Coastline management in The Netherlands: human use versus natural dynamics

The boundary between land and sea in The Netherlands changes continuously. Every kilometre of the present position of the Dutch sandy coastline is the result of the interface between natural dynamics initiated by the sea and man-made action on land. Before 1990, each year ca. 20 ha of dunes disappeared through coastal retreat. In 1990 the Dutch government decided to stop any further long-term coastal recession and chose for ‘dynamic preservation’, which primarily aims, at ensuring safety against flooding and sustainable preservation of the values and interests attached to the dunes and beaches. Five years later, a first review of the benefits and bottlenecks of the new coastal defence policy could be presented. The overall conclusion is that the 1990-choice for dynamic preservation was right. The considerable losses of dunes and beaches do not occur any longer. Sand nourishment is an effective method of coastline maintenance, which also serves the functions of the beach and dune area for human society. However, serious erosion of the deeper part of the shoreface threatens the coastline of the 21st century. Nearly a doubling of the nourishment volume is necessary to prevent a renewed landward shift of the coastline. An anticipated accelerated sea level rise (ca. 60 cm/century) will increase the sand losses by another 25%. Plans are being finalized for large-scale land reclamation in front of the coastline as an answer to growing spatial problems on land. In other plans polders, now safely protected by sea dikes, will be returned to the sea in order to restore ecologically valuable salt marshes and mud flats. The position of the coastline will continue to change in the coming decades. Besides natural dynamics, human use of the coastal zone will certainly affect this process: measures to maintain the coastline at its 1990 position need to be seen in perspective: the coastline as a part of the coastalzone.     

Developments in Dutch coastline management: Conclusions from the second governmental coastal report

In 1990 the Dutch government decided to stop any further long-term landward retreat of the coastline. This policy choice for a ‘dynamic preservation’ is primarily aimed at safety against flooding and at sustainable preservation of the values and interests concerning the dunes and beaches. Five years later, a first overview of the benefits and bottlenecks of the new coastal defence policy could be presented, which was published in the second governmental coastal report ‘Kustbalans 1995’ (coastal balance 1995). This consists of three elements: (1) evaluation of the implementation of ‘dynamic preservation’, (2) the consequences of several natural and anthropogenic developments in the coastal zone and (3) integrated coastal zone management. The present report describes experiences of Dutch coastline management and summarizes the main conclusions of the second governmental report. The overall conclusion of the evaluation study is that the 1990 choice for ‘dynamic preservation’ was right. Sand supply is an effective method of coastline maintenance, which also serves functional uses in the beach and dune area. However, nearly a doubling of the supply volume is necessary to compensate for sand losses in the coastal zone. A more integrated management of the coastal zone is necessary to find an equilibrium between the interests of socio-economic development and the maintenance of a natural, dynamic system.     

Developments in dutch coastline management: Conclusions from the second governmental coastal report

In 1990 the Dutch government decided to stop any further long-term landward retreat of the coastline. This policy choice for a ‘dynamic preservation’ is primarily aimed at safety against flooding and at sustainable preservation of the values and interests concerning the dunes and beaches. Five years later, a first overview of the benefits and bottlenecks of the new coastal defence policy could be presented, which was published in the second governmental coastal report ‘Kustbalans 1995’ (coastal balance 1995). This consists of three elements: (1) evaluation of the implementation of ‘dynamic preservation’, (2) the consequences of several natural and anthropogenic developments in the coastal zone and (3) integrated coastal zone management. The present report describes experiences of Dutch coastline management and summarizes the main conclusions of the second governmental report. The overall conclusion of the evaluation study is that the 1990 choice for ‘dynamic preservation’ was right. Sand supply is an effective method of coastline maintenance, which also serves functional uses in the beach and dune area. However, nearly a doubling of the supply volume is necessary to compensate for sand losses in the coastal zone. A more integrated management of the coastal zone is necessary to find an equilibrium between the interests of socio-economic development and the maintenance of a natural, dynamic system.     

Implications of sea level rise for coastal dune habitat conservation in Wales,UK

The potential impact of future sea level rise and climate change on 15 Welsh coastal dune systems has been investigated. Historical Trend Analysis was undertaken using Ordnance Survey maps to quantify past shoreline change and to permit extrapolation of past trends to predict possible future shoreline positions by 2080–2100. Predictions were also made using the Bruun Rule relationship between sea level rise and shoreline response and an integrated method of assessment, Expert Geomorphological Assessment (EGA), which provides a ‘best estimate’ of future coastline change, taking into account such factors as geological constraints, the nature of past, present and future environmental forcing factors, and known coastal process–response relationships. The majority of the 15 systems investigated experienced a net increase in dune area over the last 100–120 years. Only one (Whiteford Burrows) experienced significant net area loss (>5 ha). EGA predictions suggest that several systems are likely to experience significant net loss of dune habitat over the next century, whilst continued net gain is likely to occur for systems where sediment supply rates remain high. Little net change is predicted in some systems. Considering the 15 dune systems together, it is considered unlikely that net dune habitat loss will exceed net gain over the next 100 years provided that there are no major disruptions to sediment supply and natural coastal processes.     

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.     

Sustainable coastal communities in the age of coastal storms: Reconceptualising coastal planning as ‘new’ naval architecture

Hurricanes devastated the Gulf coast of the USA in 2005. Hurricane Katrina, in particular, highlighted the compelling need to build more sustainable and hazard-resilient communities. Much can be learned from recovery efforts to rebuild the Gulf coast. Personal observations and interviews with planners, academics and others involved in recovery efforts inform this analysis, which focuses on New Orleans. A conceptual framework is developed and principles and operational imperatives outlined to guide action for building sustainable, hazard-resilient communities. Such communities will remain elusive unless ‘business as usual’ is confronted by a transformational process of developmental planning. Sustainable, hazard-resilient coastal communities are founded upon robust ‘critical infrastructure’ that is secured by planning and decision-making processes that enable coastal communities to build ‘layers of resilience’ to overcome ‘waves of adversity’. Planners need to take on a redefined role—as ‘new naval architects’—to design and build communities that are ‘sea-worthy’ in this age of coastal storms.

Atlantic storminess and historical sand drift in Western Europe: implications for future management of coastal dunes

Historical records of sand drift and dune-building along the coastline of Western Europe provide insights into the natural processes of sand dune accretion and both the impacts of, and human responses to, sand incursions. The analysis of documentary records, instrumental data and proxy records over the last 1,000 years indicates that this period, which included the Little Ice Age (AD 1570–1900), featured numerous episodes of sand drift and dune development driven by strong winds associated with Atlantic storms. It is estimated that sand drift affected over a quarter of a million hectares of coastal land in Western Europe. The widespread use of vegetation to stabilise coastal dune systems and prevent sand drift is documented across Europe from AD 1100 and by the start of the 20th century all of the larger coastal dune systems in Portugal, France, Britain and Denmark were comparatively inactive. Given that Atlantic storminess has remained more or less unchanged over the last 200 years, modern dune management strategies which consider dune devegetation, driven by an increasing focus on ‘naturalness’, may give rise to a recurrence of sand drift problems. Predictions of increased storm frequencies by the end of the 21st century, coupled with sea level rise and potential changes in sand supply will present further challenges for the more ‘dynamic’ dune management strategies.     

Ecological responses to reductions in freshwater supply and quality in South Africa’s estuaries: lessons for management and conservation

Fresh water, a fundamental element of all estuarine ecosystems, is South Africa’s most limited natural resource. Recent projections indicate that by the year 2020 the country will be utilizing all its exploitable freshwater sources. Steeply increasing demands by a rapidly growing population on this limited commodity have already resulted in a severe reduction of water supplies to natural users such as estuaries — this trend is predicted to increase in the future. Concurrent with excessive water abstraction, poor land husbandry (e.g. soil erosion) in many catchment basins and pollution (e.g. salinization) in return flows have led to a serious deterioration in water quality. In contrast, a review of estuarine responses to varying flow regimes stresses the strong dependence of local systems on riverine fresh water inputs of adequate quantity and quality. Freshwater dependence is i.a. expressed in: flooding events that scour accumulated sediments, riverine nutrient input to drive estuarine phyto- and zooplankton production, axial salinity gradients that increase habitat and species diversity, and maintenance of open tidal inlets that prevent salinity and temperature extremes and facilitate larval exchange, fish migrations and tidal flushing of salt marshes. Thus, estuarine conservation will have to encompass management of rivers and watersheds and play an increasingly political role in decision processes concerning water allocations among ‘human’ and ‘natural’ users.     

Dynamic preservation of the coastline in the Netherlands

In 1990, the Government and Parliament of the Netherlands decided on a new national policy for coastal defence. To ensure the enduring safety of the low-lying polders as well as the sustainable preservation of the coastal dunes, it was decided to maintain the coastline in its 1990 position. The main method for coastline preservation in the Netherlands is beach nourishment. Since 1991, approximately 7 million m³ of sand is added to the Dutch beaches annually. From an evaluation study of sand nourishment projects it is concluded that nourishment is an effective and efficient method to preserve the coastline. The evaluation study also proves that nourishment projects should be ‘tailor-made’, taking the local morphological and hydraulic conditions into account. The first results of an experimental shoreface nourishment are discussed. The choice for nourishment as the principal method to combat erosion is well in line with the intention to restore the natural dynamics of the dune-coast in the Netherlands. The key probably is a less strict policy with regard to the maintenance of the foredunes. Plans for the development of typical coastal features such as slufters^*, wash-overs, blow-outs and mobile dunes are currently under discussion. A slufter is a breakthrough in the first dune-ridge whereby the sea invades former dune slacks or beach plains situated behind the duneridge. In this way a tidal marsh is formed within the dune zone.     

A ‘coastal-hazard GIS’ for Sri Lanka

Following the 2004 tsunami disaster in Sri Lanka, it was apparent that mapping the coast’s vulnerability was essential for future protection of the local populations. We therefore developed a prototype ‘Coastal-hazard GIS’ for Sri Lanka so as to provide an effective tool for decision makers to limit the impact of natural coastal hazards such as sea level rise, tsunamis, storm surges and coastal erosion, and thus protect the exposed assets (population, property, settlements, communications networks, etc.). The prototype was developed on a pilot site in Galle through building up homogeneous data on the land/sea interface from studies conducted on the exposure of the coastal populations, the aim being to enable an evaluation of the hazards combined with the vulnerability and thus an analysis of the risks. Coastal risk scenarios are developed so as to estimate the impacts and consequences of an event (tsunami, storm, etc.) on the assets, the principle behind this being that if, in general, the coastal hazard cannot be decreased, then a better knowledge of it through simulation should make it possible to limit the vulnerability and thus the risk. The Coastal-hazard GIS will also provide a planning tool in terms of locating new settlements, expanding urban areas, siting coastal protection works, etc.     

On the integrated modelling of coastal changes

This paper introduces a possible approach to integrated modelling of coastal change, focusing on coastal land use and cover change. Some of the mostimportant open issues in the context of integrated modelling of coastal change are introduced. The paper focuses on methdological aspects. Specific reference is made to Physiographic Unit Modelling as an approach to better handle spatial variability and ‘morphogenesis’, and as a way to focus on coastal change mechanisms instead of absolute coastal dynamics for achieving an important simplification of the problem. The application is briefly discussed with reference to a ‘minimal model’. The methodological structure introduced is considered particularly suitable to represent, according to a variable degree of simplification, the integrative dynamics between resources and uses of the resources.     

Managing mangroves in Bangladesh: A strategy analysis

Bangladesh, favoured by a tropical climate, houses the world’s largest stretch of mangroves forests (Sundarbans Reserved Forest) and plantations. Around half of the forests of the country occur in the coastal zone. People extract various goods and services from the mangroves. Nevertheless the mangrove forests are depleting. Although the extent of the Sundarbans forest has not changed much, its decline is of a qualitative nature. Mangrove plantations are increasing in area but they are losing growing stock. To arrest this, Bangladesh has adopted several strategies. The ‘Sustainable Ecosystem Management’ strategy has now been adopted instead of the ‘Sustained Yield Principle’. Biodiversity conservation and enhancement has been taken as a key management goal. A zoning system is being developed for both production and protection purposes. The government facilitates alternative income for the local people by generating activities for the communities which are dependent on the forest. Different non-governmental organizations collaborate with the government in reducing the local people’s dependence on the forest. Coastal plantations are erected to protect people from cyclones and to make the land more suitable for habitation. Through this greening of the coastal belt tree plantation is encouraged in coastal villages. Coastal embankments are being planted and leased to poor settlers in exchange for routine maintenance of the embankments. Plantations on newly accreted mud flats help in stabilizing the land, which can later on be settled by victims of erosion elsewhere. These adopted management measures do not only contribute to forestry resource management but also to the social, environmental and economic wellbeing of the coastal communities. These efforts are at present being integrated into an Integrated Coastal Zone Management (ICZM) project.     

Towards a Coastal Area Management Act for the Russian Federation

Coastal area management should be considered as an element of a more general philosophy—that of natural resource management—which is in the process of replacing the purely ‘protection of the environment’ approach which was dominated most of the 20th century. Specific legislation on coastal management has been adopted by many countries, and today steps have been taken to acumulate all experience accumulated and to harmonize legal regulations on the international level. For the Russian Federation, formerly the Soviet Union, with an enormous sea-shore line to cope with, it is a new experience to develop a concept and a legal regulation specifically tackling coastal area management. The draft of a legislative act on coastal area management reflects the attempts to find ways for harmonizing various economic, environmental and social interests in this huge area, encompassing relevant Russian legislation in force as well as international conventions and treaties, and taking into considerations and treatices, and taking into consideration foregin expereience in this field.     

On the shoals of giants: natural catastrophes and the overall destruction of the Caribbean’s archaeological record

In this paper I review a host of natural and cultural processes that have affected the preservation and integrity of archaeological sites on islands in the West Indies, many of which are located in low-lying coastal areas. Given the position of the Caribbean lithospheric plate—juxtaposed between four others—it is no surprise that by its very nature the region is volcanically active and frequently associated with earthquake and tsunami events. This makes coastal zones, and related archaeological sites in the region, highly susceptible to a wide range of destructive natural events. The high frequency of tropical systems (hurricanes and storms) in the Caribbean and rising sea level, coupled with human activities such as sand mining, development, and looting, makes the region’s archaeological record one of the most vulnerable and threatened in the world. Ongoing research is dedicated to understanding how past populations may have been affected by these events in the past.     

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.     

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.     

GIS assessment of coastal vulnerability to climate change and coastal adaption planning in Vietnam

Vietnam’s coastal zone provides a diverse range of natural resources and favourable conditions for social and economic development. However, its coastal ecosystems are highly vulnerable, due to several natural coastal hazards, over-exploitation and other human activities. In spite of diverse interventions, Vietnam’s coastal zone continues to experience significant damage from floods, erosion and typhoons. These hazards are being intensified by climate change and associated rising sea levels. This paper assesses the potential vulnerability of Vietnam’s coast to climate change and discusses possible adaptation policies and plan to reduce the impacts. GIS analysis was used for the assessment of coastal vulnerability. Related literature was reviewed to develop detailed understanding of coastal adaptation to climate change. Adaptation policies and plans were appraised to identify potential coastal adaptation policies and plans that could be adapted by Vietnam. It was identified that vulnerability of the coastal zone of Vietnam could not be attributed only to climatic factors, but also to the physical condition of the coastline. Much of Vietnam’s coastline, particularly, areas around the Red River delta and the Mekong River have elevations below 1 m. These coastlines are largely developed and serve as economic centres of the country, which makes the coast more vulnerable to climate change and the rising sea level. The paper concluded that a non-structural approach (coastal buffer zones, building houses on stilts, storm warning systems, growing of flood-resistant crops and elevated storm shelters with medicine and food storage) could be used by Vietnam to adapt her low-lying coastline around the two deltas to climate change as this strategy enables vulnerable areas to be occupied for longer before eventual retreat. However, for these policies to be successful, it should be planned, implemented well in advance, monitored and evaluated over time.     

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.     

Application of a ‘bio-engineering’ technique to protect ghoramara island (Bay of Bengal) from severe erosion

Ghoramara Island is located ca. 150 km south of Kolkata, Bay of Bengal, India, in the Sundarban Delta complex. This sparsely populated island is suffering from severe coastal erosion and areal reduction for the last three decades, which results in the loss of major areas on the northwest coast. Both numerous households and a significant area of agricultural land and coastal stretches for fish drying have been lost. This has rendered thousands of people homeless as ‘environmental refugess’. In the present paper an attempt is made to study the erosion and accretion process through time series analysis using a GIS technique. Also, a study of remedial measures to protect the island using a ‘bio-engineering’ technique is reported in this paper. It has been shown that, in the absence of protection measures, the eastern shore will merge with the Indian mainland during the next 25 years, while the western part will be completely washed off.     

Coastal setbacks for the Mediterranean: a challenge for ICZM

Coastal development along the Mediterranean coast needs to be tackled with an integrated approach, in order to safeguard people and properties from extreme events, maintain environmental flows and ecosystems functions, protect coastal landscapes and ensure public accessibility to the shore. The complexity of the Mediterranean countries legal and administrative framework and its morphological heterogeneity make the implementation of new the Protocol on ICZM provisions on coastal setbacks,—claiming for a 100 m wide buffer zone where construction is not allowed— a challenge for the success of the initiative. European countries and the European Commission are party to the protocol but the European legal framework lacks of specific provisions addressing the definition of coastal setbacks. Moreover, climate change, in terms of sea level rise and maritime climate, could play a major role in the future position of setback lines. While arbitrary setbacks should be put in place to halt short-term unwise coastal development, science can improve the identification of coastal setbacks by providing integrated methodologies to be implemented at the local level. The objective of this paper is to review concepts and practices in the use of coastal setbacks, in the context of the provisions of the ICZM protocol and taking into account new challenges posed by climate change. A stepwise route map is proposed as a base to identify coastal setbacks, applicable to the Mediterranean region and elsewhere, to be used as a base to improve arbitrary setback approaches.