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1.
The quantity of coastline retreat resulting from storm erosion is one of the most important phenomena that needs to be accurately quantified to facilitate effective coastal management strategies. Historically, the volume of storm erosion (and coastline retreat) accommodated for coastal planning decisions has been directly linked to the storm (usually defined by considering wave height and duration only) with a certain pre-defined return period, known as a Synthetic Design Storm (SDS) (e.g. 1 in 100 year storm). The SDS method of estimating storm erosion volumes for coastal planning thus assumes that, for example, the 1 in 100 year storm event also results in a 1 in 100 year erosion event. This communication discusses the physical reality of this assumption and demonstrates the improved performance of a new method, based on Joint Probability Distributions (JPD) for estimating storm erosion volumes proposed by Callaghan et al. [Callaghan, D.P., Nielsen, P., Short, A.D. and Ranasinghe, R., 2008. Statistical simulation of wave climate and extreme beach erosion. Coastal Engineering, 55(5): 375–390] using one of the world's longest beach profile surveys from Sydney, Australia.  相似文献   

2.
Coastal hazards are in the interface of human activities with natural coastal processes. The conflicts arising from this relationship require new approaches suitable for coastal management that consider the dynamic of coastal areas. A method to assess hazard in rock cliffs is presented, combining cliff evolution forcing mechanisms along with protection factors, according to a weighted factors system. This method provides a rapid evaluation of vulnerability for cliffed areas, supporting coastal management and hazard mitigation. The method was applied to the rocky cliffs of the densely populated coastal zone between Galé and Olhos de Água (Southern Portugal), where high and very high hazard values were found to be dominant. A method validation was made using the vulnerability areas and the recorded mass movements over a 45 year period in the same area.  相似文献   

3.
《Coastal Engineering》2006,53(4):311-318
The extended mild-slope equations of Suh et al. [Suh, K.D., Lee, C., Park, W.S., 1997. Time-dependent equations for wave propagation on rapidly varying topography. Coastal Eng., 32, 91–117] and Lee et al. [Lee, C., Kim, G., Suh, K.D., 2003. Extended mild-slope equation for random waves. Coastal Eng., 48, 277–287] are compared analytically and numerically to determine their applicability to random wave transformation. The geometric optics approach is used to compare the two models analytically. In the model of Suh et al., the wave number of the component wave with a local angular frequency ω is approximated with an accuracy of O(ω − ω¯) at a constant water depth, where ω¯ is the carrier frequency of random waves. In the model of Suh et al., however, the diffraction effects and higher-order bottom effects are considered only for monochromatic waves, and the shoaling coefficient of random waves is not accurately approximated. This inaccuracy arises because the model of Suh et al. was derived for regular waves. In the model of Lee et al., all the parameters of random waves such as wave number, shoaling coefficient, diffraction effects, and higher-order bottom effects are approximated with an accuracy of O(ω − ω¯). This approximation is because the model of Lee et al. was developed using the Taylor series expansion technique for random waves. The result of dispersion relation analysis suggests the use of the peak and weighted-average frequencies as a carrier frequency for Suh et al. and Lee et al. models, respectively. All the analytical results are verified by numerical experiments of shoaling of random waves over a slightly inclined bed and diffraction of random waves through a breakwater gap on a flat bottom.  相似文献   

4.
Nadarajah [Nadarajah, S., 2008. Letter to the Editor. Coastal Engineering 55, 189–190] pointed out several errors in the paper by Muraleedharan et al. [Muraleedharan, G., Rao, A. D., Kurup, P. G., Unnikrishnan Nair, N., Sinha, M., in press. Modified Weibull distribution for maximum and significant wave height simulation and prediction. Coastal Engineering] which suggested a modified Weibull distribution for maximum and significant wave height simulation and prediction. In response to Nadarajah's [Nadarajah, S., 2008. Letter to the Editor. Coastal Engineering 55, 189–190] comments, Muraleedharan [Muraleedharan, G., 2008. Reply to Saralees Nadarajah. Coastal Engineering 55, 191–193] argued that there were no errors in the original paper by Muraleedharan et al. [Muraleedharan, G., Rao, A. D., Kurup, P. G., Unnikrishnan Nair, N., Sinha, M., in press. Modified Weibull distribution for maximum and significant wave height simulation and prediction. Coastal Engineering]. Here, it is pointed out that the response by Muraleedharan [Muraleedharan, G., 2008. Reply to Saralees Nadarajah. Coastal Engineering 55, 191–193] is at least as incorrect as Muraleedharan et al. [Muraleedharan, G., Rao, A. D., Kurup, P. G., Unnikrishnan Nair, N., Sinha, M., in press. Modified Weibull distribution for maximum and significant wave height simulation and prediction. Coastal Engineering].  相似文献   

5.
The numerical model COBRAS-UC [Losada, I.J., Lara, J.L., Guanche,R., Gonzalez-Ondina, J.M. (2008). Numerical analysis of wave overtopping of rubble mound breakwaters. Coastal Engineering, Vol 55 (1), 47–62.] is used to carry out a two-dimensional analysis of wave induced loads on coastal structures. The model calculates pressure, forces and moments for two different cross-sections corresponding to a low-mound and a conventional rubble-mound breakwater with a crown-wall under regular and irregular incident wave conditions. Predicted results are compared with experimental information provided in Losada et al. [Losada, I.J., Lara, J.L., Guanche,R., Gonzalez-Ondina, J.M. (2008). Numerical analysis of wave overtopping of rubble mound breakwaters. Coastal Engineering, Vol 55 (1), 47–62.] and Lara et al. [Lara, J.L., Losada, I.J., Guanche, R. (2008). “Wave interaction with low mound breakwaters using a RANS model”. Ocean engineering (35), pp 1388–1400; doi:10.1016/j.oceaneng.2008.05.006.] on a 1:20 scale. Good agreement is found, and the differences between both typologies are explained in detail. Additionally, numerical results are also compared with several semi-empirical formulae recommended for design at both the 1:20 model scale and two prototype cross-sections. Results suggest that COBRAS-UC is able to provide realistic stability information that can be used to complete the approach based on currently existing methods and tools.  相似文献   

6.
Dissolved gaseous mercury (DGM) was measured continuously using two newly developed techniques and a manual technique. The continuous techniques were based on the equilibrium between the aqueous and gaseous phase (DGM = Hgextr / H', Hgextr is the measured mercury concentration in the gas phase, H' is the Henry's Law coefficient at the desired temperature). In order to calculate the annual mercury evasion from the Mediterranean Sea, diurnal and seasonal measurements of DGM, total gaseous mercury in air (TGM), water temperature and wind speed were performed. During August 2003, March–April 2004 and October–November 2004 measurements of these parameters were conducted on board the RV Urania. The continuous measurements of DGM showed a diurnal variation in concentration, at both coastal and off shore sites, with higher concentrations during daytime than nighttime. The concentration difference could be as large as 130 fM between day and night. The degree of saturation was calculated directly from the measurements, S = Hgextr / TGM and was found to vary between the different seasons. The highest average degree of saturation (850%) and the largest variation in saturation (600–1150%) was observed during the summer. The spring showed the lowest variation (260–360%) and the lowest average degree of saturation (320%). The autumn also showed a large variation in saturation (500–1070%) but a lower average (740%) compared to the summer cruise. This might be explained by the temperature difference between the different seasons, since that parameter varied the most. The flux from the sea surface was calculated using the gas exchange model developed by Nightingale et al. [Nightingale, P.D., Malin, G., Law, C.S., Watson, A.J., Liss, P.S., Liddicoat, M.I., Boutin, J., Upstill-Goddard, R. C., 2000. In situ evaluation of air–sea gas exchange parameterization using novel conservative and volatile tracers. Global Biogeochemical Cycles, 14(1):373–387]. The evasion varied between the different seasons with the highest evasion during the autumn, 24.6 pmol m− 2 h− 1. The summer value was estimated to 22.3 pmol m− 2 h− 1 and the spring to 7.6 pmol m− 2 h− 1. Using this data the yearly evasion from the Mediterranean Sea surface was estimated to 77 tons.  相似文献   

7.
Coastal erosion and storms represent a source of risk for settlements and infrastructure along the coast. At the same time, coastal natural assets, including landscape, are threatened by increasing development mainly driven by tourism. The Mediterranean coast is especially vulnerable to these processes, considering its high biological and cultural diversity. An additional challenge is represented by climate change, as it will force coastal communities to apply more or less drastic adaptation strategies. Coastal setbacks, used to protect coastal communities and infrastructure from storms and erosion, and to preserve coastal habitats and landscapes from degradation, is one of the main instruments suggested by the Protocol on Integrated Coastal Zone Management of the Barcelona Convention, entered into force on the 24 of March 2011. Its implementation has the potential to influence coastal policies in other regions, such as the neighbouring Black Sea.The CONSCIENCE project has formalized concepts and conducted specific studies to provide new tools for coastal erosion management practice. The objective of this paper is to present a synthesis of the research conducted into coastal setbacks for coastal erosion management and climate change adaptation. This is done by analysing the requirement of the Protocol, current processes and management practices in two case study areas (Costa Brava Bays in Spain and Danube Delta, in Romania) and the new challenges posed by climate change.  相似文献   

8.
《Ocean & Coastal Management》2006,49(7-8):421-441
This paper evaluates governance arrangements in Solomon Islands in terms of their ability to achieve the integrated management of coastal environments. The paper uses a modified version of the framework proposed by Ehler CN [Indicators in measure governance performance in integrated coastal management. Ocean & Coastal Management 2003; 46: 335–345] for evaluating governance performance. The results point to a systemic failure of coastal governance in Solomon Islands. The paper identifies the strategic issues for governance reform if the management of coastal environments and resources in Solomon Islands is to be improved.  相似文献   

9.
Despite many efforts in the past 10 years, Integrated Coastal Management (ICM) evaluation remains much of a challenge. Building on theoretical resources provided by three bodies of work (strategic analysis of environmental management, integrated coastal management and evaluation of public policies), this paper first underlines some of the most critical weaknesses and “black boxes” in current ICM evaluation. It explains why a single purpose program evaluation model is unsatisfactory, and how it hinders evaluation in practice. It then suggests ways to re-think ICM evaluation, proposing a dual-level framework that combines evaluation of ICM initiatives with evaluation of coastal management systems.  相似文献   

10.
《Coastal Engineering》2007,54(6-7):463-475
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11.
Mar Chiquita Coastal Lagoon is located on the Atlantic coast of Argentina, and it has been declared a Biosphere Reserve under the UNESCO Man and Biosphere Programme (MAB). This coastal lagoon constitutes an estuarine environment with a very particular behaviour and it is ecologically important due to its biological diversity. The aim of the present study was to evaluate the distribution and geochemical behaviour of several heavy metals in this coastal system, focusing on their distribution in both the dissolved phase (<0.45 μm) and the suspended particulate matter. Therefore, the general hydrochemical parameters (salinity, temperature, turbidity, pH and dissolved oxygen) and concentration of total particulate and dissolved metals (Cd, Cu, Ni, Zn, Fe, Pb, Cr and Mn) were measured along 2 years (2004–2006) at two different sites. As regards their distribution, hydrological parameters did not present any evidence of deviation with respect to historical values. Suspended particulate matter showed no seasonal variation or any relationship with the tide, thus indicating that in this shallow coastal lagoon neither tides nor freshwater sources regulate the particulate matter input. Heavy metals behaviour, both in dissolved and particulate phases did not reveal any relationship with tide or seasons. Mar Chiquita Coastal Lagoon showed a large input of dissolved and particulate metals, which is probably due to intensive agriculture within the drainage basin of this system.  相似文献   

12.
《Ocean & Coastal Management》2000,43(4-5):389-407
In the early 1990s, integrated coastal management (ICM) in the Mediterranean basin found general acceptance as an important issue both at national and international levels, and since then it has been, though slowly, steadily developed. Donor organizations such as the European Union and the World Bank, and the UNEP's Mediterranean Action Plan played catalyst roles in this development by initiating and supporting pilot projects. In 1992, the European Union launched the Mediterranean programs in by 1999 which the environment, and especially the coastal environment, was considered as a priority issue. Parallel to this development, several NGO initiatives took place for public awareness on pressing coastal issues and in training and education. The idea of MEDCOAST, which is an NGO network of Euro-Mediterranean academic institutions, was born in 1990 and the new initiative was launched in two directions in 1993. One of these was the organization of the First International Conference on the Mediterranean Coastal Environment (2–5 November 1993, Antalya, Turkey), which placed strong emphasis on the management issues. The second was the development of a project proposal to the Med-Campus program of the European Union. The project, which had the title of Educational Programs in Coastal Zone Management, was selected for funding and became operational in early 1994. The first international training program organized by MEDCOAST was the MEDCOAST Institute 94: Coastal Zone Management in the Mediterranean. This three-week long training effort took place in August–September 1994. Since then, MEDCOAST organized eight training programs in by 1999 five different countries, which were participated by 173 professionals representing 31 countries. Development of an international Masters Degree program in ICM was the second goal of the MEDCOAST's Med-Campus project. Efforts for pursuing this goal are still continuing. This paper elaborates the potential for the NGO's contribution to training and education in the field of integrated coastal management in the Mediterranean and the Black Sea by introducing the MEDCOAST experience. It presents the past and planned MEDCOAST efforts and discusses the strengths and limitations of the role of NGOs at the regional scale.  相似文献   

13.
Sediment stability in the shallow Venice Lagoon was investigated by means of numerical modelling. Results from a hydrodynamic model allowed for the determination of the wave climate and bottom effective parameters so that simulations with a Lagrangian model for suspended particulate matter could be performed. A spring–neap cycle in summer 1998 was chosen as integration period since data for calibration and verification were collected within the European project F-ECTS between summer 1998 and spring 1999. Deposition on shallow mud flats as well as short term erosion during a strong wind event were reproduced and mass balances for two areas computed. A relation of patterns of SPM in the water and in the sediment was found and can be ascribed to the displacement of material during storm events from shallow areas to the bottom of very small channels. Assuming about 10 to 14 storm events during the year comparable to the Bora event during the integration time, estimates for long-term trends of sediment loss on shallow flats by Day et al. [Day, J.W., Rybczyk, J., Scarton, F., Rismondo, A., Are, D., Cecconi, G., 1999. Soil accretionary dynamics, sea-level rise and the survival of wetlands in Venice Lagoon: a field and modelling approach. Estuarine, Coastal and Shelf Science 49, 607–628] are met by the simulation results. Evidently, long-term sediment evolution of the lagoon is therefore not dominated by the average (residual) processes that occur in the lagoon, but by the few peak events that happen randomly over the year.  相似文献   

14.
The Tanga Coastal Zone Conservation and Development Programme, initiated in 1994, was among the first such projects to make livelihoods improvement a key objective, and to use a community-based approach. It developed an approach to coastal management planning that is broadly satisfactory to both communities and the government. Six fisheries management areas and two mangrove management areas were established. Institutional arrangements for the collaborative approach were strengthened and community leaders and local government officers were trained in a range of relevant skills. A coastal environmental education programme for primary schools involved several thousand schoolchildren, and a gender programme built the confidence of women. Implementation of the management measures was noticeably harder than planning, particularly elimination of destructive fishing methods. Fishers and coastal communities now however have a much greater involvement in, and understanding of, coastal management and consequently a greater sense of ownership.  相似文献   

15.
Coastal environments are increasingly under threat from multiple stressors and pressure from human activities across the land-sea interface. Managing these pressures from people requires, more than ever, understanding what is at stake in terms of the benefits and values associated with coastal waters. This article presents the results of a choice experiment which was designed to elicit society׳s willingness to pay in the context of economic and environmental trade-offs people to improve coastal water quality. The study site is a coastal Australian city, Adelaide, South Australia. The city discharges a large proportion of its stormwater and treated wastewater to the coastal waters of Gulf St Vincent. Willingness to pay for a package of improvements to urban water management is considerable. A mix of projects that restores 25 days per year of water clarity, seagrass area from 60% to 70% of the original area and five reef areas is worth $AUS67.1 M to households in the Adelaide metropolitan area. The results can inform public policy discussions including the cost-benefit analysis of different water management strategies including investments in urban infrastructure.  相似文献   

16.
Coastal dunes located in densely populated areas provide various services to man, such as protection against flooding during storm surges. Since coastal dunes are dynamic features, the level of protection they provide varies in time. Therefore, management interventions are often undertaken to stabilize the dunes to reduce the natural variability. This study provides quantitative insight into the morphologic variability of managed foredunes over time spans of decades. We used Empirical Orthogonal Function (EOF) analysis on a 45 year data set of annually surveyed dune profiles along 97 km of the Netherlands' coast. On average, 70% of the deviations from the time-averaged profiles could be related to cross-shore coherent changes in foredune shape as mapped onto EOF 1. These changes are often largely due to morphologic developments occurring near the dunefoot. Changes in dune shape were coherent over time as well as in the longshore direction albeit with different characteristic patterns along the coast. These results show that managed foredunes may still exhibit considerable morphologic variability that should not be ignored in long-term dune safety assessment studies.  相似文献   

17.
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18.
Coastal and marine areas the world over provide food, transportation, recreation, and energy resources to increasing numbers of people each year. As demands for these resources rise, the potential for user conflicts is radically heightened. This situation can be avoided or counteracted by instigating proactive multiple use planning. Multiple use zoning plans can only exist in a concrete management framework: marine and coastal protected areas provide just such a foundation. Nature-based or ecotourism can be encouraged in coastal protected areas aimed at achieving sustainability. Well-planned tourism provides economic and political incentives for management and for conservation, and may bring additional benefits to local communities and regional economies. Examples where nature-based tourism has been or is becoming successfully integrated into multiple use planning can be found in Quintana Roo, Mexico; the Lesser Antilles; and Australia, among other areas.  相似文献   

19.
Coastal zones are characterized by large concentrations of population, unique and vital ecosystems, and many industrial and other economic activities on land and at sea. The many and diverse activities result in different types of conflicts of use and access to resources in coastal areas. This calls for integrated management of coastal zones. However, successful integrated coastal management must be supported by reliable data and information that will lead to informed decision-making and planning. The International Oceanographic Data and Information Exchange (IODE) network which is a project of the Intergovernmental Oceanographic Commission (IOC) of UNESCO is playing a key role in capacity building for ocean and coastal data and information management in Africa. Currently, about 25 data and information centers have been established in coastal African countries through these efforts. These data and information centers should support effective management of coastal zones.  相似文献   

20.
Member States of the European Union and the Mediterranean Regional Sea need to elaborate national strategies for coastal management according to ICZM principles and to undertake national stock-taking, which must consider major actors, laws and institutions influencing the management of their national coastal zone. However, different approaches to coastal management and defence and various degrees of development and implementation of national ICZM strategies can be found. The research presented in this article aims to analyze the different situations and to contribute to the further development of a common approach in terms of methodology to establish stakeholder and users participation in ICZM. An extensive survey was conducted in five pilot sites along the European Mediterranean coastal zone (Greece, Italy and France) show beach visitors’ perception of ICZM, coastal erosion and coastal defence systems, and beach visitors’ Willingness To Pay (WTP) for beach defence. The survey yielded important information for coastal and beach managers. Surprisingly, the level of awareness about generic Coastal Zone Management was found to be rather low in all regions except Riccione Southern beach, Emilia-Romagna Region. In the Languedoc-Roussillon Region, this is justified by the fact that most of the respondents were not local people or beach visitors (other than recreational day-visitors). As regards coastal erosion it appears significant that, despite the lack of awareness demonstrated overall by stakeholders in the Region of East Macedonia and Thrace, visitors respond very positively to definitions and show awareness of the erosion process in their coastal system. In conclusion, in order to raise public awareness about ICZM, erosion and coastal defence systems, it is suggested that education, training and public awareness should be promoted as well as identification of local needs for the implementation of specific demand-driven studies.  相似文献   

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