Socio-economic vulnerability of the megacity of Shanghai (China) to sea-level rise and associated storm surges

Sea-level rise (SLR) poses a significant threat to many coastal areas and will likely have important impacts on socio-economic development in those regions. Located on the eastern coast in China, the megacity of Shanghai is particularly vulnerable to SLR and associated storm surge risks. Using the municipality of Shanghai as a case study, the possible impacts of flooding risks caused by SLR and associated storm surges on socio-economic development in the region were analysed by a Source–Pathway–Receptor–Consequence (SPRC) conceptual model. The projections of flooding risk in the study area were simulated by MIKE21 (a two-dimensional hydrodynamic model) for the three time periods of 2030, 2050 and 2100. An index system for vulnerability assessment was devised, in which flooding depth, density of population, GDP per capita, GDP per unit land, loss rate under flooding and fiscal revenue were selected as the key indicators. A quantitative spatial assessment method based on a GIS platform was established by quantifying each indicator, calculating and then grading the vulnerability index. The results showed that in the 2030 projection, 99.3 % of the areas show no vulnerability to SLR and associated storm surges under the present infrastructure. By 2050, the areas with low, moderate and high vulnerabilities change significantly to 5.3, 8.0 and 23.9 %, respectively, while by 2100, the equivalent figures are 12.9, 6.3 and 30.7 %. The application of the SPRC model, the methodology and the results from this study could assist with the objective and quantitative assessment of the socio-economic vulnerability of other similar coastal regions undergoing the impacts of SLR and associated storm surges. Based on the results of this study, mitigation and adaptation measures should be considered, which include the controlling the rate of land subsidence, the reinforcement of coastal defence systems and the introduction of adaptation in long-term urban planning.     

Coastal vulnerability assessment of the predicted sea level rise in the coastal zone of Krishna–Godavari delta region,Andhra Pradesh,east coast of India

The Krishna–Godavari coastal region in east coast of India has a 525.15-km-long coastline with low-lying tidal mudflats, beaches, mangrove swamp, creek and tidal channels. Recently, the increasing frequency of tropical cyclones in the Bay of Bengal, i.e., Phylin and Hudhud in Andhra Pradesh coast, and the devastating impact of the 2004 tsunami in India increased the significance in assessing the vulnerability of the coastal lands to inundation and flooding, notably in the context of climate change-induced sea level rise. This study aims to estimate a coastal vulnerability index (CVI) for the coastal subregion of Krishna–Godavari delta and to use the calculated index to evaluate the vulnerability of 14 coastal talukas of the Krishna–Godavari delta region. This CVI is calculated by using four geological and three physical parameters characterizing the vulnerability of the study coastal region, including regional slope, coastal elevation, geomorphology, significant wave height, mean tidal range and relative sea level using different conventional and remotely sensed data. Using a composite coastal vulnerability index based on the relative risk rating of those parameters, each of the 14 coastal talukas was classified according to their vulnerability. The CVI results depict that coasts are least and most vulnerable to inundation, flooding and erosion of coastal lands where geological parameters are more efficient to CVI. The paper alerts to decision makers and planners to mitigate the natural disaster and manage the coastal zone and is a primary step toward prioritizing coastal lands for climate change adaptation strategies in the view of increased storminess and projected sea level rise.     

Practical tools for quantitative analysis of coastal vulnerability and sea level rise impacts—application in a Caribbean island and assessment of the 1.5 °C threshold

The quantitative analysis of hurricane impacts on coastal development in the Caribbean is surprisingly infrequent and many tools to assess physical vulnerability to sea level rise (SLR) are insufficient to evaluate risk in coastal areas exposed to wave attack during extreme events. This paper proposes a practical methodology to quantify coastal hazards and evaluate SLR impact scenarios in coastal areas, providing quantitative input for coastal vulnerability analysis. We illustrate the implementation of the proposed methodology with results from a site-specific analysis. We quantify how storm wave impacts penetrate farther inland and reach higher elevations for increasing SLR conditions. We also show that the increase in elevation of storm wave impacts is more than the nominal increase in mean sea level, and that elevation increase may be on the order of up to twice the nominal SLR. By developing design parameters for multiple scenarios, as opposed to the determination of a single SLR value for design established by consensus, this approach generates information that we argue encourages resilient design and embedding future adaptation in coastal design. We discuss how government planners and regulators, as well as real estate developers, lenders, and investors, can improve coastal planning and resilient design of coastal projects by using this approach.     

Assessing coastal vulnerability to climate change: comparing segmentation at global and regional scales

Recent concerns about potential climate-change effects on coastal systems require the application of vulnerability assessment tools in order to define suitable adaptation strategies and improve coastal zone management effectiveness. In fact, while various research efforts were devoted to evaluate coastal vulnerability to climate change on a national to global level, fewer applications were carried out so far to develop more comprehensive and site-specific vulnerability assessments suitable to plan possible adaptation measures at the regional scale. In this respect, specific indicators are needed to address climate-change-related issues for coastal zones and to identify vulnerable areas at the regional level. Two sets of coastal vulnerability indicators were selected, one for regional and one for global studies, respectively, concerning the same features of coastal systems, including topography and slope, geomorphological characteristics, presence and distribution of wetlands and vegetation cover, density of coastal population and number of coastal inhabitants. The proposed set of indicators for the regional scale was chosen taking into account the availability of environmental and territorial data for the whole coastal area of the Veneto region and was based on site-specific datasets characterized by a spatial resolution appropriate for a regional analysis. Moreover, a GIS-based segmentation procedure was applied to divide the coastline into linear segments, homogeneous in terms of vulnerability to climate change and sea-level rise at the regional scale. This approach allowed to divide the Veneto shoreline into 140 segments with an average length of about 1 km, while the global scale approach identified four coastal segments with an average length of about 66 km. The performed comparison indicated how the more detailed approach adopted at the regional scale is essential to understand and manage the complexities of the specific study area. In fact, the 25-m DEM employed at the regional scale provided a more accurate differentiation of the coastal area's elevation and thus of coastal susceptibility to the inundation risks, compared to the 1-km DEM used at the global level. Moreover, at the regional level the use of a 1:20,000 geomorphological map allowed to differentiate the unique landform class detected at the global level (e.g., fluvial plain) in a variety of more detailed coastal typologies (e.g., open coast eroding sandy shores backed by bedrock) characterized by a different sensitivity to climate change and sea-level rise. Accordingly, the information provided by regional indicators can support decision-makers in improving the management of coastal resources by considering the potential impacts of climate change and in the definition of appropriate actions to reduce inundation risks, to avoid the potential loss of valuable wetlands and vegetation and to plan the nourishment of sandy beaches subject to erosion processes.     

Livelihood vulnerability approach to assessing climate change impacts on mixed agro-livestock smallholders around the Gandaki River Basin in Nepal

Climate change vulnerability depends upon various factors and differs between places, sectors and communities. People in developing countries whose subsistence livelihood depends mainly upon agriculture and livestock production are identified as particularly vulnerable. Nepal, where the majority of people are in a mixed agro-livestock system, is identified as the world’s fourth most vulnerable country to climate change. However, there is limited knowledge on how vulnerable mixed agro-livestock smallholders are and how their vulnerability differs across different ecological regions in Nepal. This study aims to test two vulnerability assessment indices, livelihood vulnerability index and IPCC vulnerability index, around the Gandaki River Basin of central Nepal. A total of 543 households practicing mixed agro-livestock were surveyed from three districts, namely Dhading, Syangja and Kapilvastu representing three major ecological zones: mountain, mid-hill and Terai (lowland). Data on socio-demographics, livelihood determinants, social networks, health, food and water security, natural disasters and climate variability were collected and combined into the indices. Both indices differed for mixed agro-livestock smallholders across the three districts, with Dhading scoring as the most vulnerable and Syangja the least. Substantial variation across the districts was observed in components, sub-components and three dimensions (exposure, sensitivity and adaptive capacity) of vulnerability. The findings help in designing site-specific intervention strategies to reduce vulnerability of mixed agro-livestock smallholders to climate change.     

Characterising the nature of household vulnerability to climate variability: empirical evidence from two regions of Ghana

This paper builds on national- and regional-level vulnerability assessments by developing and applying a livelihood vulnerability index at the community and household scales to explore the nature of climate vulnerability. It provides innovative methodological steps in relation to livelihood assessment to identify the vulnerability of households and communities to drought. This will help to improve drought vulnerability assessments in Ghana and more widely as it shows extra information can be obtained from local-level vulnerability assessment that may be lacking in national- and regional-level analysis. The research employs quantitative and qualitative data collected through participatory methods, key informant interviews and a questionnaire survey with 270 households across 6 communities in two regions in Ghana. Results show that within the same agroecological zone, households and communities experience different degrees of climate vulnerability. These differences can be largely explained by socioeconomic characteristics such as wealth and gender, as well as access to capital assets. Results identify vulnerable households within resilient communities as well as more resilient households within vulnerable communities. These outliers are studied in detail. It is found that outlier households in vulnerable communities have an array of alternative livelihood options and tend to be socially well connected, enabling them to take advantage of opportunities associated with environmental and economic changes. To sustain and enhance the livelihoods of vulnerable households and communities, policymakers need to identify and facilitate appropriate interventions that foster asset building, improve institutional capacity as well as build social capital.     

Micro-level social vulnerability assessment towards climate change adaptation in semi-arid Ghana,West Africa

This study determined the social vulnerability index (SoVI) of households to climate change impacts for three identified locations (upper, mid and lower) in the Vea catchment, semi-arid Ghana. This study adapted the social, economic and demographic indicator approach. The data used were obtained from a survey of 186 randomly sampled farm households and direct field measurements of 738 farm plots belonging to the same sampled farm households. Information from the literature, expert judgement and principal component analysis were useful for computing and analysing the SoVI. The variables were normalized, weighted and subsequently recombined to determine the index of the three locations towards climate change. Although the SoVI to climate change was highest (0.77) for the upper part of the catchment, the mid- and lower parts of the catchment show a high SoVI of 0.72 each. The overall SoVI for the catchment is 0.73. The study re-emphasizes the high vulnerability level of dry areas to climate change. Moreover, it shows there is variability at micro-scale. There is a need to put appropriate measures to address the vulnerability of households to climate change in the semi-arid areas of West Africa. Factors aggravating dry land’s vulnerability towards climate change should be prevented with implementable policies. Furthermore, it is important to identify conditions that have made some areas less vulnerable to climate change, and then, we can work out the possibility of adapting such to the vulnerable places.     

Sea-Level Rise Risk Communication: Public Understanding,Risk Perception,and Attitudes about Information

We present the results of a study using a document-based evaluation method to better understand how residents in vulnerable coastal areas respond to risk communications about sea-level rise (SLR) and to determine whether communications localized for specific populations improve reception. Similar to climate change communication, SLR risk communication presents challenges involving complex science, uncertainty, invisibility, and politicization. To be comprehensible and persuasive, risk messages must be appropriately framed and visually compelling and must take into account risk perceptions and diverse viewpoints. Our approach involves assessing people's encounters with actual risk messages to determine their reactions and responses. Participants in this study had difficulty understanding information and expressed attitudes including fear, fatalism, skepticism, and loss. SLR risks were also perceived as both temporally and spatially distant, creating a challenge for communicators trying to convey a sense of urgency. We conclude by considering the implications of audience-focused research for SLR risk communication.     

Coastal protection structures in Tarawa Atoll, Republic of Kiribati

In the context of rapid population growth and urbanization, atoll countries have engaged in reclamation works and in the construction of coastal defences to extend inhabitable areas and reduce the threats posed by coastal erosion and flooding. Despite their major role in asset protection, coastal structures are still poorly documented. However, a better knowledge of the characteristics of these structures (location, type, condition, management status, etc.) would facilitate the establishment of consistent construction and maintenance programmes, and also contribute to a better understanding of shoreline changes. To address this need, this paper provides an assessment of coastal structures on Tarawa Atoll in Kiribati. The results highlight the abundance of structures, mostly seawalls (94.7 % of the total), which stretch along 29 % of the coastline. The protected shoreline decreases from urban (53.9 % at Bairiki) to rural islands (27.3 % at Buota), in proportion to population pressure. The occurrence and height of structures are greater on windward, ocean shores than on lagoon shores. Seawall condition is better in rural islands, compared to urban and semi-urban areas. The observed differences in the characteristics and physical condition of coastal structures mainly reflect differences in the management status of structures and the availability of building materials and funding. More generally, the occurrence and characteristics of coastal structures are strongly correlated to population densities, land-use dynamics and shoreline mobility. At some locations, the failure of coastal protection highlights the seriousness of the problems raised by land-use practices in Tarawa.     

Impacts of predicted sea level rise on land use/land cover categories of the adjacent coastal areas of Mumbai megacity,India

Physical and ecological responses of the coastal areas in the vicinity of Mumbai, India, due to relative sea level rise are examined by different inundation scenarios. Evaluation of potential habitat loss under sea level rise was made by incorporating the land use/land cover (LULC) adopted from the digital elevation model with the satellite imagery. LULC categories overlaid on 1.0, 2.0, 3.0 and 4.0 m coastal elevation showed that the coastal areas of Mumbai were mostly covered by vegetation followed by barren land, agricultural land, urban areas and water bodies. For the relative sea level rise scenarios of 1.0, 2.0, 3.0 and 4.0 m, the tidal inundation areas were estimated to be 257.85, 385.58, 487.56 and 570.63 km², respectively, using GIS techniques. The losses of urban areas were also estimated at 25.32, 41.64, 54.61 and 78.86 km² for the 1.0, 2.0, 3.0 and 4.0 m relative sea level rise, respectively, which is most alarming information for the most populated city on the eastern coast of India. The results conclude that relative sea level rise scenario will lead profound impacts on LULC categories as well as on coastal features and landforms in the adjoining part of Mumbai. The sea level rise would also reduce the drainage gradients that promote flooding condition to rainstorms and subsequently increase saltwater intrusion into coastal regions. Alterations in the coastal features and landforms correlated with inundation characteristics that make the coastal region more vulnerable in the coming decades due to huge development activities and population pressures in Mumbai.     

Socioeconomic development and vulnerability to land degradation in Italy

In recent years, the surface area affected by land degradation (LD) has significantly increased in southern European regions where the socioeconomic development has been proposed as a basic factor underlying the degree of vulnerability to LD. This paper investigates the correlation between several socioeconomic indicators and the level of vulnerability to LD in Italy, expressed as changes (1990–2000) in a composite index of land vulnerability (ΔLVI). The analysis was carried out over 784 local districts. The impact of per capita value added, agricultural intensity, industrial and tourism concentration, and urban growth was separately tested on ΔLVI. Results indicate that a lower district value added, crop intensification, irrigation, and the level of land vulnerability to degradation are strongly associated with the increasing level of land vulnerability over time, highlighting the role of the socioeconomic development as a main process underlying LD. In this framework, spatially equitable sustainable development may represent the effective strategy to mitigate the detrimental effects of economic growth and regional disparities on Mediterranean LD.     

Exposure and vulnerability to climate extremes: population and asset exposure to coastal flooding in Dar es Salaam, Tanzania

The paper provides a first quantitative estimate of the potential number of people and value of assets exposed to coastal flooding in Dar es Salaam, Tanzania. The study used an elevation-based geographic information system-analysis based on physical exposure and socio-economic vulnerability under a range of climate and socio-economic scenarios. It particularly considered a worst-case scenario assuming even if defences (natural and/or man-made) exist, they are subjected to failure under a 100-year flood event. About 8% of Dar es Salaam lies within the low-elevation coastal zone (below the 10 m contour lines). Over 210,000 people could be exposed to a 100-year coastal flood event by 2070, up from 30,000 people in 2005. The asset that could be damaged due to such event is also estimated to rise from US35 million (2005) to US35 million (2005) to US10 billion (2070). Results show that socio-economic changes in terms of rapid population growth, urbanisation, economic growth, and their spatial distribution play a significant role over climate change in the overall increase in exposure. However, the study illustrates that steering development away from low-lying areas that are not (or less) threatened by sea-level rise and extreme climates could be an effective strategic response to reduce the future growth in exposure. Enforcement of such policy where informal settlements dominate urbanisation (as in many developing countries) could undoubtedly be a major issue. It should be recognised that this analysis only provides indicative results. Lack of sufficient and good quality observational local climate data (e.g. long-term sea-level measurements), finer-resolution spatial population and asset distribution and local elevation data, and detailed information about existing coastal defences and current protection levels are identified as limitations of the study. As such, it should be seen as a first step towards analysing these issues and needs to be followed by more detailed, city-based analyses.     

Shocks and coping strategies of coastal communities in war–conflict-affected areas of the north and east of Sri Lanka

A quantitative survey of 1,377 households in three war-affected coastal districts of Jaffna, Mannar and Trincomalee in the north and east of Sri Lanka shows that inflation or price hikes, specially fuel, and natural disasters such as floods and droughts are highlighted as the shocks with the biggest impacts on fisher and non-fisher households. We hypothesise that the pattern/severity of households’ coping strategies to face these shocks depends on a set of household characteristics: livelihood diversity, asset ownership, level of education and the ability to borrow. Livelihood diversity, asset ownership and borrowings correlate significantly with the severity of coping strategies adopted by households for both fisher and non-fisher households. Education and livelihood diversification does not show a significant correlation for fisher households although it significantly affects livelihood diversification of both types of households.     

Livelihood asset maps: a multidimensional approach to measuring risk-management capacity and adaptation policy targeting—a case study in Bhutan

The application of a livelihood asset-based approach to adaptation policy targeting is presented through the creation of maps highlighting the spatial contrasts of access to various types of livelihood assets utilizing primary household data. Thus, the livelihood maps provide policy-makers with a tool to quickly identify areas with limited access to certain types of assets, making the latter less able to react to a changing level of climate-related risks. In the case of Bhutan, distinct spatial patterns of asset endowments is identified using five different asset indicators drawing attention to the fact that some areas facing increased level of climate-related risks lack access to productive and human capital, while other areas facing a similar situation have relatively insufficient access to financial assets. This again shows that any non-targeted policy aiming at improving households’ risk-management capacities through asset-building would have quite diverse results even among closely located districts in Bhutan. Finally, relevant policy options concerning the various dimensions of asset holdings are discussed so as to identify options that may benefit poor and vulnerable no matter if the expected outcomes of a changing climate are realized or not.     

Benefits of adapting to sea level rise: the importance of ecosystem services in the French Mediterranean sandy coastline

Regional Environmental Change - This article proposes an innovative approach to assess the benefits of adapting to sea level rise (SLR) in a coastal area on a regional scale. The valuation...     

Isotope tracing of submarine groundwater discharge offshore Ubatuba, Brazil: results of the IAEA-UNESCO SGD project

Results of groundwater and seawater analyses for radioactive ((3)H, (222)Rn, (223)Ra, (224)Ra, (226)Ra, and (228)Ra) and stable (D and (18)O) isotopes are presented together with in situ spatial mapping and time series (222)Rn measurements in seawater, direct seepage measurements using manual and automated seepage meters, pore water investigations using different tracers and piezometric techniques, and geoelectric surveys probing the coast. This study represents first time that such a new complex arsenal of radioactive and non-radioactive tracer techniques and geophysical methods have been used for simultaneous submarine groundwater discharge (SGD) investigations. Large fluctuations of SGD fluxes were observed at sites situated only a few meters apart (from 0cmd(-1) to 360cmd(-1); the unit represents cm(3)/cm(2)/day), as well as during a few hours (from 0cmd(-1) to 110cmd(-1)), strongly depending on the tidal fluctuations. The average SGD flux estimated from continuous (222)Rn measurements is 17+/-10cmd(-1). Integrated coastal SGD flux estimated for the Ubatuba coast using radium isotopes is about 7x10(3)m(3)d(-1) per km of the coast. The isotopic composition (deltaD and delta(18)O) of submarine waters was characterised by significant variability and heavy isotope enrichment, indicating that the contribution of groundwater in submarine waters varied from a small percentage to 20%. However, this contribution with increasing offshore distance became negligible. Automated seepage meters and time series measurements of (222)Rn activity concentration showed a negative correlation between the SGD rates and tidal stage. This is likely caused by sea level changes as tidal effects induce variations of hydraulic gradients. The geoelectric probing and piezometric measurements contributed to better understanding of the spatial distribution of different water masses present along the coast. The radium isotope data showed scattered distributions with offshore distance, which imply that seawater in a complex coast with many small bays and islands was influenced by local currents and groundwater/seawater mixing. This has also been confirmed by a relatively short residence time of 1-2 weeks for water within 25km offshore, as obtained by short-lived radium isotopes. The irregular distribution of SGD seen at Ubatuba is a characteristic of fractured rock aquifers, fed by coastal groundwater and recirculated seawater with small admixtures of groundwater, which is of potential environmental concern and has implications on the management of freshwater resources in the region.     

Australian approaches to coastal vulnerability assessment

The Australian coastline is one of the longest and most diverse of any in the world, and Australian researchers have developed preliminary models of the behaviour of major coastal systems such as beaches and reefs. The Australian population is particularly focused along the coastline, especially in metropolitan centres; however, the population of regional centres along the coast is increasing steadily in response to a phenomenon termed seachange. Coastal systems are increasingly threatened by potential impacts as a result of climate change, as indicated by the successive assessments by the Intergovernmental Panel on Climate Change (IPCC). Although Australia played a central role in applying a common methodology (CM), developed from IPCC guidelines in the 1990s, and in devising alternative approaches, which were initially trialled at nine sites on the Australian coast, there has not been a nationally co-ordinated approach to assessing the coastal vulnerability of Australia, and such an approach is only emerging now. Instead, there have been a series of different approaches adopted to look at the different parts of the Australian coast, including wetland mapping in northern Australia; geomorphic unit mapping in South Australia; storm surge vulnerability modelling in Queensland; probabilistic approaches to beach erosion in New South Wales; indicative mapping of potential coastal retreat in Tasmania. Additionally, there have been methods proposed by insurers and coastal engineers to meet their requirements. Since 2005, the Australian government has once again seen the need for a national coastal vulnerability assessment, and a series of studies are planned or under way to achieve the aims of a National Climate Change Adaptation Framework.     

Perception of the effects of climate change in winter and summer tourist areas: the Pyrenees and the Catalan and Balearic coasts,Spain

In this study, we compare the perception of climate change in two different tourist settings of northeastern Spain: the Catalan Pyrenees and the Catalan Mediterranean coast and the Balearic Islands. We carried out a survey of 906 cases (506 in the coastal areas of Catalonia and the Balearic Islands and 400 in the Catalan Pyrenees) asking residents on those areas to assess the possible effects of climate change on tourist-related activities. While the existence of climate change and of its estimated impacts is widely accepted, we observe statistically significant differences in most of the questions between residents in the coastal areas and residents in the Pyrenees. In general terms, respondents from the Pyrenees display a much higher concern regarding the economic impacts of climate change on tourism. On the other hand, the results also show that some demographic groups, such as women, members of large households, or unemployed, tend to present higher levels of concern. This study may give new hints on which tourist modalities and which groups are more concerned for the impacts of climate change in Mediterranean tourist environments and could translate into more targeted adaptive and mitigation practices.     

Dose assessment for marine biota and humans from discharge of (131)I to the marine environment and uptake by algae in Sydney, Australia

Iodine-131 reaches the marine environment through its excretion to the sewer by nuclear medicine patients followed by discharge through coastal and deepwater outfalls. ¹³¹I has been detected in macroalgae, which bio-accumulate iodine, growing near the coastal outfall of Cronulla sewage treatment plant (STP) since 1995. During this study, ¹³¹I levels in liquid effluent and sludge from three Sydney STPs as well as in macroalgae (Ulva sp. and Ecklonia radiata) growing near their shoreline outfalls were measured. Concentration factors of 176 for Ulva sp. and 526 for E. radiata were derived. Radiation dose rates to marine biota from ¹³¹I discharged to coastal waters calculated using the ERICA dose assessment tool were below the ERICA screening level of 10 μGy/hr. Radiation dose rates to humans from immersion in seawater or consumption of Ulva sp. containing ¹³¹I were three and two orders of magnitude below the IAEA screening level of 10 μSv/year, respectively.     

Physical basis of coastal adaptation on tropical small islands

Small tropical islands are widely recognized as having high exposure and vulnerability to climate change and other natural hazards. Ocean warming and acidification, changing storm patterns and intensity, and accelerated sea-level rise pose challenges that compound the intrinsic vulnerability of small, remote, island communities. Sustainable development requires robust guidance on the risks associated with natural hazards and climate change, including the potential for island coasts and reefs to keep pace with rising sea levels. Here we review these issues with special attention to their implications for climate-change vulnerability, adaptation, and disaster risk reduction in various island settings. We present new projections for 2010–2100 local sea-level rise (SLR) at 18 island sites, incorporating crustal motion and gravitational fingerprinting, for a range of Intergovernmental Panel on Climate Change global projections and a semi-empirical model. Projected 90-year SLR for the upper limit A1FI scenario with enhanced glacier drawdown ranges from 0.56 to 1.01 m for islands with a measured range of vertical motion from ?0.29 to +0.10 m. We classify tropical small islands into four broad groups comprising continental fragments, volcanic islands, near-atolls and atolls, and high carbonate islands including raised atolls. Because exposure to coastal forcing and hazards varies with island form, this provides a framework for consideration of vulnerability and adaptation strategies. Nevertheless, appropriate measures to adjust for climate change and to mitigate disaster risk depend on a place-based understanding of island landscapes and of processes operating in the coastal biophysical system of individual islands.