastal erosion and the disappearance of beaches as a result of wrong planning decisions and lack of effective legislation are among the most damaging effects and to reverse them requires application of a series of engineering techniques. Beach nourishment projects as a way towards shore protection and utilization through recreational purposes in the Spanish and Italian coasts are noteworthy in this respect. In beach nourishment projects, the roles of various entities, both public and private, should be clearly indicated and in the evaluation and execution stage a series of questions should be answered for the successful completion of any nourishment project. Past projects in the Mediterranean and experiences from recent Italian projects in Anzio and Nettuno confirm this. For example, dredging of the entrance channel of the port of Anzio enabled middle-sized ferryboats once again to enter the port (which had not been possible before). This will in turn increase the tourism potential of the town. Nourishment of two beaches at these sites prevented further erosion and provided more area for recreational purposes. Expected economic contribution of beach nourishments to the regional authority was estimated for Nettuno and Anzio; the resulting theoretical payback period was found to be 3 yr for the former and 15 yr for the latter.     

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.     

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.     

Modelling of coastal vulnerability in the stretch between the beaches of Porto de Mós and Falésia, Algarve (Portugal)

Coastal systems are characterized by high geophysical and biophysical sensitivity as being their massive occupation a serious issue concerning their self-regulation. Worldwide coastal areas are exposed to problems such as coastal erosion, degradation and destruction of marine habitats, pollution and rising sea level. Thus, it is crucial to design models of coastal vulnerability assessment to ensure a better management of coastal areas. This study characterizes the vulnerability of the coastal stretch between the beaches of Porto de Mós and Falésia in the Algarve, corresponding to 52?km of the south coast of Portugal. The expansion of urban areas was modelled using a Cellular Automata (CA) based approach. Results show that 65% of the coastal stretch has high and very high vulnerability caused by both physical and human factors. Results further indicate that urban growth may interfere with the natural evolution of the coastal geomorphology. The scenario of urban expansion for the year 2015 highlights the need to develop effective urban planning processes to ensure a correct balance between the geophysical resilience of coastal systems and the promotion of the coastal sector as a strategic asset for the regional and national economy.     

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.     

A GIS-based vulnerability assessment of coastal natural hazards,state of Pará, Brazil

Studies carried out in the NE coastal zone of the State of Pará (Brazil) have recorded, in the last 25 years, numerous evidence of natural impacts of the flood and erosion processes. As a consequence, diverse strategies and measures of population adaptation have been implemented but with limited success. Therefore, in order to subsidize the Coastal Zone Management Program of Pará, this paper aims to identify, assess and classify natural and socio-economic vulnerabilities of this coastal zone by means of a Geographical Information Systems (GIS)-based composite coastal vulnerability index (CVI). In spite of the data problems and shortcomings, using ESRI’s Arcview 3.2 program, the CVI score, to classify, weight and combine a number of 16 separate natural and socio-economic variables to create a single indicator provides a reliable measure of differences (5 classes) among regions and communities that are exposed to similar ranges of hazards. The results are presented in three maps referred to as Natural, Socioeconomic and Total Vulnerability. The confidence associated with the results obtained, the need to utilize another variables, and to frequently update the ones used already were analyzed and discussed.     

Coastal zone management challenges in Ghana: issues associated with coastal sediment mining

Coastal erosion is a serious environmental problem that has caused the loss of private infrastructure and national assets along Ghana’s coast. Several hard engineering measures have thus been used to protect some communities and vital state assets when they became threatened. Regardless of this problem, sediment mining activities are increasingly practiced along most of Ghana’s coast, further exacerbating coastal erosion intensity and degrading coastal ecosystems. This paper provides an overview of the activities of coastal sediment miners along four administrative Districts in the Central Region of Ghana and identifies how issues arising from the practice are managed at the local community level as well as by state environmental regulators. The study uses a mixed-method approach, involving individual and group interviews, administration of a set of structured questionnaire and field observations, to identify coastal sediment mining and emerging management issues. Overall, three main categories of coastal sediment mining activities were identified in the area. Results indicate that coastal sediment mining is widely practiced by both commercial contractors and community members, giving rise to the high perception among residents that it is the reason for the degradation of the coastline in the studied areas. The study also established that state environmental regulators have weak inter-agency cooperation leading to poor enforcement of environmental laws and non-prosecution of offending individuals. The paper suggests that since each identified sediment mining activity has its own peculiar issues and mode of operation, coastal managers should address each category independently in order to derive lasting impacts in curtailing the practice.     

Coastal directories and beyond: Providing multidisciplinary coastal zone resource information for resource management

Baseline resource information in an easily accessible form is a vital starting point for developing coastal zone management. On behalf of a wide-ranging group of organizations involved in the management of the U.K. maritime zone, the Joint Nature Conservation Committee (JNCC) is compiling a series of 16 regional volumes. The volumes contain multidisciplinary coastal zone resource information arranged in ten chapters under the general title ‘Coasts and Seas of the UK’. These volumes form part of a series of paper and electronic publications of coastal information being produced by JNCC's Coastal Directories Project and are designed to meet the needs of planners and all others involved in decision-making and management of the coast.     

Coastal directories and beyond: providing multidisciplinary coastal zone resource information for resource management

Baseline resource information in an easily accessible form is a vital starting point for developing coastal zone management. On behalf of a wide-ranging group of organizations involved in the management of the U.K. maritime zone, the Joint Nature Conservation Committee (JNCC) is compiling a series of 16 regional volumes. The volumes contain multi-disciplinary coastal zone resource information arranged in ten chapters under the general title ‘Coasts and Seas of the UK’. These volumes form part of a series of paper and electronic publications of coastal information being produced by JNCC’s Coastal Directories Project and are designed to meet the needs of planners and all others involved in decision-making and management of the coast.     

Assessment of shoreline changes over the Northern Tamil Nadu Coast,South India using WebGIS techniques

Coastal zone is often vulnerable to natural hazards such as cyclones, storm surges, tsunamis, erosion, accretion, and coastal flooding; and man-made hazards like ports, jetties, seawalls, breakwaters, and groins. These disasters are frequently affecting the shorelines, beaches, and headlands that lead to loss of human life, properties, and natural ecosystems. To prevent further loss in the coastal zone and to conserve the existing natural resources, it is important to map and monitor vulnerable shorelines at frequent time intervals. The current study, conducted over the Northern TN (Tamil Nadu) coast of India, is highly dynamic due to its nature of coast and shoreline changes. The temporal remote sensing data and Survey of India (SOI) topographic maps over the period of 40 years (i.e., 1976–2016) were used to capture shorelines and then the erosion and accretion from the shorelines were assessed by performing the overlay analysis. These geospatial datasets of shorelines were incorporated into WebGIS platform, which was developed and demonstrated using open source software. This latest WebGIS technology allows users to store a large volume of geospatial datasets in the server and access through internet with a web browser that lead to manipulation, visualization, interaction, and dissemination. The results revealed that there were 61 layers, which include district-wise shorelines, erosion, and accretion for Tiruvallur, Chennai, and Kanchipuram. These geospatial datasets in WebGIS showed that the dynamism on the morphological structure of the shorelines, over the Northern TN lost 1,925 ha and gained 1,578 ha due to erosion and accretion, respectively. It is reported that in this study spatial reduction in the coastline may be attributed to natural and anthropogenic activities. However, this research will be useful for various stakeholders, including coastal management authorities to formulate policies and to regulate the coastal development activities.     

Physical damage to coastal dunes and ecological impacts caused by vehicle tracks associated with beach camping on sandy shores: a case study from Fraser Island,Australia

As coastal populations expand, demands for recreational opportunities on beaches and coastal dunes grow correspondingly. Although dunes are known to be sensitive to direct human disturbance and provide irreplaceable ecosystem services (e.g. erosion control, critical habitat and nesting sites), dunes serve as campsites for large numbers of people (∼90,000 p.a.) on the ocean-exposed shores of Fraser Island, Australia. Campsites are located in the established dunes and can only be accessed with 4WD vehicles along tracks cut directly from the beach through the foredunes. Here we quantified the extent of physical damage to foredunes caused by this practice, and tested whether human-induced physical changes to foredunes translate into biological effects. Of the 124 km of ocean-exposed beaches, 122 km (98%) are open to vehicles driven on the beaches, and camping zones cover 28.7 km or 23% of the dunes. A total of 235 vehicle tracks are cut across the foredunes at an average density of eight tracks per km of beach. These tracks have effectively destroyed one-fifth (20.2%) of the dune front in camping zones, deeply incising the dune-beach interface. There is evidence of accelerated erosion and shoreline retreat centred around vehicle tracks, resulting in a “scalloping” of the shoreline. No dune vegetation remains in the tracks and the abundance of ghost crabs (Ocypode spp.) is significantly reduced compared with the abutting dunes. Because current levels of environmental change caused by dune camping may not be compatible with the sustainable use of coastal resources and conservation obligations for the island (listed as a World Heritage Area and gazetted as a National Park), restoration and mitigation interventions are critical. These will require spatial prioritisation of effort, and we present a multi-criteria ranking method, based on quantitative measures of environmental damage and ecological attributes, to objectively target rehabilitation and conservation measures. Ultimately, coastal management needs to develop and implement strategies that reconcile demands for human recreation, including beach camping, with conservation of coastal dune ecosystems.     

A model for the implementation of ICM in the Mediterranean region

The Integrated Coastal Zone Management (ICZM) Protocol in the Mediterranean means the coastal zone can be better protected and problems can be targeted in a coordinated manner. This research developed a model to improve Integrated Coastal Management (ICM) implementation in the region. The methodology collected data from Mediterranean coastal zone experts via semi-structured interviews and a review of Mediterranean Coastal Foundation ICM Conferences in 2007, 2008 and 2009. Results identified issues and recommended solutions at various points in the policy process and these were used to propose a model for the implementation of ICM. Research demonstrated the need for non symbolic engagement with science especially during the ex-ante, interim and ex-post reports of implementation. Improved and considered horizontal governance and capacity building was highlighted as crucial. Findings also emphasised the importance of legislatively supported bottom-up policy implementation for the Mediterranean to help develop local coastal management ownership. Finally, the particular complexity of coastal policy in an administratively and culturally diverse region was identified as the main difficulty for successful implementation of coastal policies.     

Basis for a national strategy for integrated coastal zone management—in Portugal

This paper includes the proposals made in the report “Basis for a National Strategy for Coastal Zone Management” prepared for the Portuguese Ministry of Environment, Territorial Planning and Regional Development. The final version of that report was presented in June 2006. This paper describes a theme framework followed by a discussion of concepts. Nine Primary Principles, eight Principal Objectives, and 37 Strategic Options for an Integrated Coastal Zone Management are then presented. These Strategic Options are set hierarchically according to their sequential priority, identifying the dominant types of Associated Measures. The analysis of these arrives at a set of Structural Measures, which interlink and aggregate various actions and propose a new method of integrated management for the coastal zone, which includes the “Legal Basis of Coastal Zone”; the Organization System; the Action Plan and Monitoring.     

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.     

Spatial assessment of sea level rise on Martinique’s coastal zone and analysis of planning frameworks for adaptation

Accelerated sea level rise and hurricanes are increasingly influencing human coastal activities. With respect to the projected continuation of accelerated sea level rise and global warming one must count with additional expenses for adaptation strategies along the coasts. On the mountainous island Martinique the majority of settlements are situated along the coast almost at sea level. But potential rises in sea level and its impacts are not addressed in coastal management, even though saltwater intrusion and coastal erosion with increasing offshore loss of sediment are locally already a severe problem. At a sea level rise of 50 cm, one fourth of Martinique’s coastline will be affected by erosion and one fifth of the islands surface will have high probability to get flooded during coastal hazards. This is a growth of 5% of the impact area in comparison to present conditions. This article analyses potential adaptation strategies and argues that the development of a coastal zone management plan considering sea level rise and its impact area is of utmost importance. Empirical assessment models in combination with spatial analysis are useful in obtaining statements about coastal impacts concerning sea level rise. This paper sees itself as recommendation of action not only for Martinique.