Climate Change-induced Sea Level Rise Research Articles

Assess the human and environmental vulnerability for coastal hazard by using a multi-criteria decision analysis

ABSTRACTThis study provides an integrated approach using geographical information system (GIS) based on a multi-criteria approach (MCDA) to assess coastal vulnerability, resulting from human activity, population density, erosion, and climate change-induced sea level rise. A coastal vulnerability index (CVI) for erosion and floods was calculated and mapped (∼24 km in length; ∼400 m in width, and 11.47 km2 in surface) for the lagoon barrier of Nador located on the Mediterranean coast of Morocco. Results suggest that 54% (∼13 km) of the shoreline is moderately vulnerable, while 42% (∼10 km) is highly vulnerable and only 4% (1 km) present a low vulnerability. The vulnerability map of the socio-economic activities indicates that most wetlands and forest areas 83% (∼31 ha) and 50% (∼440 ha) respectively, present low vulnerability. 52% percent of artificial areas (∼23 ha), 73% of agricultural land (∼128 ha), and 41% of natural areas (∼363 ha) present moderate vulnerability. However, the level of vulnerability of the remaining artificial and agricultural areas classifies from high to very high. The north-western sector was classified as the most vulnerable area, characterized by an erosion (−0.6 m/yr to −1.20 m/yr) for 70% of this area, while the south-eastern part shows a low to moderate vulnerability marked by an erosion (−0.1 m/yr to −1m/yr) for 40% of this area. Coastal vulnerability maps have potential as decision tools to prepare and respond to sea level rise, and identify exposed coastal zones, as such contributing to national climate action and disaster risk reduction sustainable development goals (goals 13 and 11, respectively).

Projection of climate change-induced sea-level rise for the coasts of Tamil Nadu and Puducherry, India using SimCLIM: a first step towards planning adaptation policies

Climate change-induced sea-level rise (SLR) is one of the greatest challenges of the low-lying coastal regions of the world. Adaptation to the rising sea level is considered the most appropriate response measure to face this global challenge. However, this requires a pragmatic approach that’s locally suitable. The first step would be projecting SLR locally under different scenarios and at different time slices. SLR projections for specific coastal regions, particularly for developing countries are seldom available and this study puts forth a research question as to what will be the SLR projections under different scenarios for the chosen study area, i.e. the Tamil Nadu and Puducherry coast of India. SimCLIM climate modeling software has been used to project SLR for the Tamil Nadu and Puducherry coast in India for four periods of time slice namely 2025, 2050, 2075 and 2100 for all four RCP scenarios viz., RCP 2.6, RCP 4.5, RCP 6.0 and RCP 8.5 of IPCC AR5. It has been estimated that the projected average medium range of SLR for the chosen study area may range from 7.12 cm to 36.98 cm for RCP 2.6; 7.39 cm to 50.01 cm for RCP 4.5; 7.18 cm to 51.91 cm for RCP 6.0; 7.40 cm to 78.15 cm for RCP 8.5 for the time slices from 2025 to 2100. It is expected that the numbers gleaned from this study will be of a potential source of information for coastal policy-planners and decision-makers to take the first step towards planning time bound SLR adaptation policies to conserve coastal resources particularly for the coast of Tamil Nadu and Puducherry.

Building biogenic beachrock: Visualizing microbially-mediated carbonate cement precipitation using XFM and a strontium tracer

The fate of reef islands is a topic of ongoing debate in the face of climate change-induced sea-level rise and increased cyclone intensity. Increased erosion and changes to the supply of reef-derived sediment may put sand reef cays at risk of dramatic morphological changes. These changes may have negative implications for the existence of reef cay environments, which host vital sea turtle and bird rookery habitats. Beachrock, consolidated carbonate beach sediment in the intertidal zone, forms naturally on many tropical beaches and reduces the erosion rates of these beaches when compared to unconsolidated sand. In spite of the critical role beachrock plays in stabilizing some reef cay shores, the method of beachrock formation is still incompletely understood. In this investigation, beachrock was synthesized using beach sand and beachrock samples from Heron Island (Great Barrier Reef, Australia) in aquarium experiments in which natural beachrock formation conditions were simulated. Beachrock was produced in two aquaria wherein the water chemistry was influenced by microorganisms derived from the natural beachrock ‘inoculum’, whereas no cementation occurred in an aquarium that lacked a microbial inoculum and was controlled only by physicochemical evapoconcentration. The new cements in the synthesized beachrock were analyzed using synchrotron-based X-ray fluorescence microscopy and were identified using a Sr-tracer added to the experimental seawater. The resulting precipitates cement sand grains together and contain abundant microfossils of the microorganisms on whose exopolymer they nucleated, demonstrating the fundamental role microbes play in beachrock formation. These results are of interest because beachrock could be utilized as a natural coastline stabilization strategy on sand reef cays, and in turn, protect the unique habitats reef islands support.

Subsidizing Risk: The Regressive and Counterproductive Nature of National Flood Insurance Rate Setting in Massachusetts

In order to evaluate the progressivity of National Flood Insurance Program (NFIP) premiums in a coastal US state that is directly exposed to the impact of climate changeinduced sea level rise, this study examines the relationship between the average NFIP premium and the average property values of NFIP insured properties in 331 Massachusetts municipalities. We utilize community level average premium to property value ratio as a measure for comparison. Findings reveal an inverse relationship between insurance premiums paid (as a percentage of property value) and total property value. The greater the average property value, the lower the average premium paid. Conversely, the lower the average property value, the greater the average premium paid. In addition, the study analyzes subsets of municipalities that had certain thresholds of total property in flood prone areas. The strength of the inverse relationship between insurance premiums paid and total property value increases when subsets of municipalities with greater total property value at-risk are analyzed independently. Results suggest current policies in setting flood insurance rates in Massachusetts result in regressive premiums and, as a result, can increase incentives for risk taking.

Predicting the impacts of Mississippi River diversions and sea-level rise on spatial patterns of eastern oyster growth rate and production

There remains much debate regarding the perceived tradeoffs of using freshwater and sediment diversions for coastal restoration in terms of balancing the need for wetland restoration versus preserving eastern oyster (Crassostrea virginica) production. Further complicating the issue, climate change-induced sea-level rise (SLR) and land subsidence are also expected to affect estuarine water quality. In this study, we developed a process-based numerical modeling system that couples hydrodynamic, water quality, and oyster population dynamics. We selected Breton Sound Estuary (BSE) (∼2740km2) in the eastern Mississippi River Deltaic Plain since it is home to several of the largest public oyster seed grounds and private leases for the Gulf coast. The coupled oyster population model was calibrated and validated against field observed oyster growth data. We predicted the responses of oyster population in BSE to small- (142m3s−1) and large-scale (7080m3s−1) river diversions at the Caernarvon Freshwater Diversion structure planned in the 2012 Coastal Master Plan (Louisiana) under low (0.38m) and high (1.44m) relative sea-level rise (RSLR=eustatic SLR+subsidence) compared to a baseline condition (Year 2009). Model results showed that the large-scale diversion had a stronger negative impact on oyster population dynamics via freshening of the entire estuary, resulting in reduced oyster growth rate and production than RSLR. Under the large-scale diversion, areas with optimal oyster growth rates (>15mg ash-free dry weight (AFDW) oyster−1wk−1) and production (>500g AFDWm−2yr−1) would shift seaward to the southeastern edge of the estuary, turning the estuary into a very low oyster production system. RSLR however played a greater role than the small-scale diversion on the magnitude and spatial pattern of oyster growth rate and production. RSLR would result in an overall estuary-wide decrease in oyster growth rate and production as a consequence of decreased salinities in the middle and lower estuary because rising sea level likely causes increased stage and overbank flow downstream along the lower Mississippi River.

A Modeling Study of the Impacts of Mississippi River Diversion and Sea-Level Rise on Water Quality of a Deltaic Estuary

Freshwater and sediment management in estuaries affects water quality, particularly in deltaic estuaries. Furthermore, climate change-induced sea-level rise (SLR) and land subsidence also affect estuarine water quality by changing salinity, circulation, stratification, sedimentation, erosion, residence time, and other physical and ecological processes. However, little is known about how the magnitudes and spatial and temporal patterns in estuarine water quality variables will change in response to freshwater and sediment management in the context of future SLR. In this study, we applied the Delft3D model that couples hydrodynamics and water quality processes to examine the spatial and temporal variations of salinity, total suspended solids, and chlorophyll-α concentration in response to small (142 m3 s−1) and large (7080 m3 s−1) Mississippi River (MR) diversions under low (0.38 m) and high (1.44 m) relative SLR (RSLR = eustatic SLR + subsidence) scenarios in the Breton Sound Estuary, Louisiana, USA. The hydrodynamics and water quality model were calibrated and validated via field observations at multiple stations across the estuary. Model results indicate that the large MR diversion would significantly affect the magnitude and spatial and temporal patterns of the studied water quality variables across the entire estuary, whereas the small diversion tends to influence water quality only in small areas near the diversion. RSLR would also play a significant role on the spatial heterogeneity in estuary water quality by acting as an opposite force to river diversions; however, RSLR plays a greater role than the small-scale diversion on the magnitude and spatial pattern of the water quality parameters in this deltaic estuary.

PS 18-09 THE EFFECT OF SALT CONTAMINATED DRINKING WATER ON BLOOD PRESSURE OF YOUNG POPULATIONS IN COASTAL BANGLADESH

Objective: More than 35 million people in coastal Bangladesh are vulnerable to increasing freshwater salinization. This will continue to affect more people and to a greater extent as climate change projections are realised in this area. However the evidence for health effects of consuming high salinity potable water is limited. This research examined the association between high salinity potable water and blood pressure in young adults in coastal Bangladesh. Design and Method: We conducted a cross-sectional study during May-June 2014 in a rural coastal sub-district of Bangladesh. Data on BP and salinity of potable water sources was collected from 251 participants aged 19–25 years. A linear regression method was used to examine the association between water salinity exposure categories and systolic (SBP) and diastolic BP (DBP) level. Results: Mean salinity concentration in drinking water was 817 mg/L, which was above the Bangladesh standard for salinity in drinking water. Multivariable linear regression analyses identified that compared to the low water salinity exposure category (< 600 mg/L), those in the high water salinity category (> 600 mg/L), had statistically significantly higher SBP (B 3.35, 95% CI 0.66, 6.05; p = 0.015) and DBP (B 2.85, 95% CI 0.40, 5.30; p = 0.023). Conclusions: Our research shows that elevated salinity in drinking water is associated with an increase in BP in young coastal populations. Blood pressure is an important biomarker of hypertension and cardiovascular diseases. Given the extent of salinization of freshwater in many low-lying countries including in Bangladesh, and the likely exacerbation related to climate change-induced sea level rise, implementation of preventative strategies through dietary interventions along with promotion of low saline drinking water must be a priority in these settings.

Growth of Coastal Population: Likely Exposure to Sea Level Rise and Associated Storm Surge Flooding in the Sultanate of Oman

Coastal zones are densely populated than the hinterland and exhibit higher rates of population growth and urbanization. As this trend is expected to continue into the future in the case of Oman as well since more population is living the along coast. On the other hand, this population has likely exposure to coastal hazards including sea-level rise and associated storm surge flooding effects. This study investigated extent of inundation to sea level rise and built up areas exposure to possible storm surge flooding cross governorates at different scenarios. Use of remote sensing data and GIS applications employed for the assessments. Results show that the coastal area of the Governorates of Al- Wusta and South Al Sharquiya will be highly exposed to the most likely tropical cyclones since these areas are characterized by a flat topography. Further, the results of assessment show that Oman is highly vulnerable to climate change-induced sea level rise (SLR). At the national scale, nearly 400 square kilometer of total land area is projected to be inundated under the smallest SLR scenario. Overall, the assessment results highlight that Oman is vulnerable to coastal flooding and SLR therefore policies and adaptive planning for building resilient coastal communities are essential for the future.

Phenotypic plasticity and population differentiation in response to salinity in the invasive cordgrass Spartina densiflora

Salinity and tidal inundation induce physiological stress in vascular plant species and influence their distribution and productivity in estuarine wetlands. Climate change-induced sea level rise may magnify these abiotic stressors and the physiological stresses they can cause. Understanding the potential of invasive plants to respond to predicted salinity increases will elucidate their potential niche breadth. To examine potential phenotypic plasticity and functional trait responses to salinity stress in the invasive cordgrass Spartina densiflora, we collected rhizomes from four invasive populations occurring from California to Vancouver Island, British Columbia on the Pacific Coast of North America. In a glasshouse common garden experiment, we measured plant traits associated with growth and allocation, photosynthesis, leaf pigments, and leaf chemistry and calculated plasticity indices across imposed salinity treatments. Fifteen of 21 leaf chemistry, pigment, morphological and physiological traits expressed plastic responses to salinity. When averaged across all measured traits, degree of plasticity did not vary among sampled populations. However, differences in plasticity among populations in response to salinity were observed for 9 of 21 measured plant traits. Leaf chemistry and adaxial leaf rolling trait responses demonstrated the highest degree of plasticity, while growth and allocation measures were less plastic. Phenotypic plasticity of leaf functional traits to salinity indicates the potential of S. densiflora to maintain invasive growth in response to rising estuarine salinity with climate change.

Small-scale benthos distribution modelling in a North Sea tidal basin in response to climatic and environmental changes (1970s-2009)

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 551:13-30 (2016) - DOI: https://doi.org/10.3354/meps11756 Small-scale benthos distribution modelling in a North Sea tidal basin in response to climatic and environmental changes (1970s-2009) A. Singer1,2,*, U. Schückel1, M. Beck3, O. Bleich4, H.-J. Brumsack3, H. Freund3, C. Geimecke5, K. A. Lettmann3, G. Millat6, J. Staneva5, A. Vanselow3, H. Westphal7, J.-O. Wolff3, A. Wurpts7, I. Kröncke1 1Senckenberg am Meer, Dept. for Marine Research, Südstrand 40, 26382 Wilhelmshaven, Germany 2INTERCOAST Research Training Group, University of Bremen, Leobener Strasse, 26359 Bremen, Germany 3Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl von Ossietzky University, Carl-von-Ossietzky-Str. 9-11, 26129 Oldenburg, Germany 4Fraunhofer Institute for Wind Energy and Energy System Technology, Am Seedeich 45, 27572 Bremerhaven, Germany 5Helmholtz-Centre Geesthacht (HZG), Max-Planck-Straße 1, 21502 Geesthacht, Germany 6National Park Administration Wadden Sea Lower Saxony (NLPV), Virchowstraße 1, 26382 Wilhelmshaven, Germany 7Coastal Research Station - Lower Saxony Water Management, Coastal Defence and Nature Conservation Agency (NLWKN), An der Mühle 5, 26548 Norderney, Germany *Corresponding author: anja.singer@senckenberg.de ABSTRACT: We used small-scale species distribution models to predict the past and present spatial distribution of 7 characteristic macrofauna species in response to climatic and environmental changes that have been recorded for the Jade Bay (German Wadden Sea) over the last 4 decades (1970s to 2009). Four presence-absence modelling algorithms (RF, MARS, GLM, GBM) were merged within the ensemble forecasting platform ‘biomod2’. The present spatial distribution (representing 2009) was modelled based on statistical relationships between species presences, true species absences and 7 high-resolution (5 m) environmental grids. The past spatial distribution (representing the 1970s) was then hindcast in response to climate change-induced (1) sea-level rise, (2) water temperature increase and (3) seagrass recovery due to de-eutrophication. The past distribution scenario was evaluated using independent historical macrofauna data from the 1970s. Present ensemble prediction maps accurately captured the potential ecological niches of the modelled species throughout Jade Bay (i.e. good to excellent true skill statistic [TSS] and area under the receiver operating characteristic curve [AUC] evaluation measures). The predicted present macrofauna distribution correlated most significantly with hydrodynamic conditions (submergence time, shear stress) and sediment characteristics (mud content). The past distribution scenario revealed significant changes in small-scale spatial distribution patterns of the characteristic modelled species (1970s to 2009) and showed a very good match with historical macrofauna data. Climate change-induced sea-level rise and its local implications for Jade Bay (changes in topography, tidal range and submergence time), and water temperature increase explained the potential macrofauna distribution shifts over the last 4 decades. KEY WORDS: Ensemble models · Hindcasting · Sea-level rise · Water temperature increase · Wadden Sea World Heritage Site · Seagrass recovery · Marine ecosystems · Benthos Full text in pdf format Supplementary material PreviousNextCite this article as: Singer A, Schückel U, Beck M, Bleich O and others (2016) Small-scale benthos distribution modelling in a North Sea tidal basin in response to climatic and environmental changes (1970s-2009). Mar Ecol Prog Ser 551:13-30. https://doi.org/10.3354/meps11756 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 551. Online publication date: June 09, 2016 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2016 Inter-Research.

The effect of drinking water salinity on blood pressure in young adults of coastal Bangladesh

More than 35 million people in coastal Bangladesh are vulnerable to increasing freshwater salinization. This will continue to affect more people and to a greater extent as climate change projections are realised in this area in the future. However the evidence for health effects of consuming high salinity water is limited. This research examined the association between drinking water salinity and blood pressure in young adults in coastal Bangladesh. We conducted a cross-sectional study during May-June 2014 in a rural coastal sub-district of Bangladesh. Data on blood pressure (BP) and salinity of potable water sources was collected from 253 participants aged 19–25 years. A linear regression method was used to examine the association between water salinity exposure categories and systolic BP (SBP) and diastolic BP (DBP) level. Sixty five percent of the study population were exposed to highly saline drinking water above the Bangladesh standard (600 mg/L and above). Multivariable linear regression analyses identified that compared to the low water salinity exposure category (<600 mg/L), those in the high water salinity category (>600 mg/L), had statistically significantly higher SBP (B 3.46, 95% CI 0.75, 6.17; p = 0.01) and DBP (B 2.77, 95% CI 0.31, 5.24; p = 0.03). Our research shows that elevated salinity in drinking water is associated with higher BP in young coastal populations. Blood pressure is an important risk factor of hypertension and cardiovascular diseases. Given the extent of salinization of freshwater in many low-lying countries including in Bangladesh, and the likely exacerbation related to climate change-induced sea level rise, implementation of preventative strategies through dietary interventions along with promotion of low saline drinking water must be a priority in these settings.

Contrasting Effects of Historical Sea Level Rise and Contemporary Ocean Currents on Regional Gene Flow of Rhizophora racemosa in Eastern Atlantic Mangroves

Mangroves are seafaring taxa through their hydrochorous propagules that have the potential to disperse over long distances. Therefore, investigating their patterns of gene flow provides insights on the processes involved in the spatial genetic structuring of populations. The coastline of Cameroon has a particular geomorphological history and coastal hydrology with complex contemporary patterns of ocean currents, which we hypothesize to have effects on the spatial configuration and composition of present-day mangroves within its spans. A total of 982 trees were sampled from 33 transects (11 sites) in 4 estuaries. Using 11 polymorphic SSR markers, we investigated genetic diversity and structure of Rhizophora racemosa, a widespread species in the region. Genetic diversity was low to moderate and genetic differentiation between nearly all population pairs was significant. Bayesian clustering analysis, PCoA, estimates of contemporary migration rates and identification of barriers to gene flow were used and complemented with estimated dispersal trajectories of hourly released virtual propagules, using high-resolution surface current from a mesoscale and tide-resolving ocean simulation. These indicate that the Cameroon Volcanic Line (CVL) is not a present-day barrier to gene flow. Rather, the Inter-Bioko-Cameroon (IBC) corridor, formed due to sea level rise, allows for connectivity between two mangrove areas that were isolated during glacial times by the CVL. Genetic data and numerical ocean simulations indicated that an oceanic convergence zone near the Cameroon Estuary complex (CEC) presents a strong barrier to gene flow, resulting in genetic discontinuities between the mangrove areas on either side. This convergence did not result in higher genetic diversity at the CEC as we had hypothesized. In conclusion, the genetic structure of Rhizophora racemosa is maintained by the contrasting effects of the contemporary oceanic convergence and historical climate change-induced sea level rise.

Assessment of the Impacts of Sea Level Rise on Mangrove Dynamics in the Indian Part of Sundarbans Using Geospatial Techniques

The intertidal mangrove ecosystem of Indian Sundarban is now as a critical ecosystem due to climate changeinduced sea level rise. The present study analyses the responses, migration, destruction and vulnerability of the four deltaic mangrove ecosystem, such as Jambudwip, Bulcherry, Dalhousie and Bangaduni Islands along the ocean sides. The changes in this deltaic ecosystem studied by using GIS and remote sensing with collecting data about sea level of nearest tidal gauge station Haldia (2.59 ± 1.0 mm/year) and Diamond Harbor (4.67 ± 0.68 mm/year). The study finds that if the sea level rises about mangrove surface, the mangrove retreats landward and also decline the land areas, increases soil erosion that affected in the southern and south-western part where these vulnerable mangrove islands are located. Moreover, the study indicates that the low-level mangrove islands would threaten with the rates of increasing sea level under present climate change. However, the amount of net loss is about 10009 ha at the rate of 164.08 ha per year of the four more vulnerable islands. In the context of climate change induced sea level rise there also needs long-term thinking and coastal zone management option that must have economic feasibility. Thus, the dynamics of the mangrove ecosystem in response to projected sea level rise enable to take appropriate planning for reducing threats and human safety along the coastal areas.

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.

Comparing the economic effects of climate change and zooanthroponosis in Korea: Prerequisites for the creative economy?

Societies in the 21st century require more proactive management of risks in many areas owing to the complexities people have built into socioeconomic systems, ranging from science and technology, economics, and finance to education, entertainment, and tourism infrastructure. All these systems thrive on stability, which can easily be challenged by unexpected risks. This study compares zooanthroponosis and climate change-induced sea level rise through a cost–benefit analysis in Korea. Borrowing from other methodological approaches, this study shows that the cost–benefit estimation is consistent with the existing macroeconomic speculations, which assume potential loss of GDP due to the two risks. This paper also presents a policy alternative of creating research institutions specializing in the two risks from a cost–benefit perspective as a prerequisite for the "Creative Economy".

Realizing managed retreat and innovation in state-level coastal management planning

U.S. coastal areas are projected to experience varying degrees of climate-change induced sea level rise (SLR), erosion and inundation in the next century. More than half of the country's population lives in a coastal area, putting growth on a collision course with observed and anticipated climate change impacts. This research examines the current status of the state-level coastal management toolbox and their ease of implementation compared to the ideal of managed retreat, and the emergence of innovative tools in response to climate change impacts. The first of a two-phased methodology, the authors conducted document collection to generate a regulatory context for each coastal state, followed by survey administration to record a temporal slice of both the managed retreat efforts and the self-identified and empirically determined coastal management innovations in 29 coastal states. The authors generated a new definition of innovation in the coastal management canon, and conducted follow-up interviews with those empirically innovative states. Despite site-contingent application of the managed retreat ideal tools, soft stabilization remains the most ubiquitous and easiest tool category to implement in urban coastal areas. The managed retreat ideal's fixed setbacks, land acquisition, and hazardous zoning tools are used more frequently than most modification of development tools, particularly in the innovative states. Coastal management tool innovations reflect the managed retreat ideal's holistic ocean/estuarine shoreline management intent. But additional innovation is needed to generate long-term strategies that balance growth pressure with dynamic coastal processes. Program implementation still lags, given the property rights battles that are increasingly relevant in the current political climate.

GIS-based Framework for the Simulation of the Impacts of Sea Level Rise and Coastal Flooding on Oman

The Sultanate of Oman has a shoreline of 3,165 km and offers a diverse range of natural resources and promising circumstances for social and economic development According to the Oman general census of 2010, 80% of the Omani population lives in low-lying areas such as coastal plains and could be threatened by Sea Level Rise (SLR). During the last five years the country witnessed two strong tropical cyclones, Gonu 2007 and Phet 2010 revealed the extreme vulnerability of the populated Omani coast to storm surge and flooding. The impact of SLR on the entire Omani coastal zone was assessed to develop estimates of inundated land area relative to a set of SLR scenarios. The impact of SLR was evaluated through the use of a GIS framework. A total of 7 SLR scenarios were considered: 0.2 meters, 0.5 meters, 1 meter, 2 meters, 3 meters, 4 meters and 5 meters. The sea level scenarios were overlain on land use/elevation datasets to estimate the inundation risk among all land use categories. All the grid cells that would be inundated based on a user-defined horizontal spatial resolution of 0.5 meters for the entire coastline. The results of the assessment show that Oman is highly vulnerable to climate change-induced SLR. At the national scale, nearly 400 km2 of total land area is projected to be inundated under the smallest SLR scenario. Under the highest SLR scenario, over 900 km2 is potentially inundated. An assessment of the vulnerability of productive land use shows that the Al-Batinah and Muscat governorates are the most vulnerable under all SLR scenarios. The findings of this study, shows that an urgent need to develop a strategic coastal management plan to face the challenges of the climate change, and to provide a clear outlook of the Omani coastal areas for better adaptive resilience and responses.

Simulations of Hurricane Katrina (2005) under sea level and climate conditions for 1900

Global warming may result in substantial sea level rise and more intense hurricanes over the next century, leading to more severe coastal flooding. Here, observed climate and sea level trends over the last century (c. 1900s to 2000s) are used to provide insight regarding future coastal inundation trends. The actual impacts of Hurricane Katrina (2005) in New Orleans are compared with the impacts of a similar hypothetical hurricane occurring c. 1900. Estimated regional sea level rise since 1900 of 0.75 m, which contains a dominant land subsidence contribution (0.57 m), serves as a ‘prototype’ for future climate-change induced sea level rise in other regions. Landform conditions c. 1900 were estimated by changing frictional resistance based on expected additional wetlands at lower sea levels. Surge simulations suggest that flood elevations would have been 15 to 60 % lower c. 1900 than the conditions observed in 2005. This drastic change suggests that significantly more flood damage occurred in 2005 than would have occurred if sea level and climate conditions had been like those c. 1900. We further show that, in New Orleans, sea level rise dominates surge-induced flooding changes, not only by increasing mean sea level, but also by leading to decreased wetland area. Together, these effects enable larger surges. Projecting forward, future global sea level changes of the magnitude examined here are expected to lead to increased flooding in coastal regions, even if the storm climate is unchanged. Such flooding increases in densely populated areas would presumably lead to more widespread destruction.

Sea-level rise and planning: retrospect and prospect

Twenty-five years on from Graeme Pearman's review of coastal planning issues arising from climate change-induced sea-level rise, this article reviews the progress of our understanding of the scientific and geomorphological processes that are beginning to impact upon coastal communities. We outline legal and policy developments and specifically address perhaps the thorniest question facing governments – namely, how to address existing coastal developments threatened by rising sea levels. A Decision Mapping approach designed to assist local councils in analysing threats and developing policy initiatives is described.

California coastal management with a changing climate

With over 2,000 miles (3,218 km) of ocean and estuarine coastline, California faces significant coastal management challenges as a result of climate change-induced sea level rise. Under high emission scenarios, recent models predict 1.4 m or more of sea level rise by 2100, accompanied by increasing storm surges. This article investigates the most important issues facing coastal managers, explores the policy tools available for adapting to the impacts of climate change, assesses institutional constraints to adaptation, and identifies priorities for future research and policy action. We find that adaptation tools exist for dealing with anticipated increases in coastal erosion and flooding, but they involve significant costs and tradeoffs. In particular, coastal armoring, such as seawalls, can protect developed coastal lands, but destroys beaches and habitat. Although California already has policies and institutions that aim to balance the competing objectives for coastal development, management agencies are at the early stages of understanding how to facilitate adaptation. Research priorities to inform coastal adaptation planning include: (i) inventorying coastal resources to provide a firmer basis for balancing decisions on property and habitat protection, (ii) identifying opportunities for coastal habitat migration, (iii) assessing the vulnerabilities of existing and planned coastal infrastructure, and (iv) experimenting with alternatives to armoring as a way of managing the changing coastline.