The role of coastal setbacks in the context of coastal erosion and climate change

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.     

Assessing climate change impacts on coastal infrastructure in the Eastern Caribbean

Expected effects of changes in global climate include warmer temperatures, rising sea levels, and potentially more frequent and severe extreme weather events such as hurricanes and tropical storms. Low-lying states in the Caribbean are especially vulnerable to these effects, posing significant risks to public safety and natural resources.This paper highlights expected trends in the Eastern Caribbean and examines the impacts of urbanization and supporting infrastructure, siting of major structures in high-hazard areas, and negative land-use practices on fragile coastal ecosystems. It focuses on the need to reduce the vulnerability of coastal infrastructure and land uses, arguing for effective linkages between climate change issues and development planning. The paper also provides general recommendations and identifies challenges for the incorporation of climate change impacts and risk assessment into long-term land-use national development plans and strategies.     

中国沿海地区对全球变化的响应及风险研究

中国沿海地区对全球变化的响应及风险具有高度的复杂性及不确定性,亟需深入开展相关研究。本研究着重回顾了近年来有关我国沿海地区陆域及海域对全球变化的响应特征、机制以及风险的若干研究成果。分析表明,自1960年代以来,全球变暖背景下我国沿海地区陆域及相邻海域的表面温度上升趋势十分显著,上升幅度和速率均高于全球平均值;生物与非生物的物候变化显著,温暖期(春、秋季)明显变长,并以东中国海(渤、黄、东海)最为显著;海洋物种地理分布变化、生物季节演替和群落结构与功能异常突显,赤潮、绿潮等生态灾害频繁,赤潮有年代际增加现象,热带海域珊瑚白化加剧。分析还表明,自1980年以来,我国沿海地区出现越来越多的高温热浪,沿海海平面持续上升并不断达到新高度,特别是破纪录的极端高海温事件、超强台风-风暴潮和极端高水位频发,这使得沿海地区社会-生态系统的气候暴露度不断增大;同时,沿岸海域富营养化、大规模围填海、破坏性以及过度捕捞等人类活动加剧了社会-生态系统的气候脆弱性,沿海地区的洪涝灾害严重,滨海湿地生境和生物多样性减少。未来不同气候情景下中国东部尤其是东中国海很可能是全球升温和海平面上升幅度最大的海区之一。这表明未来我国沿海地区的灾害风险格局趋于复杂多变。为此,本研究指出了急需深入研究我国沿海地区全球变化综合风险的若干科学问题与关键技术。     

气候变化与我国海洋灾害风险治理探讨

本文基于观测数据和文献资料,分析了近几十年来气候变化下我国沿海海平面和海表温度,以及台风、风暴潮和赤潮等主要致灾因子及灾害损失的变化。结果表明,近40年来,我国沿海海平面和海表温度显著上升,上升速率分别为3.3 mm/a和0.016°C/a,高于全球平均和我国的历史变化水平,2017年中国沿海的海表温度达到了1960年有记录以来的最高值,并且自2000年以来,超强台风、风暴潮和赤潮等致灾事件的发生频次呈显著增加趋势;气候变化下,受关键海洋环境要素变迁和超强台风、风暴潮等极端事件的影响,我国沿海地区暴露度明显加大。随着我国海洋防灾减灾水平的提高,近30年来海洋灾害损失出现下降趋势。值得指出的是,每年各类海洋灾害总损失仍高达百亿元量级(年均直接经济损失约120亿元),其中,2005年总损失达到最高值,约332亿元,这与致灾事件的强度以及各致灾事件、灾种的叠加放大效应有密切关系。本文进一步从气候变化综合风险理论角度出发,结合海岸带及沿海地区致灾因子危险性、承灾体暴露度和脆弱性及其相互作用关系,分析了气候变化背景下我国沿海地区海洋灾害风险的特征,探讨了有关海洋灾害的监测、预测预警和风险治理能力建设等若干科学问题,以期为我国沿海地区社会经济的可持续发展提供科学参考。     

长江口及邻近海域浮游植物生态系统气候变化综合风险评估

近几十年来,在气候变化和人类活动的影响下,我国近岸河口海域尤其是长江口及邻近海域生态灾害频繁发生,严重影响了海洋生态系统的健康及其服务功能。本研究基于政府间气候变化专门委员会（Intergovernmental Panel on Climate Change, IPCC）气候变化风险理论框架,构建了河口浮游植物生态系统的气候变化综合风险评估指标体系,并利用IPCC 第五次耦合模式比较计划（CMIP5）地球系统模式数据,分别计算分析了在温室气体低（RCP 2.6）、中等（RCP 4.5）和高（RCP 8.5）浓度排放情景下未来不同时期（2030—2039、2050—2059、2090—2099年）长江口及邻近海域浮游植物生态的致灾因子危害性、承灾体暴露度和脆弱性及其综合风险。结果表明： RCP 2.6、4.5和8.5情景下,到21世纪中期,致灾因子危害性均有明显上升,其中RCP 4.5和8.5情景下,到21世纪末,还将大幅度增加,且以RCP 8.5情景最为显著,而RCP 2.6情景下则相反,有所下降;RCP 2.6情景下,高暴露度区域主要位于长江口附近,不同年代的变化差异较小;RCP 4.5和8.5情景下高暴露度区域明显大于RCP 2.6情景,尤其是后者到21世纪末期扩大至长江口邻近海域;脆弱性总体呈现近岸高远岸低的分布特征,且变化均较小;RCP 2.6、4.5和8.5情景下,综合风险均呈现近岸高远岸低,且有增加的趋势,但以RCP 8.5情景最为明显,并在21世纪末达到最大。     

High-resolution characterization and integrated study of a reservoir formation: the danian carbonate platform in the Aquitaine Basin (France)

This paper provides an example of an integrated multi-scale study of a carbonate reservoir. The Danian Lower R2 carbonate reservoir is located in the South of the Aquitaine Basin (France) and represents a potential underground gas storage site for Gaz de France. The Danian Lower R2 reservoir was deposited as a prograding carbonate platform bordered by a reef barrier. The effects of sedimentary and diagenetic events on the reservoir properties, particularly dolomitization, were evaluated. In this study, the reservoir quality has been assessed by seismic analyses at the basin scale, by log-analysis at the reservoir scale, by petrographic methods and by petrophysical tools at the pore-core scale.Two dolomitization stages, separated by a compaction event with associated fracturing and stylolites, have been identified. These diagenetic events have significantly improved the Lower R2 carbonate reservoir properties. It is demonstrated that the reservoir quality is mainly controlled by the pore-geometry, which is determined by various diagenetic processes. The permeability values of the reservoir range over 4 orders of magnitude, from 0.1 to 5600 mD and the porosity values range between 2 and 42%. Reservoir unit 4 (a karstic dolomite) shows the best reservoir properties with average porosity values ranging between 11.1% and 19.3% and an average permeability ranging between 379 and 766 mD. Reservoir unit 2 (a fine-grained limestone) shows the worst reservoir properties. The cementation factors range from 1.68 to 2.48. The dolomitic crystal carbonate texture (mainly units 3 and 4) shows the highest value of the cementation factor (1.98–2.48) and formation factor (9.54–36.97), which is due to its high degree of cementation. The saturation exponents vary between 1.2 and 3.4. Using these experimental electrical parameters and the resistivity laterolog tool we predicted the water saturation in the various reservoir units. The permeability was predicted by combining the formation factor with the micro-geometric characteristic length. The best fit is obtained with the Katz and Thompson's model and for a constant of 1/171.     

基于海洋气候数据集的区域海平面变化非线性预测

本文基于中国首套长时间序列、高精度、高时空一致性的全球海洋气候数据集产品, 利用1993年1月至2015年12月的山东半岛近海海平面异常数据, 构建了基于集合经验模式分解(EEMD)和长短期记忆神经网络(LSTM)的海平面非线性变化组合预测模型。EEMD可以得到海平面异常的各周期项、线性趋势及残差部分, LSTM模型可对其进行逐个预测并重构得到最终的海平面异常预测结果。EEMD-LSTM组合模型海平面异常预测的均方根误差仅为25.87 mm, 取得了令人满意的效果。基于该组合模型预测2016-2025年山东半岛近海海平面上升速率将达到3.54 mm·a^-1。     

自然气候变率对近百年气候变化的影响研究进展

对近年来关于自然气候变率对近百年全球、中国气候以及海洋影响的研究成果进行了详细的总结分析。目前的研究认为,20世纪后50年的气温变化,更可能是人类活动的结果,而20世纪的前50年的气候变化,被认为是自然外力和人类活动共同的影响结果;对于中国20世纪气候增暖的原因,研究认为人类活动可能已经对中国的气候变暖产生了影响,但太阳活动、火山爆发及气候系统内部的低频振动对气候变化可能也具有重要影响。另外研究认为引起全球海洋总热容量增加的重要原因是人类活动的影响。     

Preparedness of key coastal and marine sectors in Ireland to adapt to climate change

Preparedness to adapt to the impacts of climate change was assessed for three important sectors of activity within the Irish coastal and marine environment, namely tourism, fisheries, and conservation of biodiversity. Information on the current status of each sector is a valuable point of reference in terms of accessing contribution to the implementation of future national adaptation efforts. A modified version of the National Adaptive Capacity (NAC) framework developed by the World Resources Institute was used to assess the three sectors of activity. This framework is structured around five functions: assessment, prioritisation, coordination, information management, and climate risk reduction; results of the assessment suggest that all three sectors are at the nascent stages of the climate change adaptation process. Currently there is no dedicated national policy guidance or legal support mechanism on adaptation in Ireland; hence there is no national financial commitment to support implementation of adaptation actions for any of the sectors assessed. Subjecting these three selected sectors of activity to such an assessment enables identification of existing actions that can potentially support current adaptation, as well as where issues such as knowledge gaps and lack of policy support hinder progress.     

The impact of climate change on prawn postlarvae fishing in coastal Bangladesh: Socioeconomic and ecological perspectives

In Bangladesh, prawn (Macrobrachium rosenbergii) farming remains dependent on the capture of wild postlarvae as hatchery production is still inadequate. However, prawn postlarvae fishing has been accompanied by concerns over recent climate change. Different climatic variables including cyclone, salinity, sea level rise, water temperature, flood, rainfall, and drought have had adverse effects on coastal ecosystem, thus determining a decline in the availability of prawn postlarvae and thereby catch. The households of postlarvae fishers also face a variety of socioeconomic constraints due to climate change. Considering extreme vulnerability to the effects of climate change, an integrated approach needs to be introduced to cope with the challenges.     

Development and application of a methodology for vulnerability assessment of climate change in coastal cities

This research is based on the need to develop methodology for climate change vulnerability assessment in coastal cities. While there have been some studies on the development of methodologies for vulnerability assessment on a national scale, there have been few attempts to develop a method for local vulnerability assessment with application to coastal cities. The objective of this study was to develop a general methodology to assess vulnerability to climate change and to apply it to the metropolitan coastal city of Busan in South Korea. We followed the conceptual framework for assessing climate change vulnerability provided by the Intergovernmental Panel on Climate Change (IPCC), which is composed of climate exposure, sensitivity, and adaptive capacity. Sea level rises of 0.5 m, 1 m, 2 m, and 3 m were considered as the climate exposure. Sensitivity to sea level rise was measured based on the percentage of flooded area calculated using flood simulation with a GIS tool. The population density and the population at age 65 years and over were also included in the calculation of sensitivity index. Sensitivities to heat wave and heavy rainstorm were quantified using the expert opinions from the Delphi survey and information on land use classification. Adaptive capacity was assessed in three sections: economic capability, infrastructure, and institutional capabilities. By combining the adaptive capacity and three different sensitivities, vulnerability to sea level rise (SLR-V), vulnerability to heavy rainstorm (HR-V), and vulnerability to heat wave (HW-V) were separately evaluated in 16 counties of Busan. Using cluster analysis, we could classify four major groups of counties based on SLR-V, HR-V, HW-V, and reported damage cost. For clustered groups, different adaptation strategies were suggested based on the different vulnerability patterns. Application of our methodology to Busan indicated that our methodology is easy to use and provides concrete policy implications when setting up adaptation strategies. The methodology developed in this study could also be used in mainstreaming climate change into Integrated Coastal Management (ICM).     

Impact of climate change on potential habitat distribution of Sciaenidae in the coastal waters of China

Climate change has affected and will continue to affect the spatial distribution patterns of marine organisms. To understand the impact of climate change on the distribution patterns and species richness of the Sciaenidae in China’s coastal waters, the maximum entropy model was used to combine six environmental factors and predict the potential distribution of 12 major species of Sciaenidae by 2050s under Representative Concentration Pathways(RCPs) 2.6 and 8.5. The results showed that the averag...     

Growth and demise of the Jurassic carbonate platform in the intracratonic Paris Basin (France): Interplay of climate change,eustasy and tectonics

It is usually very difficult to identify and quantify the relative influence of tectonics, eustasy and climate on carbonate system evolution from sedimentary records. In order to improve our understanding of these mechanisms, we have traced for the first time, the evolution of the eastern Paris Basin platform throughout the entire Jurassic period. This carbonate platform underwent eight successive growth and demise phases, with different depositional profiles ranging from ramps to flat-topped geometries. The eight carbonate growth periods are compared with the standard sea-level curves, local tectonic regimes and recently published oxygen-isotope and/or clay mineralogy databases. Prograding heterozoan facies along ramp profiles mark periods dominated by second-order eustatic sea-level rise, relatively cool sea surface temperatures, and mesotrophic and humid conditions (Hettangian, Pliensbachian, late Oxfordian, Tithonian). During these periods, variable detrital contents in the sedimentary succession hampered the efficiency of shallow-marine carbonate factories. Higher sea surface temperatures, oligotrophic and humid conditions associated with either eustatic sea-level rise or very high local subsidence occurred during the early Bajocian and the mid-Oxfordian. These seawater properties seem to have favoured the aggradation of scleractinian corals forming dome-shaped bioherm buildups. An oolitic and lime-mud carbonate system, deposited during the Bathonian second-order eustatic sea-level fall, is characterised by miliolid-rich micritic facies on a rimmed-ramp under stable, cooler and drier conditions. The second-order maximum flooding associated with a sea surface temperature decline and/or a seawater eutrophication caused at least five carbonate demise periods (i.e. Toarcian, earliest late Bajocian, Callovian/Oxfordian transition, earliest late Oxfordian and Kimmeridgian).     

Limits and barriers to adaptation to climate variability and change in Bangladeshi coastal fishing communities

Limits and barriers to adaptation restrict people’s ability to address the negative impacts of climate change or manage risks in a way that maximises their wellbeing. There is a lack of evidence of this on small-scale fishing communities in developing countries. This study identifies and characterises limits and barriers to adaptation of fishing activities to cyclones and examines interactions between them in two fishing communities in Bangladesh, using household questionnaires, oral history interviews, vulnerability matrices and focus group discussions. The limits include physical characteristics of climate and sea like higher frequency and duration of cyclones, and hidden sandbars. Barriers include technologically poor boats, inaccurate weather forecast, poor radio signal, lack of access to credit, low incomes, underestimation of cyclone occurrence, coercion of fishermen by the boat owners and captains, lack of education, skills and livelihood alternatives, unfavourable credit schemes, lack of enforcement of fishing regulations and maritime laws, and lack of access to fish markets. These local and wider scale factors interact in complex ways and constrain completion of fishing trips, coping with cyclones at sea, safe return of boats from sea, timely responses to cyclones and livelihood diversification. The findings indicate a need for further detailed research into the determinants and implications of such limits and barriers, in order to move towards an improved characterisation of adaptation and to identify most suitable means to overcome the limits and barriers.     

Linking early diagenesis and sedimentary facies to sequence stratigraphy on a prograding oolitic wedge: The Bathonian of western France (Aquitaine Basin)

To improve the understanding of the distribution of reservoir properties along carbonate platform margins, the connection between facies, sequence stratigraphy, and early diagenesis of discontinuities along the Bathonian prograding oolitic wedge of the northeastern Aquitaine platform was investigated. Eight facies are distributed along a 50 km-outcropping transect in (1) toe-of-slope, (2) infralittoral prograding oolitic wedge, (3) platform margin (shoal), (4) open marine platform interior, (5) foreshore, and (6) terrestrial settings. The transition from shallow platform to toe-of-slope facies is marked in the field by clinoforms hundred of meters long. Carbonate production was confined to the shallow platform but carbonates were exported basinward toward the breakpoint where they cascaded down a 20–25° slope. Ooid to intraclast grainstones to rudstones pass into alternating marl-limestone deposits at an estimated paleodepth of 40–75 m. Three sea-level falls of about 10 m caused the formation of discontinuities corresponding to sequence boundaries. Along these discontinuities, erosional marine hardgrounds formed in a high-hydrodynamic environment at a water depth of less than 10 m, displaying isopachous fibrous cements and meniscus-type cements. The cements pass landward into meniscus and microstalactitic forms along the same discontinuities, which are characteristic of subaerial exposure. During the deposition of transgressive systems tracts, carbonate accumulation remained located mostly on the shallow platform. Energy level increased and carbonates were exported during the deposition of highstand systems tracts forming the infralittoral prograding oolitic wedge. During the deposition of lowstand systems tracts, carbonate production fell to near zero and intraclast strata, derived from the erosion of hardgrounds on the shallow platform, prograded basinward. Early diagenetic cements are related exclusively to discontinuities that are not found within the prograding wedge because of the continuous high sedimentation rate under lower hydrodynamic conditions. This absence of early cementation within the infralittoral prograding oolitic wedge was conducive to porosity conservation, making such features good targets for carbonate reservoir exploration. This study proposes a novel sequence stratigraphy model for oolitic platform wedges, including facies and early diagenesis features.     

Down-scaled regional ocean modeling system (ROMS) for high-resolution coastal hydrodynamics in Korea

A down-scaled operational oceanographic system is developed for the coastal waters of Korea using a regional ocean modeling system(ROMS).The operational oceanographic modeling system consists of atmospheric and hydrodynamic models.The hydrodynamic model,ROMS,is coupled with wave,sediment transport,and water quality modules.The system forecasts the predicted results twice a day on a 72 h basis,including sea surface elevation,currents,temperature,salinity,storm surge height,and wave information for the coastal waters of Korea.The predicted results are exported to the web-GIS-based coastal information system for real-time dissemination to the public and validation with real-time monitoring data using visualization technologies.The ROMS is two-way coupled with a simulating waves nearshore model,SWAN,for the hydrodynamics and waves,nested with the meteorological model,WRF,for the atmospheric surface forcing,and externally nested with the eutrophication model,CE-QUAL-ICM,for the water quality.The operational model,ROMS,was calibrated with the tidal surface observed with a tide-gage and verified with current data observed by bottom-mounted ADCP or AWAC near the coastal waters of Korea.To validate the predicted results,we used real-time monitoring data derived from remote buoy system,HF-radar,and geostationary ocean color imager(GOCI).This down-scaled operational coastal forecasting system will be used as a part of the Korea operational oceanographic system(KOOS) with other operational oceanographic systems.     

Facies, internal structures and sequences of modern Gironde-derived muds on the Aquitaine inner shelf, France

Seventy cores from the Aquitaine continental shelf were examined using radiographic and grain-size techniques in order to describe the sedimentary structures of the muddy deposits, and to evaluate their depositional processes. Four lithofacies are identified in this fine-grained deposit: (a) homogeneous silty sand, (b) interbedded homogeneous mud and sand, (c) silty-clayey mud, and (d) mottled mud. They show a logical pattern in relationship to the water depth and the distance from the coast.

Primary structures are present particularly in the landward and central portion of the mud fields, where the sediment is organized into sequences with a sharp-based erosional contact, overlain by a fining-up succession (centimetre to decimetre scale). The beginning of each of these is characteristic of a high-energy storm event, which is common on this shelf. The settling of suspended fine sediment corresponds to the flood estuarine discharge during quiet periods. Primary sedimentary structures decrease in the distal area where the muddy sediment is frequently reworked by infauna. Finally, primary structures and their preservation depend on the relative magnitudes of surface waves, storms, infaunal mixing and fluvial sediment deposition rates (i.e. floods).     

Downscaling of greenhouse gas induced climate change in two GCMs with the Rossby Centre regional climate model for northern Europe

Two 2×10‐year climate change experiments made with the Rossby Centre regional Atmospheric climate model (RCA) are reported. These two experiments are driven by boundary data from two global climate change simulations, one made with HadCM2 and the other with ECHAM4/OPYC3, in which the global mean warming is virtually the same, 2.6°C. The changes in mean temperature and precipitation show similarities (including broadly the same increase in temperature and in northern Europe a general increase in annual precipitation) as well as differences between the two RCA experiments. These changes are strongly governed by the driving GCM simulations. Even on the RCA grid box scale, the differences in change between RCA and the driving GCM are generally smaller than the differences between the two GCMs. Typically about a half of the local differences between the two RCA simulations are attributed to noise generated by internal variability, which also seems to explain a substantial part of the RCA‐GCM differences particularly for precipitation change. RCA includes interactive model components for the Baltic Sea and inland lakes of northern Europe. The simulated changes in these water bodies are discussed with emphasis on the wintertime ice conditions. Comparison with an earlier RCA experiment indicates that a physically consistent treatment of these water bodies is also of importance for the simulated atmospheric climate change.     

Effect of climate change on design wind at the Indian offshore locations

The impact of climate change on design wind speeds corresponding to different return periods at two selected offshore locations in India has been assessed. Extreme daily wind speeds corresponding to various return periods were derived based on the observations made by wave rider buoys during the period 1998–2005. Thereafter, the future climate over the next century was simulated at these locations using the input from the climate model: GCM-CGCM3 corresponding to the A2 scenario. The underlying downscaling model was developed with the help of artificial neural networks and using observed wind as output. The local wind speeds corresponding to these projected wind data were generated for the next century and return period wind speeds were extracted by the distribution fitting. Comparison of design wind speeds derived with and without consideration of future climate showed that the magnitude of the long term wind speed would certainly and significantly increases if the effect of global climate change is incorporated in the analysis. For the two locations considered, the increase in the 100-year wind was found to be varying from 44% to 74%.