Classification of Beach Erosion Vulnerability on the Yucatan Coast

Beach erosion can have important socioeconomic and environmental consequences, particularly in tropical regions where tourism is a significant source of income. Although caused by natural processes, erosion is often aggravated by disorderly anthropogenic modification of the coast and extreme events. In Yucatan, Mexico, increasing urban development and deficient coastal management strategies as well as hurricanes have affected beach stability. This has highlighted the need for adequate coastal planning and policies that ensure the protection of key coastal ecosystems, such as beaches and sand dunes. To address this, a methodology to classify the coast according to its vulnerability is presented in this work. This methodology assumes that morphological features are indicators of beach evolution and the processes driving it and that these can be associated with different levels of vulnerability. The features considered are beach width, dune vegetation, anthropogenic pressure, and shoreline orientation, which were analyzed through aerial images and a multicriteria evaluation. It was observed that the most vulnerable areas are found near the most developed parts of the coast, where narrow beaches with little dune vegetation dominate. It is expected that this index will be of use to coastal planners and decision makers, particularly in the identification of critical zones.     

Some economic aspects of conflicts over land use in the coastal zone

Abstract

Recent land use legislation pays particular attention to the coastal zone where age‐old conflicts have recently accelerated. Flexibility is required in policy because visible conflicts are tied into complex physical and social systems which may require changing patterns of land use over time. Public policy is altering property rights and a thorough understanding of the economic and social roles played by those rights is required. Economic models can be used to understand some major changes such as types of alteration of the environment, but may be ignored or misused unless a better understanding of coastal decision processes is developed.     

Constraint Mapping as a Means of Further Refining Saltmarsh Re-Creation Opportunities for the UK Solent Region

Based on geomorphological criteria, the Coastal Habitat Management Plan (CHaMP) for the Solent identified some 4,800 hectares of land potentially suitable for the creation of intertidal habitat, principally saltmarsh, through the use of managed realignment. Using “constraint mapping,” this study set out to illustrate that limitations to habitat re-creation through inundation are not merely geomorphological in nature. Indeed, a broad range of social, political, legal, technical, and economic constraints exist and must be evaluated in conjunction with physical parameters if the objectives of the European Birds and Habitats Directives are to be met, and so that future coastal defense policies ensure maintenance of the “favorable conservation status” of designated sites. A numerical filter system has been used to re-evaluate individual sites to establish “realistic” opportunities for compensatory saltmarsh creation in the Solent. As a result of taking into account wider socioeconomic constraints, it is clear that fewer areas are available for habitat creation purposes than were initially identified in the Solent CHaMP study.     

The Role of Universities in Supporting Integrated Coastal Management in the United Kingdom

Integrated coastal management has been seen as the way to deal with the challenges currently facing managers of our coastal zones. In the tropics, these areas are typified with resources such as coral reefs and mangroves that are able to support a variety of activities. Integrated coastal management takes a multi-disciplinary approach that involves the integration of the different institutions and stakeholder groups in the coastal zone. A survey of tropical coastal locations revealed that fully implemented integrated coastal management is limited with programs apparently failing at the implementation stage. These coastal zones share a number of common challenges exacerbated by poverty and conflicts between the coastal activities. Conflict management needs to be incorporated into the management process that pays particular attention to the overextraction of resources and destructive resource use.     

Assessing the Utility of Beach Ecolabels for Use by Local Management

Ecolabels for beaches have been around since 1985 and have grown rapidly over the past decade. However, effects from ecolabels on beach ecology and local coastal cultures are unknown. This study reviews the literature on tourism ecolabels and environmental certification for beaches, analyzes the criteria of the most prominent beach ecolabel, and identifies considerations and proposes recommendations for local management that address sandy beach ecology and local cultures. The Blue Flag ecolabel is evaluated for how well the program criteria balance tourism, the processes of sandy beach ecology, and accommodate for local cultural values. This Blue Flag's criteria leave out protecting sandy beach ecology and fail to incorporate local community values in program design. The results of the study include three areas that beach managers need to consider for better understanding the utility of beach ecolabel programs: opportunity costs of participation and consequences of losing certification; evaluate investment in multiple certifications; and identify potential changes from the implementation of ecolabels.     

长江中游宜都水道河床演变分析及治理对策初探

通过实测资料,系统分析了长江中游宜都水道演变特点,并重点对三峡蓄水后的演变规律进行了分析,提出初步治理对策。结果表明:宜都水道是长江中游离三峡枢纽最近、受其影响最早的碍航水道,天然情况下属枯季碍航浅水道;蓄水后,水浅的碍航问题得到了一定的改善,但其支汊发展、边滩冲刷现象明显,其对宜昌水位的控制作用受到威胁,因此及时实施该水道控导工程以稳定控制节点作用十分必要。     

Review of Countermeasures against Beach Erosion on the Taiwanese Coast

Beach erosion is one of the most significant coastal preservation problems in the world. This study first briefly addresses the influences of human activity on beach erosion. The seriousness of beach erosion in Taiwan has received considerable attention since the 1960s, following rapid population growth and economic development in the coastal areas. Hard solutions of stabilized structures against beach erosion in Taiwan at that time are reviewed based on their effectiveness in protecting property and their ability to produce a landscape that harmonizes with the adjacent coastal environment. Soft coastal defense solutions implemented recently in coastal regions in Taiwan are introduced and their benefits are discussed. This study concludes that various methods designed to prevent wave- and current-induced beach erosion should be based on analyses of nearshore hydrodynamics, sediment transport, coastal processes, and physiographic features of beaches.     

The importance of polynyas, ice edges, and leads to marine mammals and birds

The correlation between areas of open water in ice-covered seas and increased biological productivity has been noted for some time. To date, most attention has been focused on larger polynyas, such as the Northeast Water and the Northwater. Although spectacular in their own right, these large polynyas represent only part of a vitally important continuum of biological productivity that varies significantly between geographic areas and ice habitats, that includes the multi-year pack of the polar ocean and small localized polynyas in annual ice. Surveys of the distribution and abundance of ringed seals in the Canadian Arctic Archipelago have shown differences in density that are correlated with the presence or absence of polynyas. There is also significant variation in the biological productivity of polynya areas of the Canadian High Arctic Archipelago and northern Greenland, all of which receive inflow from the polar basin. Long-term studies of polar bears and ringed seals in western Hudson Bay and the eastern Beaufort Sea show significant but dissimilar patterns of change in condition and reproductive rates between the two regions and suggest that fundamentally different climatic or oceanographic processes may be involved. Projections of climate models suggest that, if warming occurs, then the extent of ice cover in Hudson Bay may be among the first things affected. Long-term studies of polar bears and ringed seals in the eastern Beaufort Sea and Hudson Bay would suggest these two species to be suitable indicators of significant climatic or oceanographic changes in the marine ecosystem.     

A Review of Dunes in Today's Society

Prior to Superstorm Sandy, the importance of dunes had been widely overlooked in many coastal societies. However, the stark contrast between New Jersey coastal areas that were and were not protected by dunes has created a positive paradigm shift in coastal law and public dune opinion. Government officials are mandating the construction of artificial dunes along New Jersey's coast, but it is necessary for communities to first understand the complex nature of these unique systems. With the proper knowledge, a dune can be both a protective structure as well as a working habitat that will ultimately better protect upland infrastructure and improve beach health. However, a general lack of terminological consistency among formal media and governing entities makes properly quantifying and assessing dune health difficult and unwarranted ecological conclusions inevitable. Here, dune terminology, “blowout,” “washout,” and “bowling” is clarified and defined and the dynamic nature of dunes is explained.     

Rates and mechanisms of climate change: Implications for ports and harbours

The paper explores some of the key ocean-atmosphere processes relevant to the themes of ‘global warming“ and ‘sea level rise“ addressing some of issues that form the basis of the science. It is shown that both processes as well as the data used to characterise such processes demonstrate that a) there is no such thing as a single global sea level and b) changes in extreme storminess are not uniform worldwide. Instead, trends in storminess (including Asian typoon and Atlantic hurricane activity) exhibit marked regional variability with strong regional signature linked to episodes of major El Niño and La Niña activity. Similarly, satellite data demonstrates that whereas some ocean areas have recently experienced sea level rise caused principally by thermal expansion effects, other ocean areas have been subject to cooling and sea level lowering. This account provides an introductory account that discusses the rationale for understanding the regional variability in the nature of coastal flood risk to the world’s ports and harbours.     

Rehabilitating the Mangrove Resources of Cogtong Bay,Philippines: A Comanagement Perspective

The local management of mangrove resources in Cogtong Bay, Philippines, dates back to the 1940s and 1950s when some families informally designated mangrove areas under their care and management. The 1960s and 1970s saw several exogenous events that led to the progressive denudation of mangrove stands and the decline in fish catch per fishing trip. This article draws attention to the forces that prompted coastal villages and external agents to collaborate with the national and local government units in resource rehabilitation. It also assesses the performance of a coastal resources comanagement project at Cogtong Bay.     

Information Presentation of Coastal Morphological Change: Potential Implications for Perceptions of Climate Change Impacts

Visual imagery of costal morphological change processes must be accompanied by supporting information to make change processes understandable. We explored the influence of supporting information (graphs and numeric values) on perceptions of coastal morphological change processes through an experiment delivered to coastal recreationists. Supporting information was presented alongside four imagery types: human perspective digital elevation models (DEMs), human perspective digital photographs, aerial views of DEMs and aerial photography. We found neither the use of graphs nor numeric values influenced respondents' perceptions of coastal environmental change. However, perceptions varied significantly across imagery type; human perspective digital photographs and aerial photographs yielded higher ratings compared to human perspective DEMs and aerial views of DEMs. The results suggest supporting information representing increasingly severe rates of beach erosion and shoreline movement does not translate into perceptions of increasingly dramatic geophysical processes; this is consistent with previous empirical findings. The results also suggest individuals perceive coastal change processes as more severe when those processes are presented through photographs, particularly aerial photographs. Scientists, educators and coastal land use managers struggling to communicate the magnitude and severity associated with coastal geophysical processes are advised to use comparative aerial photography when possible.     

Climate Change and Tourist Comfort on Europe's Beaches in Summer: A Reassessment

Major impacts of climate change have been projected for tourism in Europe. Typically, these projections took general tourism activities such as sight-seeing and their climate requirements as their point of reference. The purpose of this study is to reassess the impact of climate change, by looking specifically at beach tourism in summer, a crucial market segment in Europe and more specifically in the Mediterranean. As beach tourism requires relatively high temperatures, relatively modest shifts in attractiveness are found. With respect to climate, the Mediterranean is likely to remain Europe's prime region for summer-time beach tourism for at least the next 50 years. Coastal managers in Mediterranean destinations are advised to focus some of their attention on other climate change impacts such as sea-level rise or water availability, and include environmental quality and diversification of activities in their deliberations. In non-Mediterranean regions, a promising strategy may be to focus on short- and medium-distance visitors who can take advantage of the new opportunities for beach tourism, and to explore the merits of seasonal climate forecasting.     

A Review of Beach Bye-Law Usage in Supporting Coastal Management in Ireland

Coastal areas are commonly the focus of a range of human activities and uses. Beaches are one example of multi-use coastal environments, accommodating activities linked to leisure and recreation, amenity, conservation and business, often simultaneously. Ireland is no different in this regard, as its beach resources provide a range of goods and services of societal value. Ireland has 16 coastal counties and their associated local authorities have a beach management remit, a role that can present a number of challenges. The use of beach bye-laws is one option to support management of beach environments by local authorities. Local authority personnel tasked with beach management from each coastal local authority were surveyed to assess the actual and potential role of beach bye-laws in contributing to more effective management of beach environments and to broader coastal management. Usage of beach bye-laws varied across local authority areas and evidence suggested that the efficacy, use, and implementation of beach bye-laws differed from county to county. Beach bye-laws offer potential but interaction with other initiatives as part of a wider program for coastal management may yield improved results.     

Merging Socioeconomic Imperatives with Geospatial Data: A Non-Negotiable for Coastal Risk Management in South Africa

The current approach to coastal development set-back delineation in South Africa is producing high-tech empirical methodologies that attempt to pinpoint areas at risk from physical coastal processes and the subsequent positioning of set-backs in relation to these risk areas. Experience in the Western Cape province of South Africa has shown that this approach contributes only partially to coastal risk management. In the context of an urban and peri-urban environment, and bearing in mind that set-backs have significant socioeconomic implications, the development of a set-back line at the local scale requires an expansion beyond just relying on the numerical modeling of physical coastal processes. This research reveals that such an approach is parochial and socially detached and a more inclusive and integrated approach grounded in and spanning localized social, cultural, economic, political, and ecological intricacies of the coastal space is required. Fundamental to achieving this is a re-consideration of the broader project management processes applied in the development of set-backs. The article concludes with a set of principles and guidelines for determining set-backs in complex coastal contexts at the local scale.     

The demand for local access to coastal recreation in southern New England

Coastal lands provide popular outdoor recreation opportunities including beach recreation, fishing, boating, and wildlife viewing. Published studies measuring the demand for access to coastal lands generally have focused on the recreational value of intensively used beaches, which comprise only a portion of the New England coastline. This article examines the recreational demand for coastal access to a local, free‐access site in southern New England. The study uses data obtained from on‐site interviews conducted during the summer of 1995 at Gooseberry Island, Massachusetts. The estimated average value of a visitor‐day during the summer season is $3.06 for weekdays and $4.18 for weekends and holidays. While these values are at the low end of the range of values published in existing literature addressing beach recreation, the aggregate value of recreation benefits derived from public access to undeveloped coastal areas likely are significant.     

Quantitative estimation of the influence of surface thermal fronts over chlorophyll concentration at the Patagonian shelf

Eighteen-year (1985–2002) mean monthly SST Pathfinder data with 9 km spatial resolution have been used to estimate surface gradients by finite differences. Then the seasonal climatological means have been calculated from the intensity of these gradients, and surface thermal fronts present in the Patagonian Continental Shelf (PCS) have been located. Moreover, 6 years (1998–2003) of SeaWiFS data with approximately 4 km spatial resolution have been used to estimate monthly composite images of surface chlorophyll concentration, after which seasonal climatological means distributions have been generated. Both seasonal distributions have been analyzed together and by combining the knowledge of oceanographic processes and phytoplankton responses to light and nutrient availability, regions where the presence of a thermal front affects photosynthetic activity have been identified. Subjective criteria have been applied to define eighteen areas where phytoplankton biomass is influenced by the presence of a thermal front. In these areas, the surface chlorophyll (spatial mean and total), its relationship with the surface chlorophyll of the whole region, and the seasonal evolution of this relationship have been calculated. All frontal areas cover less than 15% of the total surface, but they contribute with over 23% of the phytoplankton annual mean biomass. Considered as a group, during summer they show high chlorophyll values very similar to those in spring. During the cold period, when the water column is vertically mixed in practically the whole of PCS, the influence of physical fronts over the biological production is minimum. The frontal zone image remains clearly defined during summer, when approximately 85% of the area will have a determined mean chlorophyll concentration, while the other 15% has a 2.45 times larger value. While three pattern trends have been identified in the frontal areas, only two of them condition the pattern of the group, due to their horizontal extension.     

Climate–ocean variability and Pacific hake: A geostatistical modeling approach

Climate forcing of the California Current has been known to impact the distribution and abundance of a number of local fish populations, but the mechanisms involved remain poorly understood. Climate metrics such as the Pacific Decadal Oscillation (PDO) and the El Niño Southern Oscillation (ENSO) are usually used to represent climate processes and direct links are made between climate forcing and production variability. This involves aggregation of impacts across large spatial scales and range of species. However, fluctuations in productivity are often the result of changes in physical habitat. In order to fully understand the relationship between climate and productivity, habitat changes should be addressed. In this study we use a geostatistical approach to quantify adult Pacific hake habitat during different climate regimes. Several authors have suggested that the distribution and intensity of the sub-surface poleward flow (the undercurrent) plays a key role in defining adult hake habitat along the west coast of North America. Here we build a model designed to predict hake habitat distribution in space based on sub-surface poleward flow distribution and bottom depth. Our results show that hake habitat expands in 1998 El Niño year compared to 1995. Given the important predatory role that hake plays in the CC, the amount and distribution of adult hake habitat has large implications for the Pacific Northwest food web and could thus serve as an ecosystem indicator representing important physical–biological interactions. Spatially based ecosystem indicators such as the one we develop here address two important yet neglected areas in the ‘Ecosystem Indicators debate’: the importance of developing metrics explicitly representing spatial and environmental processes shaping ecosystem structure. Without these, our power to fully describe ecosystems will be limited.     

Evaluating the long term impacts of transport policy: The case of passenger rail privatisation

Britain's national rail system was ‘privatised’ as a result of the 1993 Railways Act, with most of the organisational and ownership changes implemented by 1997. This paper examines the long term impacts of these changes. A key issue when examining long term changes is that of the counterfactual – what would have happened if the changes had not occurred? A simple econometric model of the demand for passenger rail services was developed and used in conjunction with extrapolative methods for key variables such as fares and train km to determine demand-side counterfactuals. Extrapolative methods were also used to determine counterfactual infrastructure and train operation costs. Although our results are sensitive to the assumptions we have made concerning the counterfactual they suggest a number of impacts. Since privatisation, rail demand has grown strongly but our analysis indicates that transitional disruptions suppressed demand by around 9% over a prolonged period (1992/3 to 2005/6), whilst the Hatfield accident reduced demand by about 5%, albeit over a shorter period (2000/1 to 2006/7). A welfare analysis suggests that although consumers seem to have gained as a result of privatisation, for most years this has been offset by increases in costs. An exception is provided by the two years immediately before the Hatfield accident. Overall the loss in welfare since the reforms were introduced far exceeds the net receipts from the sale of rail businesses. Thus although the reforms have had advantages in terms of lower fares and better service levels than otherwise would have been the case, this appears to have been offset by increased infrastructure and train operations costs. The source of these high costs remains an area of speculation but appear to be related to aspects of both market and regulatory failure.     

Estuary Management and Recreational Fishing Benefits

Recognition of the benefits to society supported by estuary ecosystem functions and services, and threats to these benefits posed by human activities, has led to various public programs to restore and protect estuaries at the federal, state, and local levels. As available budgets shrink, program administrators and public elected officials struggle to allocate limited restoration and protection funds to the highest priority areas. Economic benefit and cost information can provide useful inputs into this decision-making process by quantifying estuary restoration and protection benefits and costs in commensurate terms. In this paper, a combined actual and intended travel behavior model is described that can be applied to estimate the recreational fishing benefits of estuary restoration and protection. The model was estimated for recreational fishing in the Lower Atchafalaya River Basin estuary along the Gulf of Mexico, Louisiana, USA coast. Changes in freshwater flows into this estuary may affect redfish and speckled trout game fish populations. The model indicates that changes in catch rates of these two species would have a relatively minor affect on annual fishing trips per angler. However, because total effects may be large when effects per angler are aggregated across total anglers, resource management agencies should consider these changes in recreation benefits when evaluating projects that influence the ecology of coastal estuaries, fish populations, and catch rates. Moreover, in other coastal areas or situations, the responsiveness of angling trips to changes in catch rates may vary because of differences in user populations, environmental conditions, fish populations, and fishing experiences.