Contingent valuation analysis of willingness to pay for beach erosion control through the stabiplage technique: A study in Djerba (Tunisia)

Beach erosion can have major economic implications because of the potential impact on coastal recreation demand – particularly for countries where coastal tourism is one of the main sources of external revenue. Djerba Island (Tunisia) falls in that category. With about 125 km of coastline, Djerba Island is one of the most important Tunisian destinations. However, the island is experiencing coastal erosion problems. The Tunisia government launched a project to fight costal erosion through the Stabiplage technique. This study provides the first economic valuation of beach erosion control in Tunisia and is the first one that focuses on the Stabiplage technique. Specifically, a contingent valuation survey is carried out to elicit the public willingness to pay (WTP) for the project. An interval payment card question format is used to obtain information about WTP from representative samples of residents and tourists in Djerba. The results reveal a positive WTP for the project. Aggregate WTP estimates range from €133,459 (median value) to €5,180,269 (mean value). These values can help inform decisions about whether to undertake the project based on either the benefit-cost ratio rule or majority voting rule.     

Recreational benefits of coastal protection: a case study

In the UK, cost–benefit analysis of coastal protection schemes that expect to receive grant assistance is required by H.M. Government. A recommended procedure for evaluating the recreational benefits of coastal protection is based on a variant of contingent valuation methodology (CVM), and involves the estimation of the gains and losses in the value of enjoyment by beach users associated with different project scenarios (including the option of allowing erosion to occur). The paper reports the results of a study which applies this approach to coastal protection at an important UK seaside resort. It focusses on the suitability of the value of enjoyment (VOE) elicitation method, and stresses the need to test the validity of the results from all such studies that apply this approach.     

Current countermeasure of beach erosion control and its application in Taiwan

The shoreline of Taiwan is approximately 1100 km long, composed of sandy beach, rocky coast, and reef coast. Almost half of the shoreline has been protected by seawalls, which play an important role for coastal protection and prevent people and infrastructure from coastal hazard. Besides, offshore breakwaters and groynes are also built in the serious erosion coastal shores. All these hard engineering structures made our coastal land safety to some extent at last fifty years. However, until now, the hard engineering structures applied for shore protection do not always work well on all the coasts around Taiwan. Some coastal areas still get eroded seriously with structures being damaged. Furthermore in the recent years, people gradually value the shore protection from different viewpoints, like environment, recreation, and ecology. The objectives of the shore protection are diversified by these new demands.Therefore, the purpose of this study is to evaluate the strategy on how to conjoint soft solutions into the current hard engineering structures for beach erosion control throughout Taiwan coast. Meanwhile, this paper will also introduce environmentally, user-oriented, and technically sound creditable protection works to meet the new trends of shore protection. For application purpose, two local sites in the southwestern Taiwan coast are selected for field experimental study to integrate the proposed soft solution with hard shore protection system at present. Furthermore for coastal management purpose, this paper also collects and analyzes hydro-morphodynamic data around Taiwan in order to identify beach erosion mechanism. Lastly, the results are presented by database and geographic information system.     

Characteristics of coastal erosion geometry under regular and irregular waves

An experimental investigation of coastal erosion generated by the action of regular and irregular waves was carried out in laboratory channels. Natural beach sand, with medium diameter of 0.35 mm and specific gravity of 2.63, was used in this study. A 1:5 initial beach slope was selected for the model tests. Different wave groups were generated over the initially flat beach, and the characteristics of coastal erosion geometry such as erosion lengths, erosion depths, location of maximum erosion point, and total erosion areas were measured. The most important parameters governing coastal erosion were evaluated by using earlier investigations and experimental results. These parameters were expressed as a dimensionless group by using π theory. The empirical relationships between the geometric characteristics of coastal erosion and the dimensionless group are proposed through regression analysis for pure regular waves, pure irregular waves, and regular-irregular waves. The parameters, which were used to define geometric characteristics of coastal erosion, were evaluated and some ratios of these parameters gave a constant value.     

Application of non-market valuation to California's coastal policy decisions

Regulatory agencies in the United States do not generally consider economic values of ecosystem services in their policy decisions. We report the results of a collaborative effort by a team of economists, conservation biologists, and staff members of the California Ocean Protection Council to provide spatially explicit and policy-relevant values for ecosystem services generated in coastal regions in California. We developed a matrix in which the rows are types of ecosystem services and the columns are types of marine ecosystems along the California coast. Where possible, we populated this matrix with ecosystem service values per unit of area drawn from the economics literature. We then evaluated whether the values for given services, in given ecosystems, could be reasonably approximated by applying the replacement cost or the avoided cost method. Reported values of coastal ecosystems varied widely, and much of the valuation research did not address specific ecosystem services. Even when ecosystem services were explicitly addressed, the services often were not described or valued in a spatially explicit manner. These results suggest that rigorous application of non-market values to policy decisions requires original valuation studies for specific services in specific ecosystems. Where original, place-based valuation studies are not possible, valuation by replacement or avoided cost methods is feasible for some ecosystem services.     

Design and performance of headland bays in Chesapeake Bay,USA

The use of headland-breakwater systems along the shore of Chesapeake Bay began in the early 1980s. Properly designed and installed headland breakwaters with beach fill and wetlands plantings provide shore protection and create a “full” coastal profile of beach/backshore/dune which enhances habitat. They create a tertiary buffer for upland runoff and groundwater and provide access and recreation. The wetland grasses also create an erosion resistant turf. The coastal profile accommodates environmental permitting requirements of habitat enhancement for shore protection structures.     

海阳市典型砂质海岸侵蚀机制与防护对策研究

海阳市砂质海岸资源丰富,延绵近120 km,尤以万米沙滩浴场著称,但近年岸滩侵蚀严重影响其社会经济发展.本研究基于海阳市羊角畔两侧长约20 km典型砂质海岸连续3 a的海岸线蚀和典型剖面蚀淤调查,定量化研究海滩侵蚀及其变化,辅以一维数值模型,研究人类活动影响下的泥沙运动特征和海滩侵蚀机制.研究结果表明,调查区42.5％和5.90％的砂质海岸分别处于侵蚀和强侵蚀状态,羊角畔东侧海岸侵蚀强度高于西侧,海阳港至海阳核电厂之间海滩侵蚀强度最高,海滩侵蚀强度与人类活动扰动程度密切相关.海岸工程、临海养殖和人为采砂导致海阳市部分砂质海岸侵蚀严重的主要原因,导致羊角畔两侧海岸侵蚀机制也不同.基于各岸段侵蚀机制特征有针对性地提出退养还滩、凸堤拆除和沙滩喂养等对策,以减缓海阳砂质海岸侵蚀威胁.     

ICZM and coastal defence perception by beach users: Lessons from the Mediterranean coastal area

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.     

Managing erosion-induced problems in NW Mediterranean urban beaches

The applicability of recommendations of the Eurosion project to define a policy to manage coastal erosion has been tested at the “beach” scale in the Mediterranean coast. Thus, a favourable sediment status has been defined for these beaches taking into account their main functions: recreation and protection. Because they act at two different seasons, this status needs to be seasonally defined. For the protection function, the favourable sediment status depends on the level of safety fixed by the manager taking into account the importance of existing infrastructures and, for recreation it depends on the use density of the beach. The concept has been formalized for beach management within a framework where benchmarking plays a crucial role to determine the need of intervention. This has been illustrated for open cell beaches where one of its boundaries can permit variations in the sediment budget and for pocket beaches that act as closed sediment cells.     

Coastal and marine ecosystem services valuation for policy and management: Managed realignment case studies in England

The recognition of the economic value of nature and the services it provides to humanity has become increasingly essential in the context of coastal zone management. In this paper we review the progress to date on both the necessary conceptual framework and empirical valuation studies required to bolster decision support systems (DSS) targeted at integrated coastal zone management goals. We highlight the importance of using an ecosystem services approach and recommend some basic sequential, although overlapping, analytical steps for appropriate environmental valuation and policy assessment: spatial explicitness; marginal changes; double counting; non-linearities; and threshold effects. We illustrate the practical use of the DSS by reviewing an existing UK case study on managed coastal realignment along the Eastern coast of England, and a new UK case study on managed realignment implemented in a southern area on the same coast. Comparing the two studies, the importance of spatial explicitness and the need for a sequential decision support system when dealing with ecosystem services valuation and project policy appraisal become particularly evident.     

Wave farm impact on the beach profile: A case study

If wave energy is to become a fully-fledged renewable, its environmental impacts must be fully understood. The objective of the present work is to examine the impact of a wave farm on the beach profile through a case study. The methodology is based on two coupled numerical models: a nearshore wave propagation model and a morphodynamic model, which are run in two scenarios, both with and without the wave farm. Wave data from a nearby coastal buoy are used to prescribe the boundary conditions. A positive effect on the wave climate, the cross-shore sediment transport and, consequently, the evolution of the beach profile itself due to the presence of the wave farm was found. The wave farm leads to a reduction in the erosion of the beach face. This work constitutes the first stage of the investigation of the effectiveness of a wave farm as a coastal defence measure, and the accuracy of the quantification of the erosion reduction will be enhanced in future research. In any case, the overarching picture that emerges is that wave farms, in addition to providing carbon-free energy, can be used as elements of a coastal defence scheme.     

大鹏湾岬湾型海滩季节性变化特征及原因分析——以官湖海滩为例

随着全球海平面的上升及极端气象的频发,全球海滩总体呈现出一定的退化现象,海滩保护成为海岸带生态修复的焦点问题之一。我国华南地区岬湾型海滩分布广泛,以深圳市大鹏湾官湖海滩为代表,基于2020—2021年实测海滩剖面高程数据,分析岬湾型海滩季节性变化特征。研究表明,官湖海滩剖面坡度夏秋缓冬春陡,夏秋侵蚀冬春淤积;海滩沉积物粒径季节性变化不明显。海滩剖面形态受风浪、平均潮位的季节性变化控制,以夏秋季为例,平均潮位逐渐升高,南向波浪强度较大,在二者的共同作用下,海滩后滨侵蚀明显,泥沙离岸输运,并在前滨淤积。补沙方案宜在夏秋季进行,且重点区域为官湖海滩东侧与观海湾海滩,防御方案应主要削弱南向波浪。     

Public willingness to pay for alternative management regimes of remote marine protected areas in the North Sea

Despite increasing attention paid to the value of marine resources, in particular marine protected areas (MPAs), their economic valuation focuses mainly on use values of ecosystem services such as fishery and tourism. Furthermore, most MPA related studies are carried out for coastal ecosystems, especially tropical coral reefs. The valuation of remote marine ecosystems is rare. The main objective of this paper is to estimate public willingness to pay (WTP) for alternative management regimes of a network of offshore MPAs in the North Sea under the Marine Strategy Framework Directive (MSFD). In a baseline valuation study carried out just before the adoption of the MSFD, beach visitors and a random sample of coastal and non-coastal residents were asked for their preferences for two alternative management options of three remote, ecologically sensitive areas with multiple use conflicts. Despite the lack of public awareness and familiarity with the offshore marine areas, a majority of 70% is willing to pay extra tax for their protection. Using a conservative value elicitation procedure, Dutch households are willing to pay on average maximum 0.25% of their annual disposable income to ban access and economic use. This serves as an indicator of what a network of remote MPAs in the MSFD is allowed to cost according to the Dutch tax payer.     

An approach to assess flooding and erosion risk for open beaches in a changing climate

This paper examines the vulnerability to flooding and erosion of four open beach study sites in Europe. A framework for the quantitative estimation of present and future coastal flood and erosion risks is established using methods, data and tools from across a range of disciplines, including topographic and bathymetric data, climate data from observation, hindcast and model projections, statistical modelling of current and future climates and integrated risk analysis tools. Uncertainties in the estimation of future coastal system dynamics are considered, as are the consequences for the inland systems. Different implementations of the framework are applied to the study sites which have different wave, tidal and surge climate conditions. These sites are: Santander, Spain—the Atlantic Ocean; Bellocchio, Italy—the Adriatic Sea; Varna, Bulgaria—the Black Sea; and the Teign Estuary, UK—the northern Atlantic Ocean. The complexity of each system is first simplified by sub-division into coastal “impact units” defined by homogeneity in the local key forcing parameters: wave, wind, tide, river discharge, run-off, etc. This reduces the simulation to that of a number of simpler linear problems which are treated by applying the first two components of the Source–Pathway–Receptor–Consequence (S–P–R–C) approach. The case studies reveal the flexibility of this approach, which is found useful for the rapid assessment of the risks of flooding and erosion for a range of scenarios and the likely effectiveness of flood defences.     

Study on headland-bay sandy coast stability in South China coasts

Headland-bay beach equilibrium planform has been a crucial problem abroad to long-term sandy beach evolution and stabilization,extensively applied to forecast long-term coastal erosion evolvement and the influences of coastal engineering as well as long-term coastal management and protection.However,little concern focuses on this in China.The parabolic relationship is the most widely used empirical relationship for determining the static equilibrium shape of headland-bay beaches.This paper utilizes the relation to predict and classify 31 headland-bay beaches and concludes that these bays cannot achieve the ultimate static equilibrium planform in South China.The empirical bay equation can morphologically estimate beach stabilization state,but it is just a referential predictable means and is difficult to evaluate headland-bay shoreline movements in years and decades.By using Digital Shoreline Analysis System suggested by USGS,the rates of shoreline recession and accretion of these different headland-bay beaches are quantitatively calculated from 1990 to 2000.The conclusions of this paper include that (a) most of these 31 bays maintain relatively stable and the rates of erosion and accretion are relatively large with the impact of man-made constructions on estuarine within these bays from 1990 to 2000;(b) two bays,Haimen Bay and Hailingshan Bay,originally in the quasi-static equilibrium planform determined by the parabolic bay shape equation,have been unstable by the influence of coastal engineering;and (c) these 31 bays have different recession and accretion characters occurring in some bays and some segments.On the one hand,some bays totally exhibit accretion,but some bays show erosion on the whole.Shanwei Bay,Houmen Bay,Pinghai Bay and Yazhou Bay have the similar planforms,characterized by less accretion on the sheltering segment and bigger accretion on the transitional and tangential segments.On the other hand,different segments of some bays have two dissimilar evolvement characters.Dacheng Bay,Shenquan Bay,Hudong Bay,Wukan Bay,Fengjia Bay,Wuchang Bay,Lingshui Bay and Tufu Bay produce accretion on the tangential segment,erosion on the transitional segment and accretion on the sheltering segment.However,Guang’ao Bay,Haimen Bay,Jinghai Bay,Sanya Bay(a),Dajiao Bay,Hailingshan Bay,Hebei Bay,Fuhu Bay,Shuidong Bay,Wangcun Bay and Bomao Bay generate erosion on the tangential part,accretion on the transitional part and accretion on the sheltering part.It seems to imply some relations between headland-bay beach evolvement and controls on headland-bay beaches,which may possibly to classify headland-bay beach types and should be further studied.     

半遮蔽型海滩剖面长期时空演化过程的经验正交函数分析

半遮蔽型海滩由于一侧海岬的差异作用而影响海滩的演变过程。本文以青岛石老人海水浴场海滩为例,基于对3条典型剖面连续11年现场监测的高程数据,利用经验正交函数(empirical orthogonalfunction,EOF)分析方法将该海滩各剖面高程数据组成的原始距平矩阵依次分解为相应的空间和时间特征函数,分析了石老人海滩的形态演化特征、蚀淤趋势及驱动因素,并采用方差总占比超过77%的前3个经验正交函数来反映此类海滩的基本演化情况,分别为:表征长时间尺度砂质海滩滩面最主要蚀淤变化趋势的第一模态、表征季节性蚀淤变化及其引起的滩肩剖面形成增长或削弱消亡的第二模态和表征人类活动、偶发因素或海岸地形等引起的具有随机性的不规律蚀淤变化的第三模态。结果表明:11年来石老人海滩经历了三个阶段,第一阶段为平稳期(2009年1月—2011年7月),第二阶段为突变期(2011年7月—2012年9月),该阶段之后至今,是第三阶段的平稳期(2012年9月—2019年12月)。海滩剖面在自然和人类活动影响下的高程变化范围在0.1—2.0m范围内。波浪是影响该海滩形态演化的最主要水动力因素,岬角对半遮蔽型海滩的差异庇护作用导致不同位置的剖面演化存在差异。高频率台风的影响、海平面阶段性升高并长期保持较高水平导致了远离岬角的开放岸段存在明显阶段性调整,剖面滩肩宽度减少约30m,岬湾内部剖面则相对稳定,目前海滩剖面形态在第二阶段突变期后达到了新的稳定状态。     

Visitors' awareness of ICZM and WTP for beach preservation in four European Mediterranean regions

This paper discusses the results of a multi-country survey about private stakeholders' contribution to coastal preservation. It was conducted in four coastal sites of Greece, Italy and France, in order to collect information about beach visitors' perception of Integrated Coastal Zone Management (ICZM) and their willingness to pay (WTP) for beach preservation, intended here as defence from erosion. In order to find out whether ICZM perception is a determinant of WTP, regression analysis is applied. Results show that in these sites respondents have a low level of information about the nature of ICZM, despite local authorities having implemented some ICZM strategies for preserving the coast. Nevertheless, those who are informed about ICZM have a higher probability of paying for beach preservation. This suggests to policymakers that promoting public awareness about ICZM may increase the probability of paying. Finally, some categories of visitors, such as women and young and middle-aged people, have a higher probability of paying than men and older people, thus suggesting a more sensitive attitude to beach preservation. Therefore, policy-makers should also pay attention to the categories of visitors less likely to pay.     

基于多源数据的福建东山岛海岸侵蚀及其不同时空尺度成因分析

海岸侵蚀对海岛紧缺的陆地资源及旅游价值较大的沙滩危害巨大。基于卫星遥感、有人航空摄影、无人机航测、GPS和现场调查等多源数据,利用GIS分析了东山岛海岸线类型、位置与长度变化及滩面冲蚀演变。研究表明,东山岛多处曲折自然岸线转化为较为平直的人工岸线致使整体岸线长度减少,无人机高程反演满足滩面排水冲蚀监测精度要求,乌礁湾和山南湾不同养殖排水方式形成不同特征的滩面冲沟,改变了沙滩微地貌形态。海平面上升和台风风暴潮是长期趋势性和短期突发性侵蚀因素的代表,当前短时间尺度的人类活动已成为滩面冲蚀的最主要因素,且有可能转变为长期趋势性因素。     

我国硬式护岸、渔港工程和人工岛等3类典型海岸工程对相邻海滩的影响研究

我国硬式护岸、渔港工程和人工岛等3类典型海岸工程对相邻海滩有显著影响.本研究以泉州青山湾护岸、泉州崇武中心渔港、海口南海明珠人工岛等建设前后海滩变化为例,开展对海滩岸线形态及部分典型剖面形态的对比分析.结果表明,临海硬式护岸岸前海滩发生明显下蚀,护岸下游海滩岸线侵蚀后退,发育侵蚀热点,剖面伴有下蚀;渔港工程拦沙堤附近岸线局部淤涨,下游海滩岸线大范围侵蚀后退,出现侵蚀热点,侵蚀热点处剖面明显下蚀;人工岛后波影区内海滩淤积,形成沙岬或连岛沙坝突出体,突出体两侧岸线均发生不同程度侵蚀后退.通过分析典型工程案例,探讨了3类海岸工程对相邻海滩的影响方式、影响尺度和原因,对比分析不同类型海岸工程对相邻海滩的负面影响,可为海岸工程建设管理和海滩保护提供参考.     

基于高空间分辨率卫星遥感影像的砂质海岸空间整治效果分析——以营口月亮湾为例

采用2005年采集的SPORT5卫星遥感影像和2015年采集的GF-1卫星遥感影像,分别对2006-2014年之间营口月亮湾海岸空间整治项目实施前后的海岸景观格局进行监测,在此基础上构建了沙滩面积系数、适宜游乐水域指数、主体功能度指数、景观多样性系数、景观变化指数等评估指标,评估了营口月亮湾海岸空间整治效果。结果表明:营口月亮湾沙滩养护工程实施后沙滩面积大幅增加,沙滩面积系数为2.44,适宜游泳嬉水娱乐区面积略有增加,适宜游乐区指数为1.10。海岸空间整理工程实施使月亮湾海岸游乐功能分区明显,月亮湖公园、高尔夫休闲区、山海广场区、农业生态旅游度假区和滨海嬉水观光区主体功能度指数分别达到0.89、0.76、0.68、0.65和0.77。海岸景观美化工程整体改变了海岸景观格局,使各功能分区海岸景观多样性提高,海岸景观格局更为优化,总体景观多样性系数达到1.13,景观变化指数达到0.30。