WorldWideScience

Sample records for century sea-level rise

  1. Probabilistic reanalysis of twentieth-century sea-level rise

    Science.gov (United States)

    Hay, Carling C.; Morrow, Eric; Kopp, Robert E.; Mitrovica, Jerry X.

    2015-01-01

    Estimating and accounting for twentieth-century global mean sea-level (GMSL) rise is critical to characterizing current and future human-induced sea-level change. Several previous analyses of tide gauge records--employing different methods to accommodate the spatial sparsity and temporal incompleteness of the data and to constrain the geometry of long-term sea-level change--have concluded that GMSL rose over the twentieth century at a mean rate of 1.6 to 1.9 millimetres per year. Efforts to account for this rate by summing estimates of individual contributions from glacier and ice-sheet mass loss, ocean thermal expansion, and changes in land water storage fall significantly short in the period before 1990. The failure to close the budget of GMSL during this period has led to suggestions that several contributions may have been systematically underestimated. However, the extent to which the limitations of tide gauge analyses have affected estimates of the GMSL rate of change is unclear. Here we revisit estimates of twentieth-century GMSL rise using probabilistic techniques and find a rate of GMSL rise from 1901 to 1990 of 1.2 +/- 0.2 millimetres per year (90% confidence interval). Based on individual contributions tabulated in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, this estimate closes the twentieth-century sea-level budget. Our analysis, which combines tide gauge records with physics-based and model-derived geometries of the various contributing signals, also indicates that GMSL rose at a rate of 3.0 +/- 0.7 millimetres per year between 1993 and 2010, consistent with prior estimates from tide gauge records. The increase in rate relative to the 1901-90 trend is accordingly larger than previously thought; this revision may affect some projections of future sea-level rise.

  2. Contemporary sea level rise.

    Science.gov (United States)

    Cazenave, Anny; Llovel, William

    2010-01-01

    Measuring sea level change and understanding its causes has considerably improved in the recent years, essentially because new in situ and remote sensing observations have become available. Here we report on most recent results on contemporary sea level rise. We first present sea level observations from tide gauges over the twentieth century and from satellite altimetry since the early 1990s. We next discuss the most recent progress made in quantifying the processes causing sea level change on timescales ranging from years to decades, i.e., thermal expansion of the oceans, land ice mass loss, and land water-storage change. We show that for the 1993-2007 time span, the sum of climate-related contributions (2.85 +/- 0.35 mm year(-1)) is only slightly less than altimetry-based sea level rise (3.3 +/- 0.4 mm year(-1)): approximately 30% of the observed rate of rise is due to ocean thermal expansion and approximately 55% results from land ice melt. Recent acceleration in glacier melting and ice mass loss from the ice sheets increases the latter contribution up to 80% for the past five years. We also review the main causes of regional variability in sea level trends: The dominant contribution results from nonuniform changes in ocean thermal expansion.

  3. Determination and characterization of 20th century global sea level rise

    Science.gov (United States)

    Kuo, Chung-Yen

    In this study, we provide a determination of the 20th Century (1900--2002) global sea level rise, the associated error budgets, and the quantifications of the various geophysical sources of the observed sea level rise, using data and geophysical models. We analyzed significant geographical variations of the global sea level including those caused by the steric component (heat and salinity) in the ocean, and the self-gravitational signal as a result of ice sheets melting, including the effects of glacial isostatic adjustment (GIA) since the Pleistocene. In particular, relative sea level data from long-term (longest is 150 year records) and over 600 tide gauge sites globally from PSMSL and other sources, and geocentric sea level data from multiple satellite altimetry (1985--2005) have been used to determine and characterize 20th century global sea level rise. Altimeter and selected tide gauge sea level data have been used for the 20th century sea level determination, accounting for relative biases between the altimeters, effects of sea level corresponding to oceanic thermal expansion, vertical motions affecting tide gauge measurements, self gravitations, and barotropic ocean response. This study is also characterized by the roles of the polar ocean in the global sea level study and addressing the question whether there is a detectable sea level rise acceleration during the last decade. Vertical motions have been estimated by combining geocentric sea level measurements from satellite altimetry (TOPEX/POSEIDON) and long-term relative (crust-fixed) sea level records from global tide gauges using the Gauss-Markov (GM) model with stochastic constraints. The study provided a demonstration of improved vertical motion solutions in semi-enclosed seas and lakes, including Fennoscandia and the Great Lakes region, showing excellent agreement with independent GPS observed radial velocities, or with predictions from GIA models. In general, the estimated uncertainty of the observed

  4. Efficacy of geoengineering to limit 21st century sea-level rise.

    Science.gov (United States)

    Moore, J C; Jevrejeva, S; Grinsted, A

    2010-09-07

    Geoengineering has been proposed as a feasible way of mitigating anthropogenic climate change, especially increasing global temperatures in the 21st century. The two main geoengineering options are limiting incoming solar radiation, or modifying the carbon cycle. Here we examine the impact of five geoengineering approaches on sea level; SO(2) aerosol injection into the stratosphere, mirrors in space, afforestation, biochar, and bioenergy with carbon sequestration. Sea level responds mainly at centennial time scales to temperature change, and has been largely driven by anthropogenic forcing since 1850. Making use a model of sea-level rise as a function of time-varying climate forcing factors (solar radiation, volcanism, and greenhouse gas emissions) we find that sea-level rise by 2100 will likely be 30 cm higher than 2000 levels despite all but the most aggressive geoengineering under all except the most stringent greenhouse gas emissions scenarios. The least risky and most desirable way of limiting sea-level rise is bioenergy with carbon sequestration. However aerosol injection or a space mirror system reducing insolation at an accelerating rate of 1 W m(-2) per decade from now to 2100 could limit or reduce sea levels. Aerosol injection delivering a constant 4 W m(-2) reduction in radiative forcing (similar to a 1991 Pinatubo eruption every 18 months) could delay sea-level rise by 40-80 years. Aerosol injection appears to fail cost-benefit analysis unless it can be maintained continuously, and damage caused by the climate response to the aerosols is less than about 0.6% Global World Product.

  5. Coastal flood damage and adaptation costs under 21st century sea-level rise.

    Science.gov (United States)

    Hinkel, Jochen; Lincke, Daniel; Vafeidis, Athanasios T; Perrette, Mahé; Nicholls, Robert James; Tol, Richard S J; Marzeion, Ben; Fettweis, Xavier; Ionescu, Cezar; Levermann, Anders

    2014-03-04

    Coastal flood damage and adaptation costs under 21st century sea-level rise are assessed on a global scale taking into account a wide range of uncertainties in continental topography data, population data, protection strategies, socioeconomic development and sea-level rise. Uncertainty in global mean and regional sea level was derived from four different climate models from the Coupled Model Intercomparison Project Phase 5, each combined with three land-ice scenarios based on the published range of contributions from ice sheets and glaciers. Without adaptation, 0.2-4.6% of global population is expected to be flooded annually in 2100 under 25-123 cm of global mean sea-level rise, with expected annual losses of 0.3-9.3% of global gross domestic product. Damages of this magnitude are very unlikely to be tolerated by society and adaptation will be widespread. The global costs of protecting the coast with dikes are significant with annual investment and maintenance costs of US$ 12-71 billion in 2100, but much smaller than the global cost of avoided damages even without accounting for indirect costs of damage to regional production supply. Flood damages by the end of this century are much more sensitive to the applied protection strategy than to variations in climate and socioeconomic scenarios as well as in physical data sources (topography and climate model). Our results emphasize the central role of long-term coastal adaptation strategies. These should also take into account that protecting large parts of the developed coast increases the risk of catastrophic consequences in the case of defense failure.

  6. Glaciers dominate eustatic sea-level rise in the 21st century

    Science.gov (United States)

    Meier, Mark Frederick; Dyurgerov, M.B.; Rick, Ursula K.; Pfeffer, William Tad; Anderson, Suzanne P.; Glazovsky, Andrey F.

    2007-01-01

    Ice loss to the sea currently accounts for virtually all of the sea-level rise that is not attributable to ocean warming, and about 60% of the ice loss is from glaciers and ice caps rather than from the two ice sheets. The contribution of these smaller glaciers has accelerated over the past decade, in part due to marked thinning and retreat of marine-terminating glaciers associated with a dynamic instability that is generally not considered in mass-balance and climate modeling. This acceleration of glacier melt may cause 0.1 to 0.25 meter of additional sea-level rise by 2100.

  7. 21st-Century Sea Level Rise, Economic Growth, and Seawater Intrusion in Coastal Aquifers of California

    Science.gov (United States)

    Loaiciga, H. A.; Pingel, T.

    2008-12-01

    21st-century sea-level rise predictions for California's coastal waters range from 0.10 m to 0.80 m. In coastal semiarid aquifers of California with low topographic relief and heavy groundwater pumping this might lead to pervasive landward migration of seawater plumes. In other coastal aquifers with pronounced seaward hydraulic gradient, the effect of sea-level rise might not be as pronounced. This paper implements a variable- fluid-density, 3-D, finite element numerical flow and transport model to assess the evolution of coastal aquifer salinity during the 21st century due to sea level rise by ice melting and oceanic thermal expansion, and by extraction driven by economic and population growth in semiarid coastal regions of California. The paper focuses on contrasting two different hydrogeologic settings in two heavily mined coastal aquifer with a state- of-the-art numerical simulation model.

  8. Twentieth-century global-mean sea-level rise: is the whole greater than the sum of the parts?

    NARCIS (Netherlands)

    Gregory, J.M.; White, N.J.; Church, J.A.; Bierkens, M.F.P.; Box, J.E.; Broeke, M.R. van den; Cogley, J.G.; Fettweis, X.; Hanna, E.; Huybrechts, P.; Konikow, L.F.; Leclercq, P.W.; Marzeion, B.; Oerlemans, J.; Tamisiea, E.; Wada, Y.

    2012-01-01

    Confidence in projections of global-mean sea level rise (GMSLR) depends on an ability to account for GMSLR during the twentieth century. There are contributions from ocean thermal expansion, mass loss from glaciers and ice sheets, groundwater extraction, and reservoir impoundment. Progress has been

  9. Observed sea-level rise in the north Indian Ocean coasts during the past century

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.

    . Res. 99, 1224-1235. Church, J.A., Gregory, J.M, Huybrechts, M. Kuhn, K., Lambeck, M.T. Nhuan, Qin, D., Woodworth, P.L., 2001. Changes in sea level, 2001, In: Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third... by Emery and Aubrey (1989) and Douglas (1991) and recent work include those from Unnikrishnan et al. (2006) and Unnikrishnan and Shankar (2007). Even though studies on sea-level rise trends are a few in the north Indian Ocean, there had many studies...

  10. Sea-Level Rise by 2100

    Digital Repository Service at National Institute of Oceanography (India)

    Church, J.A.; Clark, P.A.; Cazenave, A.; Gregory, J.M.; Jevrejeva, S.; Levermann, A.; Merrifield, M.A.; Milne, G.A.; Nerem, R.S.; Nunn, P.D.; Payne, A.J.; Pfeffer, W.T.; Stammer, D.; Unnikrishnan, A.S.

    the average rate of rise during the 20th century. In the calibrated uncertainty language of the IPCC, this assessed likelihood means that there is roughly a one-third probability that sea-level rise by 2100 may lie outside the “likely” range. That is...

  11. The land-ice contribution to 21st-century dynamic sea level rise

    NARCIS (Netherlands)

    Howard, T.; Ridley, J.; Pardaens, A. K.; Hurkmans, R. T. W. L.; Payne, A. J.; Giesen, R. H.; Lowe, J. A.; Bamber, J. L.; Edwards, T. L.; Oerlemans, J.

    2014-01-01

    Climate change has the potential to influence global mean sea level through a number of processes including (but not limited to) thermal expansion of the oceans and enhanced land ice melt. In addition to their contribution to global mean sea level change, these two processes (among others) lead to l

  12. Relative sea-level rising and its control strategy in coastal regions of China in the 21st century

    Institute of Scientific and Technical Information of China (English)

    武强; 郑铣鑫; 徐华; 应玉飞; 侯艳声; 谢晓程; 王世训

    2003-01-01

    The Chinese coastal regions are the high risk areas of natural disasters for their low land and weak and sensitive eco-evironment. The relative sea-level rising (RSLR), resulting from the piling of global sea-level rising and regional land subsidence, is to speed up in the 21st century. Certainly the RSLR will exacerbate the land submerging, the disaster from storm-tide and flood- waterlogging and the water shortage, and then affect urban withstanding function, construction safety and eco-resources. According to sustainable development theory, the sustainable utilization of resources and environment and sustainable development of economy and society can both be effectively achieved in coastal regions of China in the 21st century only by the implementation of controlling discharge of greenhouse gas, optimal exploitation of and artificial recharge of groundwater, systematic control of land subsidence, higher design standards for tide and flood control engineering, improving urban anti-disaster ability, a study on strategy and policy for RSLR and establishment of forecast and pre-warning institution.

  13. Impacts and responses to sea-level rise: a global analysis of the SRES scenarios over the twenty-first century.

    Science.gov (United States)

    Nicholls, Robert J; Tol, Richard S J

    2006-04-15

    Taking the Special Report on Emission Scenarios (SRES) climate and socio-economic scenarios (A1FI, A2, B1 and B2 'future worlds'), the potential impacts of sea-level rise through the twenty-first century are explored using complementary impact and economic analysis methods at the global scale. These methods have never been explored together previously. In all scenarios, the exposure and hence the impact potential due to increased flooding by sea-level rise increases significantly compared to the base year (1990). While mitigation reduces impacts, due to the lagged response of sea-level rise to atmospheric temperature rise, impacts cannot be avoided during the twenty-first century by this response alone. Cost-benefit analyses suggest that widespread protection will be an economically rational response to land loss due to sea-level rise in the four SRES futures that are considered. The most vulnerable future worlds to sea-level rise appear to be the A2 and B2 scenarios, which primarily reflects differences in the socio-economic situation (coastal population, Gross Domestic Product (GDP) and GDP/capita), rather than the magnitude of sea-level rise. Small islands and deltaic settings stand out as being more vulnerable as shown in many earlier analyses. Collectively, these results suggest that human societies will have more choice in how they respond to sea-level rise than is often assumed. However, this conclusion needs to be tempered by recognition that we still do not understand these choices and significant impacts remain possible. Future worlds which experience larger rises in sea-level than considered here (above 35 cm), more extreme events, a reactive rather than proactive approach to adaptation, and where GDP growth is slower or more unequal than in the SRES futures remain a concern. There is considerable scope for further research to better understand these diverse issues.

  14. Anthropogenic forcing dominates sea level rise since 1850

    DEFF Research Database (Denmark)

    Jevrejeva, Svetlana; Grinsted, Aslak; Moore, John

    2009-01-01

    The rate of sea level rise and its causes are topics of active debate. Here we use a delayed response statistical model to attribute the past 1000 years of sea level variability to various natural (volcanic and solar radiative) and anthropogenic (greenhouse gases and aerosols) forcings. We show...... that until 1800 the main drivers of sea level change are volcanic and solar radiative forcings. For the past 200 years sea level rise is mostly associated with anthropogenic factors. Only 4 ± 1.5 cm (25% of total sea level rise) during the 20th century is attributed to natural forcings, the remaining 14 ± 1...

  15. Sea-level rise and its possible impacts given a ‘beyond 4°C world’ in the twenty-first century

    NARCIS (Netherlands)

    Nicholls, R.; Marinova, N.A.; Lowe, J.; Brown, S.; Vellinga, P.

    2011-01-01

    The range of future climate-induced sea-level rise remains highly uncertain with continued concern that large increases in the twenty-first century cannot be ruled out. The biggest source of uncertainty is the response of the large ice sheets of Greenland and west Antarctica. Based on our analysis,

  16. Sea-level rise and its possible impacts given a 'beyond 4°C world' in the twenty-first century.

    Science.gov (United States)

    Nicholls, Robert J; Marinova, Natasha; Lowe, Jason A; Brown, Sally; Vellinga, Pier; de Gusmão, Diogo; Hinkel, Jochen; Tol, Richard S J

    2011-01-13

    The range of future climate-induced sea-level rise remains highly uncertain with continued concern that large increases in the twenty-first century cannot be ruled out. The biggest source of uncertainty is the response of the large ice sheets of Greenland and west Antarctica. Based on our analysis, a pragmatic estimate of sea-level rise by 2100, for a temperature rise of 4°C or more over the same time frame, is between 0.5 m and 2 m--the probability of rises at the high end is judged to be very low, but of unquantifiable probability. However, if realized, an indicative analysis shows that the impact potential is severe, with the real risk of the forced displacement of up to 187 million people over the century (up to 2.4% of global population). This is potentially avoidable by widespread upgrade of protection, albeit rather costly with up to 0.02 per cent of global domestic product needed, and much higher in certain nations. The likelihood of protection being successfully implemented varies between regions, and is lowest in small islands, Africa and parts of Asia, and hence these regions are the most likely to see coastal abandonment. To respond to these challenges, a multi-track approach is required, which would also be appropriate if a temperature rise of less than 4°C was expected. Firstly, we should monitor sea level to detect any significant accelerations in the rate of rise in a timely manner. Secondly, we need to improve our understanding of the climate-induced processes that could contribute to rapid sea-level rise, especially the role of the two major ice sheets, to produce better models that quantify the likely future rise more precisely. Finally, responses need to be carefully considered via a combination of climate mitigation to reduce the rise and adaptation for the residual rise in sea level. In particular, long-term strategic adaptation plans for the full range of possible sea-level rise (and other change) need to be widely developed.

  17. Is sea-level rising?

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.

    be converted into sea level height by using the hydrostatic equation. Radar gauge uses a radar sensor, kept at a height looking down the sea, sends out a pulse of radio waves and measures the travel time to be reflected off the surface and back... to the sensor. By using the travel time and the speed of radio waves one can estimate the sea surface height. The tide gauge data have been analysed and used to predict the time of ‘high tide’ and ‘low tide’, which are used by ships to decide the timing...

  18. Projected sea level rise and changes in extreme storm surge and wave events during the 21st century in the region of Singapore

    Science.gov (United States)

    Cannaby, Heather; Palmer, Matthew D.; Howard, Tom; Bricheno, Lucy; Calvert, Daley; Krijnen, Justin; Wood, Richard; Tinker, Jonathan; Bunney, Chris; Harle, James; Saulter, Andrew; O'Neill, Clare; Bellingham, Clare; Lowe, Jason

    2016-05-01

    Singapore is an island state with considerable population, industries, commerce and transport located in coastal areas at elevations less than 2 m making it vulnerable to sea level rise. Mitigation against future inundation events requires a quantitative assessment of risk. To address this need, regional projections of changes in (i) long-term mean sea level and (ii) the frequency of extreme storm surge and wave events have been combined to explore potential changes to coastal flood risk over the 21st century. Local changes in time-mean sea level were evaluated using the process-based climate model data and methods presented in the United Nations Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5). Regional surge and wave solutions extending from 1980 to 2100 were generated using ˜ 12 km resolution surge (Nucleus for European Modelling of the Ocean - NEMO) and wave (WaveWatchIII) models. Ocean simulations were forced by output from a selection of four downscaled ( ˜ 12 km resolution) atmospheric models, forced at the lateral boundaries by global climate model simulations generated for the IPCC AR5. Long-term trends in skew surge and significant wave height were then assessed using a generalised extreme value model, fit to the largest modelled events each year. An additional atmospheric solution downscaled from the ERA-Interim global reanalysis was used to force historical ocean model simulations extending from 1980 to 2010, enabling a quantitative assessment of model skill. Simulated historical sea-surface height and significant wave height time series were compared to tide gauge data and satellite altimetry data, respectively. Central estimates of the long-term mean sea level rise at Singapore by 2100 were projected to be 0.52 m (0.74 m) under the Representative Concentration Pathway (RCP)4.5 (8.5) scenarios. Trends in surge and significant wave height 2-year return levels were found to be statistically insignificant and/or physically

  19. Sea level rise and its coastal impacts

    OpenAIRE

    Cazenave, Anny; Le Cozannet, Gonéri

    2014-01-01

    Link to the paper: http://onlinelibrary.wiley.com/doi/10.1002/2013EF000188/abstract; International audience; Global warming in response to accumulation of human-induced greenhouse gases inside the atmosphere has already caused several visible consequences, among them increase of the Earth's mean temperature and ocean heat content, melting of glaciers, and loss of ice from the Greenland and Antarctica ice sheets. Ocean warming and land ice melt in turn are causing sea level to rise. Sea level ...

  20. Accelerated contributions of Canada's Baffin and Bylot Island glaciers to sea level rise over the past half century

    Directory of Open Access Journals (Sweden)

    A. Gardner

    2012-10-01

    Full Text Available Canadian Arctic glaciers have recently contributed large volumes of meltwater to the world's oceans. To place recently observed glacier wastage into a historical perspective and to determine the region's longer-term (~50 years contribution to sea level, we estimate mass and volume changes for the glaciers of Baffin and Bylot Islands using digital elevation models generated from airborne and satellite stereoscopic imagery and elevation postings from repeat airborne and satellite laser altimetry. In addition, we update existing glacier mass change records from GRACE satellite gravimetry to cover the period from 2003 to 2011. Using this integrated approach, we find that the rate of mass loss from the region's glaciers increased from 11.1 ± 3.4 Gt a−1 (271 ± 84 kg m−2 a−1 for the period 1963–2006 to 23.8 ± 6.1 Gt a−1 (581 ± 149 kg m−2 a−1 for the period 2003–2011. The doubling of the rate of mass loss is attributed to higher temperatures in summer with little change in annual precipitation. Through both direct and indirect effects, changes in summer temperatures accounted for 70–98% of the variance in the rate of mass loss, to which the Barnes Ice Cap was found to be 1.7 times more sensitive than either the Penny Ice Cap or the region's glaciers as a whole. This heightened sensitivity is the result of a glacier hypsometry that is skewed to lower elevations, which are shown to have a higher mass change sensitive to temperature compared to glacier surfaces at higher elevations. Between 2003 and 2011 the glaciers of Baffin and Bylot Islands contributed 0.07 ± 0.02 mm a−1 to sea level rise accounting for 16% of the total contribution from glaciers outside of Greenland and Antarctica, a rate much higher than the longer-term average of 0.03 ± 0.01 mm a−1 (1963 to 2006.

  1. Potential impact of sea level rise on French islands worldwide

    Directory of Open Access Journals (Sweden)

    Celine Bellard

    2013-11-01

    Full Text Available Although sea level rise is one of the most certain consequences of global warming, yet it remains one of the least studied. Several studies strongly suggested that sea level rise will accelerate in the future with a potentially rise from 0.5 to 2 m at the end of the century. However, currently island conservation programs do not take into account the potential effects of sea level rise. Therefore, we investigated the potential consequences of sea level rise for 1,269 French islands worldwide, by assessing the total number of island that will be totally submerged for three different scenarios (1, 2 and 3 m. Under the worst scenario, up to 12% of all islands could be entirely submerged. Two regions displayed the most significant loss of island: New Caledonia and French Polynesia. Focusing on New Caledonia, we highlighted that endemic plant species that are already classified as critically endangered by the IUCN will be the most vulnerable to sea level rise. Losses of insular habitats will thus be important in the next decades for the French islands. Given that French islands covers all latitudes in the Pacific, Indian and Atlantic oceans and in the Mediterranean, our results suggested that the implications for the 180 000 islands around the world should be considerable. Therefore, decision makers are required to define island conservation priorities that will suffer of the future sea level rise.

  2. Sea level rise projections for northern Europe under RCP8.5

    OpenAIRE

    Grinsted, A.; Jevrejeva, S.; R. E. M. Riva; D. Dahl-Jensen

    2015-01-01

    Sea level rise poses a significant threat to coastal communities, infrastructure, and ecosystems. Sea level rise is not uniform globally but is affected by a range of regional factors. In this study, we calculate regional projections of 21st century sea level rise in northern Europe, focusing on the British Isles, the Baltic Sea, and the North Sea. The input to the regional sea level projection is a probabilistic projection of the major components of the global sea level budget. Local sea lev...

  3. Sea level rise: A literature survey

    NARCIS (Netherlands)

    Oude Essink, G.H.P.

    1992-01-01

    In order to assess the impact of sea level rise on Water Management, it is useful to understand the mechanisrns that determine the level of the sea. In this study, a literature survey is executed to analyze these mechanisms. Climate plays a centra! role in these mechanisms, Climate mainly changes du

  4. Sea level rise projections for Northern Europe under RCP8.5

    NARCIS (Netherlands)

    Grinsted, A.; Jevrejeva, S.; Riva, R.E.M.; Dahl-Jensen, D.

    2015-01-01

    Sea level rise poses a significant threat to coastal communities, infrastructure, and ecosystems. Sea level rise is not uniform globally but is affected by a range of regional factors. In this study, we calculate regional projections of 21st century sea level rise in northern Europe, focusing on the

  5. Impacts of 21st century sea-level rise on a Danish major city - an assessment based on fine-resolution digital topography and a new flooding algorithm

    Science.gov (United States)

    Erenskjold Moeslund, Jesper; Klith Bøcher, Peder; Svenning, Jens-Christian; Mølhave, Thomas; Arge, Lars

    2009-11-01

    This study examines the potential impact of 21st century sea-level rise on Aarhus, the second largest city in Denmark, emphasizing the economic risk to the city's real estate. Furthermore, it assesses which possible adaptation measures that can be taken to prevent flooding in areas particularly at risk from flooding. We combine a new national Digital Elevation Model in very fine resolution (~2 meter), a new highly computationally efficient flooding algorithm that accurately models the influence of barriers, and geospatial data on real-estate values to assess the economic real-estate risk posed by future sea-level rise to Aarhus. Under the A2 and A1FI (IPCC) climate scenarios we show that relatively large residential areas in the northern part of the city as well as areas around the river running through the city are likely to become flooded in the event of extreme, but realistic weather events. In addition, most of the large Aarhus harbour would also risk flooding. As much of the area at risk represent high-value real estate, it seems clear that proactive measures other than simple abandonment should be taken in order to avoid heavy economic losses. Among the different possibilities for dealing with an increased sea level, the strategic placement of flood-gates at key potential water-inflow routes and the construction or elevation of existing dikes seems to be the most convenient, most socially acceptable, and maybe also the cheapest solution. Finally, we suggest that high-detail flooding models similar to those produced in this study will become an important tool for a climate-change-integrated planning of future city development as well as for the development of evacuation plans.

  6. Impacts of 21st century sea-level rise on a Danish major city - an assessment based on fine-resolution digital topography and a new flooding algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Moeslund, Jesper Erenskjold; Svenning, Jens-Christian [Ecoinformatics and Biodiversity Group, Department of Biological Sciences, Aarhus University (Denmark); Boecher, Peder Klith [Department of Agroecology and Environment, Aarhus University (Denmark); Moelhave, Thomas; Arge, Lars, E-mail: jesper.moeslund@biology.au.d [MADALGO - Center for Massive Data Algorithmics, Aarhus University (Denmark)

    2009-11-01

    This study examines the potential impact of 21st century sea-level rise on Aarhus, the second largest city in Denmark, emphasizing the economic risk to the city's real estate. Furthermore, it assesses which possible adaptation measures that can be taken to prevent flooding in areas particularly at risk from flooding. We combine a new national Digital Elevation Model in very fine resolution ({approx}2 meter), a new highly computationally efficient flooding algorithm that accurately models the influence of barriers, and geospatial data on real-estate values to assess the economic real-estate risk posed by future sea-level rise to Aarhus. Under the A2 and A1FI (IPCC) climate scenarios we show that relatively large residential areas in the northern part of the city as well as areas around the river running through the city are likely to become flooded in the event of extreme, but realistic weather events. In addition, most of the large Aarhus harbour would also risk flooding. As much of the area at risk represent high-value real estate, it seems clear that proactive measures other than simple abandonment should be taken in order to avoid heavy economic losses. Among the different possibilities for dealing with an increased sea level, the strategic placement of flood-gates at key potential water-inflow routes and the construction or elevation of existing dikes seems to be the most convenient, most socially acceptable, and maybe also the cheapest solution. Finally, we suggest that high-detail flooding models similar to those produced in this study will become an important tool for a climate-change-integrated planning of future city development as well as for the development of evacuation plans.

  7. CoSMoS (Coastal Storm Modeling System) Southern California v3.0 projections of shoreline change due to 21st century sea level rise

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Summary: This dataset contains projections of shoreline positions and uncertainty bands for future scenarios of sea-level rise. Projections were made using...

  8. CoSMoS (Coastal Storm Modeling System) Southern California v3.0 projections of coastal cliff retreat due to 21st century sea-level rise

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Summary: This dataset contains projections of coastal cliff-retreat rates and positions for future scenarios of sea-level rise (SLR). Projections were made using...

  9. Modelling dynamics of Jakobshavn Isbræ and its contribution to sea level rise over the past and future century

    DEFF Research Database (Denmark)

    Muresan, Ioana Stefania

    with observations of changes in glacier terminus. An initial, and most probably the first significant acceleration of JI after the end of LIA was modelled in ~1930. Overall, I found that the ocean influence in JI’s behaviour overthe last century is significant and most of the JI retreat during 1840–2014 is driven...... by the ocean parametrization and the glacier’s subsequent response, which waslargely governed by its own bed geometry. In my simulations, the retreat of the frontreduced the buttressing at the terminus and generated a dynamic response in theupstream region of JI which finally led to flow acceleration...... change is dynamic in origin). The study further indicates that the change in mass loss at JI is already triggered and that an eminent collapse of the terminus by the end of the century with retreat of up to 40 km along JI’s downward-sloping, marine-based bed is inevitable. A cooling experiment suggested...

  10. Sea-level rise: towards understanding local vulnerability

    Science.gov (United States)

    Rahmstorf, Stefan

    2012-06-01

    Projections of global sea-level rise into the future have become more pessimistic over the past five years or so. A global rise by more than one metre by the year 2100 is now widely accepted as a serious possibility if greenhouse gas emissions continue unabated. That is witnessed by the scientific assessments that were made since the last IPCC report was published in 2007. The Delta Commission of the Dutch government projected up to 1.10 m as a 'high-end' scenario (Vellinga et al 2009). The Scientific Committee on Antarctic Research (SCAR) projected up to 1.40 m (Scientific Committee on Antarctic Research 2009), and the Arctic Monitoring and Assessment Programme (AMAP) gives a range of 0.90-1.60 m in its 2011 report (Arctic Monitoring and Assessment Programme 2011). And recently the US Army Corps of Engineers recommends using a 'low', an 'intermediate' and a 'high' scenario for global sea-level rise when planning civil works programmes, with the high one corresponding to a 1.50 m rise by 2100 (US Army Corps of Engineers 2011). This more pessimistic view is based on a number of observations, most importantly perhaps the fact that sea level has been rising at least 50% faster in the past decades than projected by the IPCC (Rahmstorf et al 2007, IPCC 2007). Also, the rate of rise (averaged over two decades) has accelerated threefold, from around 1 mm yr-1 at the start of the 20th century to around 3 mm yr-1 over the past 20 years (Church and White 2006), and this rate increase closely correlates with global warming (Rahmstorf et al 2011). The IPCC projections, which assume almost no further acceleration in the 20th century, thus look less plausible. And finally the observed net mass loss of the two big continental ice sheets (Van den Broeke et al 2011) calls into question the assumption that ice accumulation in Antarctica would largely balance ice loss from Greenland in the course of further global warming (IPCC 2007). With such a serious sea-level rise on the horizon

  11. Projection of the Zhujiang (Pearl) River Delta’s potential submerged area due to sea level rise during the 21st century based on CMIP5 simulations

    Institute of Scientific and Technical Information of China (English)

    XIA Jiangjiang; YAN Zhongwei; ZHOU Wen; FONG Soi Kun; LEONG Ka Cheng; TANG Iu Man; CHANG S W; LEONG W K; JIN Shaofei

    2015-01-01

    Projections of potential submerged area due to sea level rise are helpful for improving understanding of the influence of ongoing global warming on coastal areas. The Ensemble Empirical Mode Decomposition method is used to adaptively decompose the sea level time series in order to extract the secular trend component. Then the linear relationship between the global mean sea level (GMSL) change and the Zhujiang (Pearl) River Delta (PRD) sea level change is calculated:an increase of 1.0 m in the GMSL corresponds to a 1.3 m (uncertainty interval from 1.25 to 1.46 m) increase in the PRD. Based on this relationship and the GMSL rise projected by the Coupled Model Intercomparison Project Phase 5 under three greenhouse gas emission scenarios (representative concentration pathways, or RCPs, from low to high emission scenarios RCP2.6, RCP4.5, and RCP8.5), the PRD sea level is calculated and projected for the period 2006–2100. By around the year 2050, the PRD sea level will rise 0.29 (0.21 to 0.40) m under RCP2.6, 0.31 (0.22 to 0.42) m under RCP4.5, and 0.34 (0.25 to 0.46) m under RCP8.5, respectively. By 2100, it will rise 0.59 (0.36 to 0.88) m, 0.71 (0.47 to 1.02) m, and 1.0 (0.68 to 1.41) m, respectively. In addition, considering the extreme value of relative sea level due to land subsidence (i.e., 0.20 m) and that obtained from intermonthly variability (i.e., 0.33 m), the PRD sea level will rise 1.94 m by the year 2100 under the RCP8.5 scenario with the upper uncertainty level (i.e., 1.41 m). Accordingly, the potential submerged area is 8.57×103 km2 for the PRD, about 1.3 times its present area.

  12. A Critical Assessment of Sea-Level Rise Projections for the Northeast United States in the 21st Century: Discrepancies and Their Cost

    Science.gov (United States)

    Zhang, M.

    2015-12-01

    Several studies have projected the magnitudes of sea-level rise (SLR) in the Northeast United States for the 21th Century as a result of anthropogenic climate change. Among them are those by NOAA, the New York City Panel on Climate Change (NPCC), and the US Army Corps of Engineers (COE). The projected magnitudes of SLR from some of these sources are being used by policymakers to make difficult choices of investments on infrastructure that can be resilient against anticipated SLR. While there is no question that SLR will happen and resilience measures against SLR is very necessary, this presentation questions the rigor of science behind some of these projections that can have significant costs to the society. A critical assessment of available SLR projections for the northeast US and their discrepancies is presented. It is concluded from the current understanding of science that the mean values and upper bounds of SLR from NOAA, NPCC and COE are likely exaggerated for the region. It is also argued that scientists should treat the SLR projection as a separate problem from policies so that the best cost-benefit analysis can be performed in the decision process.

  13. Barrier response to Holocene sea-level rise

    DEFF Research Database (Denmark)

    Pejrup, Morten; Andersen, Thorbjørn Joest; Johannessen, Peter N

    Normally it is believed that sea-level rise causes coastal barrier retreat. However, sea-level is only one of the parameters determining the long term coastal development of barrier coasts. Sediment supply is an equally important determinant and may overshadow the effects of sea-level rise...... show quite different responses to sea-level rise. The southernmost island Rømø has survived 17 m of sea-level rise at the same position illustrating the control from sediment supply; whereas the northernmost island Skallingen has shifted its position several times during the same period indicating...... a much stronger component of sea-level control. The distance between the islands is only 50 km, and therefore our study shows that prediction of barrier development during a period of rising sea level may be more complicated than formerly believed....

  14. Future sea level rise constrained by observations and long-term commitment.

    Science.gov (United States)

    Mengel, Matthias; Levermann, Anders; Frieler, Katja; Robinson, Alexander; Marzeion, Ben; Winkelmann, Ricarda

    2016-03-08

    Sea level has been steadily rising over the past century, predominantly due to anthropogenic climate change. The rate of sea level rise will keep increasing with continued global warming, and, even if temperatures are stabilized through the phasing out of greenhouse gas emissions, sea level is still expected to rise for centuries. This will affect coastal areas worldwide, and robust projections are needed to assess mitigation options and guide adaptation measures. Here we combine the equilibrium response of the main sea level rise contributions with their last century's observed contribution to constrain projections of future sea level rise. Our model is calibrated to a set of observations for each contribution, and the observational and climate uncertainties are combined to produce uncertainty ranges for 21st century sea level rise. We project anthropogenic sea level rise of 28-56 cm, 37-77 cm, and 57-131 cm in 2100 for the greenhouse gas concentration scenarios RCP26, RCP45, and RCP85, respectively. Our uncertainty ranges for total sea level rise overlap with the process-based estimates of the Intergovernmental Panel on Climate Change. The "constrained extrapolation" approach generalizes earlier global semiempirical models and may therefore lead to a better understanding of the discrepancies with process-based projections.

  15. Storminess helps coastal marshes withstand sea level rise

    Science.gov (United States)

    Balcerak, Ernie

    2013-03-01

    Rising sea levels are predicted to threaten many coastal sea marshes around the world in the coming decades as the Earth's climate warms. In addition to accelerating sea level rise, global climate change is predicted to increase the frequency and severity of storms in many places around the world. However, few studies have taken into account how an increased storminess might affect the ability of coastal marshes to withstand sea level rise.

  16. The social values at risk from sea-level rise

    Energy Technology Data Exchange (ETDEWEB)

    Graham, Sonia, E-mail: sonia.graham@unimelb.edu.au [Department of Resource Management and Geography, The University of Melbourne, 221 Bouverie St., Carlton, Victoria 3053 (Australia); Barnett, Jon, E-mail: jbarn@unimelb.edu.au [Department of Resource Management and Geography, The University of Melbourne, 221 Bouverie St., Carlton, Victoria 3053 (Australia); Fincher, Ruth, E-mail: r.fincher@unimelb.edu.au [Department of Resource Management and Geography, The University of Melbourne, 221 Bouverie St., Carlton, Victoria 3053 (Australia); Hurlimann, Anna, E-mail: anna.hurlimann@unimelb.edu.au [Faculty of Architecture, Building and Planning, The University of Melbourne, Architecture and Planning Building, Parkville, Victoria 3010 (Australia); Mortreux, Colette, E-mail: colettem@unimelb.edu.au [Department of Resource Management and Geography, The University of Melbourne, 221 Bouverie St., Carlton, Victoria 3053 (Australia); Waters, Elissa, E-mail: elissa.waters@unimelb.edu.au [Department of Resource Management and Geography, The University of Melbourne, 221 Bouverie St., Carlton, Victoria 3053 (Australia)

    2013-07-15

    Analysis of the risks of sea-level rise favours conventionally measured metrics such as the area of land that may be subsumed, the numbers of properties at risk, and the capital values of assets at risk. Despite this, it is clear that there exist many less material but no less important values at risk from sea-level rise. This paper re-theorises these multifarious social values at risk from sea-level rise, by explaining their diverse nature, and grounding them in the everyday practices of people living in coastal places. It is informed by a review and analysis of research on social values from within the fields of social impact assessment, human geography, psychology, decision analysis, and climate change adaptation. From this we propose that it is the ‘lived values’ of coastal places that are most at risk from sea-level rise. We then offer a framework that groups these lived values into five types: those that are physiological in nature, and those that relate to issues of security, belonging, esteem, and self-actualisation. This framework of lived values at risk from sea-level rise can guide empirical research investigating the social impacts of sea-level rise, as well as the impacts of actions to adapt to sea-level rise. It also offers a basis for identifying the distribution of related social outcomes across populations exposed to sea-level rise or sea-level rise policies.

  17. PERSPECTIVE: The tripping points of sea level rise

    Science.gov (United States)

    Hecht, Alan D.

    2009-12-01

    When President Nixon created the US Environmental Protection Agency (EPA) in 1970 he said the environment must be perceived as a single, interrelated system. We are nowhere close to achieving this vision. Jim Titus and his colleagues [1] highlight one example of where one set of regulations or permits may be in conflict with another and where regulations were crafted in the absence of understanding the cumulative impact of global warming. The issue here is how to deal with the impacts of climate change on sea level and the latter's impact on wetland polices, clean water regulations, and ecosystem services. The Titus paper could also be called `The tripping points of sea level rise'. Titus and his colleagues have looked at the impact of such sea level rise on the east coast of the United States. Adaptive responses include costly large- scale investment in shore protection (e.g. dikes, sand replenishment) and/or ecosystem migration (retreat), where coastal ecosystems move inland. Shore protection is limited by available funds, while ecosystem migrations are limited by available land use. The driving factor is the high probability of sea level rise due to climate change. Estimating sea level rise is difficult because of local land and coastal dynamics including rising or falling land areas. It is estimated that sea level could rise between 8 inches and 2 feet by the end of this century [2]. The extensive data analysis done by Titus et al of current land use is important because, as they observe, `property owners and land use agencies have generally not decided how they will respond to sea level rise, nor have they prepared maps delineating where shore protection and retreat are likely'. This is the first of two `tripping points', namely the need for adaptive planning for a pending environmental challenge that will create economic and environment conflict among land owners, federal and state agencies, and businesses. One way to address this gap in adaptive management

  18. Estuaries May Face Increased Parasitism as Sea Levels Rise

    Science.gov (United States)

    Wendel, JoAnna

    2014-12-01

    Invertebrates in estuaries could be at a greater risk of parasitism as climate change causes sea levels to rise. A new paper published 8 December in Proceedings of the National Academy of Sciences of the United States of America (doi:10.1073/pnas.1416747111) describes how rapid sea level rise in the Holocene affected the population of parasitic flatworms called trematodes.

  19. The Twentieth-Century Sea Level Budget: Recent Progress and Challenges

    Science.gov (United States)

    Jevrejeva, S.; Matthews, A.; Slangen, A.

    2017-01-01

    For coastal areas, given the large and growing concentration of population and economic activity, as well as the importance of coastal ecosystems, sea level rise is one of the most damaging aspects of the warming climate. Huge progress in quantifying the cause of sea level rise and closure of sea level budget for the period since the 1990s has been made mainly due to the development of the global observing system for sea level components and total sea levels. We suggest that a large spread (1.2 ± 0.2-1.9 ± 0.3 mm year-1) in estimates of sea level rise during the twentieth century from several reconstructions demonstrates the need for and importance of the rescue of historical observations from tide gauges, with a focus on the beginning of the twentieth century. Understanding the physical mechanisms contributing to sea level rise and controlling the variability of sea level over the past few 100 years are a challenging task. In this study, we provide an overview of the progress in understanding the cause of sea level rise during the twentieth century and highlight the main challenges facing the interdisciplinary sea level community in understanding the complex nature of sea level changes.

  20. New estimates of potential impacts of sea level rise and coastal floods in Poland (discussion paper)

    NARCIS (Netherlands)

    Paprotny, D.; Terefenko, P.

    2015-01-01

    Polish coastal zone is thought to be of the most exposed to sea level rise in Europe. With climate change expected to raise mean sea levels between 26 and 200 cm by the end of the century, and storms increasing in severity, accurate estimates of those phenomena are needed. Recent advances in quality

  1. Sea-Level Rise Impacts on Hudson River Marshes

    Science.gov (United States)

    Hooks, A.; Nitsche, F. O.

    2015-12-01

    The response of tidal marshes to increasing sea-level rise is uncertain. Tidal marshes can adapt to rising sea levels through vertical accretion and inland migration. Yet tidal marshes are vulnerable to submergence if the rate of sea-level rise exceeds the rate of accretion and if inland migration is limited by natural features or development. We studied how Piermont and Iona Island Marsh, two tidal marshes on the Hudson River, New York, would be affected by sea-level rise of 0.5m, 1m, and 1.5m by 2100. This study was based on the 2011-2012 Coastal New York LiDAR survey. Using GIS we mapped sea-level rise projections accounting for accretion rates and calculated the submerged area of the marsh. Based on the Hudson River National Estuarine Research Reserve Vegetation 2005 dataset, we studied how elevation zones based on vegetation distributions would change. To evaluate the potential for inland migration, we assessed land cover around each marsh using the National Land Cover Database 2011 Land Cover dataset and examined the slope beyond the marsh boundaries. With an accretion rate of 0.29cm/year and 0.5m of sea-level rise by 2100, Piermont Marsh would be mostly unchanged. With 1.5m of sea-level rise, 86% of Piermont Marsh would be flooded. For Iona Island Marsh with an accretion rate of 0.78cm/year, sea-level rise of 0.5m by 2100 would result in a 4% expansion while 1.5m sea-level rise would cause inundation of 17% of the marsh. The results indicate that Piermont and Iona Island Marsh may be able to survive rates of sea-level rise such as 0.5m by 2100 through vertical accretion. At rates of sea-level rise like 1.5m by 2100, vertical accretion cannot match sea-level rise, submerging parts of the marshes. High elevations and steep slopes limit Piermont and Iona Island Marsh's ability to migrate inland. Understanding the impacts of sea-level rise on Piermont and Iona Island Marsh allows for long-term planning and could motivate marsh conservation programs.

  2. Sea Level Enigmatic Rising - New Perspectives from an Expanding Globe

    CERN Document Server

    Scalera, Giancarlo

    2015-01-01

    In the expanding Earth framework it is possible to find additional phenomena that could contribute in a proper way to the water balance and general tectonic eustatism involved in the sea lever rising. Recent compilations seems to leave unexplained up to 12 cm/century of sea rising, and possible solutions invoking a polar ice shells melting near to the upper limit of the error bars reveal in conflict with the consequent expected decreasing of the Earth angular velocity. It is shown that taking into account possible effects of an expanding Earth, the problem can be initiated towards an appropriate solution, at least as regards the just orders of magnitude. Major effects on sea-level could come from ongoing relaxation of curvature variations that are peculiar for an expanding globe.

  3. Temporal variation of accumulation rates on a natural salt marsh in the 20th century determined by 137Cs chronologies – the impact of sea level rise and increased inundation frequency

    DEFF Research Database (Denmark)

    Andersen, Thorbjørn Joest; Svinth, Steffen; Pejrup, Morten

    2011-01-01

    Salt marshes are potentially threatened by sea level rise if sediment supply is unable to balance the rising sea. A rapid sea level rise is one of the pronounced effects of global warming and global sea level is at present rising at an elevated rate of about 3.4 mm y-1 on average. This increasing...... rate of sea level rise should make it possible to study the effect of rapidly rising sea level on salt marsh accumulation. However, such an understanding is generally hampered by lack of available data with sufficient precision. Here we present a high-precision dataset based on detailed radiometric...... accretion has generally kept pace with sea level rise since 1963 but comparison of the accumulation rates of minerogenic material in the period 1963–1986 and 1986–2003 revealed a slight decrease in accumulation with time in spite of an observed increase in inundation frequency. The observed decrease...

  4. USGS Map service: Coastal Vulnerability to Sea-Level Rise

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The coastal vulnerability index (CVI)provides a preliminary overview, at a National scale, of the relative susceptibility of the Nation's coast to sea-level rise....

  5. Humboldt Nay NWR Sea-level rise modeling

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Baseline information required to assess sea-level rise impacts to marsh habitats will be compiled. The project will provide relevant information to local managers...

  6. Overestimation of marsh vulnerability to sea level rise

    Science.gov (United States)

    Kirwan, Matthew L.; Temmerman, Stijn; Skeehan, Emily E.; Guntenspergen, Glenn R.; Fagherazzi, Sergio

    2016-01-01

    Coastal marshes are considered to be among the most valuable and vulnerable ecosystems on Earth, where the imminent loss of ecosystem services is a feared consequence of sea level rise. However, we show with a meta-analysis that global measurements of marsh elevation change indicate that marshes are generally building at rates similar to or exceeding historical sea level rise, and that process-based models predict survival under a wide range of future sea level scenarios. We argue that marsh vulnerability tends to be overstated because assessment methods often fail to consider biophysical feedback processes known to accelerate soil building with sea level rise, and the potential for marshes to migrate inland.

  7. Mangrove Retreat with Rising Sea-level, Bermuda

    Science.gov (United States)

    Ellison, Joanna C.

    1993-07-01

    Low island mangroves keep up with slow sea-level rise by peat accumulation. Holocene stratigraphic records show that they maintain the same pace as sea-level rise at rates up to 9 cm/100 years. Tide gauge records from Bermuda since 1932 show sea-level rise at a rate of 28 cm/100 years. The largest mangrove area (6·26 acres) at Hungry Bay has for the last 2000 years been building peat at a rate of 8·5 to 10·6 cm/100 years. Retreat of the seaward edge has caused loss of 2·24 acres of mangroves, commencing in the last few hundred years, with a second dieback between 1900 and 1947, and a third dieback in the last decade. The substrate elevation of the seaward margin of mangroves is below mean sea-level, the normal lower limit for mangroves. Present dieback shows problems of erosion indicating that the Bruun Rule of beach erosion with sea-level rise is also appropriate for mangrove swamps. Stratigraphy shows that before 4000 BP sea-level rose at a rate of 25 cm/100 years, from 4000 to 1000 years BP the rate of sea-level rise declined to 6 cm/100 years during which time mangroves established, and in the last 1000 years there was an increase to 14·3 cm/100 years, during which time the mangroves died back. This study indicates that low island mangroves will experience problems with the rates of sea-level rise predicted for the next 50 years.

  8. Glacial Isostatic Adjustment and Contemporary Sea Level Rise: An Overview

    Science.gov (United States)

    Spada, Giorgio

    2016-08-01

    Glacial isostatic adjustment (GIA) encompasses a suite of geophysical phenomena accompanying the waxing and waning of continental-scale ice sheets. These involve the solid Earth, the oceans and the cryosphere both on short (decade to century) and on long (millennia) timescales. In the framework of contemporary sea-level change, the role of GIA is particular. In fact, among the processes significantly contributing to contemporary sea-level change, GIA is the only one for which deformational, gravitational and rotational effects are simultaneously operating, and for which the rheology of the solid Earth is essential. Here, I review the basic elements of the GIA theory, emphasizing the connections with current sea-level changes observed by tide gauges and altimetry. This purpose is met discussing the nature of the "sea-level equation" (SLE), which represents the basis for modeling the sea-level variations of glacial isostatic origin, also giving access to a full set of geodetic variations associated with GIA. Here, the SLE is employed to characterize the remarkable geographical variability of the GIA-induced sea-level variations, which are often expressed in terms of "fingerprints". Using harmonic analysis, the spatial variability of the GIA fingerprints is compared to that of other components of contemporary sea-level change. In closing, some attention is devoted to the importance of the "GIA corrections" in the context of modern sea-level observations, based on tide gauges or satellite altimeters.

  9. Glacial Isostatic Adjustment and Contemporary Sea Level Rise: An Overview

    Science.gov (United States)

    Spada, Giorgio

    2017-01-01

    Glacial isostatic adjustment (GIA) encompasses a suite of geophysical phenomena accompanying the waxing and waning of continental-scale ice sheets. These involve the solid Earth, the oceans and the cryosphere both on short (decade to century) and on long (millennia) timescales. In the framework of contemporary sea-level change, the role of GIA is particular. In fact, among the processes significantly contributing to contemporary sea-level change, GIA is the only one for which deformational, gravitational and rotational effects are simultaneously operating, and for which the rheology of the solid Earth is essential. Here, I review the basic elements of the GIA theory, emphasizing the connections with current sea-level changes observed by tide gauges and altimetry. This purpose is met discussing the nature of the "sea-level equation" (SLE), which represents the basis for modeling the sea-level variations of glacial isostatic origin, also giving access to a full set of geodetic variations associated with GIA. Here, the SLE is employed to characterize the remarkable geographical variability of the GIA-induced sea-level variations, which are often expressed in terms of "fingerprints". Using harmonic analysis, the spatial variability of the GIA fingerprints is compared to that of other components of contemporary sea-level change. In closing, some attention is devoted to the importance of the "GIA corrections" in the context of modern sea-level observations, based on tide gauges or satellite altimeters.

  10. Vulnerability of Turkish coasts to accelerated sea-level rise

    Science.gov (United States)

    Alpar, Bedri

    2009-06-01

    Accelerated rise in sea-level, and associated geological adjustment, may result in a high impact on shorelines. On the basis of hourly sea-level observations over a 20 year period, sea-level change along the Turkish coast has been investigated. In addition to relative sea-level rise, the high level of human activities in coastal areas puts a significant amount of stress on Turkish coastal zones, especially on coastal lowland plains. Coastal erosion and ground water salinization are the most important impacts and two case studies are discussed in this paper: the Kizilirmak river delta on the Black Sea; and the tourism center of Erdek on the Marmara Sea. Coastal retreat on the Kizilirmak river delta is mostly attributed to decreasing sediment supply to the coast. The shore barriers and the enclosed lagoons are likely to respond readily to future sea-level rise. At Erdek, the most important threat is intrusion of salt water into freshwater systems caused by a combination of accelerated sea-level rise, land reclamation and overexploitation of underground aquifers.

  11. Potential for bias in 21st century semiempirical sea level projections

    DEFF Research Database (Denmark)

    Jevrejeva, S.; Moore, J. C.; Grinsted, A.

    2012-01-01

    We examine the limitations of a semiempirical model characterized by a sea level projection of 73 cm with RCP4.5 scenario by 2100. Calibrating the model with data to 1990 and then simulating the period 1993-2009 produces sea level in close agreement with acceleration in sea level rise observed...... and dynamics of Greenland ice sheet made contributions to the sea level rise in the early 20th century and therefore are included within the semiempirical model calibration period and hence are included in semiempirical sea level projections by 2100. Antarctic response is probably absent from semiempirical...... models, which will lead to a underestimate in sea level rise if, as is probable, Antarctica loses mass by 2100....

  12. Implications of accelerated sea-level rise on Louisiana coastal environments

    Science.gov (United States)

    Ramsey, Karen E.; Penland, Shea; Roberts, Harry H.

    1991-01-01

    Natural and human-induced processes have combined to produce high rates of relative sea-level rise and coastal land loss in Louisiana. This paper presents historical trends in sea-level rise and the implication of predicted accelerated rise scenarios on Louisiana's coastal environments. Mean eustatic sea-level in the Gulf of Mexico is 0.23 cm/yr. In Louisiana, relative sea-level rise, which combines eustacy and subsidence, averages from 0.50 cm/yr in the chenier plain to 1.0 cm/yr in the delta plain. Subsidence due to the compaction of Holocene sediments is believed to be the major component influencing these high rates of rise. Subsidence contributes up to 80% of the observed relative sea-level rise in coastal Louisiana. The Environmental Protection Agency (EPA) predicts the rate of sea-level rise to increase over the next century due to global climate change. If these predictions are accurate, a dramatic increase in the coastal land loss conditions in Louisiana can be expected.

  13. Barriers to and opportunities for landward migration of coastal wetlands with sea-level rise

    Science.gov (United States)

    Enwright, Nicholas M.; Griffith, Kereen T.; Osland, Michael J.

    2016-01-01

    In the 21st century, accelerated sea-level rise and continued coastal development are expected to greatly alter coastal landscapes across the globe. Historically, many coastal ecosystems have responded to sea-level fluctuations via horizontal and vertical movement on the landscape. However, anthropogenic activities, including urbanization and the construction of flood-prevention infrastructure, can produce barriers that impede ecosystem migration. Here we show where tidal saline wetlands have the potential to migrate landward along the northern Gulf of Mexico coast, one of the most sea-level rise sensitive and wetland-rich regions of the world. Our findings can be used to identify migration corridors and develop sea-level rise adaptation strategies to help ensure the continued availability of wetland-associated ecosystem goods and services.

  14. Projecting twenty-first century regional sea-level changes

    NARCIS (Netherlands)

    Slangen, A.B.A.; Carson, M.; Katsman, C.A.; van de Wal, R.S.W.; Köhl, A.; Vermeersen, L.L.A.; Stammer, D.

    2014-01-01

    We present regional sea-level projections and associated uncertainty estimates for the end of the 21 (st) century. We show regional projections of sea-level change resulting from changing ocean circulation, increased heat uptake and atmospheric pressure in CMIP5 climate models. These are combined wi

  15. Projecting twenty-first century regional sea-level changes

    NARCIS (Netherlands)

    Slangen, A. B A; Carson, M.; Katsman, C. A.; van de Wal, R. S W; Köhl, A.; Vermeersen, L. L A; Stammer, D.

    2014-01-01

    We present regional sea-level projections and associated uncertainty estimates for the end of the 21st century. We show regional projections of sea-level change resulting from changing ocean circulation, increased heat uptake and atmospheric pressure in CMIP5 climate models. These are combined with

  16. Sea Level Rise and Subsidence in the Gulf of Thailand

    Science.gov (United States)

    Niemnil, Sommart

    In the Thailand -EC GEO2TECDI-SONG Project we investigate the sea level change and vertical land motion in Thailand. First, Bangkok is situated in river delta and average height is closed to sea level. Second, it is subsiding due to ground water extraction. Third, it is experiencing post-seismic motion due to nearby mega thrust earthquakes and fourth, it suffers from rising of sea levels due to global climate change. This poses a serious threat on Thai society and economy. Before mitigation methods can be devised we aim at charting, qualifying and quantifying all contributing effects by the use of satellite altimetry, GNSS, InSAR techniques and combining results with the in situ observations like tide gauge and with geophysical modeling. Adding GPS based vertical land motion to the tide gauge sea level registration reveals the absolute sea level change, which is nicely confirmed by altimetry. We find an average absolute rise of 3.5 mm/yr + 0.7, but nears mouth of Chao Praya River (Bangkok) and the Mekong delta (Ho Chi Min City), this mounts to 4 to 5 mm/yr, faster than global average. This is reinforced when accounting for the tectonic subsidence that resulted from 2004 9.1Mw Sumatra/Andaman earthquake; from 2005 onwards we find downfall in the order of 10 mm/yr. RADARSAT InSAR analyses show subsidence rates up to 25 mm/yr at many places along coastal Bangkok.

  17. Preparing Coastal Parks for Future Sea Level Rise

    Science.gov (United States)

    Young, R.; Peek, K.

    2012-04-01

    The United States National Park Service (NPS) manages significant stretches of shoreline along the U.S. Atlantic, Pacific, and Gulf Coasts that are vulnerable to long-term sea level rise, shoreline erosion, and storm impacts. These parks have a wide variety of missions— protecting some of the nation's most important natural and cultural resources. The parks must also provide visitor access and education requiring infrastructure such as roads, visitor centers, trails, and buildings for facilities management. Planning for the likely impacts from sea level rise to both resources and infrastructure is a complex balancing act. Using coastal engineering to protect cultural resources or infrastructure may harm natural resources. At the same time, there are clearly some cultural and historical resources that are so critical that they must be protected. In an attempt to begin to attack this dilemma, the NPS Climate Change Response Program has initiated a sea level rise adaptation study that will provide a first-order tally of the park assets at risk to sea level rise and to begin to develop a plan for prioritizing those assets that must be protected, those that can be moved or abandoned, and an examination of how best to approach this without harming critical natural resources. This presentation will discuss the preliminary results of this effort along with several relevant case studies.

  18. Integrating conservation costs into sea level rise adaptive conservation prioritization

    Directory of Open Access Journals (Sweden)

    Mingjian Zhu

    2015-07-01

    Full Text Available Biodiversity conservation requires strategic investment as resources for conservation are often limited. As sea level rises, it is important and necessary to consider both sea level rise and costs in conservation decision making. In this study, we consider costs of conservation in an integrated modeling process that incorporates a geomorphological model (SLAMM, species habitat models, and conservation prioritization (Zonation to identify conservation priorities in the face of landscape dynamics due to sea level rise in the Matanzas River basin of northeast Florida. Compared to conservation priorities that do not consider land costs in the analysis process, conservation priorities that consider costs in the planning process change significantly. The comparison demonstrates that some areas with high conservation values might be identified as lower priorities when integrating economic costs in the planning process and some areas with low conservation values might be identified as high priorities when considering costs in the planning process. This research could help coastal resources managers make informed decisions about where and how to allocate conservation resources more wisely to facilitate biodiversity adaptation to sea level rise.

  19. ACCELERATION OF SEA LEVEL RISE OVER MALAYSIAN SEAS FROM SATELLITE ALTIMETER

    Directory of Open Access Journals (Sweden)

    A. I. A. Hamid

    2016-09-01

    Full Text Available Sea level rise becomes our concern nowadays as a result of variously contribution of climate change that cause by the anthropogenic effects. Global sea levels have been rising through the past century and are projected to rise at an accelerated rate throughout the 21st century. Due to this change, sea level is now constantly rising and eventually will threaten many low-lying and unprotected coastal areas in many ways. This paper is proposing a significant effort to quantify the sea level trend over Malaysian seas based on the combination of multi-mission satellite altimeters over a period of 23 years. Eight altimeter missions are used to derive the absolute sea level from Radar Altimeter Database System (RADS. Data verification is then carried out to verify the satellite derived sea level rise data with tidal data. Eight selected tide gauge stations from Peninsular Malaysia, Sabah and Sarawak are chosen for this data verification. The pattern and correlation of both measurements of sea level anomalies (SLA are evaluated over the same period in each area in order to produce comparable results. Afterwards, the time series of the sea level trend is quantified using robust fit regression analysis. The findings clearly show that the absolute sea level trend is rising and varying over the Malaysian seas with the rate of sea level varies and gradually increase from east to west of Malaysia. Highly confident and correlation level of the 23 years measurement data with an astonishing root mean square difference permits the absolute sea level trend of the Malaysian seas has raised at the rate 3.14 ± 0.12 mm yr-1 to 4.81 ± 0.15 mm yr-1 for the chosen sub-areas, with an overall mean of 4.09 ± 0.12 mm yr-1. This study hopefully offers a beneficial sea level information to be applied in a wide range of related environmental and climatology issue such as flood and global warming.

  20. Acceleration of Sea Level Rise Over Malaysian Seas from Satellite Altimeter

    Science.gov (United States)

    Hamid, A. I. A.; Din, A. H. M.; Khalid, N. F.; Omar, K. M.

    2016-09-01

    Sea level rise becomes our concern nowadays as a result of variously contribution of climate change that cause by the anthropogenic effects. Global sea levels have been rising through the past century and are projected to rise at an accelerated rate throughout the 21st century. Due to this change, sea level is now constantly rising and eventually will threaten many low-lying and unprotected coastal areas in many ways. This paper is proposing a significant effort to quantify the sea level trend over Malaysian seas based on the combination of multi-mission satellite altimeters over a period of 23 years. Eight altimeter missions are used to derive the absolute sea level from Radar Altimeter Database System (RADS). Data verification is then carried out to verify the satellite derived sea level rise data with tidal data. Eight selected tide gauge stations from Peninsular Malaysia, Sabah and Sarawak are chosen for this data verification. The pattern and correlation of both measurements of sea level anomalies (SLA) are evaluated over the same period in each area in order to produce comparable results. Afterwards, the time series of the sea level trend is quantified using robust fit regression analysis. The findings clearly show that the absolute sea level trend is rising and varying over the Malaysian seas with the rate of sea level varies and gradually increase from east to west of Malaysia. Highly confident and correlation level of the 23 years measurement data with an astonishing root mean square difference permits the absolute sea level trend of the Malaysian seas has raised at the rate 3.14 ± 0.12 mm yr-1 to 4.81 ± 0.15 mm yr-1 for the chosen sub-areas, with an overall mean of 4.09 ± 0.12 mm yr-1. This study hopefully offers a beneficial sea level information to be applied in a wide range of related environmental and climatology issue such as flood and global warming.

  1. Impacts of 21st century sea-level rise on a Danish major city - an assessment based on fine-resolution digital topography and a new flooding algorithm

    DEFF Research Database (Denmark)

    Moeslund, Jesper Erenskjold; Bøcher, Peter Klith; Svenning, J.-C.

    2009-01-01

    at risk from flooding. We combine a new national Digital Elevation Model in very fine resolution (~2 meter), a new highly computationally efficient flooding algorithm that accurately models the influence of barriers, and geospatial data on real-estate values to assess the economic real-estate risk posed...... with an increased sea level, the strategic placement of flood-gates at key potential water-inflow routes and the construction or elevation of existing dikes seems to be the most convenient, most socially acceptable, and maybe also the cheapest solution. Finally, we suggest that high-detail flooding models similar...

  2. Final report for sea-level rise response modeling for San Francisco Bay estuary tidal marshes

    Science.gov (United States)

    Takekawa, John Y.; Thorne, Karen M.; Buffington, Kevin J.; Spragens, Kyle A.; Swanson, Kathleen M.; Drexler, Judith Z.; Schoellhamer, David H.; Overton, Cory T.; Casazza, Michael L.

    2013-01-01

    The International Panel on Climate Change has identified coastal ecosystems as areas that will be disproportionally affected by climate change. Current sea-level rise projections range widely with 0.57 to 1.9 meters increase in mea sea level by 2100. The expected accelerated rate of sea-level rise through the 21st century will put many coastal ecosystems at risk, especially those in topographically low-gradient areas. We assessed marsh accretion and plant community state changes through 2100 at 12 tidal salt marshes around San Francisco Bay estuary with a sea-level rise response model. Detailed ground elevation, vegetation, and water level data were collected at all sites between 2008 and 2011 and used as model inputs. Sediment cores (taken by Callaway and others, 2012) at four sites around San Francisco Bay estuary were used to estimate accretion rates. A modification of the Callaway and others (1996) model, the Wetland Accretion Rate Model for Ecosystem Resilience (WARMER), was utilized to run sea-level rise response models for all sites. With a mean sea level rise of 1.24 m by 2100, WARMER projected that the vast majority, 95.8 percent (1,942 hectares), of marsh area in our study will lose marsh plant communities by 2100 and to transition to a relative elevation range consistent with mudflat habitat. Three marshes were projected to maintain marsh vegetation to 2100, but they only composed 4.2 percent (85 hectares) of the total marsh area surveyed.

  3. CoSMoS (Coastal Storm Modeling System) Southern California v3.0 Phase 2 projections of coastal cliff retreat due to 21st century sea-level rise

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Summary: This dataset contains projections of coastal cliff-retreat rates and positions for future scenarios of sea-level rise (SLR). Projections were made using...

  4. Sea level rise projection in the South China Sea from CMIP5 models

    Institute of Scientific and Technical Information of China (English)

    HUANG Chuanjiang; QIAO Fangli

    2015-01-01

    Future potential sea level change in the South China Sea (SCS) is estimated by using 24 CMIP5 models under different representative concentration pathway (RCP) scenarios. By the end of the 21st century (2081–2100 relative to 1986–2005), the multimodel ensemble mean dynamic sea level (DSL) is projected to rise 0.9, 1.6, and 1.1 cm under RCP2.6, RCP4.5, and RCP8.5 scenarios, respectively, resulting in a total sea level rise (SLR) of 40.9, 48.6, and 64.1 cm in the SCS. It indicates that the SCS will experience a substantial SLR over the 21st century, and the rise is only marginal larger than the global mean SLR. During the same period, the steric sea level (SSL) rise is estimated to be 6.7, 10.0, and 15.3 cm under the three scenarios, respectively, which accounts only for 16%, 21% and 24% of the total SLR in this region. The changes of the SSL in the SCS are almost out of phase with those of the DSL for the three scenarios. The central deep basin has a slightly weak DSL rise, but a strong SSL rise during the 21st century, compared with the north and southwest shelves.

  5. As the sea level rises the Earth does not stand still

    Science.gov (United States)

    Hagen, S. C.; Alizad, K.; Bilskie, M. V.; Hovenga, P. A.; Medeiros, S. C.; Passeri, D. L.; Wang, D.

    2015-12-01

    Global mean sea level rise was largely linear over the 20th century; however, according to global satellite altimetry, the rate of rise has increased from approximately 1.6 to 3.4 mm/year. It is clear that this eustatic sea level rise has been predominantly caused by thermal expansion of ocean water (i.e., it is a manifestation of an increase in the average annual global temperature). Future projections of increased global temperatures, among others, introduce additional contributions (e.g., land ice loss and changes in land water storage) resulting in higher sea level rise that can only be accommodated by accelerations in the rate of the rise. Increased temperatures lead to changes in evapotranspiration rates, precipitation rates and patterns, etc. As the sea level changes the Earth experiences many other directly or indirectly related processes (e.g., population growth and migration, local variation in subsidence, etc.). Proper assessment of the local, regional and global impacts of relative sea level rise should include as many of these linear and nonlinear processes as possible. This presentation will explain our approach to understanding the relationships between these processes and their impacts to better equip adaptation strategies and enhance coastal resiliency. References Bilskie, M. V., et al. "Dynamics of sea level rise and coastal flooding on a changing landscape." Geophys. Res. Lett., 41(3), 2014, 927-934, doi:10.1002/2013GL058759 Church, J. A. and N. J. White, "A 20th century acceleration in global sea-level rise." Geophys. Res. Lett., 33(1), 2006, L01602 Passeri, D.L., et al. "The dynamic effects of sea level rise on low-gradient coastal landscapes: a review." Earth's Future, Online, 2015. doi:10.1002/2015EF000298 Passeri, D.L., et al. "On the significance of incorporating shoreline changes for evaluating coastal hydrodynamics under sea level rise scenarios." Nat. Haz., 75 (2), 2015, 1599-1617. doi:10.1007/s11069-014-1386-y Wang, D., et al. "Climate

  6. Is the detection of accelerated sea level rise imminent?

    Science.gov (United States)

    Fasullo, J. T.; Nerem, R. S.; Hamlington, B.

    2016-08-01

    Global mean sea level rise estimated from satellite altimetry provides a strong constraint on climate variability and change and is expected to accelerate as the rates of both ocean warming and cryospheric mass loss increase over time. In stark contrast to this expectation however, current altimeter products show the rate of sea level rise to have decreased from the first to second decades of the altimeter era. Here, a combined analysis of altimeter data and specially designed climate model simulations shows the 1991 eruption of Mt Pinatubo to likely have masked the acceleration that would have otherwise occurred. This masking arose largely from a recovery in ocean heat content through the mid to late 1990 s subsequent to major heat content reductions in the years following the eruption. A consequence of this finding is that barring another major volcanic eruption, a detectable acceleration is likely to emerge from the noise of internal climate variability in the coming decade.

  7. A Bayesian network to predict coastal vulnerability to sea level rise

    Science.gov (United States)

    Gutierrez, B.T.; Plant, N.G.; Thieler, E.R.

    2011-01-01

    Sea level rise during the 21st century will have a wide range of effects on coastal environments, human development, and infrastructure in coastal areas. The broad range of complex factors influencing coastal systems contributes to large uncertainties in predicting long-term sea level rise impacts. Here we explore and demonstrate the capabilities of a Bayesian network (BN) to predict long-term shoreline change associated with sea level rise and make quantitative assessments of prediction uncertainty. A BN is used to define relationships between driving forces, geologic constraints, and coastal response for the U.S. Atlantic coast that include observations of local rates of relative sea level rise, wave height, tide range, geomorphic classification, coastal slope, and shoreline change rate. The BN is used to make probabilistic predictions of shoreline retreat in response to different future sea level rise rates. Results demonstrate that the probability of shoreline retreat increases with higher rates of sea level rise. Where more specific information is included, the probability of shoreline change increases in a number of cases, indicating more confident predictions. A hindcast evaluation of the BN indicates that the network correctly predicts 71% of the cases. Evaluation of the results using Brier skill and log likelihood ratio scores indicates that the network provides shoreline change predictions that are better than the prior probability. Shoreline change outcomes indicating stability (-1 1 m/yr) was not well predicted. We find that BNs can assimilate important factors contributing to coastal change in response to sea level rise and can make quantitative, probabilistic predictions that can be applied to coastal management decisions. Copyright ?? 2011 by the American Geophysical Union.

  8. Predicting Land-Ice Retreat and Sea-Level Rise with the Community Earth System Model

    Energy Technology Data Exchange (ETDEWEB)

    Lipscomb, William [Los Alamos National Laboratory

    2012-06-19

    Coastal stakeholders need defensible predictions of 21st century sea-level rise (SLR). IPCC assessments suggest 21st century SLR of {approx}0.5 m under aggressive emission scenarios. Semi-empirical models project SLR of {approx}1 m or more by 2100. Although some sea-level contributions are fairly well constrained by models, others are highly uncertain. Recent studies suggest a potential large contribution ({approx}0.5 m/century) from the marine-based West Antarctic Ice Sheet, linked to changes in Southern Ocean wind stress. To assess the likelihood of fast retreat of marine ice sheets, we need coupled ice-sheet/ocean models that do not yet exist (but are well under way). CESM is uniquely positioned to provide integrated, physics based sea-level predictions.

  9. Adaptive Planning for Transportation Corridors Threatened by Sea Level Rise

    OpenAIRE

    Shilling, Fraser M; Vandever, Justin; May, Kris; Gerhard, Ina; Bregoff, Robert

    2016-01-01

    This paper describes a generalizable planning and assessment process for transportation planning adaptive to sea level rise (SLR). State Route 37 (SR-37) is the California highway most vulnerable to temporary flooding and permanent inundation as a result of SLR. Like many other coastal highways in the United States, SR-37 is adjacent to protected coastal systems (e.g., beaches, tidal wetlands), meaning that any activity on the highway is s...

  10. How mangrove forests adjust to rising sea level.

    Science.gov (United States)

    Krauss, Ken W; McKee, Karen L; Lovelock, Catherine E; Cahoon, Donald R; Saintilan, Neil; Reef, Ruth; Chen, Luzhen

    2014-04-01

    Mangroves are among the most well described and widely studied wetland communities in the world. The greatest threats to mangrove persistence are deforestation and other anthropogenic disturbances that can compromise habitat stability and resilience to sea-level rise. To persist, mangrove ecosystems must adjust to rising sea level by building vertically or become submerged. Mangroves may directly or indirectly influence soil accretion processes through the production and accumulation of organic matter, as well as the trapping and retention of mineral sediment. In this review, we provide a general overview of research on mangrove elevation dynamics, emphasizing the role of the vegetation in maintaining soil surface elevations (i.e. position of the soil surface in the vertical plane). We summarize the primary ways in which mangroves may influence sediment accretion and vertical land development, for example, through root contributions to soil volume and upward expansion of the soil surface. We also examine how hydrological, geomorphological and climatic processes may interact with plant processes to influence mangrove capacity to keep pace with rising sea level. We draw on a variety of studies to describe the important, and often under-appreciated, role that plants play in shaping the trajectory of an ecosystem undergoing change.

  11. How mangrove forests adjust to rising sea level

    Science.gov (United States)

    Krauss, Ken W.; McKee, Karen L.; Lovelock, Catherine E.; Cahoon, Donald R.; Saintilan, Neil; Reef, Ruth; Chen, Luzhen

    2014-01-01

    Mangroves are among the most well described and widely studied wetland communities in the world. The greatest threats to mangrove persistence are deforestation and other anthropogenic disturbances that can compromise habitat stability and resilience to sea-level rise. To persist, mangrove ecosystems must adjust to rising sea level by building vertically or become submerged. Mangroves may directly or indirectly influence soil accretion processes through the production and accumulation of organic matter, as well as the trapping and retention of mineral sediment. In this review, we provide a general overview of research on mangrove elevation dynamics, emphasizing the role of the vegetation in maintaining soil surface elevations (i.e. position of the soil surface in the vertical plane). We summarize the primary ways in which mangroves may influence sediment accretion and vertical land development, for example, through root contributions to soil volume and upward expansion of the soil surface. We also examine how hydrological, geomorphological and climatic processes may interact with plant processes to influence mangrove capacity to keep pace with rising sea level. We draw on a variety of studies to describe the important, and often under-appreciated, role that plants play in shaping the trajectory of an ecosystem undergoing change.

  12. Salt marsh persistence is threatened by predicted sea-level rise

    Science.gov (United States)

    Crosby, Sarah C.; Sax, Dov F.; Palmer, Megan E.; Booth, Harriet S.; Deegan, Linda A.; Bertness, Mark D.; Leslie, Heather M.

    2016-11-01

    Salt marshes buffer coastlines and provide critical ecosystem services from storm protection to food provision. Worldwide, these ecosystems are in danger of disappearing if they cannot increase elevation at rates that match sea-level rise. However, the magnitude of loss to be expected is not known. A synthesis of existing records of salt marsh elevation change was conducted in order to consider the likelihood of their future persistence. This analysis indicates that many salt marshes did not keep pace with sea-level rise in the past century and kept pace even less well over the past two decades. Salt marshes experiencing higher local sea-level rise rates were less likely to be keeping pace. These results suggest that sea-level rise will overwhelm most salt marshes' capacity to maintain elevation. Under the most optimistic IPCC emissions pathway, 60% of the salt marshes studied will be gaining elevation at a rate insufficient to keep pace with sea-level rise by 2100. Without mitigation of greenhouse gas emissions this potential loss could exceed 90%, which will have substantial ecological, economic, and human health consequences.

  13. US power plant sites at risk of future sea-level rise

    Science.gov (United States)

    Bierkandt, R.; Auffhammer, M.; Levermann, A.

    2015-12-01

    Unmitigated greenhouse gas emissions may increase global mean sea-level by about 1 meter during this century. Such elevation of the mean sea-level enhances the risk of flooding of coastal areas. We compute the power capacity that is currently out-of-reach of a 100-year coastal flooding but will be exposed to such a flood by the end of the century for different US states, if no adaptation measures are taken. The additional exposed capacity varies strongly among states. For Delaware it is 80% of the mean generated power load. For New York this number is 63% and for Florida 43%. The capacity that needs additional protection compared to today increases by more than 250% for Texas, 90% for Florida and 70% for New York. Current development in power plant building points towards a reduced future exposure to sea-level rise: proposed and planned power plants are less exposed than those which are currently operating. However, power plants that have been retired or canceled were less exposed than those operating at present. If sea-level rise is properly accounted for in future planning, an adaptation to sea-level rise may be costly but possible.

  14. Geologic effects and coastal vulnerability to sea-level rise, erosion, and storms

    Science.gov (United States)

    Williams, S.J.; Gutierrez, B.T.; Thieler, E.R.; Pendleton, E.

    2008-01-01

    A combination of natural and human factors are driving coastal change and making coastal regions and populations increasingly vulnerable. Sea level, a major agent of coastal erosion, has varied greatly from -120 m below present during glacial period low-stands to + 4 to 6 m above present during interglacial warm periods. Geologic and tide gauge data show that global sea level has risen about 12 to 15 cm during the past century with satellite measurements indicating an acceleration since the early 1990s due to thermal expansion and ice-sheet melting. Land subsidence due to tectonic forces and sediment compaction in regions like the mid-Atlantic and Louisiana increase the rate of relative sea-level rise to 40 cm to 100 cm per century. Sea- level rise is predicted to accelerate significantly in the near future due to climate change, resulting in pervasive impacts to coastal regions and putting populations increasingly at risk. The full implications of climate change for coastal systems need to be understood better and long-term plans are needed to manage coasts in order to protect natural resources and mitigate the effects of sea-level rise and increased storms on human infrastructure. Copyright ASCE 2008.

  15. Mangrove sedimentation and response to relative sea-level rise

    Science.gov (United States)

    Woodroffe, CD; Rogers, K.; Mckee, Karen L.; Lovelock, CE; Mendelssohn, IA; Saintilan, N.

    2016-01-01

    Mangroves occur on upper intertidal shorelines in the tropics and subtropics. Complex hydrodynamic and salinity conditions influence mangrove distributions, primarily related to elevation and hydroperiod; this review considers how these adjust through time. Accumulation rates of allochthonous and autochthonous sediment, both inorganic and organic, vary between and within different settings. Abundant terrigenous sediment can form dynamic mudbanks; tides redistribute sediment, contrasting with mangrove peat in sediment-starved carbonate settings. Sediments underlying mangroves sequester carbon, but also contain paleoenvironmental records of adjustments to past sea-level changes. Radiometric dating indicates long-term sedimentation, whereas Surface Elevation Table-Marker Horizon measurements (SET-MH) provide shorter perspectives, indicating shallow subsurface processes of root growth and substrate autocompaction. Many tropical deltas also experience deep subsidence, which augments relative sea-level rise. The persistence of mangroves implies an ability to cope with moderately high rates of relative sea-level rise. However, many human pressures threaten mangroves, resulting in continuing decline in their extent throughout the tropics.

  16. Mangrove Sedimentation and Response to Relative Sea-Level Rise

    Science.gov (United States)

    Woodroffe, C. D.; Rogers, K.; McKee, K. L.; Lovelock, C. E.; Mendelssohn, I. A.; Saintilan, N.

    2016-01-01

    Mangroves occur on upper intertidal shorelines in the tropics and subtropics. Complex hydrodynamic and salinity conditions, related primarily to elevation and hydroperiod, influence mangrove distributions; this review considers how these distributions change over time. Accumulation rates of allochthonous and autochthonous sediment, both inorganic and organic, vary between and within different settings. Abundant terrigenous sediment can form dynamic mudbanks, and tides redistribute sediment, contrasting with mangrove peat in sediment-starved carbonate settings. Sediments underlying mangroves sequester carbon but also contain paleoenvironmental records of adjustments to past sea-level changes. Radiometric dating indicates long-term sedimentation, whereas measurements made using surface elevation tables and marker horizons provide shorter perspectives, indicating shallow subsurface processes of root growth and substrate autocompaction. Many tropical deltas also experience deep subsidence, which augments relative sea-level rise. The persistence of mangroves implies an ability to cope with moderately high rates of relative sea-level rise. However, many human pressures threaten mangroves, resulting in a continuing decline in their extent throughout the tropics. *

  17. Accelerated sea level rise and Florida Current transport

    Directory of Open Access Journals (Sweden)

    J. Park

    2015-07-01

    Full Text Available The Florida Current is the headwater of the Gulf Stream and is a component of the North Atlantic western boundary current from which a geostrophic balance between sea surface height and mass transport directly influence coastal sea levels along the Florida Straits. A linear regression of daily Florida Current transport estimates does not find a significant change in transport over the last decade; however, a nonlinear trend extracted from empirical mode decomposition (EMD suggests a 3 Sv decline in mean transport. This decline is consistent with observed tide gauge records in Florida Bay and the straits exhibiting an acceleration of mean sea level (MSL rise over the decade. It is not known whether this recent change represents natural variability or the onset of the anticipated secular decline in Atlantic meridional overturning circulation (AMOC; nonetheless, such changes have direct impacts on the sensitive ecological systems of the Everglades as well as the climate of western Europe and eastern North America.

  18. Accelerated sea level rise and Florida Current transport

    Directory of Open Access Journals (Sweden)

    J. Park

    2015-04-01

    Full Text Available The Florida Current is the headwater of the Gulf Stream and is a component of the North Atlantic western boundary current from which a geostrophic balance between sea surface height and mass transport directly influence coastal sea levels along the Florida Straits. A linear regression of daily Florida Current transport estimates does not find a significant change in transport over the last decade, however, a nonlinear trend extracted from empirical mode decomposition suggests a 3 Sv decline in mean transport. This decline is consistent with observed tide gauge records in Florida Bay and the Straits, all exhibiting an acceleration of mean sea level rise over the decade. It is not known whether this recent change represents natural variability or the onset of the anticipated secular decline in Atlantic meridional overturning circulation, nonetheless, such changes have direct impacts on the sensitive ecological systems of the Everglades as well as the climate of western Europe and eastern North America.

  19. Modelling the increased frequency of extreme sea levels in the Ganges-Brahmaputra-Meghna delta due to sea level rise and other effects of climate change.

    Science.gov (United States)

    Kay, S; Caesar, J; Wolf, J; Bricheno, L; Nicholls, R J; Saiful Islam, A K M; Haque, A; Pardaens, A; Lowe, J A

    2015-07-01

    Coastal flooding due to storm surge and high tides is a serious risk for inhabitants of the Ganges-Brahmaputra-Meghna (GBM) delta, as much of the land is close to sea level. Climate change could lead to large areas of land being subject to increased flooding, salinization and ultimate abandonment in West Bengal, India, and Bangladesh. IPCC 5th assessment modelling of sea level rise and estimates of subsidence rates from the EU IMPACT2C project suggest that sea level in the GBM delta region may rise by 0.63 to 0.88 m by 2090, with some studies suggesting this could be up to 0.5 m higher if potential substantial melting of the West Antarctic ice sheet is included. These sea level rise scenarios lead to increased frequency of high water coastal events. Any effect of climate change on the frequency and severity of storms can also have an effect on extreme sea levels. A shelf-sea model of the Bay of Bengal has been used to investigate how the combined effect of sea level rise and changes in other environmental conditions under climate change may alter the frequency of extreme sea level events for the period 1971 to 2099. The model was forced using atmospheric and oceanic boundary conditions derived from climate model projections and the future scenario increase in sea level was applied at its ocean boundary. The model results show an increased likelihood of extreme sea level events through the 21st century, with the frequency of events increasing greatly in the second half of the century: water levels that occurred at decadal time intervals under present-day model conditions occurred in most years by the middle of the 21st century and 3-15 times per year by 2100. The heights of the most extreme events tend to increase more in the first half of the century than the second. The modelled scenarios provide a case study of how sea level rise and other effects of climate change may combine to produce a greatly increased threat to life and property in the GBM delta by the end

  20. Influence of Sea Level Rise and Marsh Hypsometry on the Equilibrium Morphology of Tidal Inlets

    Science.gov (United States)

    Lovering, J. L.; Adams, P. N.

    2011-12-01

    As global sea level is predicted to rise between 0.18 and 1.9 meters by the end of the 21st century, it is critical to understand how the geomorphology and ecology of coastal regions worldwide will be affected for a range of sea level rise rate scenarios. Tidal inlets along sandy, passive margin coasts are sensitive to water levels, nearshore currents, and wave fields, so changes in environmental conditions in the vicinity of inlets should drive a morphologic response. Due to their importance in commercial shipping, military navigation, and recreation, an improved understanding of tidal inlet response to sea level rise will assist in future planning efforts. The widely accepted conceptual model of tidal inlet evolution predicts that, as sea level rises, salt marshes in the lagoon become drowned and converted to subtidal environments, increasing accommodation space in the back barrier basin. This conversion increases the tidal prism, inlet cross-sectional area, and ebb shoal volume. The purpose of this study is to quantify the relationship between sea level rise, the ecomorphodynamic environment of the back barrier basin, and the resulting changes in equilibrium tidal inlet morphology. Threshold values of sea level rise rate for which marsh habitats convert to subtidal environments, determined by the tidal range and suspended sediment concentration found in the back barrier basin, were developed using previously published numerical simulations and field-based observations. We paired the threshold values with Escoffier equilibrium curve calculations, in order to predict changes in tidal inlet equilibrium cross-sectional area. Halophytic vegetation that is supplied with high suspended sediment concentrations and lives in an area with a high tidal range is able to trap sediment and drive vertical accretion at a faster pace than vegetation in areas of low sediment availability and low tidal range; therefore marshes with high sediment availability and tidal range are

  1. Salt marsh stability modelled in relation to sea level rise

    DEFF Research Database (Denmark)

    Bartholdy, Jesper; Bartholdy, Anders; Kroon, Aart

    2010-01-01

    Accretion on a natural backbarrier salt marsh was modeled as a function of high tide level, initial salt marsh level and distance to the source. Calibration of the model was based on up to ca 80 year old marker horizons, supplemented by 210Pb/137Cs datings and subsequent measurements of clay...... rise, the marsh at the specific location will eventually drown, whereas - with a sea level rise below this level – it will grow towards the top of the rising tidal frame. The short term variation of salt marsh accretion was found to correlate well with variations in the North Atlantic Oscillation...... - relatively quickly grow above the level of the highest astronomical tide, whereas this - in practice - will never happen for the latter....

  2. Salt marsh stability modelled in relation to sea level rise

    Science.gov (United States)

    Bartholdy, Jesper; Bartholdy, Anders T.; Kroon, Aart

    2010-05-01

    Accretion on a natural backbarrier salt marsh was modeled as a function of high tide level, initial salt marsh level and distance to the source. Calibration of the model was based on up to ca 80 year old marker horizons, supplemented by 210Pb/137Cs datings and subsequent measurements of clay thickness. Autocompaction was incorporated in the model, and shown to play a major role for the translation of accretion rates measured as length per unit time to accumulation rates measured as mass per area per unit time. This is important, even for shallow salt marsh deposits for which it is demonstrated that mass depth down core can be directly related to the bulk dry density of the surface layer by means of a logarithmic function. The results allow for an evaluation of the use of marker horizons in the topmost layers and show that it is important to know the level of the marker in relation to the salt marsh base. In general, deeper located markers will indicate successively smaller accretion rates with the same sediment input. Thus, stability analysis made on the basis of newly established marker horizons will be biased and indicate salt marsh stabilities far above the correct level. Running the model with a constant sea level revealed that balance between the inner and the outer salt marsh deposition can not be achieved within a reasonable time scale. Likewise it is shown that only one specific sea level rise provides equilibrium for a given location on the salt marsh. With a higher sea level rise, the marsh at the specific location will eventually drown, whereas - with a sea level rise below this level - it will grow towards the top of the rising tidal frame. The short term variation of salt marsh accretion was found to correlate well with variations in the North Atlantic Oscillation - the NAO winter index. Comparisons between the geomorphological development of wind tide affected salt marshes, like those present on the Danish North Sea coasts, and primary astronomically

  3. Global Sea Surface Temperature and Sea Level Rise Estimation with Optimal Historical Time Lag Data

    Directory of Open Access Journals (Sweden)

    Mustafa M. Aral

    2016-11-01

    Full Text Available Prediction of global temperatures and sea level rise (SLR is important for sustainable development planning of coastal regions of the world and the health and safety of communities living in these regions. In this study, climate change effects on sea level rise is investigated using a dynamic system model (DSM with time lag on historical input data. A time-invariant (TI-DSM and time-variant dynamic system model (TV-DSM with time lag is developed to predict global temperatures and SLR in the 21st century. The proposed model is an extension of the DSM developed by the authors. The proposed model includes the effect of temperature and sea level states of several previous years on the current temperature and sea level over stationary and also moving scale time periods. The optimal time lag period used in the model is determined by minimizing a synthetic performance index comprised of the root mean square error and coefficient of determination which is a measure for the reliability of the predictions. Historical records of global temperature and sea level from 1880 to 2001 are used to calibrate the model. The optimal time lag is determined to be eight years, based on the performance measures. The calibrated model was then used to predict the global temperature and sea levels in the 21st century using a fixed time lag period and moving scale time lag periods. To evaluate the adverse effect of greenhouse gas emissions on SLR, the proposed model was also uncoupled to project the SLR based on global temperatures that are obtained from the Intergovernmental Panel on Climate Change (IPCC emission scenarios. The projected SLR estimates for the 21st century are presented comparatively with the predictions made in previous studies.

  4. Responding to rising sea levels in the Mekong Delta

    Science.gov (United States)

    Smajgl, A.; Toan, T. Q.; Nhan, D. K.; Ward, J.; Trung, N. H.; Tri, L. Q.; Tri, V. P. D.; Vu, P. T.

    2015-02-01

    Vietnamese communities in the Mekong Delta are faced with the substantial impacts of rising sea levels and salinity intrusion. The construction of embankments and dykes has historically been the principal strategy of the Vietnamese government to mitigate the effects of salinity intrusion on agricultural production. A predicted sea-level rise of 30 cm by the year 2050 is expected to accelerate salinity intrusion. This study combines hydrologic, agronomic and behavioural assessments to identify effective adaptation strategies reliant on land-use change (soft options) and investments in water infrastructure (hard options). As these strategies are managed within different policy portfolios, the political discussion has polarized between choices of either soft or hard options. This paper argues that an ensemble of hard and soft policies is likely to provide the most effective results for people's livelihoods in the Mekong Delta. The consequences of policy deliberations are likely to be felt beyond the Mekong Delta as levels of rice cultivation there also affect national and global food security.

  5. NOAA Digital Coast Sea Level Rise and Coastal Flooding Impacts Viewer

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sea Level Rise and Coastal Flooding Impacts Viewer depicts potential sea level rise and its associated impacts on the nation's coastal areas. These coastal areas...

  6. Island abandonment and sea-level rise: an historical analog from the Chesapeake Bay, USA

    Energy Technology Data Exchange (ETDEWEB)

    Gibbons, S.J.A. [Wilfrid Laurier University, Waterloo (Canada). Dept. of Geography and Enivronmental Studies; Nicholls, R.J. [University of Southampton (United Kingdom). School of Civil Engineering

    2006-02-15

    Small islands are widely agreed to be vulnerable to human-induced sea-level rise during the 21st century and beyond, with forced abandonment of some low-lying oceanic islands being a real possibility. A regional abandonment of islands in the Chesapeake Bay, USA provides an historical analog of such vulnerability as this has been linked to a mid 19th Century acceleration in relative sea-level rise. Using a case study approach for Holland Island, Maryland, this hypothesis was tested using a range of physical and human historical data. While sea-level rise was the underlying driver, this analysis shows that the abandonment was more complex than a direct response to sea-level rise. Between 1850 and 1900, Holland Island was a booming community and population increased from 37 to 253, with immigration causing the majority of the increase. At the same time, the upland area where people made their homes was steadily diminishing, losing about 15 ha or 38% of the total. After 1900, the island experienced a decrease in population to 169 in 1916, with final abandonment in 1918, with the exception of one family who left by 1920. Final abandonment was triggered by this depopulation as the population fell below a level that could support critical community services, and the community lost faith in their future on Holland Island. It is likely that similar social processes determined the abandonment of the other Chesapeake Bay islands. Looking to the future, it shows that many small low-lying islands could be abandoned due to sea-level rise long before they become physically uninhabitable. (author)

  7. A Bayesian network to predict vulnerability to sea-level rise: data report

    Science.gov (United States)

    Gutierrez, Benjamin T.; Plant, Nathaniel G.; Thieler, E. Robert

    2011-01-01

    During the 21st century, sea-level rise is projected to have a wide range of effects on coastal environments, development, and infrastructure. Consequently, there has been an increased focus on developing modeling or other analytical approaches to evaluate potential impacts to inform coastal management. This report provides the data that were used to develop and evaluate the performance of a Bayesian network designed to predict long-term shoreline change due to sea-level rise. The data include local rates of relative sea-level rise, wave height, tide range, geomorphic classification, coastal slope, and shoreline-change rate compiled as part of the U.S. Geological Survey Coastal Vulnerability Index for the U.S. Atlantic coast. In this project, the Bayesian network is used to define relationships among driving forces, geologic constraints, and coastal responses. Using this information, the Bayesian network is used to make probabilistic predictions of shoreline change in response to different future sea-level-rise scenarios.

  8. Short Lived Climate Pollutants cause a Long Lived Effect on Sea-level Rise: Analyzing climate metrics for sea-level rise

    Science.gov (United States)

    Sterner, E.; Johansson, D. J.

    2013-12-01

    utilizes an upwelling diffusion energy balance model and focuses on the thermosteric part of sea-level rise. Example GSP results are 244, 15 and 278 for BC, CH4 and N2O for a time horizon of 100 years. Compare GWP and GTP values of 405, 24 and 288 as well as 62, 4.5 and 252. The main result of the study is that no climate forcer is in any absolute sense short lived when it comes to Sea Level impacts. All of the examined climate forcers have considerable influence on the thermosteric SLR, and the closely linked ocean heat content, on the time scale of centuries. The reason for this is that heat, once it has been induced by the climate drivers and warmed the surface ocean, is transported down into the slowly mixing oceans. References: Shindell, D. et al. Simultaneously mitigating near-term climate change and improving human health and food security. Science 335, 183-189 (2012). Bond, T. C. et al. Bounding the role of black carbon in the climate system: A scientific assessment. Journal of Geophysical Research: Atmospheres 118 5380-5552 (2013). Hu, A., Xu, Y., Tebaldi, C., Washington, W. M. & Ramanathan, V. Mitigation of short-lived climate pollutants slows sea-level rise. Nature Climate Change 3, 730-734 (2013).

  9. Geodesy for Evaluating the Impact of Sea Level Rise on NASA Centers and Facilities

    Science.gov (United States)

    Bell, L. J.; Nerem, R.; Masters, D. S.; Meertens, C. M.

    2012-12-01

    Sea level is rising in response to climate change. Currently the global mean rate is a little over 3 mm/year, but it is expected to accelerate significantly over this century. This will have a profound impact on coastal populations and infrastructure, including NASA centers and facilities. A detailed study proposed by the University of Colorado's Center for Astrodynamics Research on the impact of sea level rise on a few of NASA's most vulnerable facilities was recently funded by NASA. Individual surveys at several high-risk NASA centers will be conducted and used as case studies for a broader investigation that needs to be done for coastal infrastructure around the country. The first year of the study will include implementing and conducting a terrestrial laser scanning (TLS) and GPS survey at Kennedy Space Center, Cape Canaveral, Florida, and potentially at Wallops Flight Facility, Wallops Island, Virginia, and Langley Research Center, Hampton, Virginia. We will use a broad array of geodetic tools to perform this study - much of which has been developed over the last few decades by NASA and its investigators. We will use airborne lidar data and terrestrial laser scanning (TLS) data to construct detailed digital elevation models (DEMs) of the facilities that we assess. We will use GPS data to assess the rate of vertical land movement at the facilities and to tie the DEM to tide gauges and other reference points. We will use satellite altimeter data from TOPEX, Jason-1, and Jason-2 to assess the sea level changes observed near these NASA facilities over the last 20 years to see if it offers clues for the future. We will also use GRACE satellite gravity observations to predict the regional changes in sea level caused by the melting of ice complexes around the world. We will use these datasets along with sea level projections from global climate models (GCMs) and semi-empirical projections to make detailed maps of sea level inundation for the years 2050 and 2100 for

  10. Scientific Reticence and Sea Level Rise (Invited Talk)

    Science.gov (United States)

    Hansen, J. E.

    2015-12-01

    Caution is an essential ingredient in scientific investigations, as success in science depends on objective skepticism. In some cases a cultural resistance to scientific discovery has seemed to exist and there are other factors that can contribute to scientific reticence. In a case such as ice sheet instability and sea level rise there is a danger that excessive caution might serve to lock in future disasters. I discussed these issues almost a decade ago (in Environ. Res. Lett., 2, 024002, 2007, doi:10.1088/1748-9326/2/2/024002), but given all that has transpired since then, this topic has become even more relevant and urgent. I will discuss the status of this dilemma as I see it.

  11. Modeling barrier island response to sea-level rise in the outer Banks, North Carolina

    Science.gov (United States)

    Moore, Laura J.; List, Jeffrey H.; Williams, S. Jeffress; Stolper, David

    2007-01-01

    An 8500-year Holocene simulation developed in GEOMBEST provides a possible scenario to explain the evolution of barrier coast between Rodanthe and Cape Hatteras, NC. Sensitivity analyses suggest that in the Outer Banks, the rate of sea-level rise is the most important factor in determining how barrier islands evolve. The Holocene simulation provides a basis for future simulations, which suggest that if sea level rises up to 0.88 m by AD 2100, as predicted by the highest estimates of the Intergovernmental Panel on Climate Change, the barrier in the study area may migrate on the order of 2.5 times more rapidly than at present. If sea level rises beyond IPCC predictions to reach 1.4–1.9 m above modern sea level by AD 2100, model results suggest that barrier islands in the Outer Banks may become vulnerable to threshold collapse, disintegrating during storm events, by the end of the next century. Consistent with sensitivity analyses, additional simulations indicate that anthropogenic activities, such as increasing the rate of sediment supply through beach nourishment, will only slightly affect barrier island migration rates and barrier island vulnerability to collapse.

  12. Assessing Sea Level Rise Impacts on the Surficial Aquifer in the Kennedy Space Center Region

    Science.gov (United States)

    Xiao, H.; Wang, D.; Hagen, S. C.; Medeiros, S. C.; Warnock, A. M.; Hall, C. R.

    2014-12-01

    Global sea level rise in the past century due to climate change has been seen at an average rate of approximately 1.7-2.2 mm per year, with an increasing rate over the next century. The increasing SLR rate poses a severe threat to the low-lying land surface and the shallow groundwater system in the Kennedy Space Center in Florida, resulting in saltwater intrusion and groundwater induced flooding. A three-dimensional groundwater flow and salinity transport model is implemented to investigate and evaluate the extent of floods due to rising water table as well as saltwater intrusion. The SEAWAT model is chosen to solve the variable-density groundwater flow and salinity transport governing equations and simulate the regional-scale spatial and temporal evolution of groundwater level and chloride concentration. The horizontal resolution of the model is 50 m, and the vertical domain includes both the Surficial Aquifer and the Floridan Aquifer. The numerical model is calibrated based on the observed hydraulic head and chloride concentration. The potential impacts of sea level rise on saltwater intrusion and groundwater induced flooding are assessed under various sea level rise scenarios. Based on the simulation results, the potential landward movement of saltwater and freshwater fringe is projected. The existing water supply wells are examined overlaid with the projected salinity distribution map. The projected Surficial Aquifer water tables are overlaid with data of high resolution land surface elevation, land use and land cover, and infrastructure to assess the potential impacts of sea level rise. This study provides useful tools for decision making on ecosystem management, water supply planning, and facility management.

  13. Fate of water pumped from underground and contributions to sea-level rise

    Science.gov (United States)

    Wada, Yoshihide; Lo, Min-Hui; Yeh, Pat J.-F.; Reager, John T.; Famiglietti, James S.; Wu, Ren-Jie; Tseng, Yu-Heng

    2016-08-01

    The contributions from terrestrial water sources to sea-level rise, other than ice caps and glaciers, are highly uncertain and heavily debated. Recent assessments indicate that groundwater depletion (GWD) may become the most important positive terrestrial contribution over the next 50 years, probably equal in magnitude to the current contributions from glaciers and ice caps. However, the existing estimates assume that nearly 100% of groundwater extracted eventually ends up in the oceans. Owing to limited knowledge of the pathways and mechanisms governing the ultimate fate of pumped groundwater, the relative fraction of global GWD that contributes to sea-level rise remains unknown. Here, using a coupled climate-hydrological model simulation, we show that only 80% of GWD ends up in the ocean. An increase in runoff to the ocean accounts for roughly two-thirds, whereas the remainder results from the enhanced net flux of precipitation minus evaporation over the ocean, due to increased atmospheric vapour transport from the land to the ocean. The contribution of GWD to global sea-level rise amounted to 0.02 (+/-0.004) mm yr-1 in 1900 and increased to 0.27 (+/-0.04) mm yr-1 in 2000. This indicates that existing studies have substantially overestimated the contribution of GWD to global sea-level rise by a cumulative amount of at least 10 mm during the twentieth century and early twenty-first century. With other terrestrial water contributions included, we estimate the net terrestrial water contribution during the period 1993-2010 to be +0.12 (+/-0.04) mm yr-1, suggesting that the net terrestrial water contribution reported in the IPCC Fifth Assessment Report report is probably overestimated by a factor of three.

  14. Fate of Water Pumped from Underground and Contributions to Sea Level Rise

    Science.gov (United States)

    Wada, Yoshihide; Lo, Min-Hui; Yeh, Pat J.-F.; Reager, John T.; Famiglietti, James S.; Wu, Ren-Jie; Tseng, Yu-Heng

    2016-01-01

    The contributions from terrestrial water sources to sea-level rise, other than ice caps and glaciers, are highly uncertain and heavily debated1-5. Recent assessments indicate that groundwater depletion (GWD) may become the most important positive terrestrial contribution6-10 over the next 50 years, probably equal in magnitude to the current contributions from glaciers and ice caps6. However, the existing estimates assume that nearly 100% of groundwater extracted eventually ends up in the oceans. Owing to limited knowledge of the pathways and mechanisms governing the ultimate fate of pumped groundwater, the relative fraction of global GWD that contributes to sea-level rise remains unknown. Here, using a coupled climate-hydrological model11,12 simulation, we show that only 80% of GWDends up in the ocean. An increase in runo to the ocean accounts for roughly two-thirds, whereas the remainder results from the enhanced net flux of precipitation minus evaporation over the ocean, due to increased atmospheric vapour transport from the land to the ocean. The contribution of GWD to global sea-level rise amounted to 0.02 (+/- 0.004)mm yr(sup-1) in 1900 and increased to 0.27 (+/- 0.04)mm yr(sup-1) in 2000. This indicates that existing studies have substantially overestimated the contribution of GWD to global sea-level rise by a cumulative amount of at least 10 mm during the twentieth century and early twenty-first century. With other terrestrial water contributions included, we estimate the net terrestrial water contribution during the period 1993-2010 to be +0.12 +/-0.04)mm yr(sup-1), suggesting that the net terrestrialwater contribution reported in the IPCC Fifth Assessment Report report is probably overestimated by a factor of three.

  15. Statistical analysis of the acceleration of Baltic mean sea-level rise, 1900-2012

    Directory of Open Access Journals (Sweden)

    Birgit Hünicke

    2016-07-01

    Full Text Available We analyse annual mean sea-level records from tide-gauges located in the Baltic and parts of the North Sea with the aim of detecting an acceleration of sea-level rise over the 20textsuperscript{th} and 21textsuperscript{st} centuries. The acceleration is estimated as a (1 fit to a polynomial of order two in time, (2 a long-term linear increase in the rates computed over gliding overlapping decadal time segments, and (3 a long-term increase of the annual increments of sea level.The estimation methods (1 and (2 prove to be more powerful in detecting acceleration when tested with sea-level records produced in global climate model simulations. These methods applied to the Baltic-Sea tide-gauges are, however, not powerful enough to detect a significant acceleration in most of individual records, although most estimated accelerations are positive. This lack of detection of statistically significant acceleration at the individual tide-gauge level can be due to the high-level of local noise and not necessarily to the absence of acceleration.The estimated accelerations tend to be stronger in the north and east of the Baltic Sea. Two hypothesis to explain this spatial pattern have been explored. One is that this pattern reflects the slow-down of the Glacial Isostatic Adjustment. However, a simple estimation of this effect suggests that this slow-down cannot explain the estimated acceleration. The second hypothesis is related to the diminishing sea-ice cover over the 20textsuperscript{th} century. The melting o of less saline and colder sea-ice can lead to changes in sea-level. Also, the melting of sea-ice can reduce the number of missing values in the tide-gauge records in winter, potentially influencing the estimated trends and acceleration of seasonal mean sea-level This hypothesis cannot be ascertained either since the spatial pattern of acceleration computed for winter and summer separately are very similar. The all-station-average-record displays an

  16. Past and future sea-level rise along the coast of North Carolina, United States

    CERN Document Server

    Kopp, Robert E; Kemp, Andrew C; Tebaldi, Claudia

    2014-01-01

    Focusing on factors that cause relative sea-level (RSL) rise to differ from the global mean, we evaluate RSL trajectories for North Carolina, United States, in the context of tide gauge and geological sea-level proxy records spanning the last $\\mathord{\\sim}$11,000 years. RSL rise was fastest ($\\mathord{\\sim}$7 mm/yr) during the early Holocene and decreased over time. During the Common Era before the 19th century, RSL rise ($\\mathord{\\sim}$0.7 to 1.1 mm/yr) was driven primarily by glacio-isostatic adjustment, dampened by tectonic uplift along the Cape Fear Arch. Ocean/atmosphere dynamics caused centennial variability of up to $\\mathord{\\sim}$0.6 mm/yr around the long-term rate. It is extremely likely (probability $P = 0.95$) that 20th century RSL rise at Sand Point, NC, (2.8 $\\pm$ 0.5 mm/yr) was faster than during any other century in $\\geq2,900$ years. Projections based on a fusion of process models, statistical models, expert elicitation and expert assessment indicate that RSL at Wilmington, NC, is very lik...

  17. Building Stories about Sea Level Rise through Interactive Visualizations

    Science.gov (United States)

    Stephens, S. H.; DeLorme, D. E.; Hagen, S. C.

    2013-12-01

    Digital media provide storytellers with dynamic new tools for communicating about scientific issues via interactive narrative visualizations. While traditional storytelling uses plot, characterization, and point of view to engage audiences with underlying themes and messages, interactive visualizations can be described as 'narrative builders' that promote insight through the process of discovery (Dove, G. & Jones, S. 2012, Proc. IHCI 2012). Narrative visualizations are used in online journalism to tell complex stories that allow readers to select aspects of datasets to explore and construct alternative interpretations of information (Segel, E. & Heer, J. 2010, IEEE Trans. Vis. Comp. Graph.16, 1139), thus enabling them to participate in the story-building process. Nevertheless, narrative visualizations also incorporate author-selected narrative elements that help guide and constrain the overall themes and messaging of the visualization (Hullman, J. & Diakopoulos, N. 2011, IEEE Trans. Vis. Comp. Graph. 17, 2231). One specific type of interactive narrative visualization that is used for science communication is the sea level rise (SLR) viewer. SLR viewers generally consist of a base map, upon which projections of sea level rise scenarios can be layered, and various controls for changing the viewpoint and scenario parameters. They are used to communicate the results of scientific modeling and help readers visualize the potential impacts of SLR on the coastal zone. Readers can use SLR viewers to construct personal narratives of the effects of SLR under different scenarios in locations that are important to them, thus extending the potential reach and impact of scientific research. With careful selection of narrative elements that guide reader interpretation, the communicative aspects of these visualizations may be made more effective. This presentation reports the results of a content analysis of a subset of existing SLR viewers selected in order to comprehensively

  18. How effective is albedo modification (solar radiation management geoengineering) in preventing sea-level rise from the Greenland Ice Sheet?

    Science.gov (United States)

    Applegate, Patrick J.; Keller, Klaus

    2015-08-01

    Albedo modification (AM) is sometimes characterized as a potential means of avoiding climate threshold responses, including large-scale ice sheet mass loss. Previous work has investigated the effects of AM on total sea-level rise over the present century, as well as AM’s ability to reduce long-term (≫103 yr) contributions to sea-level rise from the Greenland Ice Sheet (GIS). These studies have broken new ground, but neglect important feedbacks in the GIS system, or are silent on AM’s effectiveness over the short time scales that may be most relevant for decision-making (<103 yr). Here, we assess AM’s ability to reduce GIS sea-level contributions over decades to centuries, using a simplified ice sheet model. We drive this model using a business-as-usual base temperature forcing scenario, as well as scenarios that reflect AM-induced temperature stabilization or temperature drawdown. Our model results suggest that (i) AM produces substantial near-term reductions in the rate of GIS-driven sea-level rise. However, (ii) sea-level rise contributions from the GIS continue after AM begins. These continued sea level rise contributions persist for decades to centuries after temperature stabilization and temperature drawdown begin, unless AM begins in the next few decades. Moreover, (iii) any regrowth of the GIS is delayed by decades or centuries after temperature drawdown begins, and is slow compared to pre-AM rates of mass loss. Combined with recent work that suggests AM would not prevent mass loss from the West Antarctic Ice Sheet, our results provide a nuanced picture of AM’s possible effects on future sea-level rise.

  19. Effects of long-term variability on projections of twenty-first century dynamic sea level

    Science.gov (United States)

    Bordbar, Mohammad H.; Martin, Thomas; Latif, Mojib; Park, Wonsun

    2015-04-01

    Sea-level rise is one of the most pressing aspects of anthropogenic global warming with far-reaching consequences for coastal societies. However, sea-level rise did and will strongly vary from coast to coast. Here we investigate the long-term internal variability effects on centennial projections of dynamic sea level (DSL), the local departure from the globally averaged sea level. A large ensemble of global warming integrations has been conducted with a climate model, where each realization was forced by identical CO2 increase but started from different atmospheric and oceanic initial conditions. In large parts of the mid- and high latitudes, the ensemble spread of the projected centennial DSL trends is of the same order of magnitude as the globally averaged steric sea-level rise, suggesting that internal variability cannot be ignored when assessing twenty-first-century DSL trends. The ensemble spread is considerably reduced in the mid- to high latitudes when only the atmospheric initial conditions differ while keeping the oceanic initial state identical; indicating that centennial DSL projections are strongly dependent on ocean initial conditions.

  20. Bangladesh’s dynamic coastal regions and sea-level rise

    Directory of Open Access Journals (Sweden)

    Hugh Brammer

    2014-01-01

    Full Text Available The physical geography of Bangladesh’s coastal area is more diverse and dynamic than is generally recognised. Failure to recognise this has led to serious misconceptions about the potential impacts of a rising sea-level on Bangladesh with global warming. This situation has been aggravated by accounts giving incorrect information on current rates of coastal erosion and land subsidence. This paper describes physical conditions within individual physiographic regions in Bangladesh’s coastal area based on ground-surveyed information, and it reviews possible area-specific mitigation measures to counter predicted rates of sea-level rise in the 21st century. Two important conclusions are drawn: the adoption of appropriate measures based on knowledge of the physical geography of potentially-affected areas could significantly reduce the currently-predicted displacement of many millions of people; and the impacts of a slowly-rising sea-level are currently much less than those generated by rapidly increasing population pressure on Bangladesh’s available land and water resources and by exposure to existing environmental hazards, and the latter problems need priority attention.

  1. Vulnerable areas and adapation measures for sea level rise along the coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Chauhan, O.S.; Unnikrishnan, A.S.; Menezes, A.A.A.; Jagtap, T.G.; Suneethi, J.; Furtado, R.

    to the global climatic changes, the available historical mean sea level data between 1920-1999 at 10 locations was evaluated. There is a large contrast in the deduced sea level changes. The sea level rise along the Gulf of Kachchh and the coast of West Bengal...

  2. GIS analysis of effects of future Baltic sea level rise on the island of Gotland, Sweden

    OpenAIRE

    Ebert, K.; K. Ekstedt; J. Jarsjö

    2016-01-01

    Future sea level rise as a consequence of global warming will affect the world's coastal regions. Even though the pace of sea level rise is not clear, the consequences will be severe and global. Commonly the effects of future sea level rise are investigated for relatively vulnerable development countries; however, a whole range of varying regions needs to be considered in order to improve the understanding of global consequences. In this paper we investigate consequences of ...

  3. A scaling approach to project regional sea level rise and its uncertainties

    OpenAIRE

    Perrette, M.; F. Landerer; Riva, R.; Frieler, K.; Meinshausen, M.

    2013-01-01

    Climate change causes global mean sea level to rise due to thermal expansion of seawater and loss of land ice from mountain glaciers, ice caps and ice sheets. Locally, sea level can strongly deviate from the global mean rise due to changes in wind and ocean currents. In addition, gravitational adjustments redistribute seawater away from shrinking ice masses. However, the land ice contribution to sea level rise (SLR) remains very challenging to model, and comprehensive region...

  4. Thermosteric Sea Level Rise Projections with Parametric Uncertainty

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These files contain spatial fields of simulated yearly thermosteric sea-level anomalies between 1951-2100 (referenced to year 1800) from a perturbed physics ensemble...

  5. Sea Level Rise Projections for DSL-SAMBI

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is output from the Sea Level Affecting Marshes Model (SLAMM) for the South Atlantic Migratory Bird Initiative (SAMBI) geographic planning region. It...

  6. Tidal Marshes across a Chesapeake Bay Subestuary Are Not Keeping up with Sea-Level Rise

    OpenAIRE

    Beckett, Leah H.; Baldwin, Andrew H.; Kearney, Michael S

    2016-01-01

    Sea-level rise is a major factor in wetland loss worldwide, and in much of Chesapeake Bay (USA) the rate of sea-level rise is higher than the current global rate of 3.2 mm yr-1 due to regional subsidence. Marshes along estuarine salinity gradients differ in vegetation composition, productivity, decomposition pathways, and sediment dynamics, and may exhibit different responses to sea-level rise. Coastal marshes persist by building vertically at rates at or exceeding regional sea-level rise. In...

  7. Spatial variations of sea-level rise and impacts: an application of DIVA

    OpenAIRE

    Brown, S; Nicholls, R.J.; Lowe, J A; Hinkel, J.

    2013-01-01

    Due to complexities of creating sea-level rise scenarios, impacts of climate-induced sea-level rise are often produced from a limited number of models assuming a global uniform rise in sea level. A greater number of models, including those with a pattern reflecting regional variations would help to assure reliability and a range of projections, indicating where models agree and disagree. This paper determines how nine new patterned-scaled sea-level rise scenarios (plus the uniform and pattern...

  8. Limited effectiveness of solar radiation management geoengineering in preventing sea-level rise from the Greenland Ice Sheet

    Science.gov (United States)

    Applegate, Patrick; Keller, Klaus

    2015-04-01

    The Greenland Ice Sheet (GIS) is an important contributor to present-day sea level rise, and the ice sheet's importance for sea level rise will likely increase with Arctic temperatures. Some scientists have recently suggested that geoengineering, the deliberate management of Earth's climate, could prevent sea level rise from the ice sheets. Previous efforts to assess geoengineering's effects on the GIS and sea level rise have broken important new ground, but neglect key feedbacks and/or are silent on the short-term effects of geoengineering that are perhaps most important for decision-making. Here, we use a simplified, three-dimensional model of the GIS (SICOPOLIS by Ralf Greve) to examine the response of the Greenland Ice Sheet under plausible geoengineering scenarios. We find that i) the GIS generally continues to melt over the first 100 yr after geoengineering initiation; ii) reductions in GIS sea level contributions over these first 100 yr are small; and iii) there is a delay of decades to centuries between the initiation of aggressive geoengineering and any regrowth of the ice sheet, and the rate of this regrowth is slow. However, geoengineering produces appreciable reductions in the rate of sea level rise contributions from the GIS within the first few decades. Our results suggest that past studies have overestimated the effectiveness of geoengineering in preventing mass loss from the Greenland Ice Sheet and in reversing sea level rise once it has occurred. We comment on the importance of feedbacks in the ice sheet system in assessing geoengineering's effectiveness in reducing sea level rise from the GIS.

  9. The sea level fingerprint of 21st century ice mass fluxes

    Directory of Open Access Journals (Sweden)

    J. Bamber

    2010-09-01

    Full Text Available The sea level contribution from glacial sources has been accelerating during the 21st century (Meier et al., 2007; Velicogna, 2009. This contribution is not distributed uniformly across the world's oceans due to both oceanographic and gravitational effects. We compute the sea level signature of 21st century ice mass fluxes due to changes in the gravity field, Earth's rotation and related effects. Mass loss from Greenland results in a relative sea level (RSL reduction for much of North Western Europe and Eastern Canada. RSL rise from this source is concentrated around South America. Losses in West Antarctica marginally compensate for this and produce maxima along the coastlines of North America, Australia and Oceania. The combined far-field pattern of wastage from all ice melt sources, is dominated by losses from the ice sheets and results in maxima at latitudes between 20° N and 40° S across the Pacific and Indian Oceans, affecting particularly vulnerable land masses in Oceania. The spatial pattern of RSL variations due to the observed ice mass loss is temporally invariant. Thus, sea level rise, based on the land ice losses considered here, will be amplified for this sensitive region.

  10. QUANTIFYING REGIONAL SEA LEVEL RISE CONTRIBUTIONS FROM THE GREENLAND ICE SHEET

    Directory of Open Access Journals (Sweden)

    Diandong Ren

    2013-01-01

    Full Text Available This study projects the sea level contribution from the Greenland ice sheet (GrIS through to 2100, using a recently developed ice dynamics model forced by atmospheric parameters derived from three different climate models (CGCMs. The geographical pattern of the near-surface ice warming imposes a divergent flow field favoring mass loss through enhanced ice flow. The calculated average mass loss rate during the latter half of the 21st century is ~0.64±0.06 mm/year eustatic sea level rise, which is significantly larger than the IPCC AR4 estimate from surface mass balance. The difference is due largely to the positive feedbacks from reduced ice viscosity and the basal sliding mechanism present in the ice dynamics model. This inter-model, inter-scenario spread adds approximately a 20% uncertainty to the IPCC ice model estimates. The sea level rise is geographically non-uniform and reaches 1.69±0.24 mm/year by 2100 for the northeast coastal region of the United States, amplified by the expected weakening of the Atlantic meridional overturning circulation (AMOC. In contrast to previous estimates, which neglected the GrIS fresh water input, both sides of the North Atlantic Gyre are projected to experience sea level rises. The impacts on a selection of major cities on both sides of the Atlantic and in the Pacific and southern oceans also are assessed. The other ocean basins are found to be less affected than the Atlantic Ocean.

  11. New estimates of potential impacts of sea level rise and coastal floods in Poland

    Science.gov (United States)

    Paprotny, D.; Terefenko, P.

    2015-04-01

    Polish coastal zone is thought to be of the most exposed to sea level rise in Europe. With climate change expected to raise mean sea levels between 26 and 200 cm by the end of the century, and storms increasing in severity, accurate estimates of those phenomena are needed. Recent advances in quality and availability of spatial data in Poland made in possible to revisit previous estimates. Up-to-date detailed information on land use, population and buildings were used to calculate inundation risk at a broad range of scenarios. Inclusion, though imperfect, of flood defences from a high-resolution digital elevation model contributes to a further improvement of estimates. The results revealed that even by using a static "bathtub fill" approach the amount of land, population or assets at risk has been significantly revised down. Sea level rise or storm surges are unlikely to reach intensity required to cause significant damage to the economy or endanger the population. The exposure of different kinds of assets and sectors of the economy varies to a large extent, though the structural breakdown of potential losses is remarkably stable between scenarios.

  12. New estimates of potential impacts of sea level rise and coastal floods in Poland

    Directory of Open Access Journals (Sweden)

    D. Paprotny

    2015-04-01

    Full Text Available Polish coastal zone is thought to be of the most exposed to sea level rise in Europe. With climate change expected to raise mean sea levels between 26 and 200 cm by the end of the century, and storms increasing in severity, accurate estimates of those phenomena are needed. Recent advances in quality and availability of spatial data in Poland made in possible to revisit previous estimates. Up-to-date detailed information on land use, population and buildings were used to calculate inundation risk at a broad range of scenarios. Inclusion, though imperfect, of flood defences from a high-resolution digital elevation model contributes to a further improvement of estimates. The results revealed that even by using a static "bathtub fill" approach the amount of land, population or assets at risk has been significantly revised down. Sea level rise or storm surges are unlikely to reach intensity required to cause significant damage to the economy or endanger the population. The exposure of different kinds of assets and sectors of the economy varies to a large extent, though the structural breakdown of potential losses is remarkably stable between scenarios.

  13. Cenozoic sea level and the rise of modern rimmed atolls

    Science.gov (United States)

    Toomey, Michael; Ashton, Andrew; Raymo, Maureen E.; Perron, J. Taylor

    2016-01-01

    Sea-level records from atolls, potentially spanning the Cenozoic, have been largely overlooked, in part because the processes that control atoll form (reef accretion, carbonate dissolution, sediment transport, vertical motion) are complex and, for many islands, unconstrained on million-year timescales. Here we combine existing observations of atoll morphology and corelog stratigraphy from Enewetak Atoll with a numerical model to (1) constrain the relative rates of subsidence, dissolution and sedimentation that have shaped modern Pacific atolls and (2) construct a record of sea level over the past 8.5 million years. Both the stratigraphy from Enewetak Atoll (constrained by a subsidence rate of ~ 20 m/Myr) and our numerical modeling results suggest that low sea levels (50–125 m below present), and presumably bi-polar glaciations, occurred throughout much of the late Miocene, preceding the warmer climate of the Pliocene, when sea level was higher than present. Carbonate dissolution through the subsequent sea-level fall that accompanied the onset of large glacial cycles in the late Pliocene, along with rapid highstand constructional reef growth, likely drove development of the rimmed atoll morphology we see today.

  14. The impact of selected sea level rise scenarios in the vicinity of Cochin harbour, India

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.

    . Increases in shoreline recession and associated coastal flooding that would occur are predicted which indicated that a future sea level rise will bring about extensive land use changes in the region and in the coming decades sea level rise may become one...

  15. The multi-millennial Antarctic commitment to future sea-level rise.

    Science.gov (United States)

    Golledge, N R; Kowalewski, D E; Naish, T R; Levy, R H; Fogwill, C J; Gasson, E G W

    2015-10-15

    Atmospheric warming is projected to increase global mean surface temperatures by 0.3 to 4.8 degrees Celsius above pre-industrial values by the end of this century. If anthropogenic emissions continue unchecked, the warming increase may reach 8-10 degrees Celsius by 2300 (ref. 2). The contribution that large ice sheets will make to sea-level rise under such warming scenarios is difficult to quantify because the equilibrium-response timescale of ice sheets is longer than those of the atmosphere or ocean. Here we use a coupled ice-sheet/ice-shelf model to show that if atmospheric warming exceeds 1.5 to 2 degrees Celsius above present, collapse of the major Antarctic ice shelves triggers a centennial- to millennial-scale response of the Antarctic ice sheet in which enhanced viscous flow produces a long-term commitment (an unstoppable contribution) to sea-level rise. Our simulations represent the response of the present-day Antarctic ice-sheet system to the oceanic and climatic changes of four representative concentration pathways (RCPs) from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. We find that substantial Antarctic ice loss can be prevented only by limiting greenhouse gas emissions to RCP 2.6 levels. Higher-emissions scenarios lead to ice loss from Antarctic that will raise sea level by 0.6-3 metres by the year 2300. Our results imply that greenhouse gas emissions in the next few decades will strongly influence the long-term contribution of the Antarctic ice sheet to global sea level.

  16. Prediction and prevention of the impacts of sea level rise on the Yangtze River Delta and its adjacent areas

    Institute of Scientific and Technical Information of China (English)

    施雅风; 朱季文; 谢志仁; 季子修; 蒋自巽; 杨桂山

    2000-01-01

    The Yangtze River Delta region is characterized by high density of population and rapidly developing economy. There are low lying coastal plain and deltaic plain in this region. Thus, the study area could be highly vulnerable to accelerated sea level rise caused by global warming. This paper deals with the scenarios of the relative sea level rise in the early half period of the 21st century in the study area. The authors suggested that relative sea level would rise 25-50 cm by the year 2050 in the study area, of which the magnitude of relative sea level rise in the Yangtze River Delta would double the perspective worldwide average. The impacts of sea level rise include: (i) exacerbation of coastline recession in several sections and vertical erosion of tidal flat, and increase in length of eroding coastline; (ii) decrease in area of tidal flat and coastal wetland due to erosion and inundation; (iii) increase in frequency and intensity of storm surge, which would threaten the coastal protection works; (i

  17. Glacier calving, dynamics, and sea-level rise. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Meier, M.F.; Pfeffer, W.T.; Amadei, B.

    1998-08-01

    The present-day calving flux from Greenland and Antarctica is poorly known, and this accounts for a significant portion of the uncertainty in the current mass balance of these ice sheets. Similarly, the lack of knowledge about the role of calving in glacier dynamics constitutes a major uncertainty in predicting the response of glaciers and ice sheets to changes in climate and thus sea level. Another fundamental problem has to do with incomplete knowledge of glacier areas and volumes, needed for analyses of sea-level change due to changing climate. The authors proposed to develop an improved ability to predict the future contributions of glaciers to sea level by combining work from four research areas: remote sensing observations of calving activity and iceberg flux, numerical modeling of glacier dynamics, theoretical analysis of the calving process, and numerical techniques for modeling flow with large deformations and fracture. These four areas have never been combined into a single research effort on this subject; in particular, calving dynamics have never before been included explicitly in a model of glacier dynamics. A crucial issue that they proposed to address was the general question of how calving dynamics and glacier flow dynamics interact.

  18. Morphological response of the saltmarsh habitats of the Guadiana estuary due to flow regulation and sea-level rise

    Science.gov (United States)

    Sampath, D. M. R.; Boski, T.

    2016-12-01

    In the context of rapid sea-level rise in the 21st century, the reduction of fluvial sediment supply due to the regulation of river discharge represents a major challenge for the management of estuarine ecosystems. Therefore, the present study aims to assess the cumulative impacts of the reduction of river discharge and projected sea-level rise on the morphological evolution of the Guadiana estuary during the 21st century. The assessment was based on a set of analytical solutions to simplified equations of tidal wave propagation in shallow waters and empirical knowledge of the system. As methods applied to estimate environmental flows do not take into consideration the fluvial discharge required to maintain saltmarsh habitats and the impact of sea-level rise, simulations were carried out for ten cases in terms of base river flow and sea-level rise so as to understand their sensitivity on the deepening of saltmarsh platforms. Results suggest saltmarsh habitats may not be affected severely in response to lower limit scenarios of sea-level rise and sedimentation. A similar behaviour can be expected even due to the upper limit scenarios until 2050, but with a significant submergence afterwards. In the case of the upper limit scenarios under scrutiny, there was a net erosion of sediment from the estuary. Multiplications of amplitudes of the base flow function by factors 1.5, 2, and 5 result in reduction of the estimated net eroded sediment volume by 25, 40, and 80%, respectively, with respect to the net eroded volume for observed river discharge. The results also indicate that defining the minimum environmental flow as a percentage of dry season flow (as done presently) should be updated to include the full spectrum of natural flows, incorporating temporal variability to better anticipate scenarios of sea-level rise during this century. As permanent submergence of intertidal habitats can be significant after 2050, due to the projected 79 cm rise of sea-level by the year

  19. A scaling approach to project regional sea level rise and its uncertainties

    Directory of Open Access Journals (Sweden)

    M. Perrette

    2013-01-01

    Full Text Available Climate change causes global mean sea level to rise due to thermal expansion of seawater and loss of land ice from mountain glaciers, ice caps and ice sheets. Locally, sea level can strongly deviate from the global mean rise due to changes in wind and ocean currents. In addition, gravitational adjustments redistribute seawater away from shrinking ice masses. However, the land ice contribution to sea level rise (SLR remains very challenging to model, and comprehensive regional sea level projections, which include appropriate gravitational adjustments, are still a nascent field (Katsman et al., 2011; Slangen et al., 2011. Here, we present an alternative approach to derive regional sea level changes for a range of emission and land ice melt scenarios, combining probabilistic forecasts of a simple climate model (MAGICC6 with the new CMIP5 general circulation models. The contribution from ice sheets varies considerably depending on the assumptions for the ice sheet projections, and thus represents sizeable uncertainties for future sea level rise. However, several consistent and robust patterns emerge from our analysis: at low latitudes, especially in the Indian Ocean and Western Pacific, sea level will likely rise more than the global mean (mostly by 10–20%. Around the northeastern Atlantic and the northeastern Pacific coasts, sea level will rise less than the global average or, in some rare cases, even fall. In the northwestern Atlantic, along the American coast, a strong dynamic sea level rise is counteracted by gravitational depression due to Greenland ice melt; whether sea level will be above- or below-average will depend on the relative contribution of these two factors. Our regional sea level projections and the diagnosed uncertainties provide an improved basis for coastal impact analysis and infrastructure planning for adaptation to climate change.

  20. The complex reality of sea-level rise in an atoll nation

    Science.gov (United States)

    Donner, S. D.

    2012-12-01

    Sea-level rise famously poses an existential threat to island nations like Kiribati, Tuvalu and the Maldives. Yet as the global mean sea-level rises, the response of any one location at any given time will depend on the natural variability in regional sea-level and other impact of local human activities on coastal processes. As with climate warming, the state of an individual shoreline or the extent of flooding on a given day is not proof of a sea-level trend, nor is a global sea-level trend a good predictor of individual flooding or erosion events. Failure to consider the effect of natural variability and local human activity on coastal processes often leads to misattribution of flooding events and even some long-term shoreline changes to global sea level rise. Moreover, unverified attribution of individual events or changes to specific islets to sea level rise can inflame or invite scepticism of the strong scientific evidence for an accelerating increase in the global sea level due to the impacts of human activity on the climate system. This is particularly important in developing nations like Kiribati, which are depending on international financial support to adapt to rising sea levels. In this presentation, I use gauge data and examples from seven years of field work in Tarawa Atoll, the densely populated capital of Kiribati, to examine the complexity of local sea level and shoreline change in one of the world's most vulnerable countries. First, I discuss how the combination of El Nino-driven variability in sea-level and the astronomical tidal cycle leads to flooding and erosion events which can be mistaken for evidence of sea-level rise. Second, I show that human modification to shorelines has redirected sediment supply, leading, in some cases, to expansion of islets despite rising sea levels. Taken together, the analysis demonstrates the challenge of attributing particular coastal events to global mean sea-level rise and the impact on decision-making. The

  1. Long-term sea-level rise implied by 1.5oC and 2oC warming levels

    NARCIS (Netherlands)

    Schaeffer, M.; Hare, W.; Rahmstorf, S.; Vermeer, A.

    2012-01-01

    Sea-level rise (SLR) is a critical and uncertain climate change risk, involving timescales of centuries(1). Here we use a semi-empirical model, calibrated with sea-level data of the past millennium(2), to estimate the SLR implications of holding warming below 2 degrees C or 1.5 degrees C above pre-i

  2. Two Probabilistic Methods for Attributing the Sources of Sea-Level Rise from Sparse Tide Gauge Records

    Science.gov (United States)

    Hay, C.; Morrow, E.; Kopp, R. E., III; Mitrovica, J. X.

    2014-12-01

    Recent estimates of 20th century global mean sea-level (GMSL) rise are in the range 1.6-1.9 mm/yr. However, these estimates use a temporally and spatially sparse network of tide gauge observations that may result in a biased estimate due to the incomplete sampling of a global field. Furthermore, this sparse sampling makes resolving the GMSL change into individual sources (e.g., mass loss from individual ice sheets and mountain glaciers, ocean thermal expansion, etc.) challenging. We have employed two different statistical techniques, a multi-model Kalman smoother (KS) and Gaussian process regression (GPR), to address the above challenges. Both techniques naturally accommodate spatio-temporal changes in the availability of tide gauge observations and use models of glacial isostatic adjustment, ocean dynamics, and the sea-level fingerprints of rapid land ice melt to exploit both the spatial and temporal information within observations of the sparsely-sampled global field. We present reconstructions of the global sea-level field estimated with both methods, as well as the associated constraints on the underlying sources of global mean sea-level change. Our results include estimates of the individual contributions of the world's ice sheets and mountain glaciers to 20th century sea-level change and provide new estimates of the spatial and temporal variability in sea level since 1900.

  3. Accelerated sea-level rise from West Antarctica.

    OpenAIRE

    Thomas, R; Rignot, E.; Casassa, G; Kanagaratnam, P; Acuña, C; Akins, T; Brecher, H; E Frederick; Gogineni, P.; Krabill, W.; Manizade, S.; Ramamoorthy, H; Rivera, A.; Russell, R.; Sonntag, J

    2004-01-01

    Recent aircraft and satellite laser altimeter surveys of the Amundsen Sea sector of West Antarctica show that local glaciers are discharging about 250 cubic kilometers of ice per year to the ocean, almost 60% more than is accumulated within their catchment basins. This discharge is sufficient to raise sea level by more than 0.2 millimeters per year. Glacier thinning rates near the coast during 2002-2003 are much larger than those observed during the 1990s. Most of these glaciers flow into flo...

  4. Assessment of the impact of sea-level rise due to climate change on coastal groundwater discharge.

    Science.gov (United States)

    Masciopinto, Costantino; Liso, Isabella Serena

    2016-11-01

    An assessment of sea intrusion into coastal aquifers as a consequence of local sea-level rise (LSLR) due to climate change was carried out at Murgia and Salento in southern Italy. The interpolation of sea-level measurements at three tide-gauge stations was performed during the period of 2000 to 2014. The best fit of measurements shows an increasing rate of LSLR ranging from 4.4mm/y to 8.8mm/y, which will result in a maximum LSLR of approximately 2m during the 22nd century. The local rate of sea-level rise matches recent 21st and 22nd century projections of mean global sea-level rise determined by other researchers, which include increased melting rates of the Greenland and Antarctic ice sheets, the effect of ocean thermal expansion, the melting of glaciers and ice caps, and changes in the quantity of stored land water. Subsequently, Ghyben-Herzberg's equation for the freshwater/saltwater interface was rewritten in order to determine the decrease in groundwater discharge due to the maximum LSLR. Groundwater flow simulations and ArcGIS elaborations of digital elevation models of the coast provided input data for the Ghyben-Herzberg calculation under the assumption of head-controlled systems. The progression of seawater intrusion due to LSLR suggests an impressive depletion of available groundwater discharge during the 22nd century, perhaps as much as 16.1% of current groundwater pumping for potable water in Salento.

  5. Numerical simulation of saltwater intrusion in response to sea-level rise

    Science.gov (United States)

    Langevin, C.D.; Dausman, A.M.

    2005-01-01

    A two dimensional numerical model of variable-density groundwater flow and dispersive solute transport was used to predict the extent, rate, and lag time of saltwater intrusion in response to various sea-level rise scenarios. Three simulations were performed with varying rates of sea-level rise. For the first simulation, sea-level rise was specified at a rate of 0.9 mm/yr, which is the slowest rate of sea-level rise estimated by the Intergovernmental Panel on Climate Change (IPCC). After 100 years, the 250 mg/L chloride isochlor moved inland by about 40 m, and required an additional 8 years for the system to reach equilibrium. For the next simulation, sea-level rise was specified at 4.8 mm/yr, which is the central value of the IPCC estimate. For this moderate rate of sea-level rise, the 250 mg/L isochlor moved inland by about 740 m after 100 years, and required an additional 10 years for the system to reach equilibrium. For the fastest rate of sea level rise estimated by IPCC (8.8 mm/yr), the 250 mg/L isochlor moved inland by about 1800 m after 100 years, and required more than 50 years to reach equilibrium. Copyright ASCE 2005.

  6. The Science-Policy Link: Stakeholder Reactions to the Uncertainties of Future Sea Level Rise

    Science.gov (United States)

    Plag, H.; Bye, B.

    2011-12-01

    would provide a different kind of science input to policy makers and stakeholders. Like in many other insurance problems (for example, earthquakes), where deterministic predictions are not possible and decisions have to be made on the basis of statistics and probabilities, the statistical approach to coastal resilience would require stakeholders to make decisions on the basis of probabilities instead of predictions. The science input for informed decisions on adaptation would consist of general probabilities of decadal to century scale sea level changes derived from paleo records, including the probabilities for large and rapid rises. Similar to other problems where the appearance of a hazard is associated with a high risk (like a fire in a house), this approach would also require a monitoring and warning system (a "smoke detector") capable of detecting any onset of a rapid sea level rise.

  7. Prediction and prevention of the impacts of sea level rise on the Yangtze River Delta and its adjacent areas

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The Yangtze River Delta region is characterized by high density of population and rapidly developing economy. There are low lying coastal plain and deltaic plain in this region. Thus, the study area could be highly vulnerable to accelerated sea level rise caused by global warming. This paper deals with the scenarios of the relative sea level rise in the early half period of the 21st century in the study area. The authors suggested that relative sea level would rise 25 50 cm by the year 2050 in the study area, of which the magnitude of relative sea level rise in the Yangtze River Delta would double the perspective worldwide average. The impacts of sea level rise include: (i) exacerbation of coastline recession in several sections and vertical erosion of tidal flat, and increase in length of eroding coastline; (ii) decrease in area of tidal flat and coastal wetland due to erosion and inundation; (iii) increase in frequency and intensity of storm surge, which would threaten the coastal protection works; (iv) reduction of drainage capacity due to backwater effect in the Lixiahe lowland and the eastern lowland of Taihu Lake region, and exacerbation of flood and waterlogging disasters; and (v) increase in salt water intrusion into the Yangtze Estuary. Comprehensive evaluation of sea level rise impacts shows that the Yangtze River Delta and eastern lowland of Taihu Lake region, especially Shanghai Municipality, belong in the district in the extreme risk category and the next is the northern bank of Hangzhou Bay, the third is the abandoned Yellow River delta, and the district at low risk includes the central part of north Jiangsu coastal plain and Lixiahe lowland.

  8. Responses of estuarine salinity and transport processes to sea level rise in the Zhujiang (Pearl River) Estuary

    Institute of Scientific and Technical Information of China (English)

    CHEN Yuxiang; ZUO Juncheng; ZOU Huazhi; ZHANG Min; ZHANG Kairong

    2016-01-01

    Understanding the changes of hydrodynamics in estuaries with respect to magnitude of sea level rise is important to understand the changes of transport process. Based on prediction of sea level rise over the 21st century, the Zhujiang (Pearl River) Estuary was chosen as a prototype to study the responses of the estuary to potential sea level rise. The numerical model results show that the average salt content, saltwater intrusion distance, and stratification will increase as the sea level rises. The changes of these parameters have obvious seasonal variations. The salt content in the Lingdingyang shows more increase in April and October (the transition periods). The saltwater intrusion distance has larger increase during the low-flow periods than during the high-flow periods in the Lingdingyang. The result is just the opposite in Modaomen. The stratification and its increase are larger during the low-flow periods than during the high-flow periods in Lingdingyang. The response results of transport processes to sea level rise demonstrate that: (1) The time of vertical transport has pronounced increase. The increased tidal range and currents would reinforce the vertical mixing, but the increased stratification would weaken the vertical exchange. The impact of stratification changes overwhelms the impact of tidal changes. It would be more difficult for the surface water to reach the bottom. (2) The lengthways estuarine circulation would be strengthened. Both the offshore surface residual current and inshore bottom residual current will be enhanced. The whole meridional resident flow along the transect of the Lingdingyang would be weakened. These phenomena are caused by the decrease of water surface slope (WWS) and the change of static pressure with the increase of water depth under sea level rise.

  9. Sea level rise, drought and the decline of Spartina patens in New England marshes

    Science.gov (United States)

    Already heavily impacted by coastal development, estuarine vegetated habitats (seagrasses, salt marshes, and mangroves) are increasingly affected by climate change via accelerated sea level rise, changes in the frequency and intensity of precipitation and storms, and warmer ocean...

  10. PACIFIC - Coastal Vulnerability to Sea-Level Rise: U.S. Pacific Coast

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The goal of this project is to quantify, at the National scale, the relative susceptibility of the Nation's coast to sea-level rise through the use of a coastal...

  11. GULF - Coastal Vulnerability to Sea-Level Rise: U.S. Gulf Coast

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The goal of this project is to quantify, at the National scale, the relative susceptibility of the Nation's coast to sea-level rise through the use of a coastal...

  12. Coastal Wetland Dynamics and Wildlife Populations: Modeling the Effects of Sea Level Rise and Landscape Change

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Assess the potential impacts of sea level rise on coastal ecosystems and related wildlife resources. Develop a Bayesian Belief network that projects the impact of...

  13. Examining effects of sea level rise and marsh crabs on Spartina patens using mesocosms

    Science.gov (United States)

    Coastal salt marshes provide essential ecosystem services but face increasing threats from habitat loss, eutrophication, changing precipitation patterns, and accelerating rates of sea level rise (SLR). Recent studies have suggested that herbivory and burrowing by native salt mars...

  14. A framework to investigate the economic growth impact of sea level rise

    Science.gov (United States)

    Hallegatte, Stéphane

    2012-03-01

    This article reviews the channels through which sea level rise can affect economic growth, namely the loss of land, the loss of infrastructure and physical capital, the loss of social capital, the additional cost from extreme events and coastal floods, and the increased expenditure for coastal protection. It discusses how existing studies on the direct impact of sea level rise could be used to investigate the resulting consequences on economic growth, emphasizes research needs on this question, and discusses consequences on migration.

  15. Assessment of Hammocks (Petenes) Resilience to Sea Level Rise Due to Climate Change in Mexico

    OpenAIRE

    Hernández-Montilla, Mariana C.; Martínez-Morales, Miguel Angel; Posada Vanegas, Gregorio; De Jong, Bernardus H. J.

    2016-01-01

    There is a pressing need to assess resilience of coastal ecosystems against sea level rise. To develop appropriate response strategies against future climate disturbances, it is important to estimate the magnitude of disturbances that these ecosystems can absorb and to better understand their underlying processes. Hammocks (petenes) coastal ecosystems are highly vulnerable to sea level rise linked to climate change; their vulnerability is mainly due to its close relation with the sea through ...

  16. Population dynamics of Hawaiian seabird colonies vulnerable to sea-level rise

    Science.gov (United States)

    Hatfield, Jeff S.; Reynolds, Michelle H.; Seavy, Nathaniel E.; Krause, Crystal M.

    2012-01-01

    Globally, seabirds are vulnerable to anthropogenic threats both at sea and on land. Seabirds typically nest colonially and show strong fidelity to natal colonies, and such colonies on low-lying islands may be threatened by sea-level rise. We used French Frigate Shoals, the largest atoll in the Hawaiian Archipelago, as a case study to explore the population dynamics of seabird colonies and the potential effects sea-level rise may have on these rookeries. We compiled historic observations, a 30-year time series of seabird population abundance, lidar-derived elevations, and aerial imagery of all the islands of French Frigate Shoals. To estimate the population dynamics of 8 species of breeding seabirds on Tern Island from 1980 to 2009, we used a Gompertz model with a Bayesian approach to infer population growth rates, density dependence, process variation, and observation error. All species increased in abundance, in a pattern that provided evidence of density dependence. Great Frigatebirds (Fregata minor), Masked Boobies (Sula dactylatra), Red-tailed Tropicbirds (Phaethon rubricauda), Spectacled Terns (Onychoprion lunatus), and White Terns (Gygis alba) are likely at carrying capacity. Density dependence may exacerbate the effects of sea-level rise on seabirds because populations near carrying capacity on an island will be more negatively affected than populations with room for growth. We projected 12% of French Frigate Shoals will be inundated if sea level rises 1 m and 28% if sea level rises 2 m. Spectacled Terns and shrub-nesting species are especially vulnerable to sea-level rise, but seawalls and habitat restoration may mitigate the effects of sea-level rise. Losses of seabird nesting habitat may be substantial in the Hawaiian Islands by 2100 if sea levels rise 2 m. Restoration of higher-elevation seabird colonies represent a more enduring conservation solution for Pacific seabirds.

  17. The sea level fingerprint of 21st century ice mass fluxes

    OpenAIRE

    Bamber, J.; Riva, R.

    2010-01-01

    The sea level contribution from glacial sources has been accelerating during the 21st century (Meier et al., 2007; Velicogna, 2009). This contribution is not distributed uniformly across the world's oceans due to both oceanographic and gravitational effects. We compute the sea level signature of 21st century ice mass fluxes due to changes in the gravity field, Earth's rotation and related effects. Mass loss from Greenland results in a relative sea level (RSL) reduction for much of North Weste...

  18. Processes contributing to resilience of coastal wetlands to sea-level rise

    Science.gov (United States)

    Stagg, Camille L.; Krauss, Ken W.; Cahoon, Donald R.; Cormier, Nicole; Conner, William H.; Swarzenski, Christopher M.

    2016-01-01

    The objectives of this study were to identify processes that contribute to resilience of coastal wetlands subject to rising sea levels and to determine whether the relative contribution of these processes varies across different wetland community types. We assessed the resilience of wetlands to sea-level rise along a transitional gradient from tidal freshwater forested wetland (TFFW) to marsh by measuring processes controlling wetland elevation. We found that, over 5 years of measurement, TFFWs were resilient, although some marginally, and oligohaline marshes exhibited robust resilience to sea-level rise. We identified fundamental differences in how resilience is maintained across wetland community types, which have important implications for management activities that aim to restore or conserve resilient systems. We showed that the relative importance of surface and subsurface processes in controlling wetland surface elevation change differed between TFFWs and oligohaline marshes. The marshes had significantly higher rates of surface accretion than the TFFWs, and in the marshes, surface accretion was the primary contributor to elevation change. In contrast, elevation change in TFFWs was more heavily influenced by subsurface processes, such as root zone expansion or compaction, which played an important role in determining resilience of TFFWs to rising sea level. When root zone contributions were removed statistically from comparisons between relative sea-level rise and surface elevation change, sites that previously had elevation rate deficits showed a surplus. Therefore, assessments of wetland resilience that do not include subsurface processes will likely misjudge vulnerability to sea-level rise.

  19. Coastal Vulnerability Assessment of Padre Island National Seashore (PAIS) to Sea-Level Rise

    Science.gov (United States)

    Pendleton, Elizabeth A.; Thieler, E. Robert; Williams, S. Jeffress; Beavers, Rebecca S.

    2004-01-01

    A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future sea-level rise within Padre Island National Seashore in Texas. The CVI ranks the following in terms of their physical contribution to sea-level rise-related coastal change: geomorphology, regional coastal slope, rate of relative sea-level rise, shoreline change rates, mean tidal range and mean significant wave height. The rankings for each variable were combined and an index value calculated for 1-minute grid cells covering the park. The CVI highlights those regions where the physical effects of sea-level rise might be the greatest. This approach combines the coastal system's susceptibility to change with its natural ability to adapt to changing environmental conditions, yielding a quantitative, although relative, measure of the park's natural vulnerability to the effects of sea-level rise. The CVI provides an objective technique for evaluation and long-term planning by scientists and park managers. Padre Island National Seashore consists of stable to washover dominated portions of barrier beach backed by wetland, marsh, tidal flat, or grassland. The areas within Padre that are likely to be most vulnerable to sea-level rise are those with the highest occurrence of overwash and the highest rates of shoreline change.

  20. Sea Level Rise Scenarios and Predicted Impacts on New Hampshire's Hampton-Seabrook Estuary

    Science.gov (United States)

    Haile, R.; Hale, S. R.; Rock, B. N.

    2008-12-01

    According to the Intergovernmental Panel on Climate Change, Environmental Protection Agency, and the Union of Concerned Scientist, coastal areas could experience a rise in sea level from 0.3m (conservative) to 6m (extreme). Due in part to global warming, over the last 100 years mid-Atlantic and Gulf Coast sea level has risen approximately 0.1m more than the average global rise. GIS models illustrating future sea level rise (SLR) projections were generated to assess the potential impact on beaches and estuaries of Hampton and Seabrook, New Hampshire (NH). Limited, but important, tidal wetlands are particularly at risk from rising sea levels. A raster unsupervised landcover classification and a Digital Elevation Model of the southeastern NH coastal region were overlain in ARC/GIS v. 9.0. Sea level rise predictions greater than 1.2m will result in the inundation of greater than 50 percent of the emergent area of the Hampton/Seabrook estuary and urban development fringing the estuary will be prone to greater flooding from storm surges and high tides. An approximate 6m rise in sea level will inundate greater than 95 percent of the Hampton-Seabrook tidal marsh and greater than 95 percent of New Hampshire's existing sand dunes.

  1. Portrait of a Warming Ocean and Rising Sea Levels: Trend of Sea Level Change 1993-2008

    Science.gov (United States)

    2008-01-01

    Warming water and melting land ice have raised global mean sea level 4.5 centimeters (1.7 inches) from 1993 to 2008. But the rise is by no means uniform. This image, created with sea surface height data from the Topex/Poseidon and Jason-1 satellites, shows exactly where sea level has changed during this time and how quickly these changes have occurred. It's also a road map showing where the ocean currently stores the growing amount of heat it is absorbing from Earth's atmosphere and the heat it receives directly from the Sun. The warmer the water, the higher the sea surface rises. The location of heat in the ocean and its movement around the globe play a pivotal role in Earth's climate. Light blue indicates areas in which sea level has remained relatively constant since 1993. White, red, and yellow are regions where sea levels have risen the most rapidly up to 10 millimeters per year and which contain the most heat. Green areas have also risen, but more moderately. Purple and dark blue show where sea levels have dropped, due to cooler water. The dramatic variation in sea surface heights and heat content across the ocean are due to winds, currents and long-term changes in patterns of circulation. From 1993 to 2008, the largest area of rapidly rising sea levels and the greatest concentration of heat has been in the Pacific, which now shows the characteristics of the Pacific Decadal Oscillation (PDO), a feature that can last 10 to 20 years or even longer. In this 'cool' phase, the PDO appears as a horseshoe-shaped pattern of warm water in the Western Pacific reaching from the far north to the Southern Ocean enclosing a large wedge of cool water with low sea surface heights in the eastern Pacific. This ocean/climate phenomenon may be caused by wind-driven Rossby waves. Thousands of kilometers long, these waves move from east to west on either side of the equator changing the distribution of water mass and heat. This image of sea level trend also reveals a significant

  2. Effects of Sea Level-Rise on Carbon Accretion in Coastal Wetlands (Invited)

    Science.gov (United States)

    Morris, J. T.

    2010-12-01

    Long-term storage of organic carbon in sediment is one of the key functions of coastal wetlands. Owing to the rise of sea level, a fraction of their primary production is buried annually. However, the productivity of tidelands and, hence, carbon accretion depend on their relative elevation within the tidal frame. It has been shown empirically that there is an optimum relative elevation for maximum primary production. The equilibrium elevation is a function of the rate of sea-level rise. Hence, productivity and carbon accretion are also affected by the rate of sea-level rise. Mathematically it can be shown that tidelands maintain their elevation relative to the ocean through feedbacks among primary production, flooding, and sedimentation. At the low end of the sea-level-rise spectrum, a rising sea increases the flooding of marshes, decreasing sediment salinity, stimulating primary production and increasing sedimentation. At the high end, marshes cannot keep pace with sea level and convert to tidal mud flats or open water. Consequently, the long-term storage of carbon by tidelands will depend on the future trajectory of sea-level. In general, cumulative carbon accretion of existing marshes decreases as the forecasted rise in sea level increases. Other important variables include tide range and concentration of suspended sediments. Carbon accretion will be lower in microtidal than macrotidal estuaries, particularly at high rates of sea-level rise. Sensitivity of carbon accretion to tide range decreases as the concentration of suspended sediments increases. These results indicate that future carbon accretion by coastal wetlands will not be uniform in space or time.

  3. Prediction of China's Submerged Coastal Areas by Sea Level Rise due to Climate Change

    Institute of Scientific and Technical Information of China (English)

    ZUO Juncheng; YANG Yiqiu; ZHANG Jianli; CHEN Meixiang; XU Qing

    2013-01-01

    Based on the simulation with the Ocean-Atmosphere Coupled Model CCSM and Ocean Model POP under the greenhouse gas emission scenario of the IPCC SRES A2 (IPCC,2001),and on the earth crust subsidence and glacier melting data,the relative sea level change is obtained along the coast of China in the 21 st century.Using the SRTM elevation data the submergence of coastal low land is calculated under the extreme water level with a 100-year return period.The total flooding areas are 98.3× 103 and 104.9× 103 km2 for 2050 and 2080,respectively.For the three regions most vulnerable to extreme sea level rise,i.e.,the coast of Bohai Bay,the Yangtze River Delta together with neighboring Jiangsu Province and northern Zhejiang Province,and the Pearl River Delta,the flooded areas are 5.0 × 103,64.1 × 103 and 15.3 × 103 km2 in 2050 and 5.2 × 103,67.8 × 103 and 17.2 × 103 km2 in 2080,respectively.

  4. Climate change and Sea level rise: Potential impact on the coast of the Edremit Plain, NW Turkey.

    Science.gov (United States)

    Curebal, Isa; Efe, Recep; Soykan, Abdullah; Sonmez, Suleyman

    2015-04-01

    Over the past century, most of the world's mountain glaciers and the ice sheets have lost mass due to global warming. When the temperature exceeds a particular level, glaciers and polar ice caps will continue to lose mass. Recent studies report that low-lying coastal areas will be seriously affected by sea level rise. Changes in the amount of natural and anthropogenic greenhouse gases and aerosols had a warming effect on the global climate during last century. Thus, the pace of melting of ice sheets increased, and, accordingly, sea level began to rise faster. Rise in sea level between 1961 and 2003 was equal to 1.8 mm/year while it was 3.1 mm/year between 1993 and 2003. The total rise in the 20th century is estimated to be between 17 and 19 cm. The models based on the sea level change indicate that the average global temperature at the end of the 21st century will increase by 0.3°C - 6.4°C. Global sea level is projected to rise 8-25 cm by 2030, relative to 2000 levels, 18-48 cm by 2050, and 50-140 cm by 20110. The Edremit Plain lies between Mount Madra and the Kaz Mountains on the coast of Aegean Sea in NW Turkey. It is lowland with an area of 141 km2. The widest part of the plain is 16 km along the E - W direction. The N - S direction amounts to a width of 15 km. The plain is covered with alluvial deposits that settled in the Quaternary Period. The elevation ranges from 0 to 50 m a.s.l. in the plain. This study aims to determine how the low-lying coastal land areas of the Edremit Plain may be affected by possible changes in sea level. Elevation dataset is based on the digital elevation model (DEM) of Landsat ETM + satellite images. To that end, satellite images were used to draw the current coastline. Curves of 2.5, 5, and 10 m were drawn through the use of maps with a scale of 1/25.000. Later on, the areas of the fields between these points were calculated. Current estimates show that 2.5 m rise in sea level will cause sea water to cover an area of 8.6 km2 (%14

  5. Relative impact of sea level rise, wave climate and anthropogenic actions on the recent shoreline changes of the Pacific Islands

    Science.gov (United States)

    Garcin, M.; Baills, A.; Yates, M.; Le Cozannet, G.; Bulteau, T.; Salai, E.; Sauter, J.

    2012-04-01

    Sea level rise is nowadays one of a major concern for many low-lying and highly populated areas in the world. However, it is difficult to forecast the consequences of sea levels rise in terms of erosion, due to the interactions with many forcing factors of the evolution of coastline mobility. Indeed, climatic factors such as sea level rise are combined with internal and external geodynamic processes, biological factors, wave forcing and anthropogenic actions which can also play an important role in coastline mobility. Understanding the whole system and its past evolutions is necessary to anticipate future changes. Within the on-going CECILE project, our goal is to evaluate the impact of future sea level change on some emblematic coasts located in different part of the world in order to assess their sensitivity and the variability of their response to different change rise rates. This work presents the study conducted on coastlines of two regions of the Pacific: French Polynesia (SW Pacific) and New Caledonia. In order to evaluate the sensitivity of the coastlines to sea level rise, we firstly analysed the response of each coastline during the sea level rise of the past 50 years, using a diachronic analysis of ancient and recent remote sensing images. Then we also took into account the evolution of anthropogenic actions contributing to modifications of the sedimentary budget at the coast, and finally, sea level variations, using the sea level reconstruction of Becker et al. (2012) of the 2nd half of the XXth century. Two atolls of French Polynesia (Manihi and Scilly) and six coastal stretches of New Caledonia have been studied. Although Manihi and Scilly experienced a sea level rise rate twice as important as the global mean according to Becker et al. (2012), wave forcing was, during the last 50 years, the dominant factor controlling the shoreline evolution and aggradation/erosion processes on the atolls. On the contrary, on the main island of New Caledonia, the

  6. The Blackwater NWR inundation model. Rising sea level on a low-lying coast: land use planning for wetlands

    Science.gov (United States)

    Larsen, Curt; Clark, Inga; Guntenspergen, Glenn; Cahoon, Don; Caruso, Vincent; Hupp, Cliff; Yanosky, Tom

    2004-01-01

    shallow water surfaces has solved this problem. Our team has developed a detailed LIDAR map of the BNWR area at a 30 centimeter (ca. 1 ft) contour interval (figure 2). The new map allows us to identify the present marsh vegetation zones and to predict the location and area of future zones on a decade-by- decade basis over the next century at increments of sea level rise on the order of 3 cm/decade (ca. 1 inch). We have developed two scenarios for the model. The first is a steady-state model that uses the historic rate of sea level rise of 3.1 mm/yr to predict marsh areas. The second is a 'global warming' scenario utilizing a conservative IPCC model with an exponentially-increasing rate of sea level rise. Under either scenario, the BNWR is progressively inundated with an expanding core of open water. Although their positions change in the future, the areas of intertidal marsh as well as those of the critical high marsh remain fairly constant until the year 2050. Beyond that time, the low-lying land surface is overtopped by rising sea level and the area is dominated by open water. Our model suggests that wetland habitat in the Blackwater area might be maintained and sustained through a combination of public and private preservation efforts through easements in combination with judicious Federal land acquisition into the predicted areas of suitable marsh formation - but for only the next 50 years. Beyond that time much of this area will become open water.

  7. Rising Seas: Threat to Coastal Areas, A General Study about the Sea Level Rises on Coastal Areas of Earth, its Consequences and Preventive Measures.

    Science.gov (United States)

    Kataria, A.

    2015-12-01

    Scientific research indicates that sea levels worldwide have been rising at a rate of 3 millimeters per year since the early 1990s (IPCC), which is much higher than the previous century. The recent measurements (march 2015; NASA) tells us that the present rise of sea level is 64.4 mm. Most recent satellite measurements and tide gauge readings (NASA) tell us that present rate sea level rise is 3.20 mm per year. A recent study says we can expect the oceans to rise between 2.5 and 6.5 feet (0.8 and 2 meters) by 2100. The two main causes of rising seas are thermal expansion and glacier melting which further corresponds to the root cause of sea level rise: Green House effect. For every degree Celsius that global average temperature rises, we can expect 2.3 meters of sea-level rise sometime over the ensuing 2,000 years. The main consequence of Sea level rise is increase in oceanic acidity as it releases the entrapped carbon dioxide in between the glaciers. The problem goes from bad to worse when we take into consideration that one third of the world population lives in a 60 km range from the coast. In the event of a flood, this massive population would have to move away from the coasts. The main objective of research is to find all the most vulnerable areas, to make people aware about the consequences and to take proper measurements to fight with such natural calamities. The rise in sea level would inevitably cause massive migration like never seen before. Over 25% of the world population could disappear if sea levels continues to rise with same or faster rate as present. The oceans, sea life and life of people at coastal areas will get extremely effected unless there are considerable cuts in the carbon dioxide emissions. What we need to do is just to apply all the methods and measurements in our daily life that can help reduce the green house gases emissions. Also we need to plan that how to prevent all these cities in case of such natural hazards.

  8. Semi-empirical versus process-based sea-level projections for the twenty-first century

    Science.gov (United States)

    Orlić, Mirko; Pasarić, Zoran

    2013-08-01

    Two dynamical methods are presently used to project sea-level changes during the next century. The process-based method relies on coupled atmosphere-ocean models to estimate the effects of thermal expansion and on sea-level models combined with certain empirical relationships to determine the influence of land-ice mass changes. The semi-empirical method uses various physically motivated relationships between temperature and sea level, with parameters determined from the data, to project total sea level. However, semi-empirical projections far exceed process-based projections. Here, we test the robustness of semi-empirical projections to the underlying assumptions about the inertial and equilibrium responses of sea level to temperature forcing and the impacts of groundwater depletion and dam retention during the twentieth century. Our results show that these projections are sensitive to the dynamics considered and the terrestrial-water corrections applied. For B1, which is a moderate climate-change scenario, the lowest semi-empirical projection of sea-level rise over the twenty-first century equals 62+/-14cm. The average value is substantially smaller than previously published semi-empirical projections and is therefore closer to the corresponding process-based values. The standard deviation is larger than the uncertainties of process-based estimates.

  9. Unabated global mean sea-level rise over the satellite altimeter era

    Science.gov (United States)

    Watson, Christopher S.; White, Neil J.; Church, John A.; King, Matt A.; Burgette, Reed J.; Legresy, Benoit

    2015-06-01

    The rate of global mean sea-level (GMSL) rise has been suggested to be lower for the past decade compared with the preceding decade as a result of natural variability, with an average rate of rise since 1993 of +3.2 +/- 0.4 mm yr-1 (refs , ). However, satellite-based GMSL estimates do not include an allowance for potential instrumental drifts (bias drift). Here, we report improved bias drift estimates for individual altimeter missions from a refined estimation approach that incorporates new Global Positioning System (GPS) estimates of vertical land movement (VLM). In contrast to previous results (for example, refs , ), we identify significant non-zero systematic drifts that are satellite-specific, most notably affecting the first 6 years of the GMSL record. Applying the bias drift corrections has two implications. First, the GMSL rate (1993 to mid-2014) is systematically reduced to between +2.6 +/- 0.4 mm yr-1 and +2.9 +/- 0.4 mm yr-1, depending on the choice of VLM applied. These rates are in closer agreement with the rate derived from the sum of the observed contributions, GMSL estimated from a comprehensive network of tide gauges with GPS-based VLM applied (updated from ref. ) and reprocessed ERS-2/Envisat altimetry. Second, in contrast to the previously reported slowing in the rate during the past two decades, our corrected GMSL data set indicates an acceleration in sea-level rise (independent of the VLM used), which is of opposite sign to previous estimates and comparable to the accelerated loss of ice from Greenland and to recent projections, and larger than the twentieth-century acceleration.

  10. Potential effects of sea-level rise on coastal wetlands in southeastern Louisiana

    Science.gov (United States)

    Glick, Patty; Clough, Jonathan; Polaczyk, Amy; Couvillion, Brady R.; Nunley, Brad

    2013-01-01

    Coastal Louisiana wetlands contain about 37% of the estuarine herbaceous marshes in the conterminous United States. The long-term stability of coastal wetlands is often a function of a wetland's ability to maintain elevation equilibrium with mean sea level through processes such as primary production and sediment accretion. However, Louisiana has sustained more coastal wetland loss than all other states in the continental United States combined due to a combination of natural and anthropogenic factors, including sea-level rise. This study investigates the potential impact of current and accelerating sea-level rise rates on key coastal wetland habitats in southeastern Louisiana using the Sea Level Affecting Marshes Model (SLAMM). Model calibration was conducted using a 1956–2007 observation period and hindcasting results predicted 35% versus observed 39% total marsh loss. Multiple sea-level-rise scenarios were then simulated for the period of 2007–2100. Results indicate a range of potential wetland losses by 2100, from an additional 2,188.97 km2 (218,897 ha, 9% of the 2007 wetland area) under the lowest sea-level-rise scenario (0.34 m), to a potential loss of 5,875.27 km2 (587,527 ha, 24% of the 2007 wetland area) in the highest sea-level-rise scenario (1.9 m). Model results suggest that one area of particular concern is the potential vulnerability of the region's baldcypress-water tupelo (Taxodium distichum-Nyssa aquatica) swamp habitat, much of which is projected to become permanently flooded (affecting regeneration) under all modeled scenarios for sea-level rise. These findings will aid in the development of ecosystem management plans that support the processes and conditions that result in sustainable coastal ecosystems.

  11. Tension between reducing sea-level rise and global warming through solar-radiation management

    Science.gov (United States)

    Irvine, P. J.; Sriver, R. L.; Keller, K.

    2012-02-01

    Geoengineering using solar-radiation management (SRM) is gaining interest as a potential strategy to reduce future climate change impacts. Basic physics and past observations suggest that reducing insolation will, on average, cool the Earth. It is uncertain, however, whether SRM can reduce climate change stressors such as sea-level rise or rates of surface air temperature change. Here we use an Earth system model of intermediate complexity to quantify the possible response of sea levels and surface air temperatures to projected climate forcings and SRM strategies. We find that SRM strategies introduce a potentially strong tension between the objectives to reduce (1) the rate of temperature change and (2) sea-level rise. This tension arises primarily because surface air temperatures respond faster to radiative forcings than sea levels. Our results show that the forcing required to stop sea-level rise could cause a rapid cooling with a rate similar to the peak business-as-usual warming rate. Furthermore, termination of SRM was found to produce warming rates up to five times greater than the maximum rates under the business-as-usual CO2 scenario, whereas sea-level rise rates were only 30% higher. Reducing these risks requires a slow phase-out of many decades and thus commits future generations.

  12. Coastal sea level rise with warming above 2 °C.

    Science.gov (United States)

    Jevrejeva, Svetlana; Jackson, Luke P; Riva, Riccardo E M; Grinsted, Aslak; Moore, John C

    2016-11-22

    Two degrees of global warming above the preindustrial level is widely suggested as an appropriate threshold beyond which climate change risks become unacceptably high. This "2 °C" threshold is likely to be reached between 2040 and 2050 for both Representative Concentration Pathway (RCP) 8.5 and 4.5. Resulting sea level rises will not be globally uniform, due to ocean dynamical processes and changes in gravity associated with water mass redistribution. Here we provide probabilistic sea level rise projections for the global coastline with warming above the 2 °C goal. By 2040, with a 2 °C warming under the RCP8.5 scenario, more than 90% of coastal areas will experience sea level rise exceeding the global estimate of 0.2 m, with up to 0.4 m expected along the Atlantic coast of North America and Norway. With a 5 °C rise by 2100, sea level will rise rapidly, reaching 0.9 m (median), and 80% of the coastline will exceed the global sea level rise at the 95th percentile upper limit of 1.8 m. Under RCP8.5, by 2100, New York may expect rises of 1.09 m, Guangzhou may expect rises of 0.91 m, and Lagos may expect rises of 0.90 m, with the 95th percentile upper limit of 2.24 m, 1.93 m, and 1.92 m, respectively. The coastal communities of rapidly expanding cities in the developing world, and vulnerable tropical coastal ecosystems, will have a very limited time after midcentury to adapt to sea level rises unprecedented since the dawn of the Bronze Age.

  13. A decade of sea level rise slowed by climate-driven hydrology.

    Science.gov (United States)

    Reager, J T; Gardner, A S; Famiglietti, J S; Wiese, D N; Eicker, A; Lo, M-H

    2016-02-12

    Climate-driven changes in land water storage and their contributions to sea level rise have been absent from Intergovernmental Panel on Climate Change sea level budgets owing to observational challenges. Recent advances in satellite measurement of time-variable gravity combined with reconciled global glacier loss estimates enable a disaggregation of continental land mass changes and a quantification of this term. We found that between 2002 and 2014, climate variability resulted in an additional 3200 ± 900 gigatons of water being stored on land. This gain partially offset water losses from ice sheets, glaciers, and groundwater pumping, slowing the rate of sea level rise by 0.71 ± 0.20 millimeters per year. These findings highlight the importance of climate-driven changes in hydrology when assigning attribution to decadal changes in sea level.

  14. A decade of sea level rise slowed by climate-driven hydrology

    Science.gov (United States)

    Reager, J. T.; Gardner, A. S.; Famiglietti, J. S.; Wiese, D. N.; Eicker, A.; Lo, M.-H.

    2016-02-01

    Climate-driven changes in land water storage and their contributions to sea level rise have been absent from Intergovernmental Panel on Climate Change sea level budgets owing to observational challenges. Recent advances in satellite measurement of time-variable gravity combined with reconciled global glacier loss estimates enable a disaggregation of continental land mass changes and a quantification of this term. We found that between 2002 and 2014, climate variability resulted in an additional 3200 ± 900 gigatons of water being stored on land. This gain partially offset water losses from ice sheets, glaciers, and groundwater pumping, slowing the rate of sea level rise by 0.71 ± 0.20 millimeters per year. These findings highlight the importance of climate-driven changes in hydrology when assigning attribution to decadal changes in sea level.

  15. Relative sea-level changes during the last century recorded by coral microatolls in Belloc, Haiti

    Science.gov (United States)

    Weil-Accardo, J.; Feuillet, N.; Jacques, E.; Deschamps, P.; Saurel, J.-M.; Thirumalai, K.; Demeza, S.; Anglade, D.

    2016-04-01

    record of B8, the diversity in shape of the S. siderea microatolls and the position of fossil D. strigosa corals overall indicate stable to slightly increasing relative sea-level (about 1 mm/yr). This is on the same order of magnitude, although slightly lower, as the rate we determined over the last 74 years by using eight tide gauge records around Hispaniola (1.63 ± 0.20 mm/yr) and the mean rate of sea-level rise previously published (2.0 ± 0.5 mm/yr) in the area. This study demonstrates that coral microatolls can be used to infer relative sea-level changes over the last decades or centuries in the Caribbean, where tide gauge records are often sparse, incomplete or nonexistent. This is of prime importance for the numerous small and flat Caribbean islands, highly vulnerable to the threat of global sea-level rise.

  16. River discharge contribution to sea-level rise in the Yangtze River Estuary, China

    Science.gov (United States)

    Kuang, Cuiping; Chen, Wei; Gu, Jie; Su, Tsung-Chow; Song, Hongling; Ma, Yue; Dong, Zhichao

    2017-02-01

    Sea level changes in the Yangtze River Estuary (YRE) as a result of river discharge are investigated based on the monthly averaged river discharge from 1950 to 2011 at the Datong station. Quantification of the sea level contribution is made by model computed results and the sea level rates reported by the China Sea Level Bulletin (CSLB). The coastal modeling tool, MIKE21, is used to establish a depth-averaged hydrodynamic model covering the YRE and Hangzhou Bay. The model is validated with the measured data. Multi-year monthly river discharges are statistically calculated based on the monthly river discharges at Datong station from 1950 to 2011. The four characteristic discharges (frequency of 75%, 50% and 25%, and multi-year monthly) and month-averaged river discharge from 1950 to 2011 are used to study the seasonal and long-term changes of sea level. The computed sea level at the Dajishan and Lvsi stations are used to study the multi-time scale structure of periodic variation in different time scale of river discharge series. The results reveal that (1) the sea level rises as the river discharge increases, and its amplification decreases from upstream to the offshore. (2) The sea level amplification on the south coast is greater than that on the north coast. When river discharge increases by 20,000 m3/s, the sea level will increase by 0.005-0.010 m in most of Hangzhou Bay. (3) The sea level at the Dajishan station, influenced by river discharge, increased 0.178 mm/y from 1980 to 2011. Correspondingly, the sea level rose at a rate of 2.6-3.0 mm/y during the same period. These values were provided by the CSLB. The increase in sea level (1980-2011) at the Dajishan station caused by river discharge is 6.8-8.9% of the total increase in sea level. (4) The 19-20 year dominant nodal cycle of sea level at the Dajishan and Lvsi stations is in accord with 18.6 year nodal cycle of main tidal constituents on Chinese coasts. It implies that the sea-level change period on the

  17. Assessment on the Vulnerability of Mangrove Ecosystems in the Guangxi Coastal Zone under Sea Level Rise

    Science.gov (United States)

    Li, S.; Ge, Z.; Zhang, L.

    2013-12-01

    Sea level rise caused by global climate change will have significant impacts on coastal zone. The mangrove ecosystems occur at the intertidal zone in tropical and subtropical coasts and are particularly sensitive to sea level rise. To study the responses of mangrove ecosystems to sea level rise, assess the impacts of sea level rise on mangrove ecosystem and formulate the feasible and practical mitigation strategies are the important prerequisites for securing the coastal ecosystems. In this research, taking the mangrove ecosystems in the coastal zone of Guangxi province, China as a case study, the potential impacts of sea level rise on the mangrove ecosystems were analyzed by adopting the SPRC (Source-Pathway- Receptor- Consequence) model. An index system for vulnerability assessment on coastal mangrove ecosystems under sea level rise was worked out, in which rate of sea level rise, subsidence/uplift rate, habitat elevation, daily inundation duration, intertidal slope and sedimentation rate were selected as the key indicators according to the IPCC definition of vulnerability, i.e. the aspects of exposure, sensitivity and adaptation. A quantitatively spatial assessment method based on the GIS platform was established by quantifying each indicator, calculating the vulnerability index and grading the vulnerability. The vulnerability assessment based on the sea-level rise rates of the present trend and IPCC A1F1 scenario were performed for three sets of projections of short-term (2030s), mid-term (2050s) and long-term (2100s). The results showed at the present trend of sea level rise rate of 0.27 cm/a, the mangrove ecosystems in the coastal zone of Guangxi was within the EVI score of 0 in the projections of 2030s, 2050s and 2100s, respectively. As the sedimentation and land uplift could offset the rate of sea level rise and the impact of sea level rise on habitats/species of mangrove ecosystems was negligible. While at the A1F1 scenario with a sea level rise rate of 0

  18. Development of sea level rise scenarios for climate change assessments of the Mekong Delta, Vietnam

    Science.gov (United States)

    Doyle, Thomas W.; Day, Richard H.; Michot, Thomas C.

    2010-01-01

    Rising sea level poses critical ecological and economical consequences for the low-lying megadeltas of the world where dependent populations and agriculture are at risk. The Mekong Delta of Vietnam is one of many deltas that are especially vulnerable because much of the land surface is below mean sea level and because there is a lack of coastal barrier protection. Food security related to rice and shrimp farming in the Mekong Delta is currently under threat from saltwater intrusion, relative sea level rise, and storm surge potential. Understanding the degree of potential change in sea level under climate change is needed to undertake regional assessments of potential impacts and to formulate adaptation strategies. This report provides constructed time series of potential sea level rise scenarios for the Mekong Delta region by incorporating (1) aspects of observed intra- and inter-annual sea level variability from tide records and (2) projected estimates for different rates of regional subsidence and accelerated eustacy through the year 2100 corresponding with the Intergovernmental Panel on Climate Change (IPCC) climate models and emission scenarios.

  19. The vulnerability of Indo-Pacific mangrove forests to sea-level rise

    Science.gov (United States)

    Lovelock, Catherine E.; Cahoon, Donald R.; Friess, Daniel A.; Guntenspergen, Glenn R.; Krauss, Ken W.; Reef, Ruth; Rogers, Kerrylee; Saunders, Megan L.; Sidik, Frida; Swales, Andrew; Saintilan, Neil; Thuyen, Le Xuan; Triet, Tran

    2015-10-01

    Sea-level rise can threaten the long-term sustainability of coastal communities and valuable ecosystems such as coral reefs, salt marshes and mangroves. Mangrove forests have the capacity to keep pace with sea-level rise and to avoid inundation through vertical accretion of sediments, which allows them to maintain wetland soil elevations suitable for plant growth. The Indo-Pacific region holds most of the world's mangrove forests, but sediment delivery in this region is declining, owing to anthropogenic activities such as damming of rivers. This decline is of particular concern because the Indo-Pacific region is expected to have variable, but high, rates of future sea-level rise. Here we analyse recent trends in mangrove surface elevation changes across the Indo-Pacific region using data from a network of surface elevation table instruments. We find that sediment availability can enable mangrove forests to maintain rates of soil-surface elevation gain that match or exceed that of sea-level rise, but for 69 per cent of our study sites the current rate of sea-level rise exceeded the soil surface elevation gain. We also present a model based on our field data, which suggests that mangrove forests at sites with low tidal range and low sediment supply could be submerged as early as 2070.

  20. The vulnerability of Indo-Pacific mangrove forests to sea-level rise.

    Science.gov (United States)

    Lovelock, Catherine E; Cahoon, Donald R; Friess, Daniel A; Guntenspergen, Glenn R; Krauss, Ken W; Reef, Ruth; Rogers, Kerrylee; Saunders, Megan L; Sidik, Frida; Swales, Andrew; Saintilan, Neil; Thuyen, Le Xuan; Triet, Tran

    2015-10-22

    Sea-level rise can threaten the long-term sustainability of coastal communities and valuable ecosystems such as coral reefs, salt marshes and mangroves. Mangrove forests have the capacity to keep pace with sea-level rise and to avoid inundation through vertical accretion of sediments, which allows them to maintain wetland soil elevations suitable for plant growth. The Indo-Pacific region holds most of the world's mangrove forests, but sediment delivery in this region is declining, owing to anthropogenic activities such as damming of rivers. This decline is of particular concern because the Indo-Pacific region is expected to have variable, but high, rates of future sea-level rise. Here we analyse recent trends in mangrove surface elevation changes across the Indo-Pacific region using data from a network of surface elevation table instruments. We find that sediment availability can enable mangrove forests to maintain rates of soil-surface elevation gain that match or exceed that of sea-level rise, but for 69 per cent of our study sites the current rate of sea-level rise exceeded the soil surface elevation gain. We also present a model based on our field data, which suggests that mangrove forests at sites with low tidal range and low sediment supply could be submerged as early as 2070.

  1. Comment [on “Sea level rise shown to drive coastal erosion”

    Science.gov (United States)

    Pilkey, Orrin H.; Young, Robert S.; Bush, David M.

    2000-01-01

    Leatherman et al. [2000] (Eos, Trans., AGU, February 8, 2000, p.55) affirm that global eustatic sea-level rise is driving coastal erosion. Furthermore, they argue that the long-term average rate of shoreline retreat is 150 times the rate of sea-level rise. This rate, they say, is more than a magnitude greater than would be expected from a simple response to sea-level rise through inundation of the shoreline. We agree that sea-level rise is the primary factor causing shoreline retreat in stable coastal areas.This is intuitive. We also believe, however, that the Leatherman et al. [2000] study has greatly underestimated the rate of coastal recession along most low slope shorelines. Slopes along the North Carolina continental shelf/coastal plain approach 10,000:1. To us, this suggests that we should expect rates of shoreline recession 10,000 times the rate of sea-level rise through simple inundation of the shoreline.

  2. How sea level rise affects sedimentation, plant growth, and carbon accumulation on coastal salt marshes

    Science.gov (United States)

    Mudd, S. M.; Howell, S. M.; Morris, J. T.

    2009-12-01

    The rate of accretion on coastal salt marshes depends on feedbacks between flow, macrophyte growth, and sedimentation. Under favourable conditions, marsh accretion rates will keep pace with the local rate of sea level rise. Marsh accretion is driven by both organic and inorganic sedimentation; mineral rich marshes will need less organic sedimentation to keep pace with sea level rise. Here we use a numerical model of marsh accretion, calibrated by sediment cores, to explore the relationship between sea level rise and carbon sequestration on salt marshes in the face of differing supplies of inorganic sediment. The model predicts that changes in carbon storage resulting from changing sediment supply or sea-level rise are strongly dependant on the background sediment supply: if inorganic sediment supply is reduced in an already sediment poor marsh the storage of organic carbon will increase to a far greater extent than in a sediment-rich marsh, provided that the rate of sea-level rise does not exceed a threshold. These results imply that altering sediment supply to estuaries (e.g., by damming upstream rivers or altering littoral sediment transport) could lead to significant changes in the carbon budgets of coastal salt marshes.

  3. Effects of sea-level rise and pumpage elimination on saltwater intrusion in the Hilton Head Island area, South Carolina, 2004-2104

    Science.gov (United States)

    Payne, Dorothy F.

    2010-01-01

    Saltwater intrusion of the Upper Floridan aquifer has been observed in the Hilton Head area, South Carolina since the late 1970s and currently affects freshwater supply. Rising sea level in the Hilton Head Island area may contribute to the occurrence of and affect the rate of saltwater intrusion into the Upper Floridan aquifer by increasing the hydraulic gradient and by inundating an increasing area with saltwater, which may then migrate downward into geologic units that presently contain freshwater. Rising sea level may offset any beneficial results from reductions in groundwater pumpage, and thus needs to be considered in groundwater-management decisions. A variable-density groundwater flow and transport model was modified from a previously existing model to simulate the effects of sea-level rise in the Hilton Head Island area. Specifically, the model was used to (1) simulate trends of saltwater intrusion from predevelopment to the present day (1885-2004) and evaluate the conceptual model, (2) project these trends from the present day into the future based on different potential rates of sea-level change, and (3) evaluate the relative influences of pumpage and sea-level rise on saltwater intrusion. Four scenarios were simulated for 2004-2104: (1) continuation of the estimated sea-level rise rate over the last century, (2) a doubling of the sea-level rise, (3) a cessation of sea-level rise, and (4) continuation of the rate over the last century coupled with an elimination of all pumpage. Results show that, if present-day (year 2004) pumping conditions are maintained, the extent of saltwater in the Upper Floridan aquifer will increase, whether or not sea level continues to rise. Furthermore, if all pumpage is eliminated and sea level continues to rise, the simulated saltwater extent in the Upper Floridan aquifer is reduced. These results indicate that pumpage is a strong driving force for simulated saltwater intrusion, more so than sea-level rise at current rates

  4. Tidal marsh susceptibility to sea-level rise: importance of local-scale models

    Science.gov (United States)

    Thorne, Karen M.; Buffington, Kevin J.; Elliott-Fisk, Deborah L.; Takekawa, John Y.

    2015-01-01

    Increasing concern over sea-level rise impacts to coastal tidal marsh ecosystems has led to modeling efforts to anticipate outcomes for resource management decision making. Few studies on the Pacific coast of North America have modeled sea-level rise marsh susceptibility at a scale relevant to local wildlife populations and plant communities. Here, we use a novel approach in developing an empirical sea-level rise ecological response model that can be applied to key management questions. Calculated elevation change over 13 y for a 324-ha portion of San Pablo Bay National Wildlife Refuge, California, USA, was used to represent local accretion and subsidence processes. Next, we coupled detailed plant community and elevation surveys with measured rates of inundation frequency to model marsh state changes to 2100. By grouping plant communities into low, mid, and high marsh habitats, we were able to assess wildlife species vulnerability and to better understand outcomes for habitat resiliency. Starting study-site conditions were comprised of 78% (253-ha) high marsh, 7% (30-ha) mid marsh, and 4% (18-ha) low marsh habitats, dominated by pickleweed Sarcocornia pacifica and cordgrass Spartina spp. Only under the low sea-level rise scenario (44 cm by 2100) did our models show persistence of some marsh habitats to 2100, with the area dominated by low marsh habitats. Under mid (93 cm by 2100) and high sea-level rise scenarios (166 cm by 2100), most mid and high marsh habitat was lost by 2070, with only 15% (65 ha) remaining, and a complete loss of these habitats by 2080. Low marsh habitat increased temporarily under all three sea-level rise scenarios, with the peak (286 ha) in 2070, adding habitat for the endemic endangered California Ridgway’s rail Rallus obsoletus obsoletus. Under mid and high sea-level rise scenarios, an almost complete conversion to mudflat occurred, with most of the area below mean sea level. Our modeling assumed no marsh migration upslope due to human

  5. Predicting the retreat and migration of tidal forests along the northern Gulf of Mexico under sea-level rise

    Science.gov (United States)

    Doyle, T.W.; Krauss, K.W.; Conner, W.H.; From, A.S.

    2010-01-01

    Tidal freshwater forests in coastal regions of the southeastern United States are undergoing dieback and retreat from increasing tidal inundation and saltwater intrusion attributed to climate variability and sea-level rise. In many areas, tidal saltwater forests (mangroves) contrastingly are expanding landward in subtropical coastal reaches succeeding freshwater marsh and forest zones. Hydrological characteristics of these low-relief coastal forests in intertidal settings are dictated by the influence of tidal and freshwater forcing. In this paper, we describe the application of the Sea Level Over Proportional Elevation (SLOPE) model to predict coastal forest retreat and migration from projected sea-level rise based on a proxy relationship of saltmarsh/mangrove area and tidal range. The SLOPE model assumes that the sum area of saltmarsh/mangrove habitat along any given coastal reach is determined by the slope of the landform and vertical tide forcing. Model results indicated that saltmarsh and mangrove migration from sea-level rise will vary by county and watershed but greater in western Gulf States than in the eastern Gulf States where millions of hectares of coastal forest will be displaced over the next century with a near meter rise in relative sea level alone. Substantial losses of coastal forests will also occur in the eastern Gulf but mangrove forests in subtropical zones of Florida are expected to replace retreating freshwater forest and affect regional biodiversity. Accelerated global eustacy from climate change will compound the degree of predicted retreat and migration of coastal forests with expected implications for ecosystem management of State and Federal lands in the absence of adaptive coastal management.

  6. Danish attitudes and reactions to the threat of sea-level rise

    DEFF Research Database (Denmark)

    Fenger, Jes; Buch, Erik; Jakobsen, Per Roed

    2008-01-01

    movements and projected global accelerated sea-level rise (ASLR) it is estimated that relative sea level will increase by 33-46 cm within the next 100 years-notably in the southwestern part of Denmark. Increased storm intensity may enhance the impacts of this change in water level. Dikes protect about 1100...... km of the coastline and hard structures about 700 km. Soft solutions, especially beach nourishment, are increasingly used. So far direct planning for sea-level rise above the current secular rise has been modest and purely qualitative. The same applies to most new and upgraded coastal infrastructure...... of economic, sociological, and biological interests and options. The general strategy appears to be toward the preservation of a natural coastline, if necessary at the cost of land loss....

  7. The Land Subsidence and Relative Sea Level Rise in Chinese Delta Areas

    Institute of Scientific and Technical Information of China (English)

    YeYincan; LiuDujuan

    2004-01-01

    Based on some experts' research effort, the problems of land subsidence and relative sea level rise in three Chinese delta areas(Huanghe, Changjiang and Zhujiang Delta) are analyzed and discussed in this paper. The authors' opinion is that the land subsidence is mainly induced by human activity and has made the greater contributions to the relative sea level rise and become one of the geological hazards in these areas. In Tianjin and Shanghai areas where had ever existed serious land subsidence problem, due to the positive and effective control methods, the ratio of man-induced land subsidence to relative sea level rise decreased from 80% - 90% in 1960s - 1970s to less than 60% at present. But it is estimated that in the next tens of years this ratio will still be considerable. So human being must keep its eyes on this phenomenon and take more positive countermeasures to control the land subsidenee.

  8. Bayesian methods for model uncertainty analysis with application to future sea level rise

    Energy Technology Data Exchange (ETDEWEB)

    Patwardhan, A.; Small, M.J.

    1992-01-01

    In no other area is the need for effective analysis of uncertainty more evident than in the problem of evaluating the consequences of increasing atmospheric concentrations of radiatively active gases. The major consequences of concern is global warming, with related environmental effects that include changes in local patterns of precipitation, soil moisture, forest and agricultural productivity, and a potential increase in global mean sea level. In order to identify an optimum set of responses to sea level change, a full characterization of the uncertainties associated with the predictions of future sea level rise is essential. The paper addresses the use of data for identifying and characterizing uncertainties in model parameters and predictions. The Bayesian Monte Carlo method is formally presented and elaborated, and applied to the analysis of the uncertainty in a predictive model for global mean sea level change.

  9. Analysis of the sea levels in Kiribati A Rising Sea of Misrepresentation Sinks Kiribati

    Science.gov (United States)

    Parker, Albert

    2016-03-01

    The sea levels of Kiribati have been stable over the last few decades, as elsewhere in the world. The Australian government funded Pacific Sea Level Monitoring (PSLM) project has adjusted sea level records to produce an unrealistic rising trend. Some information has been hidden or neglected, especially from sources of different management. The measured monthly average mean sea levels suffer from subsidence or manipulation resulting in a tilting from the about 0 (zero) mm/year of nearby tide gauges to 4 (four) mm/year over the same short time window. Real environmental problems are driven by the increasing local population leading to troubles including scarcity of water, localized sinking and localised erosion.

  10. Economic vulnerability to sea-level rise along the northern U.S. Gulf Coast

    Science.gov (United States)

    Thatcher, Cindy A.; Brock, John C.; Pendleton, Elizabeth A.

    2013-01-01

    The northern Gulf of Mexico coast of the United States has been identified as highly vulnerable to sea-level rise, based on a combination of physical and societal factors. Vulnerability of human populations and infrastructure to projected increases in sea level is a critical area of uncertainty for communities in the extremely low-lying and flat northern gulf coastal zone. A rapidly growing population along some parts of the northern Gulf of Mexico coastline is further increasing the potential societal and economic impacts of projected sea-level rise in the region, where observed relative rise rates range from 0.75 to 9.95 mm per year on the Gulf coasts of Texas, Louisiana, Mississippi, Alabama, and Florida. A 1-m elevation threshold was chosen as an inclusive designation of the coastal zone vulnerable to relative sea-level rise, because of uncertainty associated with sea-level rise projections. This study applies a Coastal Economic Vulnerability Index (CEVI) to the northern Gulf of Mexico region, which includes both physical and economic factors that contribute to societal risk of impacts from rising sea level. The economic variables incorporated in the CEVI include human population, urban land cover, economic value of key types of infrastructure, and residential and commercial building values. The variables are standardized and combined to produce a quantitative index value for each 1-km coastal segment, highlighting areas where human populations and the built environment are most at risk. This information can be used by coastal managers as they allocate limited resources for ecosystem restoration, beach nourishment, and coastal-protection infrastructure. The study indicates a large amount of variability in index values along the northern Gulf of Mexico coastline, and highlights areas where long-term planning to enhance resiliency is particularly needed.

  11. Recent contributions of glaciers and ice caps to sea level rise.

    Science.gov (United States)

    Jacob, Thomas; Wahr, John; Pfeffer, W Tad; Swenson, Sean

    2012-02-08

    Glaciers and ice caps (GICs) are important contributors to present-day global mean sea level rise. Most previous global mass balance estimates for GICs rely on extrapolation of sparse mass balance measurements representing only a small fraction of the GIC area, leaving their overall contribution to sea level rise unclear. Here we show that GICs, excluding the Greenland and Antarctic peripheral GICs, lost mass at a rate of 148 ± 30 Gt yr(-1) from January 2003 to December 2010, contributing 0.41 ± 0.08 mm yr(-1) to sea level rise. Our results are based on a global, simultaneous inversion of monthly GRACE-derived satellite gravity fields, from which we calculate the mass change over all ice-covered regions greater in area than 100 km(2). The GIC rate for 2003-2010 is about 30 per cent smaller than the previous mass balance estimate that most closely matches our study period. The high mountains of Asia, in particular, show a mass loss of only 4 ± 20 Gt yr(-1) for 2003-2010, compared with 47-55 Gt yr(-1) in previously published estimates. For completeness, we also estimate that the Greenland and Antarctic ice sheets, including their peripheral GICs, contributed 1.06 ± 0.19 mm yr(-1) to sea level rise over the same time period. The total contribution to sea level rise from all ice-covered regions is thus 1.48 ± 0.26 mm (-1), which agrees well with independent estimates of sea level rise originating from land ice loss and other terrestrial sources.

  12. Sea-level rise risks to coastal cities: what are the limits to adaptation?

    Science.gov (United States)

    Nicholls, R. J.; Reeder, T.; Brown, S.; Haigh, I. D.

    2015-12-01

    Understanding the consequence of sea-level rise for coastal cities has long lead times and huge political implications. Civilisation has emerged and developed during a period of several thousand years during which in geological terms sea level has been unusually stable. We have now moved out of this period raising important challenges for the future. In 2005 there were 136 coastal cities with a population exceeding one million people and a collective population of 400 million people. All these cities are threatened by flooding from the sea to varying degrees and these risks are increasing due to growing exposure (people and assets), rising sea levels due to climate change, and in some cities, significant coastal subsidence due to human agency (drainage and groundwater withdrawals from susceptible soils). City abandonment due to sea-level rise is widely discussed in the media, but most of the discussion is speculative. The limits to adaptation and abandonment of cities are not predictable in a formal sense - while the rise in mean sea level raises the likelihood of a catastrophic flood, extreme events are what cause damage and trigger a response, be it abandonment or a defence upgrade. Several types of potential adaptation limits can be recognised: (1) physical/engineering limits; (2) economic/financial limits; and (3) socio-political limits. The latter two types of limits are much less understood, and yet issues such as loss of confidence rather than a simple engineering failure may be instrumental in the future of a coastal city. There are few studies which quantify the sea-level rise threshold at which cities will be challenged, especially for large rises exceeding a metre or more. Exceptions include London and the Thames Estuary and the Amsterdam and Rotterdam (the Netherlands) where adaptation to a rise of sea level of up to 4 m or more appears feasible. This lack of knowledge on sea-level rise thresholds for coastal cities is of concern, and similar

  13. The Impact of Sea Level Rise on Developing Countries: A Comparative Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, S. [World Bank, Washington, DC (United States)

    2008-07-01

    Sea-level rise (SLR) due to climate change is a serious global threat: The scientific evidence is now overwhelming. In this paper, Geographic Information System software has been used to overlay the best available, spatially-disaggregated global data on land, population, agriculture, urban extent, wetlands, and GDP, to assess the consequences of continued SLR for 84 coastal developing countries. Estimates suggest that even a one-meter rise in sea level in coastal countries of the developing world would submerge 194,000 square kilometers of land area, and turn at least 56 million people into environmental refugees. At the country level results are extremely skewed.

  14. The Impact of Sea Level Rise on Developing Countries: A Comparative Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, Susmita (World Bank, Washington, DC (United States))

    2008-07-01

    Sea-level rise (SLR) due to climate change is a serious global threat: The scientific evidence is now overwhelming. In this paper, Geographic Information System software has been used to overlay the best available, spatially-disaggregated global data on land, population, agriculture, urban extent, wetlands, and GDP, to assess the consequences of continued SLR for 84 coastal developing countries. Estimates suggest that even a one-meter rise in sea level in coastal countries of the developing world would submerge 194,000 square kilometers of land area, and turn at least 56 million people into environmental refugees. At the country level results are extremely skewed

  15. Impact of accelerated future global mean sea level rise on hypoxia in the Baltic Sea

    Science.gov (United States)

    Meier, H. E. M.; Höglund, A.; Eilola, K.; Almroth-Rosell, E.

    2016-08-01

    Expanding hypoxia is today a major threat for many coastal seas around the world and disentangling its drivers is a large challenge for interdisciplinary research. Using a coupled physical-biogeochemical model we estimate the impact of past and accelerated future global mean sea level rise (GSLR) upon water exchange and oxygen conditions in a semi-enclosed, shallow sea. As a study site, the Baltic Sea was chosen that suffers today from eutrophication and from dead bottom zones due to (1) excessive nutrient loads from land, (2) limited water exchange with the world ocean and (3) perhaps other drivers like global warming. We show from model simulations for the period 1850-2008 that the impacts of past GSLR on the marine ecosystem were relatively small. If we assume for the end of the twenty-first century a GSLR of +0.5 m relative to today's mean sea level, the impact on the marine ecosystem may still be small. Such a GSLR corresponds approximately to the projected ensemble-mean value reported by the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. However, we conclude that GSLR should be considered in future high-end projections (>+1 m) for the Baltic Sea and other coastal seas with similar hydrographical conditions as in the Baltic because GSLR may lead to reinforced saltwater inflows causing higher salinity and increased vertical stratification compared to present-day conditions. Contrary to intuition, reinforced ventilation of the deep water does not lead to overall improved oxygen conditions but causes instead expanded dead bottom areas accompanied with increased internal phosphorus loads from the sediments and increased risk for cyanobacteria blooms.

  16. Floods in Mekong Delta Under Sea-Level Rise Projections By IPCC AR5

    Science.gov (United States)

    Takagi, H.

    2014-12-01

    One of the mightiest rivers in the planet, the Mekong ranks 10th amongst the world's great rivers on the basis of mean annual flow at the mouth. It flows southwards over a distance of approximately 4,800 km from its source to the sea, through six different countries: China, Myanmar, Lao PDR, Thailand, Cambodia and Vietnam. This great basin has been considered to be one of the most sensitive areas in the world to climate change. The present paper investigates fluvial flood hazards in urban areas in the Mekong Delta to inundation due to seasonal flooding, a phenomenon which is likely to be exacerbated by future sea-level rise. Unlike past researches which mainly focus on flooding due to river discharge from upstream or heavy precipitation, the present paper scrutinizes the influence of ocean tides. The research reveals that ocean tides predominantly determine water elevation even in an upstream location such as Can Tho City, 80 km inland from the river mouth, and that the river flow causes tidal damping and effectively reduces the energy of the incoming tides. This tidal damping is especially pronounced during the rainy season. Analysis based on the water levels monitored by the Mekong River Commission reveals that the ground near the riverbank of Can Tho had experienced inundation for a total of 215 hours between July 2009 and June 2010 (2.5% of the time over a one year period). It is also shown that inundation reached up to a maximum height of 47 cm above the roads of Can Tho downtown in this one-year period. Assuming two scenarios of sea-level rise of 25 cm in the middle of the 21st century and 60 cm in the end of the century, all based on the Fifth Assessment Report of Intergovernmental Panel on Climate Change (IPCC AR5) projections, it was found that the duration of inundation will be prolonged from the present percentage of 2.5% to 7.5% and 24% of the year, respectively. It is important to note that while at present this flooding is seasonal and limited, in the

  17. Allowances for evolving coastal flood risk under uncertain local sea-level rise

    CERN Document Server

    Buchanan, Maya K; Oppenheimer, Michael; Tebaldi, Claudia

    2015-01-01

    Sea-level rise (SLR) causes estimates of flood risk made under the assumption of stationary mean sea level to be biased low. However, adjustments to flood return levels made assuming fixed increases of sea level are also inaccurate when applied to sea level that is rising over time at an uncertain rate. To accommodate both the temporal dynamics of SLR and their uncertainty, we develop an Average Annual Design Life Level (AADLL) metric and associated Design Life SLR (DL-SLR) allowances. The AADLL is the flood level corresponding to a time-integrated annual expected probability of occurrence (AEP) under uncertainty over the design life of an asset; DL-SLR allowances are the adjustment from 2000 levels that maintain current average probability over the design life. Given non-stationary and uncertain sea-level rise, AADLL flood levels and DL-SLR allowances provide estimates of flood protection heights and offsets for different planning horizons and different levels of confidence in SLR projections in coastal area...

  18. The Impact of Sea Level Rise on Geodetic Vertical Datum of Peninsular Malaysia

    Science.gov (United States)

    Din, A. H. M.; Abazu, I. C.; Pa'suya, M. F.; Omar, K. M.; Hamid, A. I. A.

    2016-09-01

    Sea level rise is rapidly turning into major issues among our community and all levels of the government are working to develop responses to ensure these matters are given the uttermost attention in all facets of planning. It is more interesting to understand and investigate the present day sea level variation due its potential impact, particularly on our national geodetic vertical datum. To determine present day sea level variation, it is vital to consider both in-situ tide gauge and remote sensing measurements. This study presents an effort to quantify the sea level rise rate and magnitude over Peninsular Malaysia using tide gauge and multi-mission satellite altimeter. The time periods taken for both techniques are 32 years (from 1984 to 2015) for tidal data and 23 years (from 1993 to 2015) for altimetry data. Subsequently, the impact of sea level rise on Peninsular Malaysia Geodetic Vertical Datum (PMGVD) is evaluated in this study. the difference between MSL computed from 10 years (1984 - 1993) and 32 years (1984 - 2015) tidal data at Port Kelang showed that the increment of sea level is about 27mm. The computed magnitude showed an estimate of the long-term effect a change in MSL has on the geodetic vertical datum of Port Kelang tide gauge station. This will help give a new insight on the establishment of national geodetic vertical datum based on mean sea level data. Besides, this information can be used for a wide variety of climatic applications to study environmental issues related to flood and global warming in Malaysia.

  19. An inflection in the rate of early mid-Holocene eustatic sea-level rise: A new sea-level curve from Singapore

    Science.gov (United States)

    Bird, M. I.; Fifield, L. K.; Teh, T. S.; Chang, C. H.; Shirlaw, N.; Lambeck, K.

    2007-02-01

    This study presents a sea-level curve from ˜9500 to ˜6500 cal BP for the farfield location of Singapore, on the Sunda Shelf in southeast Asia. The curve is based on more than 50 radiocarbon dates from elevations of +1.43 m to -15.09 m representing sea-level index points in intertidal mangrove and shallow marine sediments deposited by sea-level rise accompanying deglaciation. The results indicate that mean sea level rose rapidly from around -17 m at 9500 cal BP to around -3 m by 8000 cal BP. After this time, the data suggest (but do not unequivocally prove) that the rate of sea-rise slowed for a period of 300-500 years centred on ˜7700 cal BP, shortly after the cessation of meltwater input to the oceans from the northern hemisphere. Renewed sea-level rise amounting to 3-5 m began around 7400 cal BP and was complete by 7000 cal BP. The existence of an inflection in the rate of sea-level rise, with a slow-down centred on ˜7700 cal BP, is broadly consistent with other available sea-level curves over this interval and is supported by evidence of stable shorelines and delta initiation elsewhere at this time, as well as evidence of comparatively rapid retreat of the West Antarctic ice sheet beginning around 7500 cal BP. 'Stepped' sea-level rise occurring shortly after 7500 cal BP and also earlier during deglaciation may have served to focus significant post-glacial episodes of human maritime/coastal dispersal, into comparatively narrow time intervals.

  20. Modelling the impacts of sea level rise on tidal basin ecomorphodynamics and mangrove habitat evolution

    Science.gov (United States)

    van Maanen, Barend; Coco, Giovanni; Bryan, Karin

    2016-04-01

    The evolution of tidal basins and estuaries in tropical and subtropical regions is often influenced by the presence of mangrove forests. These forests are amongst the most productive environments in the world and provide important ecosystem services. However, these intertidal habitats are also extremely vulnerable and are threatened by climate change impacts such as sea level rise. It is therefore of key importance to improve our understanding of how tidal systems occupied by mangrove vegetation respond to rising water levels. An ecomorphodynamic model was developed that simulates morphological change and mangrove forest evolution as a result of mutual feedbacks between physical and biological processes. The model accounts for the effects of mangrove trees on tidal flow patterns and sediment dynamics. Mangrove growth is in turn controlled by hydrodynamic conditions. Under stable water levels, model results indicate that mangrove trees enhance the initiation and branching of tidal channels, partly because the extra flow resistance in mangrove forests favours flow concentration, and thus sediment erosion in between vegetated areas. The landward expansion of the channels, on the other hand, is reduced. Model simulations including sea level rise suggest that mangroves can potentially enhance the ability of the soil surface to maintain an elevation within the upper portion of the intertidal zone. While the sea level is rising, mangroves are migrating landward and the channel network tends to expand landward too. The presence of mangrove trees, however, was found to hinder both the branching and headward erosion of the landward expanding channels. Simulations are performed according to different sea level rise scenarios and with different tidal range conditions to assess which tidal environments are most vulnerable. Changes in the properties of the tidal channel networks are being examined as well. Overall, model results highlight the role of mangroves in driving the

  1. Sea-Level Rise Implications for Coastal Protection from Southern Mediterranean to the U.S.A. Atlantic Coast

    Science.gov (United States)

    Ismail, Nabil; Williams, Jeffress

    2013-04-01

    This paper presents an assessment of global sea level rise and the need to incorporate projections of rise into management plans for coastal adaptation. It also discusses the performance of a shoreline revetment; M. Ali Seawall, placed to protect the land against flooding and overtopping at coastal site, within Abu Qir Bay, East of Alexandria, Egypt along the Nile Delta coast. The assessment is conducted to examine the adequacy of the seawall under the current and progressive effects of climate change demonstrated by the anticipated sea level rise during this century. The Intergovernmental Panel on Climate Change (IPCC, 2007) predicts that the Mediterranean will rise 30 cm to 1 meter this century. Coastal zone management of the bay coastline is of utmost significance to the protection of the low agricultural land and the industrial complex located in the rear side of the seawall. Moreover this joint research work highlights the similarity of the nature of current and anticipated coastal zone problems, at several locations around the world, and required adaptation and protection measures. For example many barrier islands in the world such as that in the Atlantic and Gulf of Mexico coasts of the U.S., lowland and deltas such as in Italy and the Nile Delta, and many islands are also experiencing significant levels of erosion and flooding that are exacerbated by sea level rise. Global Climatic Changes: At a global scale, an example of the effects of accelerated climate changes was demonstrated. In recent years, the impacts of natural disasters are more and more severe on coastal lowland areas. With the threats of climate change, sea level rise storm surge, progressive storm and hurricane activities and potential subsidence, the reduction of natural disasters in coastal lowland areas receives increased attention. Yet many of their inhabitants are becoming increasingly vulnerable to flooding, and conversions of land to open ocean. These global changes were recently

  2. Estimating the glacier contribution to sea-level rise for the period 1800-2005

    NARCIS (Netherlands)

    Leclercq, P.W.; Oerlemans, J.; Cogley, J.G.

    2011-01-01

    In this study, a new estimate of the contribution of glaciers and ice caps to the sea-level rise over the period 1800-2005 is presented. We exploit the available information on changes in glacier length. Length records form the only direct evidence of glacier change that has potential global coverag

  3. Niger's Delta vulnerability to river floods due to sea level rise

    Directory of Open Access Journals (Sweden)

    Z. N. Musa

    2014-08-01

    Full Text Available An evaluation of vulnerability to sea level rise is undertaken for the Niger delta based on 17 physical, social and human influence indicators of exposure, susceptibility and resilience. The assessment used GIS techniques to evaluate and analyse the indicators and the index of coastal vulnerability to floods, if sea level rise conditions are occurring. Each indicator value is based on data extracted from various sources including remote sensing, measured historical data series and literature search. Further indicators are ranked on a scale from 1 to 5 representing "very low" to "very high" vulnerability, based on their values. These ranks are used to determine a similar rank for the defined coastal vulnerability index (CVSLRI. Results indicate that 42.2% of the Niger delta is highly vulnerable to sea level rise; such areas been characterized by low slopes, low topography, high mean wave heights, and unconfined aquifers. Moreover the analysis of social and human influences on the environment indicate high vulnerability to sea level rise due to its ranking for type of aquifer, aquifer hydraulic conductivity, population growth, sediment supply and groundwater consumption. Such results may help decision makers during planning, to take proper adaptive measures for reducing Niger Delta's vulnerability, as well as increasing the resilience to potential future floods.

  4. Effective media reporting of sea level rise projections: 1989-2009

    Science.gov (United States)

    Rick, U. K.; Boykoff, M. T.; Pielke, R. A., Jr.

    2011-01-01

    In the mass media, sea level rise is commonly associated with the impacts of climate change due to increasing atmospheric greenhouse gases. As this issue garners ongoing international policy attention, segments of the scientific community have expressed unease about how this has been covered by mass media. Therefore, this study examines how sea level rise projections—in IPCC Assessment Reports and a sample of the scientific literature—have been represented in seven prominent United States (US) and United Kingdom (UK) newspapers over the past two decades. The research found that—with few exceptions—journalists have accurately portrayed scientific research on sea level rise projections to 2100. Moreover, while coverage has predictably increased in the past 20 years, journalists have paid particular attention to the issue in years when an IPCC report is released or when major international negotiations take place, rather than when direct research is completed and specific projections are published. We reason that the combination of these factors has contributed to a perceived problem in the sea level rise reporting by the scientific community, although systematic empirical research shows none. In this contemporary high-stakes, high-profile and highly politicized arena of climate science and policy interactions, such results mark a particular bright spot in media representations of climate change. These findings can also contribute to more measured considerations of climate impacts and policy action at a critical juncture of international negotiations and everyday decision-making associated with the causes and consequences of climate change.

  5. Living with sea-level rise and climate change: a case study of the Netherlands

    NARCIS (Netherlands)

    Koningsveld, van M.; Mulder, J.P.M.; Stive, M.J.F.; Valk, van der L.; Weck, van der A.W.

    2008-01-01

    Based on historical hindsight, this paper shows that sea-level rise has played a fundamental role in the development of the low-lying environment of the Netherlands. It was beneficial in morphological terms during the mid-Holocene, but from Roman times, it has been a threat to the coastal zone evolu

  6. Modelling Morphological Response of Large Tidal Inlet Systems to Sea Level Rise

    NARCIS (Netherlands)

    Dissanayake, P.K.

    2011-01-01

    This dissertation qualitatively investigates the morphodynamic response of a large inlet system to IPCC projected relative sea level rise (RSLR). Adopted numerical approach (Delft3D) used a highly schematised model domain analogous to the Ameland inlet in the Dutch Wadden Sea. Predicted inlet evolut

  7. Impact of sea-level rise in a Mediteranean delta: The Ebro delta cast

    NARCIS (Netherlands)

    Sánchez-Arcilla, A.; Stive, M.D.F.; Jiménez, J.A.; García, M.A.

    1993-01-01

    In anticipation of a comprehensive, multidisciplinary study on the impact of climatic change on the Ebro Delta preliminary results are here presented of the response of the outer delta coast to present and future relative sea-level rise. Due to the absence of observations and predictions of regional

  8. Sea defence and flood protection in the Netherlands anticipating increased sea-level rise

    NARCIS (Netherlands)

    Verhagen, H.J.

    1990-01-01

    The 1400 km Dutch coastline is affected by sea-level rise. At this moment a legal framework is made to guarantee safety of the dikes also in future. Also a national policy is developed for compensation of all coastal erosion. Both measures should make it possible for the Netherlands to survive an

  9. GIS analysis of effects of future Baltic sea level rise on the island of Gotland, Sweden

    Science.gov (United States)

    Ebert, Karin; Ekstedt, Karin; Jarsjö, Jerker

    2016-07-01

    Future sea level rise as a consequence of global warming will affect the world's coastal regions. Even though the pace of sea level rise is not clear, the consequences will be severe and global. Commonly the effects of future sea level rise are investigated for relatively vulnerable development countries; however, a whole range of varying regions needs to be considered in order to improve the understanding of global consequences. In this paper we investigate consequences of future sea level rise along the coast of the Baltic Sea island of Gotland, Sweden, with the aim to fill knowledge gaps regarding comparatively well-suited areas in developed countries. We study both the quantity of the loss of features of infrastructure, cultural, and natural value in the case of a 2 m sea level rise of the Baltic Sea and the effects of climate change on seawater intrusion in coastal aquifers, which indirectly cause saltwater intrusion in wells. We conduct a multi-criteria risk analysis by using lidar data on land elevation and GIS-vulnerability mapping, which gives the application of distance and elevation parameters formerly unimaginable precision. We find that in case of a 2 m sea level rise, 3 % of the land area of Gotland, corresponding to 99 km2, will be inundated. The features most strongly affected are items of touristic or nature value, including camping places, shore meadows, sea stack areas, and endangered plants and species habitats. In total, 231 out of 7354 wells will be directly inundated, and the number of wells in the high-risk zone for saltwater intrusion in wells will increase considerably. Some valuable features will be irreversibly lost due to, for example, inundation of sea stacks and the passing of tipping points for seawater intrusion into coastal aquifers; others might simply be moved further inland, but this requires considerable economic means and prioritization. With nature tourism being one of the main income sources of Gotland, monitoring and

  10. Future sea-level rise from tidewater and ice-shelf tributary glaciers of the Antarctic Peninsula

    Science.gov (United States)

    Schannwell, Clemens; Barrand, Nicholas E.; Radić, Valentina

    2016-11-01

    Iceberg calving and increased ice discharge from ice-shelf tributary glaciers contribute significant amounts to global sea-level rise (SLR) from the Antarctic Peninsula (AP). Owing to ongoing ice dynamical changes (collapse of buttressing ice shelves), these contributions have accelerated in recent years. As the AP is one of the fastest warming regions on Earth, further ice dynamical adjustment (increased ice discharge) is expected over the next two centuries. In this paper, the first regional SLR projection of the AP from both iceberg calving and increased ice discharge from ice-shelf tributary glaciers in response to ice-shelf collapse is presented. An ice-sheet model forced by temperature output from 13 global climate models (GCMs), in response to the high greenhouse gas emission scenario (RCP8.5), projects AP contribution to SLR of 28 ± 16 to 32 ± 16 mm by 2300, partitioned approximately equally between contributions from tidewater glaciers and ice-shelf tributary glaciers. In the RCP4.5 scenario, sea-level rise projections to 2300 are dominated by tidewater glaciers (∼8-18 mm). In this cooler scenario, 2.4 ± 1 mm is added to global sea levels from ice-shelf tributary drainage basins as fewer ice-shelves are projected to collapse. Sea-level projections from ice-shelf tributary glaciers are dominated by drainage basins feeding George VI Ice Shelf, accounting for ∼70% of simulated SLR. Combined total ice dynamical SLR projections to 2300 from the AP vary between 11 ± 2 and 32 ± 16 mm sea-level equivalent (SLE), depending on the emission scenario used. These simulations suggest that omission of tidewater glaciers could lead to a substantial underestimation of the ice-sheet's contribution to regional SLR.

  11. EFFECT OF SALT WEDGE INTRUSION IN KUSHIRO WETLAND CONSIDERING SEA LEVEL RISE

    Science.gov (United States)

    Nakamoto, Atsushi; Shintani, Tetsuya; Nakayama, Keisuke; Maruya, Yasuyuki; Ishida, Tetsuya; Houmura, Kenichi

    This paper describes the effect of sea-level rise (SLR) on the salt wedge intrusion in terms of ecological system in Kushiro wetland. Kushiro wetland was registered by Ramsar Treaty and the largest wetland in Japan. A previous study demonstrates that the salt wedge intrusion may not affect ecological system of Kushiro wetland, such as loss of freshwater plants along Kushiro River. However, it is revealed that SLR may occur in the end of the 21st century, which enhances the increase in the distance of the salt wedge intrusion along Kushiro River and the loss of endangered species of Kushiro wetland along Kushiro River. This study thus aims to investigate the influence of the salt wedge intrusion on freshwater plants along Kushiro River, and to clarify the salt wedge intrusion when SLR occurs due to climate change. We attempted to investigate the influence of SLR on endangered species along Kyu-Kushiro River in which sea water is likely to intrude up to about 8 km from the river mouth. As results, it is suggested from field observations that salinity may decrease freshwater plants along Kushiro River, and it clarifies the possibility that the salt wedge intrudes Kushiro River due to SLR by using 3D hydrodynamic model, Fantom3D.

  12. Vulnerability of Louisiana's coastal wetlands to present-day rates of relative sea-level rise

    Science.gov (United States)

    Jankowski, Krista L.; Törnqvist, Torbjörn E.; Fernandes, Anjali M.

    2017-03-01

    Coastal Louisiana has lost about 5,000 km2 of wetlands over the past century and concern exists whether remaining wetlands will persist while facing some of the world's highest rates of relative sea-level rise (RSLR). Here we analyse an unprecedented data set derived from 274 rod surface-elevation table-marker horizon stations, to determine present-day surface-elevation change, vertical accretion and shallow subsidence rates. Comparison of vertical accretion rates with RSLR rates at the land surface (present-day RSLR rates are 12+/-8 mm per year) shows that 65% of wetlands in the Mississippi Delta (SE Louisiana) may keep pace with RSLR, whereas 58% of the sites in the Chenier Plain (SW Louisiana) do not, rendering much of this area highly vulnerable to RLSR. At least 60% of the total subsidence rate occurs within the uppermost 5-10 m, which may account for the higher vulnerability of coastal Louisiana wetlands compared to their counterparts elsewhere.

  13. Caribbean mangroves adjust to rising sea level through biotic controls on change in soil elevation

    Science.gov (United States)

    McKee, K.L.; Cahoon, D.R.; Feller, Ilka C.

    2007-01-01

    Aim The long-term stability of coastal ecosystems such as mangroves and salt marshes depends upon the maintenance of soil elevations within the intertidal habitat as sea level changes. We examined the rates and processes of peat formation by mangroves of the Caribbean Region to better understand biological controls on habitat stability. Location Mangrove-dominated islands on the Caribbean coasts of Belize, Honduras and Panama were selected as study sites. Methods Biological processes controlling mangrove peat formation were manipulated (in Belize) by the addition of nutrients (nitrogen or phosphorus) to Rhizophora mangle (red mangrove), and the effects on the dynamics of soil elevation were determined over a 3-year period using rod surface elevation tables (RSET) and marker horizons. Peat composition and geological accretion rates were determined at all sites using radiocarbon-dated cores. Results The addition of nutrients to mangroves caused significant changes in rates of mangrove root accumulation, which influenced both the rate and direction of change in elevation. Areas with low root input lost elevation and those with high rates gained elevation. These findings were consistent with peat analyses at multiple Caribbean sites showing that deposits (up to 10 m in depth) were composed primarily of mangrove root matter. Comparison of radiocarbon-dated cores at the study sites with a sea-level curve for the western Atlantic indicated a tight coupling between peat building in Caribbean mangroves and sea-level rise over the Holocene. Main conclusions Mangroves common to the Caribbean region have adjusted to changing sea level mainly through subsurface accumulation of refractory mangrove roots. Without root and other organic inputs, submergence of these tidal forests is inevitable due to peat decomposition, physical compaction and eustatic sea-level rise. These findings have relevance for predicting the effects of sea-level rise and biophysical processes on tropical

  14. Sea Level Rise Decision Support Tools for Adaptation Planning in Vulnerable Coastal Communities

    Science.gov (United States)

    Rozum, J. S.; Marcy, D.

    2015-12-01

    NOAA is involved in a myriad of climate related research and projects that help decision makers and the public understand climate science as well as climate change impacts. The NOAA Office for Coastal Management (OCM) provides data, tools, trainings and technical assistance to coastal resource managers. Beginning in 2011, NOAA OCM began developing a sea level rise and coastal flooding impacts viewer which provides nationally consistent data sets and analyses to help communities with coastal management goals such as: understanding and communicating coastal flood hazards, performing vulnerability assessments and increasing coastal resilience, and prioritizing actions for different inundation/flooding scenarios. The Viewer is available on NOAA's Digital Coast platform: (coast.noaa.gov/ditgitalcoast/tools/slr). In this presentation we will share the lessons learned from our work with coastal decision-makers on the role of coastal flood risk data and tools in helping to shape future land use decisions and policies. We will also focus on a recent effort in California to help users understand the similarities and differences of a growing array of sea level rise decision support tools. NOAA staff and other partners convened a workshop entitled, "Lifting the Fog: Bringing Clarity to Sea Level Rise and Shoreline Change Models and Tools," which was attended by tool develops, science translators and coastal managers with the goal to create a collaborative communication framework to help California coastal decision-makers navigate the range of available sea level rise planning tools, and to inform tool developers of future planning needs. A sea level rise tools comparison matrix will be demonstrated. This matrix was developed as part of this effort and has been expanded to many other states via a partnership with NOAA, Climate Central, and The Nature Conservancy.

  15. Simulating reef response to sea-level rise at Lizard Island: A geospatial approach

    Science.gov (United States)

    Hamylton, S. M.; Leon, J. X.; Saunders, M. I.; Woodroffe, C. D.

    2014-10-01

    Sea-level rise will result in changes in water depth over coral reefs, which will influence reef platform growth as a result of carbonate production and accretion. This study simulates the pattern of reef response on the reefs around Lizard Island in the northern Great Barrier Reef. Two sea-level rise scenarios are considered to capture the range of likely projections: 0.5 m and 1.2 m above 1990 levels by 2100. Reef topography has been established through extensive bathymetric profiling, together with available data, including LiDAR, single beam bathymetry, multibeam swath bathymetry, LADS and digitised chart data. The reef benthic cover around Lizard Island has been classified using a high resolution WorldView-2 satellite image, which is calibrated and validated against a ground referencing dataset of 364 underwater video records of the reef benthic character. Accretion rates are parameterised using published hydrochemical measurements taken in-situ and rules are applied using Boolean logic to incorporate geomorphological transitions associated with different depth ranges, such as recolonisation of the reef flat when it becomes inundated as sea level rises. Simulations indicate a variable platform response to the different sea-level rise scenarios. For the 0.5 m rise, the shallower reef flats are gradually colonised by corals, enabling this active geomorphological zone to keep up with the lower rate of rise while the other sand dominated areas get progressively deeper. In the 1.2 m scenario, a similar pattern is evident for the first 30 years of rise, beyond which the whole reef platform begins to slowly drown. To provide insight on reef response to sea-level rise in other areas, simulation results of four different reef settings are discussed and compared at the southeast reef flat (barrier reef), Coconut Beach (fringing reef), Watson's Bay (leeward bay with coral patches) and Mangrove Beach (sheltered lagoonal embayment). The reef sites appear to accrete upwards

  16. Sea-level rise modeling handbook: Resource guide for coastal land managers, engineers, and scientists

    Science.gov (United States)

    Doyle, Thomas W.; Chivoiu, Bogdan; Enwright, Nicholas M.

    2015-08-24

    Global sea level is rising and may accelerate with continued fossil fuel consumption from industrial and population growth. In 2012, the U.S. Geological Survey conducted more than 30 training and feedback sessions with Federal, State, and nongovernmental organization (NGO) coastal managers and planners across the northern Gulf of Mexico coast to evaluate user needs, potential benefits, current scientific understanding, and utilization of resource aids and modeling tools focused on sea-level rise. In response to the findings from the sessions, this sea-level rise modeling handbook has been designed as a guide to the science and simulation models for understanding the dynamics and impacts of sea-level rise on coastal ecosystems. The review herein of decision-support tools and predictive models was compiled from the training sessions, from online research, and from publications. The purpose of this guide is to describe and categorize the suite of data, methods, and models and their design, structure, and application for hindcasting and forecasting the potential impacts of sea-level rise in coastal ecosystems. The data and models cover a broad spectrum of disciplines involving different designs and scales of spatial and temporal complexity for predicting environmental change and ecosystem response. These data and models have not heretofore been synthesized, nor have appraisals been made of their utility or limitations. Some models are demonstration tools for non-experts, whereas others require more expert capacity to apply for any given park, refuge, or regional application. A simplified tabular context has been developed to list and contrast a host of decision-support tools and models from the ecological, geological, and hydrological perspectives. Criteria were established to distinguish the source, scale, and quality of information input and geographic datasets; physical and biological constraints and relations; datum characteristics of water and land components

  17. Potential for shoreline changes due to sea-level rise along the U.S. mid-Atlantic region

    Science.gov (United States)

    Gutierrez, Benjamin T.; Williams, S. Jeffress; Thieler, E. Robert

    2007-01-01

    Sea-level rise over the next century is expected to contribute significantly to physical changes along open-ocean shorelines. Predicting the form and magnitude of coastal changes is important for understanding the impacts to humans and the environment. Presently, the ability to predict coastal changes is limited by the scientific understanding of the many variables and processes involved in coastal change, and the lack of consensus regarding the validity of existing conceptual, analytical, or numerical models. In order to assess potential future coastal changes in the mid-Atlantic U.S. for the U.S. Climate Change Science Program (CCSP), a workshop was convened by the U.S. Geological Survey. Assessments of future coastal change were made by a committee of coastal scientists with extensive professional experience in the mid-Atlantic region. Thirteen scientists convened for a two-day meeting to exchange information and develop a consensus opinion on potential future coastal changes for the mid-Atlantic coast in response to sea-level rise. Using criteria defined in past work, the mid-Atlantic coast was divided into four geomorphic compartments: spits, headlands, wave-dominated barriers, and mixed-energy barriers. A range of potential coastal responses was identified for each compartment based on four sea-level rise scenarios. The four scenarios were based on the assumptions that: a) the long-term sea-level rise rate observed over the 20th century would persist over the 21st century, b) the 20th century rate would increase by 2 mm/yr, c) the 20th century rate would increase by 7 mm/yr, or d) sea-level would rise by 2 m over the next few hundred years. Potential responses to these sea-level rise scenarios depend on the landforms that occur within a region and include increased likelihood for erosion and shoreline retreat for all coastal types, increased likelihood for erosion, overwash and inlet breaching for barrier islands, as well as the possibility of a threshold

  18. Conceptual framework for assessing the response of delta channel networks to Holocene sea level rise

    Science.gov (United States)

    Jerolmack, Douglas J.

    2009-08-01

    Recent research has identified two fundamental unit processes that build delta distributary channels. The first is mouth-bar deposition at the shoreline and subsequent channel bifurcation, which is driven by progradation of the shoreline; the second is avulsion to a new channel, a result of aggradation of the delta topset. The former creates relatively small, branching networks such as Wax Lake Delta; the latter generates relatively few, long distributaries such as the Mississippi and Atchafalaya channels on the Mississippi Delta. The relative rate of progradation to aggradation, and hence the creation of accommodation space, emerges as a controlling parameter on channel network form. Field and experimental research has identified sea level as the dominant control on Holocene delta growth worldwide, and has empirically linked channel network changes to changes in the rate of sea level rise. Here I outline a simple modeling framework for distributary network evolution, and use this to explore large-scale changes in Holocene channel pattern that have been observed in deltas such as the Rhine-Meuse and Mississippi. Rapid early- to mid-Holocene sea level rise forced many deltas into an aggradational mode, where I hypothesize that avulsion and the generation of large-scale branches should dominate. Slowing of sea level rise in the last ˜6000 yr allowed partitioning of sediment into progradation, facilitating the growth of smaller-scale distributary trees at the shorelines of some deltas, and a reduction in the number of large-scale branches. Significant antecedent topography modulates delta response; the filling of large incised valleys, for example, caused many deltas to bypass the aggradational phase. Human effects on deltas can be cast in terms of geologic controls affecting accommodation: constriction of channels forces rapid local progradation and mouth-bar bifurcation, while accelerated sea level rise increases aggradation and induces more frequent channel

  19. Soil Accretionary Dynamics, Sea-Level Rise and the Survival of Wetlands in Venice Lagoon: A Field and Modelling Approach

    Science.gov (United States)

    Day, J. W.; Rybczyk, J.; Scarton, F.; Rismondo, A.; Are, D.; Cecconi, G.

    1999-11-01

    Over the past century, Venice Lagoon (Italy) has experienced a high rate of wetland loss. To gain an understanding of the factors leading to this loss, from March 1993 until May 1996 the soil accretionary dynamics of these wetlands were studied. Vertical accretion, short term sedimentation, soil vertical elevation change and horizontal shoreline change were measured at several sites with varying sediment availability and wave energy. Short term sedimentation averaged 3-7 g dry m -2day -1per site with a maximum of 76 g m -2 day -1. The highest values were measured during strong pulsing events, such as storms and river floods, that mobilized and transported suspended sediments. Accretion ranged from 2-23 mm yr -1and soil elevation change ranged from -32 to 13·8 mm yr -1. The sites with highest accretion were near a river mouth and in an area where strong wave energy resuspended bottom sediments that were deposited on the marsh surface. A marsh created with dredged spoil had a high rate of elevation loss, probably due mainly to compaction. Shoreline retreat and expansion of tidal channels also occurred at several sites due to high wave energy and a greater tidal prism. The current rate of elevation gain at some sites was not sufficient to offset relative sea-level rise. The results suggest that reduction of wave energy and increasing sediment availability are needed to offset wetland loss in different areas of the lagoon. Using the data collected as part of this project, we developed a wetland elevation model designed to predict the effect of increasing rates of eustatic sea-level rise on wetland sustainability. The advantage of this model, in conjunction with measured short-term rates of soil elevation change, to determine sustainability is that the model integrates the effects of long term processes (e.g. compaction and decomposition) and takes into account feedback mechanisms that affect elevation. Specifically, changes in elevation can result in changes in

  20. Economy-Wide Estimates of the Implications of Climate Change. Sea Level Rise

    Energy Technology Data Exchange (ETDEWEB)

    Bosello, F.; Lazzarin, M. [Fondazione Eni Enrico Mattei FEEM, Milan (Italy); Roson, R. [The Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Tol, R.S.J. [Centre for Marine and Climate Research, Hamburg University, Hamburg (Germany)

    2004-06-01

    The economy-wide implications of sea level rise in 2050 are estimated using a static computable general equilibrium model. Overall, general equilibrium effects increase the costs of sea level rise, but not necessarily in every sector or region. In the absence of coastal protection, economies that rely most on agriculture are hit hardest. Although energy is substituted for land, overall energy consumption falls with the shrinking economy, hurting energy exporters. With full coastal protection, GDP increases, particularly in regions that do a lot of dike building, but utility falls, least in regions that build a lot of dikes and export energy. Energy prices rise and energy consumption falls. The costs of full protection exceed the costs of losing land.

  1. A process for developing and revising a learning progression on sea level rise using learners' explanations

    Science.gov (United States)

    McDonald, Robert Christopher

    The purpose of this study was to explore the process of developing a learning progression (LP) on constructing explanations about sea level rise. I used a learning progressions theoretical framework informed by the situated cognition learning theory. During this exploration, I explicitly described my decision-making process as I developed and revised a hypothetical learning progression. Correspondingly, my research question was: What is a process by which a hypothetical learning progression on sea level rise is developed into an empirical learning progression using learners' explanations? To answer this question, I used a qualitative descriptive single case study with multiple embedded cases (Yin, 2014) that employed analytic induction (Denzin, 1970) to analyze data collected on middle school learners (grades 6-8). Data sources included written artifacts, classroom observations, and semi-structured interviews. Additionally, I kept a researcher journal to track my thinking about the learning progression throughout the research study. Using analytic induction to analyze collected data, I developed eight analytic concepts: participant explanation structures varied widely, global warming and ice melt cause sea level rise, participants held alternative conceptions about sea level rise, participants learned about thermal expansion as a fundamental aspect of sea level rise, participants learned to incorporate authentic scientific data, participants' mental models of the ocean varied widely, sea ice melt contributes to sea level rise, and participants held vague and alternative conceptions about how pollution impacts the ocean. I started with a hypothetical learning progression, gathered empirical data via various sources (especially semi-structured interviews), revised the hypothetical learning progression in response to those data, and ended with an empirical learning progression comprising six levels of learner thinking. As a result of developing an empirically based LP

  2. Consistent estimate of ocean warming, land ice melt and sea level rise from Observations

    Science.gov (United States)

    Blazquez, Alejandro; Meyssignac, Benoît; Lemoine, Jean Michel

    2016-04-01

    Based on the sea level budget closure approach, this study investigates the consistency of observed Global Mean Sea Level (GMSL) estimates from satellite altimetry, observed Ocean Thermal Expansion (OTE) estimates from in-situ hydrographic data (based on Argo for depth above 2000m and oceanic cruises below) and GRACE observations of land water storage and land ice melt for the period January 2004 to December 2014. The consistency between these datasets is a key issue if we want to constrain missing contributions to sea level rise such as the deep ocean contribution. Numerous previous studies have addressed this question by summing up the different contributions to sea level rise and comparing it to satellite altimetry observations (see for example Llovel et al. 2015, Dieng et al. 2015). Here we propose a novel approach which consists in correcting GRACE solutions over the ocean (essentially corrections of stripes and leakage from ice caps) with mass observations deduced from the difference between satellite altimetry GMSL and in-situ hydrographic data OTE estimates. We check that the resulting GRACE corrected solutions are consistent with original GRACE estimates of the geoid spherical harmonic coefficients within error bars and we compare the resulting GRACE estimates of land water storage and land ice melt with independent results from the literature. This method provides a new mass redistribution from GRACE consistent with observations from Altimetry and OTE. We test the sensibility of this method to the deep ocean contribution and the GIA models and propose best estimates.

  3. Allowances for evolving coastal flood risk under uncertain local sea-level rise

    Science.gov (United States)

    Buchanan, M. K.; Kopp, R. E.; Oppenheimer, M.; Tebaldi, C.

    2015-12-01

    Sea-level rise (SLR) causes estimates of flood risk made under the assumption of stationary mean sea level to be biased low. However, adjustments to flood return levels made assuming fixed increases of sea level are also inaccurate when applied to sea level that is rising over time at an uncertain rate. To accommodate both the temporal dynamics of SLR and their uncertainty, we develop an Average Annual Design Life Level (AADLL) metric and associated SLR allowances [1,2]. The AADLL is the flood level corresponding to a time-integrated annual expected probability of occurrence (AEP) under uncertainty over the lifetime of an asset; AADLL allowances are the adjustment from 2000 levels that maintain current risk. Given non-stationary and uncertain SLR, AADLL flood levels and allowances provide estimates of flood protection heights and offsets for different planning horizons and different levels of confidence in SLR projections in coastal areas. Allowances are a function primarily of local SLR and are nearly independent of AEP. Here we employ probabilistic SLR projections [3] to illustrate the calculation of AADLL flood levels and allowances with a representative set of long-duration tide gauges along U.S. coastlines. [1] Rootzen et al., 2014, Water Resources Research 49: 5964-5972. [2] Hunter, 2013, Ocean Engineering 71: 17-27. [3] Kopp et al., 2014, Earth's Future 2: 383-406.

  4. Sea Level Rise and Land Subsidence Contributions to the Signals from the Tide Gauges of China

    Science.gov (United States)

    Parker, Albert

    2016-06-01

    The tide gauges measure the local oscillations of the sea level vs. the tide gauge instrument. The tide gauge instrument is generally subjected to the general subsidence or uplift of the nearby inland, plus some additional subsidence for land compaction and other localised phenomena. The paper proposes a non-linear model of the relative sea level oscillations including a long term trend for the absolute sea level rise, another term for the subsidence of the instrument, and finally a sinusoidal approximation for the cyclic oscillations of periodicities up to decades. This non-linear model is applied to the tide gauges of China. The paper shows that the limited information available for China does not permit to infer any proper trend for the relative rates of rise, as the tide gauge records are all short or incomplete and the vertical movement of the tide gauge instruments is unassessed. The only tide gauge record of sufficient length that may be assembled for China is obtained by combining the North Point and Quarry Bay tide gauges in Hong Kong (NPQB). This NQPB composite tide gauge record is shown to have similarities with the tide gauge records of Sydney, equally in the West pacific, and San Diego, in the east Pacific, oscillating about the longer term trend mostly determined by the local subsidence. As it is very well known that China generally suffers of land subsidence, and the tide gauge installations may suffer of additional subsidence vs. the inland, it may be concluded from the analysis of the other worldwide tide gauges that the sea levels of China are very likely rising about the same amount of the subsidence of the tide gauges, with the sea level acceleration component still negligible.

  5. Estimating the Greenland ice sheet surface mass balance contribution to future sea level rise using the regional atmospheric climate model MAR

    NARCIS (Netherlands)

    Fettweis, X.; Franco, B.; Tedesco, M.; van Angelen, J.H.; Lenaerts, J.T.M.; van den Broeke, M.R.; Gallée, H.

    2013-01-01

    To estimate the sea level rise (SLR) originating from changes in surface mass balance (SMB) of the Greenland ice sheet (GrIS), we present 21st century climate projections obtained with the regional climate model MAR (Mod`ele Atmosph´erique R´egional), forced by output of three CMIP5 (Coupled Model I

  6. The impact of future sea-level rise on the European Shelf tides

    Science.gov (United States)

    Pickering, M. D.; Wells, N. C.; Horsburgh, K. J.; Green, J. A. M.

    2012-03-01

    This paper investigates the effect of future sea-level rise (SLR) on the tides of the northwest European Continental Shelf. The European shelf tide is dominated by semidiurnal constituents. This study therefore focuses primarily on the changes in the M2 tidal constituent and the spring and neap tidal conditions. The validated operational Dutch Continental Shelf Model is run for the present day sea-level as well as 2 and 10 m SLR scenarios. The M2 tidal amplitude responds to SLR in a spatially non-uniform manner, with substantial amplitude increases and decreases in both scenarios. The M2 tidal response is non-linear between 2 and 10 m with respect to SLR, particularly in the North Sea. Under the 2 m SLR scenario the M2 constituent is particularly responsive in the resonant areas of the Bristol Channel and Gulf of St. Malo (with large amplitude decreases) and in the southeastern German Bight and Dutch Wadden Sea (with large amplitude increases). Changes in the spring tide are generally greater still than those in the M2 or neap tides. With 2 m SLR the spring tidal range increases up to 35 cm at Cuxhaven and decreases up to -49 cm at St. Malo. Additionally the changes in the shallow water tides are larger than expected. With SLR the depth, wave speed and wave length (tidal resonance characteristics) are increased causing changes in near resonant areas. In expansive shallow areas SLR causes reduced energy dissipation by bottom friction. Combined these mechanisms result in the migration of the amphidromes and complex patterns of non-linear change in the tide with SLR. Despite the significant uncertainty associated with the rate of SLR over the next century, substantial alterations to tidal characteristics can be expected under a high end SLR scenario. Contrary to existing studies this paper highlights the importance of considering the modification of the tides by future SLR. These substantial future changes in the tides could have wide reaching implications; including

  7. Preliminary investigation of the effects of sea-level rise on groundwater levels in New Haven, Connecticut

    Science.gov (United States)

    Bjerklie, David M.; Mullaney, John R.; Stone, Janet R.; Skinner, Brian J.; Ramlow, Matthew A.

    2012-01-01

    Global sea level rose about 0.56 feet (ft) (170 millimeters (mm)) during the 20th century. Since the 1960s, sea level has risen at Bridgeport, Connecticut, about 0.38 ft (115 mm), at a rate of 0.008 ft (2.56 mm + or - 0.58 mm) per year. With regional subsidence, and with predicted global climate change, sea level is expected to continue to rise along the northeast coast of the United States through the 21st century. Increasing sea levels will cause groundwater levels in coastal areas to rise in order to adjust to the new conditions. Some regional climate models predict wetter climate in the northeastern United States under some scenarios. Scenarios for the resulting higher groundwater levels have the potential to inundate underground infrastructure in lowlying coastal cities. New Haven is a coastal city in Connecticut surrounded and bisected by tidally affected waters. Monitoring of water levels in wells in New Haven from August 2009 to July 2010 indicates the complex effects of urban influence on groundwater levels. The response of groundwater levels to recharge and season varied considerably from well to well. Groundwater temperatures varied seasonally, but were warmer than what was typical for Connecticut, and they seem to reflect the influence of the urban setting, including the effects of conduits for underground utilities. Specific conductance was elevated in many of the wells, indicating the influence of urban activities or seawater in Long Island Sound. A preliminary steady-state model of groundwater flow for part of New Haven was constructed using MODFLOW to simulate current groundwater levels (2009-2010) and future groundwater levels based on scenarios with a rise of 3 ft (0.91 meters (m)) in sea level, which is predicted for the end of the 21st century. An additional simulation was run assuming a 3-ft rise in sea level combined with a 12-percent increase in groundwater recharge. The model was constructed from existing hydrogeologic information for the

  8. Tidal Level Response to Sea-Level Rise in the Yangtze Estuary

    Institute of Scientific and Technical Information of China (English)

    GONG Zheng; ZHANG Chang-kuan; WAN Li-ming; ZUO Jun-cheng

    2012-01-01

    The rise of tidal level in tidal reaches induced by sea-level rise has a large impact on flood control and water supply for the regions around the estuary.This paper focuses on the variations of tidal level response along the tidal reaches in the Yangtze Estuary,as well as the impacts of upstream discharge on tidal level response,due to the sea-level rise of the East China Sea.Based on the Topex/Poseidon altimeter data obtained during the period 1993~2005,a stochastic dynamic analysis was performed and a forecast model was run to predict the sea-level rise of the East China Sea.Two-dimensional hydrodynamic numerical models downscaling from the East China Sea to estuarine areas were implemented to analyze the rise of tidal level along the tidal reaches.In response to the sea-level rise,the tidal wave characteristics change slightly in nearshore areas outside the estuaries,involving the tidal range and the duration of flood and ebb tide.The results show that the rise of tidal level in the tidal reaches due to the sea-level rise has upstream decreasing trends.The step between the stations of Zhangjiagang and Shiyiwei divides the tidal reaches into two parts,in which the tidal level response declines slightly.The rise of tidal level is 1~2.5 mm/a in the upper part,and 4~6 mm/a in the lower part.The stations of Jiangyin and Yanglin,as an example of the upper part and the lower part respectively,are extracted to analyze the impacts of upstream discharge on tidal level response to the sea-level rise.The relation between the rise of tidal level and the upstream discharge can be fitted well with a quadratic function in the upper part.However,the relation is too complicated to be fitted in the lower part because of the tide dominance.For comparison purposes,hourly tidal level observations at the stations of Xuliujing and Yanglin during the period 1993~2009 are adopted.In order to uniform the influence of upstream discharge on tidal level for a certain day each year

  9. An eclectic morphostratigraphic model for the sedimentary response to Holocene sea-level rise in northwest Europe

    Science.gov (United States)

    Allen, J. R. L.

    2003-09-01

    The improved empirical understanding of silt facies in Holocene coastal sequences provided by such as diatom, foraminifera, ostracode and testate amoebae analysis, combined with insights from quantitative stratigraphic and hydraulic simulations, has led to an inclusive, integrated model for the palaeogeomorphology, stratigraphy, lithofacies and biofacies of northwest European Holocene coastal lowlands in relation to sea-level behaviour. The model covers two general circumstances and is empirically supported by a range of field studies in the Holocene deposits of a number of British estuaries, particularly, the Severn. Where deposition was continuous over periods of centuries to millennia, and sea level fluctuated about a rising trend, the succession consists of repeated cycles of silt and peat lithofacies and biofacies in which series of transgressive overlaps (submergence sequences) alternate with series of regressive overlaps (emergence sequences) in association with the waxing and waning of tidal creek networks. Environmental and sea-level change are closely coupled, and equilibrium and secular pattern is of the kind represented ideally by a closed limit cycle. In the second circumstance, characteristic of unstable wetland shores and generally affecting smaller areas, coastal erosion ensures that episodes of deposition in the high intertidal zone last no more than a few centuries. The typical response is a series of regressive overlaps (emergence sequence) in erosively based high mudflat and salt-marsh silts that record, commonly as annual banding, exceptionally high deposition rates and a state of strong disequilibrium. Environmental change, including creek development, and sea-level movement are uncoupled. Only if deposition proceeds for a sufficiently long period, so that marshes mature, are equilibrium and close coupling regained.

  10. An increase in the rate of global mean sea level rise since 2010

    Science.gov (United States)

    Yi, Shuang; Sun, Wenke; Heki, Kosuke; Qian, An

    2015-05-01

    The global mean sea level (GMSL) was reported to have dropped 5 mm due to the 2010/2011 La Niña and have recovered in 1 year. With longer observations, it is shown that the GMSL went further up to a total amount of 11.6 mm by the end of 2012, excluding the 3.0 mm/yr background trend. A reconciled sea level budget, based on observations by Argo project, altimeter, and gravity satellites, reveals that the true GMSL rise has been masked by El Niño-Southern Oscillation-related fluctuations and its rate has increased since 2010. After extracting the influence of land water storage, it is shown that the GMSL has been rising at a rate of 4.4 ± 0.5 mm/yr for more than 3 years, due to an increase in the rate of both land ice loss and steric change.

  11. Adaptation to Sea Level Rise in Coastal Units of the National Park Service (Invited)

    Science.gov (United States)

    Beavers, R. L.

    2010-12-01

    83 National Park Service (NPS) units contain nearly 12,000 miles of coastal, estuarine and Great Lakes shoreline and their associated resources. Iconic natural features exist along active shorelines in NPS units, including, e.g., Cape Cod, Padre Island, Hawaii Volcanoes, and the Everglades. Iconic cultural resources managed by NPS include the Cape Hatteras Lighthouse, Fort Sumter, the Golden Gate, and heiaus and fish traps along the coast of Hawaii. Impacts anticipated from sea level rise include inundation and flooding of beaches and low lying marshes, shoreline erosion of coastal areas, and saltwater intrusion into the water table. These impacts and other coastal hazards will threaten park beaches, marshes, and other resources and values; alter the viability of coastal roads; and require the NPS to re-evaluate the financial, safety, and environmental implications of maintaining current projects and implementing future projects in ocean and coastal parks in the context of sea level rise. Coastal erosion will increase as sea levels rise. Barrier islands along the coast of Louisiana and North Carolina may have already passed the threshold for maintaining island integrity in any scenario of sea level rise (U.S. Climate Change Science Program Synthesis and Assessment Program Report 4.1). Consequently, sea level rise is expected to hasten the disappearance of historic coastal villages, coastal wetlands, forests, and beaches, and threaten coastal roads, homes, and businesses. While sea level is rising in most coastal parks, some parks are experiencing lower water levels due to isostatic rebound and lower lake levels. NPS funded a Coastal Vulnerability Project to evaluate the physical and geologic factors affecting 25 coastal parks. The USGS Open File Reports for each park are available at http://woodshole.er.usgs.gov/project-pages/. These reports were designed to inform park planning efforts. NPS conducted a Storm Vulnerability Project to provide ocean and coastal

  12. Impacts of Sea-Level Rise and Human Activity on a Tropical Continental Shelf, RN State, NE Brazil

    Science.gov (United States)

    Vital, H.; Barros Pereira, T. R.; Lira, H. F.; Tabosa, W. F.; Eichler, P.; Stattegger, K.; Sen Gupta, B. K.; Gomes, M. P.; Nogueira, M. L. D. S.; Pierri, G. C. S.

    2014-12-01

    The northeastern Brazilian, tropical coast-shelf system along the Atlantic Ocean is a sediment-starved zone, because of low relief, small drainage basins, and a semiarid climate. This work presents the major results of a study of environmental changes, particularly those related to Holocene sea-level rise, affecting the coast and shallow waters of Rio Grande do Norte (RN) State, NE Brazil. The methods included bottom-sediment characterization, bioindicator tracking, and integrated shallow-water geophysical investigation. This coastline is marked by active sea cliffs carved into tablelands alternating with reef- or dune-barrier sections, beach rocks and lagoons, whereas the shelf is a narrow, very shallow, and highly energetic system. Overall, the area is under the natural influence of tides (with a semidiurnal mesotidal regime) and the anthropogenic influence of salt exploration, oil industry, shrimp farms, tourism, and wind-farms. Sedimentation during the Holocene has been controlled mainly by sea-level variation, longshore currents, and the advance and westward propagation of active dunes along the coast. As in other areas around the world, growing numbers of permanent and seasonal residents choose to live at or near the ocean. Coastal erosion is a cause for concern along many Brazilian beaches, and several erosion hot spots are already recognized in RN State. Curves of Holocene relative sea-level variation were established for RN State, but the absence of long-term oceanographic observations in the last centuries or that of detailed altimetry maps hinders the evaluation of different risk scenarios at the local level. Nevertheless, impacts of the current sea-level rise and human activity can be observed along the RN coastal-shelf system. Particular aspects of the study, such as oil-spill monitoring, coastal-water sewage contamination, and coastal erosion, will be highlighted.

  13. Sea-level rise in Hawaii: Implications for future shoreline locations and Hawaii coastal management

    OpenAIRE

    Bohlander, Andrew; Conger, Chris; Eversole, Dolan

    2010-01-01

    Management of coastal development in Hawaii is based on the location of the certified shoreline, which is representative of the upper limit of marine inundation within the last several years. Though the certified shoreline location is significantly more variable than long-term erosion indicators, its migration will still follow the coastline's general trend. The long-term migration of Hawaii’s coasts will be significantly controlled by rising sea level. However, land use decisions adjacent to...

  14. Uncertainty Assessment for Numerical Modeling of Dune and Backshore Evolution Under Sea-Level Rise Scenarios

    Science.gov (United States)

    Dai, H.; Ye, M.; Niedoroda, A. W.; Kish, S.; Donoghue, J. F.; Saha, B.

    2010-12-01

    The beach dunes play an essential role in the evolution of barrier island shapes and coastlines. The dunes protect the beaches and beach ecology by absorbing energy from the storms and provide sediment to the beaches or backshores when erosion occurs. While a number of models have been developed to simulate the evolution of dunes and backshores, few of the models have comprehensively addressed dune growth, dune erosion, and backshore changes. Based on the assumption that dune shapes are stationary, we develop a new model that can estimate the dune and backshore evolution (including both growth and erosion) under the influence of storms with different sea-level rise scenarios. The modeling results are inherently uncertain due to unknown storm variability and sea-level rise scenarios. The storm uncertainty, characterized as parametric uncertainty, and its propagation to the modeling results are assessed using the Monte Carlo (MC) method. A total of 1500 realizations of storm magnitude, frequency, and track through a barrier island are generated and used for the MC simulation. The numerical modeling and uncertainty analysis is conducted for a synthetic barrier island with physical features and hurrucane exposure similar to Santa Rosa Island, in northwest Florida. Uncertainty in the simulated beach dune heights, dune width, and the backshore positions is assessed for five sea-level rise scenarios. The parametric uncertainty is different for different sea-level rise scenarios. For a given scenario, uncertainty of dune height is the largest and it is mainly caused by uncertainty in storm magnitude. This uncertainty analysis provides guidelines for coastal management and protection of coastal ecology.

  15. Assessing tidal marsh vulnerability to sea-level rise in the Skagit Delta

    Science.gov (United States)

    Hood, W. Gregory; Grossman, Eric; Curt Veldhuisen,

    2016-01-01

    Historical aerial photographs, from 1937 to the present, show Skagit Delta tidal marshes prograding into Skagit Bay for most of the record, but the progradation rates have been steadily declining and the marshes have begun to erode in recent decades despite the large suspended sediment load provided by the Skagit River. In an area of the delta isolated from direct riverine sediment supply by anthropogenic blockage of historical distributaries, 0.5-m tall marsh cliffs along with concave marsh profiles indicate wave erosion is contributing to marsh retreat. This is further supported by a “natural experiment” provided by rocky outcrops that shelter high marsh in their lee, while being bounded by 0.5-m lower eroded marsh to windward and on either side. Coastal wetlands with high sediment supply are thought to be resilient to sea level rise, but the case of the Skagit Delta shows this is not necessarily true. A combination of sea level rise and wave-generated erosion may overwhelm sediment supply. Additionally, anthropogenic obstruction of historical distributaries and levee construction along the remaining distributaries likely increase the jet momentum of river discharge, forcing much suspended sediment to bypass the tidal marshes and be exported from Skagit Bay. Adaptive response to the threat of climate change related sea level rise and increased wave frequency or intensity should consider the efficacy of restoring historical distributaries and managed retreat of constrictive river levees to maximize sediment delivery to delta marshes.

  16. Assessing the impact of sea-level rise on a vulnerable coastal community in Accra, Ghana

    Directory of Open Access Journals (Sweden)

    Kwasi Appeaning Addo

    2013-03-01

    Full Text Available Climate change and its associated sea-level rise are expected to significantly affect vulnerable coastal communities. Although the extent of the impact will be localised, its assessment will adopt a monitoring approach that applies globally. The topography of the beach, the type of geological material and the level of human intervention will determine the extent of the area to be flooded and the rate at which the shoreline will move inland. Gleefe, a coastal community in Ghana, has experienced frequent flooding in recent times due to the increasing occurrence of storm surge and sea-level rise. This study used available geospatial data and field measurements to determine how the beach topography has contributed to the incidence of flooding at Gleefe. The topography is generally low-lying. Sections of the beach have elevations of around 1 m, which allows seawater to move inland during very high tide. Accelerated sea-level rise as predicted by the Intergovernmental Panel on Climate Change (IPCC will destroy homes of the inhabitants and inundate the Densu wetlands behind the beach. Destruction of infrastructure will render the inhabitants homeless, whilst flooding of the wetlands will destroy the habitats of migratory birds and some endangered wildlife species such as marine turtle. Effective adaptation measures should be adopted to protect this very important coastal environment, the ecology of the wetlands and the livelihoods of the community dwellers.

  17. Estimation of Peak Water Level in Pearl River Estuary under the Background of Sea Level Rise

    Institute of Scientific and Technical Information of China (English)

    KONG; Lan; CHEN; Xiao-hong; ZHUANG; Cheng-bin; CHEN; Dong-wei

    2012-01-01

    [Objective] The study aimed to predict the peak water level in Pearl River Estuary under the background of sea level rise. [Method] The changing trends of peak water level at Denglongshan station and Hengmen station were analyzed firstly on the basis of regression models, and then sea level rise in Pearl River Estuary in 2050 was predicted to estimate the 1-in-50-year peak water level in the same year. [Result] Regression analyses showed that the increasing rate of peak water level over past years was 6.3 mm/a at Denglongshan station and 5.8 mm/a at Hengmen station. In addition, if sea level will rise by 20, 30 and 60 cm respectively in 2050, it was predicted that the 1-in-50-year peak water level will reach 3.04, 3.14 and 3.44 m at Denglongshan station, and 3.19, 3.29 and 3.59 m at Hengmen station separately. [Conclusion] The estimation of peak water level in Pearl River Estuary could provide theoretical references for water resources planning.

  18. Future climate change driven sea-level rise: secondary consequences from human displacement for island biodiversity.

    Science.gov (United States)

    Wetzel, Florian T; Kissling, W Daniel; Beissmann, Helmut; Penn, Dustin J

    2012-09-01

    Sea-level rise (SLR) due to global warming will result in the loss of many coastal areas. The direct or primary effects due to inundation and erosion from SLR are currently being assessed; however, the indirect or secondary ecological effects, such as changes caused by the displacement of human populations, have not been previously evaluated. We examined the potential ecological consequences of future SLR on >1,200 islands in the Southeast Asian and the Pacific region. Using three SLR scenarios (1, 3, and 6 m elevation, where 1 m approximates most predictions by the end of this century), we assessed the consequences of primary and secondary SLR effects from human displacement on habitat availability and distributions of selected mammal species. We estimate that between 3-32% of the coastal zone of these islands could be lost from primary effects, and consequently 8-52 million people would become SLR refugees. Assuming that inundated urban and intensive agricultural areas will be relocated with an equal area of habitat loss in the hinterland, we project that secondary SLR effects can lead to an equal or even higher percent range loss than primary effects for at least 10-18% of the sample mammals in a moderate range loss scenario and for 22-46% in a maximum range loss scenario. In addition, we found some species to be more vulnerable to secondary than primary effects. Finally, we found high spatial variation in vulnerability: species on islands in Oceania are more vulnerable to primary SLR effects, whereas species on islands in Indo-Malaysia, with potentially 7-48 million SLR refugees, are more vulnerable to secondary effects. Our findings show that primary and secondary SLR effects can have enormous consequences for human inhabitants and island biodiversity, and that both need to be incorporated into ecological risk assessment, conservation, and regional planning.

  19. Coastal retreat and improved water quality mitigate losses of seagrass from sea level rise.

    Science.gov (United States)

    Saunders, Megan I; Leon, Javier; Phinn, Stuart R; Callaghan, David P; O'Brien, Katherine R; Roelfsema, Chris M; Lovelock, Catherine E; Lyons, Mitchell B; Mumby, Peter J

    2013-08-01

    The distribution and abundance of seagrass ecosystems could change significantly over the coming century due to sea level rise (SLR). Coastal managers require mechanistic understanding of the processes affecting seagrass response to SLR to maximize their conservation and associated provision of ecosystem services. In Moreton Bay, Queensland, Australia, vast seagrass meadows supporting populations of sea turtles and dugongs are juxtaposed with the multiple stressors associated with a large and rapidly expanding human population. Here, the interactive effects of predicted SLR, changes in water clarity, and land use on future distributions of seagrass in Moreton Bay were quantified. A habitat distribution model of present day seagrass in relation to benthic irradiance and wave height was developed which correctly classified habitats in 83% of cases. Spatial predictions of seagrass and presence derived from the model and bathymetric data were used to initiate a SLR inundation model. Bathymetry was iteratively modified based on SLR and sedimentary accretion in seagrass to simulate potential seagrass habitat at 10 year time steps until 2100. The area of seagrass habitat was predicted to decline by 17% by 2100 under a scenario of SLR of 1.1 m. A scenario including the removal of impervious surfaces, such as roads and houses, from newly inundated regions, demonstrated that managed retreat of the shoreline could potentially reduce the overall decline in seagrass habitat to just 5%. The predicted reduction in area of seagrass habitat could be offset by an improvement in water clarity of 30%. Greater improvements in water clarity would be necessary for larger magnitudes of SLR. Management to improve water quality will provide present and future benefits to seagrasses under climate change and should be a priority for managers seeking to compensate for the effects of global change on these valuable habitats.

  20. The regional patterns of the global dynamic and steric sea level variation in twenty-first century projections

    Science.gov (United States)

    Li, Juan; Tan, Wei; Chen, Meixiang; Zuo, Juncheng; Yang, Yiqiu

    2016-11-01

    This study discusses the regional sea-level variation associated with possible influence factors using Community Climate System Model version 4 (CCSM4) in the 21st century. Under the moderate emission scenario of the IPCC's Representative Concentration Pathway 4.5 (RCP4.5), the predicted sea-level variation is spatially non-uniform. The most remarkable variation of the dynamic sea level (DSL) is observed in three typical regions (North Pacific, Southern Ocean, and North Atlantic). In the North Pacific, the DSL rises significantly around Kuroshio and Kuroshio extension, while declines in the subpolar gyre. The DSL variation shows an out-of-phase relationship with the Sverdrup transport, indicating that the wind stress induced Sverdrup transport is generally responsible for the DSL variation. In the Southern Ocean, the DSL variation performs a belt-like pattern, it rises around 40°S zonal band, while declines in its southern side, this is related to the enhancement of westerly wind stress. In the North Atlantic, the DSL variation acts as a dipole mode, it rises in the north of the North Atlantic Current (NAC), and declines in the south. This dipole pattern can be also interpreted by the Sverdrup transport except in the northeast of the NAC, where the DSL rise is more affected by the weakening of the Atlantic Meridional Overturning Circulation (AMOC). Compared with the DSL, the steric sea level (SSL) rises in most of the ocean, and the thermosteric sea level (TSL) is the major contributor. Only in the Southern Ocean, the SSL descends. The decreased SSL is affected by the halosteric sea level (HSL), which is mainly attributed to the weakly increased salinity from 300 m to the bottom. To some extent, the HSL also contributes to the SSL rise in the Pacific, this is caused by the seawater freshening and warming in the upper 1500 m. However, in the Atlantic, the HSL declines, thus partly offsets the rising effect of the TSL. These opposite variations are associated with

  1. Impacts of Climate Change on Estuarine Habitats in the UK: Critical Evaluation of the Saltmarshes and Sea-Level Rise Model (SLAMM)

    Science.gov (United States)

    Pylarinou, A.; French, J.; Burningham, H.

    2013-12-01

    Estuarine wetland environments are at risk of significant transformation and loss due to sea-level rise and there is an increasing need to model such impacts. In a UK context, the relatively small size and morphological complexity of many estuaries necessitates a high spatial resolution but models must also be capable of efficient application over time scales of decades to centuries that correspond to widely used IPCC climate change scenarios. Little previous work of this kind has been carried out to date in the UK. An exception is the EU-funded BRANCH project, which simulated the drowning of intertidal topography, due to sea-level rise, and potential mudflat and saltmarsh responses to a change in inundation regime. However, this approach neglects the interplay of sea-level rise and sedimentation. Accordingly, this study investigates the potential of a more dynamic spatial landscape model to represent meso-scale impacts of sea-level rise on UK estuary environments. It takes as a starting point the Sea Level Affecting Marshes Model (SLAMM), which has been widely used in the USA. This is built around the US National Wetlands Inventory classification and adapting it to suit the tidal sedimentary environments and habitats typical of the UK requires changes to the source code. This paper presents results obtained from the application of an appropriately modified SLAMM code to contrasting estuarine environments in eastern England. The aim is to evaluate the ability of SLAMM to produce plausible projections of intertidal habitat change. The estuaries studied are covered by high-resolution altimetry data, and an extensive literature on their physical process regime allows the parameterisation of the various sub-models in SLAMM. A Matlab-based shell is used to perform an initial sensitivity analysis to better understand the nature of the modelled sea-level rise effects. This shell also provides a framework for Monte Carlo simulations forced by a set of UKCP09 sea-level rise

  2. Possible impact of rising sea levels on vector-borne infectious diseases

    Directory of Open Access Journals (Sweden)

    Surendran Sinnathamby N

    2011-01-01

    Full Text Available Abstract Background Vector-borne infectious diseases are a significant cause of human and animal mortality and morbidity. Modeling studies predict that changes in climate that accompany global warming will alter the transmission risk of many vector-borne infectious diseases in different parts of the world. Global warming will also raise sea levels, which will lead to an increase in saline and brackish water bodies in coastal areas. The potential impact of rising sea levels, as opposed to climate change, on the prevalence of vector-borne infectious diseases has hitherto been unrecognised. Presentation of the hypothesis Mosquito species possessing salinity-tolerant larvae and pupae, and capable of transmitting arboviruses and parasites are found in many parts of the world. An expansion of brackish and saline water bodies in coastal areas, associated with rising sea levels, can increase densities of salinity-tolerant vector mosquitoes and lead to the adaptation of freshwater vectors to breed in brackish and saline waters. The breeding of non-mosquito vectors may also be influenced by salinity changes in coastal habitats. Higher vector densities can increase transmission of vector-borne infectious diseases in coastal localities, which can then spread to other areas. Testing the hypothesis The demonstration of increases in vector populations and disease prevalence that is related to an expansion of brackish/saline water bodies in coastal areas will provide the necessary supportive evidence. However the implementation of specific vector and disease control measures to counter the threat will confound the expected findings. Implications of the hypothesis Rising sea levels can act synergistically with climate change and then interact in a complex manner with other environmental and socio-economic factors to generate a greater potential for the transmission of vector-borne infectious diseases. The resulting health impacts are likely to be particularly

  3. Coastal marsh response to rising sea levels in the Grand Bay, MS estuary

    Science.gov (United States)

    Alizad, K.; Hagen, S. C.; Morris, J. T.; Medeiros, S. C.; Bilskie, M. V.; Passeri, D. L.

    2015-12-01

    The Grand Bay estuary, situated along the border of Alabama and Mississippi, is a marine dominant estuary. Juncus roemerianus and Spartina alterniflora cover approximately 49% of the estuary (Eleuterius and Criss, 1991); However, this marsh system is prone to erosion more than other marsh systems in the state (Mississippi Department of Marine Resources 1999). Water level and wind-driven waves are critical factors that cause erosion in the Grand Bay estuary. Sediment transport induced by wave forces from the Gulf of Mexico and sea level rise force salt marshes to migrate landward (Schmid 2000). Understanding projected variations in vegetation can aid in productive restoration planning and coastal management decisions. An integrated hydro-marsh model was developed to incorporate the dynamic interaction between tidal hydrodynamics and salt marsh system. This model projects salt marsh productivity by coupling a two-dimensional, depth-integrated ADvanced CIRCulation (ADCIRC) finite element model and a parametric marsh model (Morris et al., 2002). The model calculates marsh productivity as a function of mean low water (MLW), mean high water (MHW), and the elevation of the marsh platform. The coupling exchange process is divided into several time intervals that capture the rate of sea level rise, and update the elevation and bottom friction from the computed marsh productivity. Accurate description of salt marsh platform is necessary for calculating accurate biomass results (Hagen et al. 2013). Lidar-derived digital elevation models (DEM) over-estimate marsh platform elevations, but can be corrected with Real Time Kinematic (RTK) survey data (Medeiros et al., 2015). Using RTK data, the salt marsh platform was updated and included in a high resolution hydrodynamic model. Four projections of sea level rise (Parris et al., 2012) were used to project salt marsh productivity for the year 2100 for the Grand Bay, MS estuary. The results showed a higher productivity under low sea

  4. Surface elevation change and susceptibility of coastal wetlands to sea level rise in Liaohe Delta, China

    Science.gov (United States)

    Wang, Guo-dong; Wang, Ming; Lu, Xian-guo; Jiang, Ming

    2016-10-01

    The Liaohe Delta in China is an ecologically and commercially important wetland system under threat from sea level rise and marsh subsidence. Sediments deposited in coastal marshes could offer wetlands a potentially important means for adjusting surface elevation with rising sea level, yet coastal wetland stability in Liaohe Delta is not well understood due to limited data from long-term experiments. In this study, wetland surface elevation and vertical accretion were measured from 2011 to 2015 using a surface elevation table (SET) and feldspar marker horizons in two Phragmites and two Suaeda marshes receiving Liaohe River water. The analysis shows that the Phragmites marshes exhibited higher rates of marsh accretion and elevation change than the Suaeda marshes. The two Phragmites marsh sites had average surface elevation change rates at 8.8 and 9.3 mm yr-1, vertical accretion at 17.4 and 17.6 mm yr-1, and shallow subsidence at 8.6 and 8.3 mm yr-1. The average rates of elevation change, vertical accretion, and shallow subsidence at two Suaeda marsh sites were 5.8 and 6.3 mm yr-1, 13.6 and 14.8 mm yr-1, and 7.8 and 8.5 mm yr-1, respectively. The trends suggest that coastal marshes in Liaohe Delta are experiencing changes in average soil elevation that range from a net increase of 0.3 mm y-1 to 6.9 mm y-1 relative to averaged sea level rise in Bohai Sea reported by the 2016 State Oceanic Administration People's Republic of China projection (2.4-5.5 mm y-1), which indicated that the four wetland sites would adjust to the sea level rise and even continue to gain elevation, especially for the Phragmites sites. Nevertheless, the vulnerability of coastal wetlands in Liaohe Delta need further assessment considering the accelerated sea level rise, the high rate of subsidence, and the declining sediment delivery owing to anthropogenic activities such as dam constructions in the river basin.

  5. The dynamic effects of sea level rise on low-gradient coastal landscapes: A review

    Science.gov (United States)

    Passeri, Davina L.; Hagen, Scott C.; Medeiros, Stephen C.; Bilskie, Matthew V.; Alizad, Karim; Wang, Dingbao

    2015-06-01

    Coastal responses to sea level rise (SLR) include inundation of wetlands, increased shoreline erosion, and increased flooding during storm events. Hydrodynamic parameters such as tidal ranges, tidal prisms, tidal asymmetries, increased flooding depths and inundation extents during storm events respond nonadditively to SLR. Coastal morphology continually adapts toward equilibrium as sea levels rise, inducing changes in the landscape. Marshes may struggle to keep pace with SLR and rely on sediment accumulation and the availability of suitable uplands for migration. Whether hydrodynamic, morphologic, or ecologic, the impacts of SLR are interrelated. To plan for changes under future sea levels, coastal managers need information and data regarding the potential effects of SLR to make informed decisions for managing human and natural communities. This review examines previous studies that have accounted for the dynamic, nonlinear responses of hydrodynamics, coastal morphology, and marsh ecology to SLR by implementing more complex approaches rather than the simplistic "bathtub" approach. These studies provide an improved understanding of the dynamic effects of SLR on coastal environments and contribute to an overall paradigm shift in how coastal scientists and engineers approach modeling the effects of SLR, transitioning away from implementing the "bathtub" approach. However, it is recommended that future studies implement a synergetic approach that integrates the dynamic interactions between physical and ecological environments to better predict the impacts of SLR on coastal systems.

  6. Predictions of extreme precipitation and sea-level rise under climate change.

    Science.gov (United States)

    Senior, C A; Jones, R G; Lowe, J A; Durman, C F; Hudson, D

    2002-07-15

    Two aspects of global climate change are particularly relevant to river and coastal flooding: changes in extreme precipitation and changes in sea level. In this paper we summarize the relevant findings of the IPCC Third Assessment Report and illustrate some of the common results found by the current generation of coupled atmosphere-ocean general circulation models (AOGCMs), using the Hadley Centre models. Projections of changes in extreme precipitation, sea-level rise and storm surges affecting the UK will be shown from the Hadley Centre regional models and the Proudman Oceanographic Laboratory storm-surge model. A common finding from AOGCMs is that in a warmer climate the intensity of precipitation will increase due to a more intense hydrological cycle. This leads to reduced return periods (i.e. more frequent occurrences) of extreme precipitation in many locations. The Hadley Centre regional model simulates reduced return periods of extreme precipitation in a number of flood-sensitive areas of the UK. In addition, simulated changes in storminess and a rise in average sea level around the UK lead to reduced return periods of extreme high coastal water events. The confidence in all these results is limited by poor spatial resolution in global coupled models and by uncertainties in the physical processes in both global and regional models, and is specific to the climate change scenario used.

  7. Towards regional projections of twenty-first century sea-level change based on IPCC SRES scenarios

    NARCIS (Netherlands)

    Slangen, A.B.A.; Katsman, C.A.; Van de Wal, R.S.W.; Vermeersen, L.L.A.; Riva, R,E.M.

    2012-01-01

    Sea-level change is often considered to be globally uniform in sea-level projections. However, local relative sea-level (RSL) change can deviate substantially from the global mean. Here, we present maps of twenty-first century local RSL change estimates based on an ensemble of coupled climate model

  8. Bayesian methods for model uncertainty analysis with application to future sea level rise

    Energy Technology Data Exchange (ETDEWEB)

    Patwardhan, A.; Small, M.J. (Carnegie Mellon Univ., Pittsburgh, PA (United States))

    1992-12-01

    This paper addresses the use of data for identifying and characterizing uncertainties in model parameters and predictions. The Bayesian Monte Carlo method is formally presented and elaborated, and applied to the analysis of the uncertainty in a predictive model for global mean sea level change. The method uses observations of output variables, made with an assumed error structure, to determine a posterior distribution of model outputs. This is used to derive a posterior distribution for the model parameters. Results demonstrate the resolution of the uncertainty that is obtained as a result of the Bayesian analysis and also indicate the key contributors to the uncertainty in the sea level rise model. While the technique is illustrated with a simple, preliminary model, the analysis provides an iterative framework for model refinement. The methodology developed in this paper provides a mechanism for the incorporation of ongoing data collection and research in decision-making for problems involving uncertain environmental change.

  9. Effects of sea-level rise on barrier island groundwater system dynamics: ecohydrological implications

    Science.gov (United States)

    Masterson, John P.; Fienen, Michael N.; Thieler, E. Robert; Gesch, Dean B.; Gutierrez, Benjamin T.; Plant, Nathaniel G.

    2014-01-01

    We used a numerical model to investigate how a barrier island groundwater system responds to increases of up to 60 cm in sea level. We found that a sea-level rise of 20 cm leads to substantial changes in the depth of the water table and the extent and depth of saltwater intrusion, which are key determinants in the establishment, distribution and succession of vegetation assemblages and habitat suitability in barrier islands ecosystems. In our simulations, increases in water-table height in areas with a shallow depth to water (or thin vadose zone) resulted in extensive groundwater inundation of land surface and a thinning of the underlying freshwater lens. We demonstrated the interdependence of the groundwater response to island morphology by evaluating changes at three sites. This interdependence can have a profound effect on ecosystem composition in these fragile coastal landscapes under long-term changing climatic conditions.

  10. Rising sea levels will reduce extreme temperature variations in tide-dominated reef habitats

    Science.gov (United States)

    Lowe, Ryan Joseph; Pivan, Xavier; Falter, James; Symonds, Graham; Gruber, Renee

    2016-01-01

    Temperatures within shallow reefs often differ substantially from those in the surrounding ocean; therefore, predicting future patterns of thermal stresses and bleaching at the scale of reefs depends on accurately predicting reef heat budgets. We present a new framework for quantifying how tidal and solar heating cycles interact with reef morphology to control diurnal temperature extremes within shallow, tidally forced reefs. Using data from northwestern Australia, we construct a heat budget model to investigate how frequency differences between the dominant lunar semidiurnal tide and diurnal solar cycle drive ~15-day modulations in diurnal temperature extremes. The model is extended to show how reefs with tidal amplitudes comparable to their depth, relative to mean sea level, tend to experience the largest temperature extremes globally. As a consequence, we reveal how even a modest sea level rise can substantially reduce temperature extremes within tide-dominated reefs, thereby partially offsetting the local effects of future ocean warming. PMID:27540589

  11. Vulnerability assessment of southern coastal areas of Iran to sea level rise: evaluation of climate change impact

    Directory of Open Access Journals (Sweden)

    Hamid Goharnejad

    2013-08-01

    Full Text Available Recent investigations have demonstrated global sea level rise as being due to climate change impact. Probable changes in sea level rise need to be evaluated so that appropriate adaptive strategies can be implemented. This study evaluates the impact of climate change on sea level rise along the Iranian south coast. Climatic data simulated by a GCM (General Circulation Model named CGCM3 under two-climate change scenarios A1b and A2 are used to investigate the impact of climate change. Among the different variables simulated by this model, those of maximum correlation with sea level changes in the study region and least redundancy among themselves are selected for predicting sea level rise by using stepwise regression. Two Discrete Wavelet artificial Neural Network (DWNN models and a Discrete Wavelet Adaptive Neuro-Fuzzy Inference system (DWANFIS are developed to explore the relationship between selected climatic variables and sea level changes. In these models, wavelets are used to disaggregate the time series of input and output data into different components. ANFIS/ANN are then used to relate the disaggregated components of predictors and predictand (sea level to each other. The results show a significant rise in sea level in the study region under climate change impact, which should be incorporated into coastal area management.

  12. Coastal sea level changes, observed and projected during the 20th and 21st century

    NARCIS (Netherlands)

    Carson, M.; Köhl, A.; Stammer, D.; A. Slangen, A. B.; Katsman, C. A.; W. van de Wal, R. S.; Church, J.; White, N.

    2015-01-01

    Timeseries of observed and projected sea level changes for the 20th and 21st century are analyzed at various coastal locations around the world that are vulnerable to climate change. Observed time series are from tide gauges and altimetry, as well as from reconstructions over the last 50 years. CMIP

  13. Predicting sea-level rise vulnerability of terrestrial habitat and wildlife of the Northwestern Hawaiian Islands

    Science.gov (United States)

    Reynolds, Michelle H.; Berkowitz, Paul; Courtot, Karen N.; Krause, Crystal M.; Reynolds, Michelle H.; Berkowitz, Paul; Courtot, Karen N.; Krause, Crystal M.

    2012-01-01

    If current climate change trends continue, rising sea levels may inundate low-lying islands across the globe, placing island biodiversity at risk. Recent models predict a rise of approximately one meter (1 m) in global sea level by 2100, with larger increases possible in areas of the Pacific Ocean. Pacific Islands are unique ecosystems home to many endangered endemic plant and animal species. The Northwestern Hawaiian Islands (NWHI), which extend 1,930 kilometers (km) beyond the main Hawaiian Islands, are a World Heritage Site and part of the Papahanaumokuakea Marine National Monument. These NWHI support the largest tropical seabird rookery in the world, providing breeding habitat for 21 species of seabirds, 4 endemic land bird species and essential foraging, breeding, or haul-out habitat for other resident and migratory wildlife. In recent years, concern has grown about the increasing vulnerability of the NWHI and their wildlife populations to changing climatic patterns, particularly the uncertainty associated with potential impacts from global sea-level rise (SLR) and storms. In response to the need by managers to adapt future resource protection strategies to climate change variability and dynamic island ecosystems, we have synthesized and down scaled analyses for this important region. This report describes a 2-year study of a remote northwestern Pacific atoll ecosystem and identifies wildlife and habitat vulnerable to rising sea levels and changing climate conditions. A lack of high-resolution topographic data for low-lying islands of the NWHI had previously precluded an extensive quantitative model of the potential impacts of SLR on wildlife habitat. The first chapter (chapter 1) describes the vegetation and topography of 20 islands of Papahanaumokuakea Marine National Monument, the distribution and status of wildlife populations, and the predicted impacts for a range of SLR scenarios. Furthermore, this chapter explores the potential effects of SLR on

  14. A prediction of sea level rising amplitude in 2030 and defen-sive countermeasures in the Zhujiang delta

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    By analysing comprehensively the factors such as theoretical sealevel, abnormal fluctuation of sea level, rising amplitude of floodtide water level and land deformation, a rising amplitude of 22-33 cm of relative sea level by the year of 2030 is forecasted in the Zhujiang Delta. From the forecasted amplitude of 30 cm, using hydraulic and hydrometric models the scope influenced by sea level rise is delimited and the reappearing periods of floodtide water level, protecting ability of embankments, design parameters of water conservancy project, drain waterlogging, saline intrusion, resource of mud beach and comprehensive prevention measures are discussed.

  15. Modeling complex flow dynamics of fluvial floods exacerbated by sea level rise in the Ganges-Brahmaputra-Meghna Delta

    Science.gov (United States)

    Ikeuchi, Hiroaki; Hirabayashi, Yukiko; Yamazaki, Dai; Kiguchi, Masashi; Koirala, Sujan; Nagano, Takanori; Kotera, Akihiko; Kanae, Shinjiro

    2015-12-01

    Global warming is likely to exacerbate future fluvial floods in the world’s mega-delta regions due to both changing climate and rising sea levels. However, the effects of sea level rise (SLR) on fluvial floods in such regions have not been taken into account in current global assessments of future flood risk, due to the difficulties in modeling channel bifurcation and the backwater effect. We used a state-of-the-art global river routing model to demonstrate how these complexities contribute to future flood hazard associated with changing climate and SLR in the world’s largest mega-delta region, the Ganges-Brahmaputra-Meghna Delta. The model demonstrated that flood water in the main channels flows into tributaries through bifurcation channels, which resulted in an increase in inundation depth in deltaic regions. We found that there were large areas that experienced an increase in inundation depth and period not directly from the SLR itself but from the backwater effect of SLR, and the effect propagated upstream to locations far from the river mouth. Projections under future climate scenarios as well as SLR indicated that exposure to fluvial floods will increase in the last part of the 21st century, and both SLR and channel bifurcation make meaningful contributions.

  16. Coastal Hazards Maps: Actionable Information for Communities Facing Sea-Level Rise (Invited)

    Science.gov (United States)

    Gibeaut, J. C.; Barraza, E.

    2010-12-01

    Barrier islands along the U.S. Gulf coast remain under increasing pressure from development. This development and redevelopment is occurring despite recent hurricanes, ongoing erosion, and sea-level rise. To lessen the impacts of these hazards, local governments need information in a form that is useful for informing the public, making policy, and enforcing development rules. We recently completed the Galveston Island Geohazards Map for the city of Galveston, Texas and are currently developing maps for the Mustang and South Padre Island communities. The maps show areas that vary in their susceptibility to, and function for, mitigating the effects of geological processes, including sea-level rise, land subsidence, erosion and storm-surge flooding and washover. The current wetlands, beaches and dunes are mapped as having the highest geohazard potential both in terms of their exposure to hazardous conditions and their mitigating effects of those hazards for the rest of the island. These existing “critical environments” are generally protected under existing regulations. Importantly, however, the mapping recognizes that sea-level rise and shoreline retreat are changing the island; therefore, 60-year model projections of the effects of these changes are incorporated into the map. The areas that we project will become wetlands, beaches and dunes in the next 60 years are not protected. These areas are the most difficult to deal with from a policy point of view, yet we must address what happens there if real progress is to be made in how we live with sea-level rise. The geohazards maps draw on decades of geological knowledge of how barrier islands behave and put it in a form that is intuitive to the public and directly useful to planners. Some of the “messages” in the map include: leave salt marshes alone and give them room to migrate inland as sea level rises; set back and move development away from the shoreline to provide space for beaches and protective dunes

  17. Sea-level rise induced amplification of coastal protection design heights

    Science.gov (United States)

    Arns, Arne; Dangendorf, Sönke; Jensen, Jürgen; Talke, Stefan; Bender, Jens; Pattiaratchi, Charitha

    2017-01-01

    Coastal protection design heights typically consider the superimposed effects of tides, surges, waves, and relative sea-level rise (SLR), neglecting non-linear feedbacks between these forcing factors. Here, we use hydrodynamic modelling and multivariate statistics to show that shallow coastal areas are extremely sensitive to changing non-linear interactions between individual components caused by SLR. As sea-level increases, the depth-limitation of waves relaxes, resulting in waves with larger periods, greater amplitudes, and higher run-up; moreover, depth and frictional changes affect tide, surge, and wave characteristics, altering the relative importance of other risk factors. Consequently, sea-level driven changes in wave characteristics, and to a lesser extent, tides, amplify the resulting design heights by an average of 48–56%, relative to design changes caused by SLR alone. Since many of the world’s most vulnerable coastlines are impacted by depth-limited waves, our results suggest that the overall influence of SLR may be greatly underestimated in many regions.

  18. Contribution of Antarctica to past and future sea-level rise.

    Science.gov (United States)

    DeConto, Robert M; Pollard, David

    2016-03-31

    Polar temperatures over the last several million years have, at times, been slightly warmer than today, yet global mean sea level has been 6-9 metres higher as recently as the Last Interglacial (130,000 to 115,000 years ago) and possibly higher during the Pliocene epoch (about three million years ago). In both cases the Antarctic ice sheet has been implicated as the primary contributor, hinting at its future vulnerability. Here we use a model coupling ice sheet and climate dynamics-including previously underappreciated processes linking atmospheric warming with hydrofracturing of buttressing ice shelves and structural collapse of marine-terminating ice cliffs-that is calibrated against Pliocene and Last Interglacial sea-level estimates and applied to future greenhouse gas emission scenarios. Antarctica has the potential to contribute more than a metre of sea-level rise by 2100 and more than 15 metres by 2500, if emissions continue unabated. In this case atmospheric warming will soon become the dominant driver of ice loss, but prolonged ocean warming will delay its recovery for thousands of years.

  19. Assessment of Hammocks (Petenes) Resilience to Sea Level Rise Due to Climate Change in Mexico

    Science.gov (United States)

    Posada Vanegas, Gregorio; de Jong, Bernardus H. J.

    2016-01-01

    There is a pressing need to assess resilience of coastal ecosystems against sea level rise. To develop appropriate response strategies against future climate disturbances, it is important to estimate the magnitude of disturbances that these ecosystems can absorb and to better understand their underlying processes. Hammocks (petenes) coastal ecosystems are highly vulnerable to sea level rise linked to climate change; their vulnerability is mainly due to its close relation with the sea through underground drainage in predominantly karstic soils. Hammocks are biologically important because of their high diversity and restricted distribution. This study proposes a strategy to assess resilience of this coastal ecosystem when high-precision data are scarce. Approaches and methods used to derive ecological resilience maps of hammocks are described and assessed. Resilience models were built by incorporating and weighting appropriate indicators of persistence to assess hammocks resilience against flooding due to climate change at “Los Petenes Biosphere Reserve”, in the Yucatán Peninsula, Mexico. According to the analysis, 25% of the study area is highly resilient (hot spots), whereas 51% has low resilience (cold spots). The most significant hot spot clusters of resilience were located in areas distant to the coastal zone, with indirect tidal influence, and consisted mostly of hammocks surrounded by basin mangrove and floodplain forest. This study revealed that multi-criteria analysis and the use of GIS for qualitative, semi-quantitative and statistical spatial analyses constitute a powerful tool to develop ecological resilience maps of coastal ecosystems that are highly vulnerable to sea level rise, even when high-precision data are not available. This method can be applied in other sites to help develop resilience analyses and decision-making processes for management and conservation of coastal areas worldwide. PMID:27611802

  20. Assessment of Hammocks (Petenes) Resilience to Sea Level Rise Due to Climate Change in Mexico.

    Science.gov (United States)

    Hernández-Montilla, Mariana C; Martínez-Morales, Miguel Angel; Posada Vanegas, Gregorio; de Jong, Bernardus H J

    2016-01-01

    There is a pressing need to assess resilience of coastal ecosystems against sea level rise. To develop appropriate response strategies against future climate disturbances, it is important to estimate the magnitude of disturbances that these ecosystems can absorb and to better understand their underlying processes. Hammocks (petenes) coastal ecosystems are highly vulnerable to sea level rise linked to climate change; their vulnerability is mainly due to its close relation with the sea through underground drainage in predominantly karstic soils. Hammocks are biologically important because of their high diversity and restricted distribution. This study proposes a strategy to assess resilience of this coastal ecosystem when high-precision data are scarce. Approaches and methods used to derive ecological resilience maps of hammocks are described and assessed. Resilience models were built by incorporating and weighting appropriate indicators of persistence to assess hammocks resilience against flooding due to climate change at "Los Petenes Biosphere Reserve", in the Yucatán Peninsula, Mexico. According to the analysis, 25% of the study area is highly resilient (hot spots), whereas 51% has low resilience (cold spots). The most significant hot spot clusters of resilience were located in areas distant to the coastal zone, with indirect tidal influence, and consisted mostly of hammocks surrounded by basin mangrove and floodplain forest. This study revealed that multi-criteria analysis and the use of GIS for qualitative, semi-quantitative and statistical spatial analyses constitute a powerful tool to develop ecological resilience maps of coastal ecosystems that are highly vulnerable to sea level rise, even when high-precision data are not available. This method can be applied in other sites to help develop resilience analyses and decision-making processes for management and conservation of coastal areas worldwide.

  1. Late Post-glacial Sea Level Rise and Its Effects On Human Activity In Asia

    Science.gov (United States)

    Oppenheimer, S. J.

    Three rapid post-glacial sea-level rises flooded coastlines with large continental shelves. The last of these, shortly before the interglacial optimum c.7,500BP, not only changed coastal Neolithic societies, but may also have stimulated maritime skills. Two Asian examples explore these aspects. First, during the Mid-Holocene, the Arabian Gulf transgressed as far inland as Ur probably laying down Woolley's famous Ur Flood silt layer between 7,000-5,500 BP. Stratigraphy and dating suggests the phase of rapid sea level rise immediately preceded the start of the 'Ubaid pottery period. Red-slipped Uruk pottery and copper items then appear from about 6,000BP, but above Woolley's silt layer. The Sumerian King Lists also record a major upheaval and dynastic change after 'the Flood'. Second, the final flooding of the Sunda shelf in Southeast Asia was followed by a maritime extension of human occupation from Northern Melanesia south into the Solomon Islands 6,000 years ago. Simultaneously, further west on the north coast of New Guinea, new archaeological assemblages ap- pear beneath a silt layer left by a pro-grading 6,000 year-old inland sea. The presence of arboriculture items such as betel nuts and the contemporary arrival of dogs and pigs in the same region suggests intrusion from Southeast Asia. This supports Solheim's suggestion that rapid sea-level rise on the eastern edge of the Sunda Shelf stimulated maritime skills and invention in Southeast Asia. This may have provided the initial stimulus to the first maritime expansion that was later to colonise the whole Pacific.

  2. Mangroves facing climate change: landward migration potential in response to projected scenarios of sea level rise

    Directory of Open Access Journals (Sweden)

    D. Di Nitto

    2013-02-01

    Full Text Available Mangrove forests prominently occupy an intertidal boundary position where the effects of sea level rise will be fast and well visible. This study in East Africa (Gazi Bay, Kenya addresses the question whether mangroves can be resilient to a rise in sea level by focusing on their potential to migrate towards landwards areas. The combinatory analysis between remote sensing, DGPS-based ground truth and digital terrain models (DTM unveils how real vegetation assemblages can shift under different projected (minimum (+9 cm, relative (+20 cm, average (+48 cm and maximum (+88 cm scenarios of sea level rise (SLR. Under SLR scenarios up to 48 cm by the year 2100, the landward extension remarkably implies an area increase for each of the dominant mangrove assemblages, except for Avicennia marina and Ceriops tagal, both on the landward side. On one hand, the increase of most species in the first 3 scenarios, including the socio-economically most important species in this area, Rhizophora mucronata and C. tagal on the seaward side, strongly depends on the colonisation rate of these species. On the other hand, a SLR scenario of +88 cm by the year 2100 indicates that the area flooded only by equinoctial tides strongly decreases due to the topographical settings at the edge of the inhabited area. Consequently, the landward Avicennia-dominated assemblages will further decrease as a formation if they fail to adapt to a more frequent inundation. The topography is site-specific; however non-invadable areas can be typical for many mangrove settings.

  3. Simulating the Effects of Sea Level Rise on the Resilience and Migration of Tidal Wetlands along the Hudson River.

    Directory of Open Access Journals (Sweden)

    Nava M Tabak

    Full Text Available Sea Level Rise (SLR caused by climate change is impacting coastal wetlands around the globe. Due to their distinctive biophysical characteristics and unique plant communities, freshwater tidal wetlands are expected to exhibit a different response to SLR as compared with the better studied salt marshes. In this study we employed the Sea Level Affecting Marshes Model (SLAMM, which simulates regional- or local-scale changes in tidal wetland habitats in response to SLR, and adapted it for application in a freshwater-dominated tidal river system, the Hudson River Estuary. Using regionally-specific estimated ranges of SLR and accretion rates, we produced simulations for a spectrum of possible future wetland distributions and quantified the projected wetland resilience, migration or loss in the HRE through the end of the 21st century. Projections of total wetland extent and migration were more strongly determined by the rate of SLR than the rate of accretion. Surprisingly, an increase in net tidal wetland area was projected under all scenarios, with newly-formed tidal wetlands expected to comprise at least 33% of the HRE's wetland area by year 2100. Model simulations with high rates of SLR and/or low rates of accretion resulted in broad shifts in wetland composition with widespread conversion of high marsh habitat to low marsh, tidal flat or permanent inundation. Wetland expansion and resilience were not equally distributed through the estuary, with just three of 48 primary wetland areas encompassing >50% of projected new wetland by the year 2100. Our results open an avenue for improving predictive models of the response of freshwater tidal wetlands to sea level rise, and broadly inform the planning of conservation measures of this critical resource in the Hudson River Estuary.

  4. Simulating the Effects of Sea Level Rise on the Resilience and Migration of Tidal Wetlands along the Hudson River.

    Science.gov (United States)

    Tabak, Nava M; Laba, Magdeline; Spector, Sacha

    2016-01-01

    Sea Level Rise (SLR) caused by climate change is impacting coastal wetlands around the globe. Due to their distinctive biophysical characteristics and unique plant communities, freshwater tidal wetlands are expected to exhibit a different response to SLR as compared with the better studied salt marshes. In this study we employed the Sea Level Affecting Marshes Model (SLAMM), which simulates regional- or local-scale changes in tidal wetland habitats in response to SLR, and adapted it for application in a freshwater-dominated tidal river system, the Hudson River Estuary. Using regionally-specific estimated ranges of SLR and accretion rates, we produced simulations for a spectrum of possible future wetland distributions and quantified the projected wetland resilience, migration or loss in the HRE through the end of the 21st century. Projections of total wetland extent and migration were more strongly determined by the rate of SLR than the rate of accretion. Surprisingly, an increase in net tidal wetland area was projected under all scenarios, with newly-formed tidal wetlands expected to comprise at least 33% of the HRE's wetland area by year 2100. Model simulations with high rates of SLR and/or low rates of accretion resulted in broad shifts in wetland composition with widespread conversion of high marsh habitat to low marsh, tidal flat or permanent inundation. Wetland expansion and resilience were not equally distributed through the estuary, with just three of 48 primary wetland areas encompassing >50% of projected new wetland by the year 2100. Our results open an avenue for improving predictive models of the response of freshwater tidal wetlands to sea level rise, and broadly inform the planning of conservation measures of this critical resource in the Hudson River Estuary.

  5. A modeling study of coastal inundation induced by storm surge, sea-level rise, and subsidence in the Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhaoqing; Wang, Taiping; Leung, Lai-Yung R.; Hibbard, Kathleen A.; Janetos, Anthony C.; Kraucunas, Ian P.; Rice, Jennie S.; Preston, Benjamin; Wilbanks, Thomas

    2013-12-10

    The northern coasts of the Gulf of Mexico are highly vulnerable to the direct threats of climate change, such as hurricane-induced storm surge, and such risks can be potentially exacerbated by land subsidence and global sea level rise. This paper presents an application of a coastal storm surge model to study the coastal inundation process induced by tide and storm surge, and its response to the effects of land subsidence and sea level rise in the northern Gulf coast. An unstructured-grid Finite Volume Coastal Ocean Model was used to simulate tides and hurricane-induced storm surges in the Gulf of Mexico. Simulated distributions of co-amplitude and co-phase of semi-diurnal and diurnal tides are in good agreement with previous modeling studies. The storm surges induced by four historical hurricanes (Rita, Katrina, Ivan and Dolly) were simulated and compared to observed water levels at National Oceanic and Atmospheric Administration tide stations. Effects of coastal subsidence and future global sea level rise on coastal inundation in the Louisiana coast were evaluated using a parameter “change of inundation depth” through sensitivity simulations that were based on a projected future subsidence scenario and 1-m global sea level rise by the end of the century. Model results suggested that hurricane-induced storm surge height and coastal inundation could be exacerbated by future global sea level rise and subsidence, and that responses of storm surge and coastal inundation to the effects of sea level rise and subsidence are highly nonlinear and vary on temporal and spatial scales.

  6. The future sea-level rise contribution of Greenland’s glaciers and ice caps

    DEFF Research Database (Denmark)

    Machguth, H.; Rastner, P.; Bolch, T.

    2013-01-01

    . Glacier extent and surface elevation are modified during the mass balance model runs according to a glacier retreat parameterization. Mass balance and glacier surface change are both calculated on a 250 m resolution digital elevation model yielding a high level of detail and ensuring that important......We calculate the future sea-level rise contribution from the surface mass balance of all of Greenland's glaciers and ice caps (GICs, ~90 000 km2) using a simplified energy balance model which is driven by three future climate scenarios from the regional climate models HIRHAM5, RACMO2 and MAR...

  7. Effects of ocean acidification and sea-level rise on coral reefs

    Science.gov (United States)

    Yates, K.K.; Moyer, R.P.

    2010-01-01

    U.S. Geological Survey (USGS) scientists are developing comprehensive records of historical and modern coral reef growth and calcification rates relative to changing seawater chemistry resulting from increasing atmospheric CO2 from the pre-industrial period to the present. These records will provide the scientific foundation for predicting future impacts of ocean acidification and sea-level rise on coral reef growth. Changes in coral growth rates in response to past changes in seawater pH are being examined by using cores from coral colonies.

  8. Rates of subsidence and relative sea level rise in the Hawaii Islands

    Science.gov (United States)

    Parker, Albert

    2016-12-01

    The major cause of the Hawaiian Islands coastal erosion is shown to be not global warming, but the sinking of the volcanic islands. The geologic "circle-of-life" beyond the Hawaiian hot spot is the true explanation of the beach erosion. The sea levels are slow rising and not accelerating worldwide as well as in the United States. In the specific of the Hawaii Islands, they have been decelerating over the last 3 decades because of the phasing of the multi-decadal oscillations for this area of the Pacific. There is therefore no evidence coastal erosion will double in the Hawaii by 2050 because of global warming.

  9. Cities and Sea Level Rise: A Roadmap for Flood Hazard Adaptation

    Science.gov (United States)

    Horn, D. P.; Cousins, A.

    2015-12-01

    Coastal cities will face a range of increasingly severe challenges as sea level rises, and adaptation to future flood risk will require more than structural defences. Many cities will not be able to rely solely on engineering structures for protection and will need to develop a suite of policy responses to increase their resilience to impacts of rising sea level. Local governments generally maintain day-to-day responsibility and control over the use of the vast majority of property at risk of flooding, and the tools to promote flood risk adaptation are already within the capacity of most cities. Policy tools available to address other land-use problems can be refashioned and used to adapt to sea level rise. This study reviews approaches for urban adaptation through case studies of cities which have developed flood adaptation strategies that combine structural defences with innovative approaches to living with flood risk. The aim of the overall project is to produce a 'roadmap' to guide practitioners through the process of analysing coastal flood risk in urban areas. Technical knowledge of flood risk reduction measures is complemented with a consideration of the essential impact that local policy has on the treatment of coastal flooding and the constraints and opportunities that result from the specific country or locality characteristics in relation to economic, political, social and environmental priorities, which are likely to dictate the approach to coastal flooding and the actions proposed. Detailed analyses of the adaptation strategies used by Rotterdam (Netherlands), Bristol (UK), and Norfolk (Virginia) are used to draw out a range of good practice elements that promote effective adaptation to sea level rise. These can be grouped into risk reduction, governance issues, and insurance, and can be used to provide examples of how other cities could adopt and implement flood adaptation strategies from a relatively limited starting position. Most cities will

  10. The effects of sea-level rise on water quality in coastal floodplain sediments

    Science.gov (United States)

    Wong, Vanessa; Johnston, Scott; Burton, Edward; Bush, Richard; Sullivan, Leigh; Slavich, Peter

    2013-04-01

    Sea level has risen approximately 1.2 mm/year over the last 100 years (Hennessy et al. 2004) and is predicted to rise up to 80 cm by 2100 relative to 1990 sea levels (IPCC 2007). The number of extreme events related to sea level such as higher sea levels and increased inter-annual variability have also increased in frequency in the same time period (Hennessy et al. 2004). Globally, large areas of coastal and estuarine floodplains are underlain by sulfidic sediments and acid sulfate soils (ASS). These sediments frequently contain high concentrations of acidity and trace metals. A significant portion of the stored acidity occurs in the form of exchangeable and hydrolysable acidic metal cations such as Al and Fe. Watertables in these environments are often close to the surface and intercepted by relatively shallow drains. Due to their low elevation and locations, these floodplains are highly susceptible to pulses of saline water caused by saltwater intrusion, storm surge and rising sea levels. Construction of extensive drainage systems has further increased the susceptibility of the floodplain to seawater inundation by increasing connectivity to the estuarine channel. This risk is likely to increase in the future with predicted increases in sea level and extreme events due to climate change. This study uses both batch experiments to determine the effects of increasing ionic strength on exchange processes and trace metal desorption in oxidised floodplain sediments and sulfidic drain sediments, and intact soil cores to determine the surface water-porewater interactions over the short term following seawater inundation in coastal floodplain sediments. We found that that saline inundation of oxidised ASS floodplain sediments, even by relatively brackish water may cause rapid, shorter-term water quality changes and a pulse release of acidity due to desorption of acidic metal cations (Wong et al. 2010). We also found that trace metals can be mobilised from sulfidic

  11. Changes induced by sea level rise on network properties of restoration areas

    Science.gov (United States)

    Jiménez, Mirian; Castanedo, Sonia; Zhou, Zeng; Coco, Giovanni; Medina, Raúl

    2015-04-01

    are quantified with the new approach (Jiménez et al.,2014), which allows to highlight the changes that induce deep behavioral changes in the system. The importance of sea level rise in these behavioral changes is also assessed in the study. References: Jiménez, M., S. Castanedo, Z. Zhou, G.Coco, R. Medina, and I. Rodriguez-Iturbe (2014). Scaling properties of tidal networks, Water Resources Research., 50, doi:10.1002/2013WR015006.

  12. Investigation of potential sea level rise impact on the Nile Delta, Egypt using digital elevation models.

    Science.gov (United States)

    Hasan, Emad; Khan, Sadiq Ibrahim; Hong, Yang

    2015-10-01

    In this study, the future impact of Sea Level Rise (SLR) on the Nile Delta region in Egypt is assessed by evaluating the elevations of two freely available Digital Elevation Models (DEMs): the SRTM and the ASTER-GDEM-V2. The SLR is a significant worldwide dilemma that has been triggered by recent climatic changes. In Egypt, the Nile Delta is projected to face SLR of 1 m by the end of the 21th century. In order to provide a more accurate assessment of the future SLR impact on Nile Delta's land and population, this study corrected the DEM's elevations by using linear regression model with ground elevations from GPS survey. The information for the land cover types and future population numbers were derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) land cover and the Gridded Population of the Worlds (GPWv3) datasets respectively. The DEM's vertical accuracies were assessed using GPS measurements and the uncertainty analysis revealed that the SRTM-DEM has positive bias of 2.5 m, while the ASTER-GDEM-V2 showed a positive bias of 0.8 m. The future inundated land cover areas and the affected population were illustrated based on two SLR scenarios of 0.5 m and 1 m. The SRTM DEM data indicated that 1 m SLR will affect about 3900 km(2) of cropland, 1280 km(2) of vegetation, 205 km(2) of wetland, 146 km(2) of urban areas and cause more than 6 million people to lose their houses. The overall vulnerability assessment using ASTER-GDEM-V2 indicated that the influence of SLR will be intense and confined along the coastal areas. For instance, the data indicated that 1 m SLR will inundate about 580 Km(2) (6%) of the total land cover areas and approximately 887 thousand people will be relocated. Accordingly, the uncertainty analysis of the DEM's elevations revealed that the ASTER-GDEM-V2 dataset product was considered the best to determine the future impact of SLR on the Nile Delta region.

  13. Decadal-scale sea level rise acceleration along the Florida Atlantic coast and its relations to sea level variability along the Florida Current

    Science.gov (United States)

    Wdowinski, S.; Thompson, P. R.; Mitchum, G. T.; Park, J.

    2015-12-01

    The US Atlantic coast is one of the most vulnerable areas to sea level rise (SLR) due to its low elevation, large population concentrations, and economic importance. Further vulnerability arises from accelerating rates of SLR, which began in the early 2000's and caused a significant increase in flooding frequency in several coastal communities. Several studies have suggested that the accelerating SLR rates are due to the slowing down of the Atlantic Meridional Overturning Circulation, in particular, a weakening of the Gulf Stream (GS). However, there are no direct observations that link the GS conditions and high sea levels along the coast. In this study we use satellite altimetry, tide gauge, and Florida Current (FC) cable data to explore possible relations between the recent SLR rate increase along the Florida Atlantic coast and various dynamical processes in the GS/FC system. Preliminary calculations indicate a good agreement between coastal sea level and nearshore altimetry series (R = 0.76-0.8) suggesting that SSH gradients from altimetry may be useful for assessing the dynamics associated with the coastal sea level change. Here we focus on spatio-temporal SSH changes along the two satellite passes located closest to the Florida Atlantic coast. Our results indicate an intriguing transition in SSH behavior around 2004-5. Prior to 2004, anomalous low coastal SSH events (strong FC) occurred every 3-5 years in correlation with warm ENSO events. After 2004, the strong relationship between ENSO and the gradient across the FC vanishes, while the mean sea level across the current increases. The observed SSH anomaly transition around 2004-5 correlates well with the initiation of accelerated rates of coastal SLR, suggesting that the decadal scale SLR acceleration has occurred during weak FC conditions. However, the forcing of this transition and the role of mean sea level variability, which is of comparable magnitude to variability in the gradient, remain unexplained.

  14. Assessing impacts of climate change, sea level rise, and drainage canals on saltwater intrusion to coastal aquifer

    Directory of Open Access Journals (Sweden)

    P. Rasmussen

    2012-07-01

    Full Text Available Groundwater abstraction from coastal aquifers is vulnerable to climate change and sea level rise because both may potentially impact saltwater intrusion and hence groundwater quality depending on the hydrogeological setting. In the present study the impacts of sea level rise and changes in groundwater recharge are quantified for an island located in the Western Baltic Sea. Agricultural land dominates the western and central parts of the island, which geologically are developed as push moraine hills and a former lagoon (later wetland area behind barrier islands to the east. The low-lying central area of the island was extensively drained and reclaimed during the second half of the 19th century. Summer cottages along the beach on the former barrier islands dominate the eastern part of the island. The main water abstraction is for holiday cottages during the summer period (June–August. The water is abstracted from 11 wells drilled to a depth of around 20 m in the upper 5–10 m of a confined chalk aquifer. Increasing chloride concentrations have been observed in several abstraction wells and in some cases the WHO drinking water standard has been exceeded. Using the modeling package MODFLOW/MT3D/SEAWAT the historical, present and future freshwater–sea water distribution is simulated. The model is calibrated against hydraulic head observations and validated against geochemical and geophysical data from new investigation wells, including borehole logs, and from an airborne transient electromagnetic survey. The impact of climate changes on saltwater intrusion is found to be sensitive to the boundary conditions of the investigated system. For the flux-controlled aquifer to the west of the drained area only changes in groundwater recharge impacts the freshwater–sea water interface whereas sea level rise do not result in increasing sea water intrusion. However, on the barrier islands to the east of the reclaimed area below which the sea is

  15. Assessing impacts of climate change, sea level rise, and drainage canals on saltwater intrusion to coastal aquifer

    Directory of Open Access Journals (Sweden)

    P. Rasmussen

    2013-01-01

    Full Text Available Groundwater abstraction from coastal aquifers is vulnerable to climate change and sea level rise because both may potentially impact saltwater intrusion and hence groundwater quality depending on the hydrogeological setting. In the present study the impacts of sea level rise and changes in groundwater recharge are quantified for an island located in the Western Baltic Sea. The low-lying central area of the investigated part of the island was extensively drained and reclaimed during the second half of the 19th century by a system of artificial drainage canals that significantly affects the flow dynamics of the area. The drinking water, mainly for summer cottages, is abstracted from 11 wells drilled to a depth of around 20 m into the upper 5–10 m of a confined chalk aquifer, and the total pumping is only 5–6% of the drainage pumping. Increasing chloride concentrations have been observed in several abstraction wells and in some cases the WHO drinking water standard has been exceeded. Using the modeling package MODFLOW/MT3D/SEAWAT the historical, present and future freshwater-sea water distribution is simulated. The model is calibrated against hydraulic head observations and validated against geochemical and geophysical data from new investigation wells, including borehole logs, and from an airborne transient electromagnetic survey. The impact of climate changes on saltwater intrusion is found to be sensitive to the boundary conditions of the investigated system. For the flux-controlled aquifer to the west of the drained area only changes in groundwater recharge impacts the freshwater–sea water interface whereas sea level rise does not result in increasing sea water intrusion. However, on the barrier islands to the east of the reclaimed area, below which the sea is hydraulically connected to the drainage canals, and the boundary of the flow system therefore controlled, the projected changes in sea level, groundwater recharge and stage of the

  16. Tagus estuary and Ria de Aveiro salt marsh dynamics and the impact of sea level rise

    Science.gov (United States)

    Valentim, J. M.; Vaz, N.; Silva, H.; Duarte, B.; Caçador, I.; Dias, J. M.

    2013-09-01

    Different characteristics of Spartina maritima found in two distinct salt marshes located in different estuaries were analysed through interpretation of their local hydrodynamic patterns, as well as the impact of sea level rise on physical processes and consequently on plant dynamics and salt marshes stability. These salt marshes are situated in two of the most important Portuguese coastal systems, Tagus estuary (Rosário salt marsh) and Ria de Aveiro lagoon (Barra salt marsh), which are dominated by physical processes that induce strong tidal currents. They were monitored during one year and plant and sediment samples of S. maritima were collected quarterly in order to determine the vegetation coverage, above and belowground biomass, organic matter and sediment moisture. Residual circulation, tidal asymmetry and tidal dissipation were determined from numerical modelling results of the MOHID 2D model that was applied to each coastal system, considering the actual sea level and a sea level rise (SLR) scenario. Results suggest that the different characteristics found for Spartina maritima in the Rosário and the Barra salt marshes may be related with the diverse hydrodynamic conditions identified for each salt marsh. Consequently, the exploration of SLR scenario predictions indicates how these salt marshes could evolve in the future, showing that the important changes in these hydrodynamic parameters under climate change context might induce significant modifications in the salt marshes dynamics and stability. SLR scenario could lead to changes in nutrients and sediments patterns around the salt marshes and thus vegetation coverage percentage would be affected. Additionally, as a consequence of flood duration increase, sediment moisture will increase causing a stress condition to plants. Hence, the ratio below/aboveground biomass might increase, becoming critical to plants survival under conditions of accelerated sea level rise. Accordingly, both SLR and expected

  17. ATLANTIC - Coastal Vulnerability to Sea-Level Rise: A Preliminary Database for the U.S. Atlantic Coast

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The goal of this project is to provide a preliminary overview, at a National scale, the relative susceptibility of the Nation's coast to sea-level rise through the...

  18. Hydrodynamic response of a fringing coral reef to a rise in mean sea level

    Science.gov (United States)

    Taebi, Soheila; Pattiaratchi, Charitha

    2014-07-01

    Ningaloo Reef, located along the northwest coast of Australia, is one of the longest fringing coral reefs in the world extending ~300 km. Similar to other fringing reefs, it consists of a barrier reef ~1-6 km offshore with occasional gaps, backed by a shallow lagoon. Wave breaking on the reef generates radiation stress gradients that produces wave setup across the reef and lagoon and mean currents across the reef. A section of Ningaloo Reef at Sandy Bay was chosen as the focus of an intense 6-week field experiment and numerical simulation using the wave model SWAN coupled to the three-dimensional circulation model ROMS. The physics of nearshore processes such as wave breaking, wave setup and mean flow across the reef was investigated in detail by examining the various momentum balances established in the system. The magnitude of the terms and the distance of their peaks from reef edge in the momentum balance were sensitive to the changes in mean sea level, e.g. the wave forces decreased as the mean water depth increased (and hence, wave breaking dissipation was reduced). This led to an increase in the wave power at the shoreline, a slight shift of the surf zone to the lee side of the reef and changes in the intensity of the circulation. The predicted hydrodynamic fields were input into a Lagrangian particle tracking model to estimate the transport time scale of the reef-lagoon system. Flushing time of the lagoon with the open ocean was computed using two definitions in renewal of semi-enclosed water basins and revealed the sensitivity of such a transport time scale to methods. An increase in the lagoon exchange rate at smaller mean sea-level rise and the decrease at higher mean sea-level rise was predicted through flushing time computed using both methods.

  19. Saltmarsh boundary modulates dispersal of mangrove propagules: implications for mangrove migration with sea-level rise.

    Directory of Open Access Journals (Sweden)

    Jennifer M Peterson

    Full Text Available Few studies have empirically examined the suite of mechanisms that underlie the distributional shifts displayed by organisms in response to changing climatic condition. Mangrove forests are expected to move inland as sea-level rises, encroaching on saltmarsh plants inhabiting higher elevations. Mangrove propagules are transported by tidal waters and propagule dispersal is likely modified upon encountering the mangrove-saltmarsh ecotone, the implications of which are poorly known. Here, using an experimental approach, we record landward and seaward dispersal and subsequent establishment of mangrove propagules that encounter biotic boundaries composed of two types of saltmarsh taxa: succulents and grasses. Our findings revealed that propagules emplaced within saltmarsh vegetation immediately landward of the extant mangrove fringe boundary frequently dispersed in the seaward direction. However, propagules moved seaward less frequently and over shorter distances upon encountering boundaries composed of saltmarsh grasses versus succulents. We uniquely confirmed that the small subset of propagules dispersing landward displayed proportionately higher establishment success than those transported seaward. Although impacts of ecotones on plant dispersal have rarely been investigated in situ, our experimental results indicate that the interplay between tidal transport and physical attributes of saltmarsh vegetation influence boundary permeability to propagules, thereby directing the initial phase of shifting mangrove distributions. The incorporation of tidal inundation information and detailed data on landscape features, such as the structure of saltmarsh vegetation at mangrove boundaries, should improve the accuracy of models that are being developed to forecast mangrove distributional shifts in response to sea-level rise.

  20. Saltmarsh boundary modulates dispersal of mangrove propagules: implications for mangrove migration with sea-level rise.

    Science.gov (United States)

    Peterson, Jennifer M; Bell, Susan S

    2015-01-01

    Few studies have empirically examined the suite of mechanisms that underlie the distributional shifts displayed by organisms in response to changing climatic condition. Mangrove forests are expected to move inland as sea-level rises, encroaching on saltmarsh plants inhabiting higher elevations. Mangrove propagules are transported by tidal waters and propagule dispersal is likely modified upon encountering the mangrove-saltmarsh ecotone, the implications of which are poorly known. Here, using an experimental approach, we record landward and seaward dispersal and subsequent establishment of mangrove propagules that encounter biotic boundaries composed of two types of saltmarsh taxa: succulents and grasses. Our findings revealed that propagules emplaced within saltmarsh vegetation immediately landward of the extant mangrove fringe boundary frequently dispersed in the seaward direction. However, propagules moved seaward less frequently and over shorter distances upon encountering boundaries composed of saltmarsh grasses versus succulents. We uniquely confirmed that the small subset of propagules dispersing landward displayed proportionately higher establishment success than those transported seaward. Although impacts of ecotones on plant dispersal have rarely been investigated in situ, our experimental results indicate that the interplay between tidal transport and physical attributes of saltmarsh vegetation influence boundary permeability to propagules, thereby directing the initial phase of shifting mangrove distributions. The incorporation of tidal inundation information and detailed data on landscape features, such as the structure of saltmarsh vegetation at mangrove boundaries, should improve the accuracy of models that are being developed to forecast mangrove distributional shifts in response to sea-level rise.

  1. Interactive Sea Level Rise App & Online Viewer Offers Deep Dive Into Climate

    Science.gov (United States)

    Turrin, M.; Porter, D. F.; Ryan, W. B. F.; Pfirman, S. L.

    2015-12-01

    Climate has captured the attention of the public but its complexity can cause interested individuals to turn to opinion pieces, news articles or blogs for information. These platforms often oversimplify or present heavily interpreted or personalized perspectives. Data interactives are an extremely effective way to explore complex geoscience topics like climate, opening windows of understanding for the user that have previously been closed. Layering data onto maps through programs like GeoMapApp and the Earth Observer App has allowed users to dig directly into science data, but with only limited scaffolding. The interactive 'Polar Explorer: Sea Level Explorer App' provides a richly layered introduction to a range of topics connected to sea level rise. Each map is supported with a pop up and a short audio file of supplementary material, and an information page that includes the data source and links for further reading. This type of learning platform works well for both the formal and informal learning environment. Through science data displayed as map visualizations the user is invited into topics through an introductory question, such as "Why does sea level change?" After clicking on that question the user moves to a second layer of questions exploring the role of the ocean, the atmosphere, the contribution from the world's glaciers, world's ice sheets and other less obvious considerations such as the role of post-glacial rebound, or the mining of groundwater. Each question ends in a data map, or series of maps, that offer opportunities to interact with the topic. Under the role of the ocean 'Internal Ocean Temperature' offers the user a chance to touch to see temperature values spatially over the world's ocean, or to click through a data series starting at the ocean surface and diving to 5000 meters of depth showing how temperature changes with depth. Other sections, like the role of deglaciation of North America, allow the user to click and see change through

  2. Potential vulnerability implications of sea level rise for the coastal zones of Cochin, southwest coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    DineshKumar, P.K.

    of climate change and potential risks to coastal cities have not been fulfilled – though, since very long it has been recognized that these perspectives are required for a range of purposes. It is well known that the land areas adjacent to the shorelines... of human settlements. Besides the destruction through inundation and increased rates of erosion, sea level rise situations also increase the risk of flooding. POTENTIAL VULNERABILITY IMPLICATIONS OF SEA LEVEL RISE 337 Considering these and in order...

  3. 气候变暖与海平面上升%Climate warming and sea level rise

    Institute of Scientific and Technical Information of China (English)

    岳军; Dong YUE; 吴桑云; 耿秀山; 赵长荣

    2012-01-01

    Based on a large number of actual data, the author believe that the modem global warming and sea level rise resulted from climate warming after the cold front of the Little Ice Age about 200 years ago and the developmnet of the sea level rise phase. In the past 30 years, the rate of sea level rise was increasing, which is under the background of the average temperature uplift 0.2F°(0.11℃)every 10 years in succession from the 1980s to the past 10 years this century. On the basis of the absolute and relative sea-level rise rate that was calculated from the tidal data during the same period at home and abroad in the last 30 years, in accordance with the resolutions of the 2010 climate conference in Cancun, at the same time, considering the previous prediction and research, the world's sea levels and the relative sea level in Tianjin, Shanghai, Dongying, Xiamen, Haikou and other coastal cities that have severe land subsidence in 2050 and 2100 are calculated and evaluated.%本文通过大量实际资料分析认为,现代全球变暖与海平面上升,源于200多年前小冰期冷峰出现后的气候返暖、海平面回升过程演变的结果。近30年的世界海平面上升的速率,有着上世纪80、90年代和本世纪前10年世界平均气温每10年以0.2F°(0.11℃)为梯度的连续抬升为背景。在此以CO。含量为气候指标,划分出了公元200年以来的八个暖段(暖期)。若按冷暖极值距200年或250年计算,则由目前正在发展的暖期,将在公元2050年或2100年前后结束,而后开始降温。作者依据最近30年同一时段国内外验潮资料计算获得的绝对海平面升降速率为+1.52±0.27mm/a及相对海平面升降速率为+1.39±0.26mm/a。按照2010年坎昆气候大会决议要求,在对前人有关研究成果进行考量时,对将来的2050和2100年世界海平面预测及我国地面沉降较明显的沿海城市如天

  4. Cities and Sea Level Rise: A Roadmap for Flood Hazard Adaptation

    Science.gov (United States)

    Horn, Diane; Cousins, Ann

    2016-04-01

    Coastal cities will face a range of increasingly severe challenges as sea level rises, and adaptation to future flood risk will require more than structural defences. Many cities will not be able to rely solely on engineering structures for protection and will need to develop a suite of policy responses to increase their resilience to impacts of rising sea level. The tools to promote flood risk adaptation are already within the capacity of most cities, with an assortment of policy tools available to address other land-use problems which can be refashioned and used to adapt to sea level rise. This study reviews approaches for urban adaptation through detailed analyses of case studies of cities which have developed flood adaptation strategies that combine structural defences with innovative approaches to living with flood risk. The aim of the overall project is to produce a 'roadmap' to guide practitioners through the process of analysing coastal flood risk in urban areas. Methodologies and tools to estimate vulnerability to coastal flooding, damages suffered, and the assessment of flood defences and adaptation measures are complemented with a discussion on the essential impact that local policy has on the treatment of coastal flooding and the constraints and opportunities that result from the specific country or locality characteristics in relation to economic, political, social and environmental priorities, which are likely to dictate the approach to coastal flooding and the actions proposed. Case studies of adaptation strategies used by Rotterdam, Bristol, Ho Chi Minh City and Norfolk, Virginia, are used to draw out a range of good practice elements that promote effective adaptation to sea level rise. These can be grouped into risk reduction, governance issues, and insurance, and can be used to provide examples of how other cities could adopt and implement flood adaptation strategies from a relatively limited starting position. Most cities will neither be able to

  5. Resilience of Infrastructure Systems to Sea-Level Rise in Coastal Areas: Impacts, Adaptation Measures, and Implementation Challenges

    Directory of Open Access Journals (Sweden)

    Beatriz Azevedo de Almeida

    2016-11-01

    Full Text Available Expansive areas of low elevation in many densely populated coastal areas are at elevated risk of storm surges and flooding due to torrential precipitation, as a result of sea level rise. These phenomena could have catastrophic impacts on coastal communities and result in the destruction of critical infrastructure, disruption of economic activities and salt water contamination of the water supply. The objective of the study presented in this paper was to identify various impacts of sea level rise on civil infrastructures in coastal areas and examine the adaptation measures suggested in the existing literature. To this end, a systemic review of the existing literature was conducted in order to identify a repository of studies addressing sea level rise impacts and adaptation measures in the context of infrastructure systems. The study focused on three infrastructure sectors: water and wastewater, energy, and road transportation. The collected information was then analyzed in order to identify different categories of sea level rise impacts and corresponding adaptation measures. The findings of the study are threefold: (1 the major categories of sea level rise impacts on different infrastructure systems; (2 measures for protection, accommodation, and retreat in response to sea level rise impacts; and (3 challenges related to implementing adaptation measures.

  6. Modeling and Analysis of Sea-level Rise Impacts on Salinity in the Lower St. Johns River

    Science.gov (United States)

    Bacopoulos, P.

    2015-12-01

    There is deliberate attention being paid to studying sea-level rise impacts on the lower St. Johns River, a drowned coastal plain-type estuary with low topographic drive, located in northeastern Florida. One area of attention is salinity in the river, which influences the entire food web, including sea and marsh grasses, juvenile crustaceans and fishes, wading birds and migratory waterfowl, marine mammals and other predator animals. It is expected that elevated ocean levels will increase the salinity of the estuarine waters, leading to deleterious effects on dependent species of the river biology. The objective of the modeling and analysis was: 1) to establish baseline conditions of salinity for the lower St. Johns River; and 2) to examine future conditions of salinity, as impacted by sea-level rise. Establishing baseline conditions entailed validation of the model for present-day salinity in the lower St. Johns River via comparison to available data. Examining future conditions entailed application of the model for sea-level rise scenarios, with comparison to the baseline conditions, for evaluation of sea-level rise impacts on salinity. While the central focus was on the physics of sea-level rise impacts on salinity, some level of salinity-biological assessment was conducted to identify sea-level rise/salinity thresholds, as related to negatively impacting different species of the river biology.

  7. Coastal vulnerability assessment of the Northern Gulf of Mexico to sea-level rise and coastal change

    Science.gov (United States)

    Pendleton, E.A.; Barras, J.A.; Williams, S.J.; Twichell, D.C.

    2010-01-01

    A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future sea-level rise along the Northern Gulf of Mexico from Galveston, TX, to Panama City, FL. The CVI ranks the following in terms of their physical contribution to sea-level rise-related coastal change: geomorphology, regional coastal slope, rate of relative sea-level rise, historical shoreline change rate, mean tidal range, and mean significant wave height. The rankings for each variable are combined and an index value is calculated for 1-kilometer grid cells along the coast. The CVI highlights those regions where the physical effects of sea-level rise might be the greatest. The CVI assessment presented here builds on an earlier assessment conducted for the Gulf of Mexico. Recent higher resolution shoreline change, land loss, elevation, and subsidence data provide the foundation for a better assessment for the Northern Gulf of Mexico. The areas along the Northern Gulf of Mexico that are likely to be most vulnerable to sea-level rise are parts of the Louisiana Chenier Plain, Teche-Vermillion Basin, and the Mississippi barrier islands, as well as most of the Terrebonne and Barataria Bay region and the Chandeleur Islands. These very high vulnerability areas have the highest rates of relative sea-level rise and the highest rates of shoreline change or land area loss. The information provided by coastal vulnerability assessments can be used in long-term coastal management and policy decision making.

  8. Simulated Sea-Level Rise Effects on the Above and Below-Ground Growth of Two Tidal Marsh Plant Species

    Science.gov (United States)

    Schile, L. M.; Callaway, J. C.; Kelly, M.

    2011-12-01

    Sea-level is expected to rise between 55 and 140 cm in the next century and is likely to have significant effects on the distribution and maintenance of tidal wetlands; however, little is known about the effects of increased sea level on Pacific coast tidal marsh vegetation. We initiated a field experiment in March 2011 to examine how increased depth and duration of inundation affect above and below-ground growth of two tidal wetland plant species: Schoenoplectus acutus and S. americanus. PVC planters, referred to as marsh organs, were installed at fixed elevations in channels at two ancient marshes in the San Francisco Bay Estuary: Browns Island and Rush Ranch. Each marsh organ structure is comprised of five rows of three six-inch PVC pipes, with each row 15cm lower than the row above, and was filled with surrounding mudflat sediment. Elevations span 60 cm and were chosen to be lower than the average current elevations of both species at each marsh to reflect projected increases in sea level. Rhizomes were collected from Browns Island, the less-saline site, and were cut to uniform sizes before planting. In every row, each species was grown individually and together. On a monthly basis, plant heights were recorded and pore-water sulfide concentration, salinity, and soil oxidation-reduction potential were measured. Schoenoplectus americanus growth and density significantly decreased with increased inundation at both sites. Schoenoplectus acutus growth was impacted more significantly at lower elevations at Rush Ranch but had little variation in density and growth across elevations at Browns Island. Salinity and sulfide concentrations varied little across elevations within a site but differed between sites. Above and belowground biomass will be collected in September 2011 to measure total annual productivity. The experiment provides basic yet crucial information on the impacts of increased inundation on tidal wetland vegetation and insight into potential changes in

  9. Impacts of past climate and sea level change on Everglades wetlands: placing a century of anthropogenic change into a late-Holocene context

    Science.gov (United States)

    Willard, D.A.; Bernhardt, C.E.

    2011-01-01

    We synthesize existing evidence on the ecological history of the Florida Everglades since its inception ~7 ka (calibrated kiloannum) and evaluate the relative impacts of sea level rise, climate variability, and human alteration of Everglades hydrology on wetland plant communities. Initial freshwater peat accumulation began between 6 and 7 ka on the platform underlying modern Florida Bay when sea level was ~6.2 m below its current position. By 5 ka, sawgrass and waterlily peats covered the area bounded by Lake Okeechobee to the north and the Florida Keys to the south. Slower rates of relative sea level rise ~3 ka stabilized the south Florida coastline and initiated transitions from freshwater to mangrove peats near the coast. Hydrologic changes in freshwater marshes also are indicated ~3 ka. During the last ~2 ka, the Everglades wetland was affected by a series of hydrologic fluctuations related to regional to global-scale fluctuations in climate and sea level. Pollen evidence indicates that regional-scale droughts lasting two to four centuries occurred ~1 ka and ~0.4 ka, altering wetland community composition and triggering development of characteristic Everglades habitats such as sawgrass ridges and tree islands. Intercalation of mangrove peats with estuarine muds ~1 ka indicates a temporary slowing or stillstand of sea level. Although sustained droughts and Holocene sea level rise played large roles in structuring the greater Everglades ecosystem, twentieth century reductions in freshwater flow, compartmentalization of the wetland, and accelerated rates of sea level rise had unprecedented impacts on oxidation and subsidence of organic soils, changes/loss of key Everglades habitats, and altered distribution of coastal vegetation.

  10. Hydroclimatic modelling of local sea level rise and its projection in future

    Science.gov (United States)

    Naren, A.; Maity, Rajib

    2016-09-01

    Studies on sea level rise (SLR) in the context of climate change are gaining importance in the recent past. Whereas there is some clear evidence of SLR at global scale, its trend varies significantly from location to location. The role of different meteorological variables on sea level change (SLC) is explored. We hypothesise that the role of such variables varies from location to location and modelling of local SLC requires a proper identification of specific role of individual factors. After identifying a group of various local meteorological variables, Supervised Principal Component Analysis (SPCA) is used to develop a location specific Combined Index (CI). The SPCA ensures that the developed CI possesses highest possible association with the historical SLC at that location. Further, using the developed CI, an attempt is made to model the local sea level (LSL) variation in synchronous with the changing climate. The developed approach, termed as hydroclimatic semi-empirical approach, is found to be potential for local SLC at different coastal locations. The validated hydroclimatic approach is used for future projection of SLC at those coastal locations till 2100 for different climate change scenarios, i.e. different Representative Concentration Pathways (RCPs). Future hydrometeorological variables are obtained from Global Climate Models (GCMs) for different such scenarios, i.e. RCP2.6, RCP4.5 and RCP8.5. Effect of glacial isostatic readjustment (GIA) is not included in this study. However, if the reliable information on GIA is available for a location, the same can be arithmetically added to the final outcome of the proposed hydrometeorological approach.

  11. A preliminary vulnerability assessment for Ísafjörður, Iceland : coastal management options to reduce impacts of sea-level rise and storm surges

    OpenAIRE

    Manuel Meidinger

    2011-01-01

    Climate change science argues that by the end of the 21st century, the global mean sea-level rise may easily exceed 1 metre, possibly accompanied by an increase in storm intensity. Although climate change is a global phenomenon, its impacts vary greatly according to scale and geographic region. This study took into account the United Nations’ recommendations and the research objectives stated by the Icelandic Ministry of the Environment, and conducted a preliminary coastal vulnerability asses...

  12. Adaptation to the impact of sea level rise in the Northeastern Nile Delta, Egypt

    Science.gov (United States)

    Mabrouk, Badr; Farhat Abd-Elhamid, Hany; Badr, Marmar; Ludwig, Ralf

    2013-04-01

    Northeastern Delta is one of the most promising developmental areas in Egypt. This area is characterized by a prominent watershed having abundant water resources (especially groundwater). Currently, this area undergoes a rapid environmental degradation, such as land subsidence, water and soil salinaization. It accommodates about 60% of the total arable lands of the Delta, and inhabited by about 45 % of its total population. In addition, the northern part of this area comprises about 25% of the total Mediterranean wetlands. In this area a number of desalination plants were installed to desalinate brackish water and inject the brine to the aquifer using deep wells. This work aims to evaluate the environmental impact of injecting brine water on groundwater quality. Also, the impact of climate change and sea level rise are considered. The work is a combination of field work and simulation processes of groundwater flow and seawater intrusion using numerical models. The field work was used to collect and analyze data, information pertaining to the groundwater resources, interpretation of aerial photos and satellite images and preparation of ground water potential maps has. This was followed by detailed test boring wells as chemical analysis of seawater intrusion detection and pollution flow mapping were done. Numerical models (MODFLOW and MT3D) were used to evaluate both current and future situation of the groundwater flow and seawater intrusion in the Nile Delta aquifer in the studied area. The aquifer in the studied area is divided into five barrier beds according to its hydrological characteristics. The increase in extraction rates of brackish water and increasing the salinity of groundwater were experienced in details. Different scenarios to mitigate the severe salinity effect of injected brine water of high salinity rejected from desalination process. The brine water is assumed to be injected into deep wells to different depths and observation of changes in salinity

  13. Effects of future sea-level rise on tidal processes on the Patagonian Shelf

    Science.gov (United States)

    Carless, Stacey J.; Green, J. A. Mattias; Pelling, Holly E.; Wilmes, Sophie-Berenice

    2016-11-01

    The response of tidally driven processes on the Patagonian Shelf to sea-level rise (SLR) is revisited using large but realistic levels of change in a numerical tidal model. The results relate to previous studies through significant differences in the impact, depending on how SLR is implemented. This is true for how the boundary at the coastline is treated, i.e., if we allow for inundation of land or assume flood defences along the coast, but also for how the sea-level change itself is implemented. Simulations with uniform SLR provide a different, and slightly larger, response than do runs where SLR is based on observed trends. In all cases, the effect on the tidal amplitudes is patchy, with alternating increases and decreases in amplitude along the shelf. Furthermore, simulations with a realistic future change in vertical stratification, thus affecting tidal conversion rates, imply that there may be a small but significant decrease in the amplitudes along the coast. Associated processes, e.g., the location of mixing fronts and potential impacts on biogeochemical cycles on the shelf are also discussed.

  14. Vulnerability of the peatland carbon sink to sea-level rise

    Science.gov (United States)

    Whittle, Alex; Gallego-Sala, Angela V.

    2016-06-01

    Freshwater peatlands are carbon accumulating ecosystems where primary production exceeds organic matter decomposition rates in the soil, and therefore perform an important sink function in global carbon cycling. Typical peatland plant and microbial communities are adapted to the waterlogged, often acidic and low nutrient conditions that characterise them. Peatlands in coastal locations receive inputs of oceanic base cations that shift conditions from the environmental optimum of these communities altering the carbon balance. Blanket bogs are one such type of peatlands occurring in hyperoceanic regions. Using a blanket bog to coastal marsh transect in Northwest Scotland we assess the impacts of salt intrusion on carbon accumulation rates. A threshold concentration of salt input, caused by inundation, exists corresponding to rapid acidophilic to halophilic plant community change and a carbon accumulation decline. For the first time, we map areas of blanket bog vulnerable to sea-level rise, estimating that this equates to ~7.4% of the total extent and a 0.22 Tg yr‑1 carbon sink. Globally, tropical peatlands face the proportionally greatest risk with ~61,000 km2 (~16.6% of total) lying ≤5 m elevation. In total an estimated 20.2 ± 2.5 GtC is stored in peatlands ≤5 m above sea level, which are potentially vulnerable to inundation.

  15. Estimating the sources of global sea level rise with data assimilation techniques

    Science.gov (United States)

    Hay, Carling C.; Morrow, Eric; Kopp, Robert E.; Mitrovica, Jerry X.

    2013-02-01

    A rapidly melting ice sheet produces a distinctive geometry, or fingerprint, of sea level (SL) change. Thus, a network of SL observations may, in principle, be used to infer sources of meltwater flux. We outline a formalism, based on a modified Kalman smoother, for using tide gauge observations to estimate the individual sources of global SL change. We also report on a series of detection experiments based on synthetic SL data that explore the feasibility of extracting source information from SL records. The Kalman smoother technique iteratively calculates the maximum-likelihood estimate of Greenland ice sheet (GIS) and West Antarctic ice sheet (WAIS) melt at each time step, and it accommodates data gaps while also permitting the estimation of nonlinear trends. Our synthetic tests indicate that when all tide gauge records are used in the analysis, it should be possible to estimate GIS and WAIS melt rates greater than ∼0.3 and ∼0.4 mm of equivalent eustatic sea level rise per year, respectively. We have also implemented a multimodel Kalman filter that allows us to account rigorously for additional contributions to SL changes and their associated uncertainty. The multimodel filter uses 72 glacial isostatic adjustment models and 3 ocean dynamic models to estimate the most likely models for these processes given the synthetic observations. We conclude that our modified Kalman smoother procedure provides a powerful method for inferring melt rates in a warming world.

  16. The coastal area of Togo: A space vulnerable to sea level rise hotly disputed

    Science.gov (United States)

    Adjoussi, P. D.

    2015-12-01

    Abstract Erosion caused in the coastal area of Togo especially in the cell to the east of the harbor of Lomé some reorganization of space and a reallocation of tasks functions of the importance of existing issues. This reorganization is an important race against time between the various stakeholders which paradoxically make this area a very dynamic environment. In spite of the disaster situation in the area, it is changing. This mutation has been observed for a decade in many ways. Fishing is a traditional activity disappears causing the emergence of new activities such as the extraction of gravel, the gardening, the informal trade of any kind, installing hotels, etc.. At the socio-economic transformation is associated with a beach in state of deficit causing the decline of the coastline that reaches approximately 500 m over a few kilometers according to the old marks missing. The decline of the coastline is by undermining the beach by the waves at high tide. These issues are reshaping the land use map that passes a distribution of fishing villages on the coast in 1980 to a suburban area exposed to sea level rise corollary to anticipated climate change. Keywords: Space, Reorganization, Vulnerability, Stakeholders, Sea Level, Fishing

  17. Coastal vertebrate exposure to predicted habitat changes due to sea level rise

    Science.gov (United States)

    Hunter, Elizabeth A.; Nibbelink, Nathan P.; Alexander, Clark R.; Barrett, Kyle; Mengak, Lara F.; Guy, Rachel; Moore, Clinton; Cooper, Robert J.

    2015-01-01

    Sea level rise (SLR) may degrade habitat for coastal vertebrates in the Southeastern United States, but it is unclear which groups or species will be most exposed to habitat changes. We assessed 28 coastal Georgia vertebrate species for their exposure to potential habitat changes due to SLR using output from the Sea Level Affecting Marshes Model and information on the species’ fundamental niches. We assessed forecasted habitat change up to the year 2100 using three structural habitat metrics: total area, patch size, and habitat permanence. Almost all of the species (n = 24) experienced negative habitat changes due to SLR as measured by at least one of the metrics. Salt marsh and ocean beach habitats experienced the most change (out of 16 categorical land cover types) across the three metrics and species that used salt marsh extensively (rails and marsh sparrows) were ranked highest for exposure to habitat changes. Species that nested on ocean beaches (Diamondback Terrapins, shorebirds, and terns) were also ranked highly, but their use of other foraging habitats reduced their overall exposure. Future studies on potential effects of SLR on vertebrates in southeastern coastal ecosystems should focus on the relative importance of different habitat types to these species’ foraging and nesting requirements. Our straightforward prioritization approach is applicable to other coastal systems and can provide insight to managers on which species to focus resources, what components of their habitats need to be protected, and which locations in the study area will provide habitat refuges in the face of SLR.

  18. Coastal Vertebrate Exposure to Predicted Habitat Changes Due to Sea Level Rise

    Science.gov (United States)

    Hunter, Elizabeth A.; Nibbelink, Nathan P.; Alexander, Clark R.; Barrett, Kyle; Mengak, Lara F.; Guy, Rachel K.; Moore, Clinton T.; Cooper, Robert J.

    2015-12-01

    Sea level rise (SLR) may degrade habitat for coastal vertebrates in the Southeastern United States, but it is unclear which groups or species will be most exposed to habitat changes. We assessed 28 coastal Georgia vertebrate species for their exposure to potential habitat changes due to SLR using output from the Sea Level Affecting Marshes Model and information on the species' fundamental niches. We assessed forecasted habitat change up to the year 2100 using three structural habitat metrics: total area, patch size, and habitat permanence. Almost all of the species ( n = 24) experienced negative habitat changes due to SLR as measured by at least one of the metrics. Salt marsh and ocean beach habitats experienced the most change (out of 16 categorical land cover types) across the three metrics and species that used salt marsh extensively (rails and marsh sparrows) were ranked highest for exposure to habitat changes. Species that nested on ocean beaches (Diamondback Terrapins, shorebirds, and terns) were also ranked highly, but their use of other foraging habitats reduced their overall exposure. Future studies on potential effects of SLR on vertebrates in southeastern coastal ecosystems should focus on the relative importance of different habitat types to these species' foraging and nesting requirements. Our straightforward prioritization approach is applicable to other coastal systems and can provide insight to managers on which species to focus resources, what components of their habitats need to be protected, and which locations in the study area will provide habitat refuges in the face of SLR.

  19. Projecting future sea level

    Science.gov (United States)

    Cayan, Daniel R.; Bromirski, Peter; Hayhoe, Katharine; Tyree, Mary; Dettinger, Mike; Flick, Reinhard

    2006-01-01

    California’s coastal observations and global model projections indicate that California’s open coast and estuaries will experience increasing sea levels over the next century. Sea level rise has affected much of the coast of California, including the Southern California coast, the Central California open coast, and the San Francisco Bay and upper estuary. These trends, quantified from a small set of California tide gages, have ranged from 10–20 centimeters (cm) (3.9–7.9 inches) per century, quite similar to that estimated for global mean sea level. So far, there is little evidence that the rate of rise has accelerated, and the rate of rise at California tide gages has actually flattened since 1980, but projections suggest substantial sea level rise may occur over the next century. Climate change simulations project a substantial rate of global sea level rise over the next century due to thermal expansion as the oceans warm and runoff from melting land-based snow and ice accelerates. Sea level rise projected from the models increases with the amount of warming. Relative to sea levels in 2000, by the 2070–2099 period, sea level rise projections range from 11–54 cm (4.3–21 in) for simulations following the lower (B1) greenhouse gas (GHG) emissions scenario, from 14–61 cm (5.5–24 in) for the middle-upper (A2) emission scenario, and from 17–72 cm (6.7–28 in) for the highest (A1fi) scenario. In addition to relatively steady secular trends, sea levels along the California coast undergo shorter period variability above or below predicted tide levels and changes associated with long-term trends. These variations are caused by weather events and by seasonal to decadal climate fluctuations over the Pacific Ocean that in turn affect the Pacific coast. Highest coastal sea levels have occurred when winter storms and Pacific climate disturbances, such as El Niño, have coincided with high astronomical tides. This study considers a range of projected future

  20. Trends of sea level rise in the South China Sea during the 1990s: An altimetry result

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Using 7 years of TOPEX/POSEIDON satellite altimetry data, we have identified a general trend of sea level rising in the South China Sea between January 1993 and December 1999. The estimated bulk rising rate of the entire basin is ~1 cm/a. The rise of sea level appears to be spatially non-homogeneous, which shows a highest rate of 2.7 cm/a in the deep basin west of Luzon and generally Iow (even negafive) rates over the shallow continental shelves. It is believed that the observed rapid rising of sea level is a regional phenomenon and is mainly caused by warming of the upper layer of the South China Sea, which showed a bulk warming rate of 0.15℃/a in the same period. It is also suggested that the observed rising trend is mainly a decadal signal, which is possibly associated with decadal variation of the Pacific warm pool region.

  1. Diving In To Sea Level Rise Using The Polar Explorer ';App'

    Science.gov (United States)

    Turrin, M.; Ryan, W. B.; Bell, R. E.; Pfirman, S. L.; Bell, B.; Porter, D. F.

    2013-12-01

    The vast majority of our lifetime is spent learning outside the classroom, yet the major emphasis in developing climate change instructional materials has been the traditional K16 school environment. The Polar Learning and Responding (PoLAR) project of the National Science Foundation supported Climate Change Education Partnership (CCEP) program chose to move beyond the classroom to focus on lifelong learners, in order to engage the adult population in building public understanding about climate change. Yet reaching individuals who make their own decisions about what and how they choose to learn requires a very different approach to developing educational materials. With an adult audience how we deliver content can be as critical as what we deliver. Using materials and platforms that are readily available and familiar to the user is important. With a significant segment of our time spent connected to smart phones and tablets, employing these platforms to deliver content makes sense. Whether at work, home or in transit, portable devices are critical companions and trusted tools in providing information on everything from the latest news to the daily weather. The world of Apps is equally as familiar to the adult user, so developing an engaging climate App for a portable device offers a successful strategy. The 'Polar Explorer - Sea Level Rise (SLR) App', is one of the new interactive products developed as part of the PoLAR project. Modeled after Columbia's Earth Observer App, a data exploration and data visualization tool, the Polar Explorer SLR App includes a wide range of real Earth data from ocean and atmospheric temperatures to depth of ice layers, underlying topography and human impacts. The Polar Explorer SLR App is grounded in the concept that scientists gain insights into climate change and climate processes through directly examining data. With some scaffolding, the public can gain similar insights using the same data. Structured to be 'question driven' the

  2. Steric Sea Level Change in Twentieth Century Historical Climate Simulation and IPCC-RCP8.5 Scenario Projection: A Comparison of Two Versions of FGOALS Model

    Institute of Scientific and Technical Information of China (English)

    DONG Lu; ZHOU Tianjun

    2013-01-01

    To reveal the steric sea level change in 20th century historical climate simulations and future climate change projections under the IPCC's Representative Concentration Pathway 8.5 (RCP8.5) scenario,the results of two versions of LASG/IAP's Flexible Global Ocean-Atmosphere-Land System model (FGOALS) are analyzed.Both models reasonably reproduce the mean dynamic sea level features,with a spatial pattern correlation coefficient of 0.97 with the observation.Characteristics of steric sea level changes in the 20th century historical climate simulations and RCP8.5 scenario projections are investigated.The results show that,in the 20th century,negative trends covered most parts of the global ocean.Under the RCP8.5 scenario,global-averaged steric sea level exhibits a pronounced rising trend throughout the 21st century and the general rising trend appears in most parts of the global ocean.The magnitude of the changes in the 21st century is much larger than that in the 20th century.By the year 2100,the global-averaged steric sea level anomaly is 18 cm and 10 cm relative to the year 1850 in the second spectral version of FGOALS (FGOALS-s2) and the second grid-point version of FGOALS (FGOALS-g2),respectively.The separate contribution of the thermosteric and halosteric components from various ocean layers is further evaluated.In the 20th century,the steric sea level changes in FGOALS-s2 (FGOALS-g2) are largely attributed to the thermosteric (halosteric) component relative to the pre-industrial control run.In contrast,in the 21st century,the thermosteric component,mainly from the upper 1000 m,dominates the steric sea level change in both models under the RCP8.5 scenario.In addition,the steric sea level change in the marginal sea of China is attributed to the thermosteric component.

  3. Investigating sea level rise due to global warming in the teaching laboratory using Archimedes’ principle

    Science.gov (United States)

    Hughes, Stephen; Pearce, Darren

    2015-11-01

    A teaching laboratory experiment is described that uses Archimedes’ principle to precisely investigate the effect of global warming on the oceans. A large component of sea level rise is due to the increase in the volume of water due to the decrease in water density with increasing temperature. Water close to 0 °C is placed in a beaker and a glass marble hung from an electronic balance immersed in the water. As the water warms, the weight of the marble increases as the water is less buoyant due to the decrease in density. In the experiment performed in this paper a balance with a precision of 0.1 mg was used with a marble 40.0 cm3 and mass of 99.3 g, yielding water density measurements with an average error of -0.008 ± 0.011%.

  4. ANALISA SEA LEVEL RISE PERAIRAN INDONESIA MENGGUNAKAN DATA SATELIT ALTIMETRI JASON-2 TAHUN 2009-2012

    Directory of Open Access Journals (Sweden)

    Nur Rahman

    2015-02-01

    Full Text Available Kenaikan muka air laut (Sea Level Rise disebabkan oleh semakin meningkatnya suhu global bumi atau yang biasa disebut dengan pemanasan global. Fenomena ini harus diwaspadai, mengingat luas perairan di Indonesia mendominasi sebesar 75,32 % serta banyak terdapat pemukiman maupun pusat perekonomian yang terletak dekat dengan perairan. Dengan luas perairan yang sangat besar maka metode pengamatan konvensional seperti menggunakan kapal survei kelautan bukanlah metode yang efektif dan efisien. Penggunaan teknologi satelit altimetri menjadi salah satu alternatif yang tepat untuk mengamati fenomena ini. Salah satu satelit altimetri tersebut adalah Satelit Jason-2. Pemantauan kenaikan muka air laut dilakukan pada perairan Indonesia dalam kurun waktu 4 tahun (2009-2012 dengan mengambil 20 titik pengamatan. Terdapat 12 titik yang mengalami kenaikan dengan kenaikan terbesar mencapai 12 mm/tahun yaitu di titik Samudera Pasifik tepatnya sebelah utara Papua Barat, sedangkan kenaikan muka air laut terkecil terjadi pada titik Selat Makassar dengan kenaikan sebesar 0,587 mm/tahun.

  5. Practical Tips and Techniques on the Process of Transdisciplinary Sea Level Rise Research

    Science.gov (United States)

    DeLorme, D.; Hagen, S. C.; Kidwell, D.; Stephens, S. H.

    2015-12-01

    There is increasing awareness of the need for transdisciplinary science to address complex climate change issues, yet practical guidance is lacking. This presentation describes the iterative planning, implementation, and evaluation process of an ongoing transdisciplinary sea level rise (SLR) research project. Observations, reflections, and recommendations from firsthand experience are shared, illustrated with examples, and placed within a transdisciplinary research framework. The NOAA-sponsored project, Ecological Effects of Sea Level Rise in the Northern Gulf of Mexico (EESLR-NGOM) is a six-year regional study involving a team of biology, ecology, civil/coastal engineering, and communication scholars working with government agency personnel and industry professionals; supervising students and post-doctoral researchers; and engaging a group of non-academic stakeholders (i.e., coastal resource managers). EESLR-NGOM's focus is on detailed assessment and process-based modeling to project SLR impacts on northern Gulf of Mexico coastal wetland habitats and flood plains. This presentation highlights collaboration, communication, and project management considerations, and explains knowledge co-production from a dynamic combination of natural and social scientific methods (secondary data analysis, computer modeling, field observations, field and laboratory experiments, focus group interviews, surveys) and interrelated stakeholder engagement mechanisms (advisory committee, project flow chart, workshops, focus groups, webinars) infused throughout the EESLR-NGOM project to improve accessibility and utility of the scientific results and products. Attention is also given to project evaluation including monitoring, multiple quantitative and qualitative measures, and recognition of challenges and limitations. This presentation should generate productive dialogue and direction for similar endeavors to find transformative solutions to pressing problems of climate change.

  6. Sensitivity of Circulation in the Skagit River Estuary to Sea Level Rise and Future Flows

    Energy Technology Data Exchange (ETDEWEB)

    Khangaonkar, Tarang; Long, Wen; Sackmann, Brandon; Mohamedali, Teizeen; Hamlet, Alan F.

    2016-01-01

    Future climate simulations based on the Intergovernmental Panel on Climate Change emissions scenario (A1B) have shown that the Skagit River flow will be affected, which may lead to modification of the estuarine hydrodynamics. There is considerable uncertainty, however, about the extent and magnitude of resulting change, given accompanying sea level rise and site-specific complexities with multiple interconnected basins. To help quantify the future hydrodynamic response, we developed a three dimensional model of the Skagit River estuary using the Finite Volume Coastal Ocean Model (FVCOM). The model was set up with localized high-resolution grids in Skagit and Padilla Bay sub-basins within the intermediate-scale FVCOM based model of the Salish Sea (greater Puget Sound and Georgia Basin). Future changes to salinity and annual transport through the basin were examined. The results confirmed the existence of a residual estuarine flow that enters Skagit Bay from Saratoga Passage to the south and exits through Deception Pass. Freshwater from the Skagit River is transported out in the surface layers primarily through Deception Pass and Saratoga Passage, and only a small fraction (≈4%) is transported to Padilla Bay. The moderate future perturbations of A1B emissions, corresponding river flow, and sea level rise of 0.48 m examined here result only in small incremental changes to salinity structure and inter-basin freshwater distribution and transport. An increase in salinity of ~1 ppt in the near-shore environment and a salinity intrusion of approximately 3 km further upstream is predicted in Skagit River, well downstream of the drinking water intakes.

  7. Coastal Vulnerability to Sea Level Rise and Erosion in Northwest Alaska (Invited)

    Science.gov (United States)

    Gorokhovich, Y.; Leiserowitz, A.

    2009-12-01

    Northwest Alaska is experiencing significant climate change and human impacts. The study area includes the coastal zone of Kotzebue Sound and the Chukchi Sea and provides the local population (predominantly Inupiaq Eskimo) with critical subsistence resources of meat, fish, berries, herbs, and wood. The geomorphology of the coast includes barrier islands, inlets, estuaries, deltas, cliffs, bluffs, and beaches that host modern settlements and infrastructure. Coastal dynamics and sea-level rise are contributing to erosion, intermittent erosion/accretion patterns, landslides, slumps and coastal retreat. These factors are causing the sedimentation of deltas and lagoons, and changing local bathymetry, morphological parameters of beaches and underwater slopes, rates of coastal dynamics, and turbidity and nutrient cycling in coastal waters. This study is constructing vulnerability maps to help local people and federal officials understand the potential consequences of sea-level rise and coastal erosion on local infrastructure, subsistence resources, and culturally important sites. A lack of complete and uniform data (in terms of methods of collection, geographic scale and spatial resolution) creates an additional level of uncertainty that complicates geographic analysis. These difficulties were overcome by spatial modeling with selected spatial resolution using extrapolation methods. Data include subsistence resource maps obtained using Participatory GIS with local hunters and elders, geological and geographic data on coastal dynamics from satellite imagery, aerial photos, bathymetry and topographic maps, and digital elevation models. These data were classified and ranked according to the level of coastal vulnerability (Figure 1). The resulting qualitative multicriteria model helps to identify the coastal areas with the greatest vulnerability to coastal erosion and of the potential loss of subsistence resources. Acknowldgements: Dr. Ron Abileah (private consultant, j

  8. Potential vulnerability implications of sea level rise for the coastal zones of Cochin, southwest coast of India.

    Science.gov (United States)

    Kumar, P K Dinesh

    2006-12-01

    This study presents the results of the impact assessment analysis of the coastal zones of Cochin along the southwest coast of India. The climatological cycle of sea level derived for the region for the period 1939-2003 has shown a range of about 17 cm. From the results obtained on the coastal sedimentary environments, it is found that climate-induced sea level rise scenarios will bring profound effects. It is also revealed that the mean beach slope and relief play a vital role in land loss of the region. The local relief of coastal zone will decrease as sea level rises, thus increasing the percentage of land above mean sea level subjected to episodic inundations. Results of the yearly probability of damages indicated the urgency to upgrade the existing designs of coastal protection structures. A brief characterisation of the issues on infrastructure and uncertainties in policy planning also are attempted.

  9. Interdisciplinary assessment of sea-level rise and climate change impacts on the lower Nile delta, Egypt.

    Science.gov (United States)

    Sušnik, Janez; Vamvakeridou-Lyroudia, Lydia S; Baumert, Niklas; Kloos, Julia; Renaud, Fabrice G; La Jeunesse, Isabelle; Mabrouk, Badr; Savić, Dragan A; Kapelan, Zoran; Ludwig, Ralf; Fischer, Georg; Roson, Roberto; Zografos, Christos

    2015-01-15

    CLImate-induced changes on WAter and SECurity (CLIWASEC) was a cluster of three complementary EC-FP7 projects assessing climate-change impacts throughout the Mediterranean on: hydrological cycles (CLIMB - CLimate-Induced changes on the hydrology of Mediterranean Basins); water security (WASSERMed - Water Availability and Security in Southern EuRope and the Mediterranean) and human security connected with possible hydro-climatic conflicts (CLICO - CLImate change hydro-COnflicts and human security). The Nile delta case study was common between the projects. CLIWASEC created an integrated forum for modelling and monitoring to understand potential impacts across sectors. This paper summarises key results from an integrated assessment of potential challenges to water-related security issues, focusing on expected sea-level rise impacts by the middle of the century. We use this common focus to illustrate the added value of project clustering. CLIWASEC pursued multidisciplinary research by adopting a single research objective: sea-level rise related water security threats, resulting in a more holistic view of problems and potential solutions. In fragmenting research, policy-makers can fail to understand how multiple issues can materialize from one driver. By combining efforts, an integrated assessment of water security threats in the lower Nile is formulated, offering policy-makers a clearer picture of inter-related issues to society and environment. The main issues identified by each project (land subsidence, saline intrusion - CLIMB; water supply overexploitation, land loss - WASSERMed; employment and housing security - CLICO), are in fact related. Water overexploitation is exacerbating land subsidence and saline intrusion, impacting on employment and placing additional pressure on remaining agricultural land and the underdeveloped housing market. All these have wider implications for regional development. This richer understanding could be critical in making better

  10. Simulating the Effects of Sea Level Rise on the Resilience and Migration of Tidal Wetlands along the Hudson River

    OpenAIRE

    Tabak, Nava M.; Magdeline Laba; Sacha Spector

    2016-01-01

    Sea Level Rise (SLR) caused by climate change is impacting coastal wetlands around the globe. Due to their distinctive biophysical characteristics and unique plant communities, freshwater tidal wetlands are expected to exhibit a different response to SLR as compared with the better studied salt marshes. In this study we employed the Sea Level Affecting Marshes Model (SLAMM), which simulates regional- or local-scale changes in tidal wetland habitats in response to SLR, and adapted it for appli...

  11. Global coastal wetland change under sea-level rise and related stresses: The DIVA Wetland Change Model

    Science.gov (United States)

    Spencer, Thomas; Schuerch, Mark; Nicholls, Robert J.; Hinkel, Jochen; Lincke, Daniel; Vafeidis, A. T.; Reef, Ruth; McFadden, Loraine; Brown, Sally

    2016-04-01

    The Dynamic Interactive Vulnerability Assessment Wetland Change Model (DIVA_WCM) comprises a dataset of contemporary global coastal wetland stocks (estimated at 756 × 103 km2 (in 2011)), mapped to a one-dimensional global database, and a model of the macro-scale controls on wetland response to sea-level rise. Three key drivers of wetland response to sea-level rise are considered: 1) rate of sea-level rise relative to tidal range; 2) lateral accommodation space; and 3) sediment supply. The model is tuned by expert knowledge, parameterised with quantitative data where possible, and validated against mapping associated with two large-scale mangrove and saltmarsh vulnerability studies. It is applied across 12,148 coastal segments (mean length 85 km) to the year 2100. The model provides better-informed macro-scale projections of likely patterns of future coastal wetland losses across a range of sea-level rise scenarios and varying assumptions about the construction of coastal dikes to prevent sea flooding (as dikes limit lateral accommodation space and cause coastal squeeze). With 50 cm of sea-level rise by 2100, the model predicts a loss of 46-59% of global coastal wetland stocks. A global coastal wetland loss of 78% is estimated under high sea-level rise (110 cm by 2100) accompanied by maximum dike construction. The primary driver for high vulnerability of coastal wetlands to sea-level rise is coastal squeeze, a consequence of long-term coastal protection strategies. Under low sea-level rise (29 cm by 2100) losses do not exceed ca. 50% of the total stock, even for the same adverse dike construction assumptions. The model results confirm that the widespread paradigm that wetlands subject to a micro-tidal regime are likely to be more vulnerable to loss than macro-tidal environments. Countering these potential losses will require both climate mitigation (a global response) to minimise sea-level rise and maximisation of accommodation space and sediment supply (a regional

  12. Comparing the role of absolute sea-level rise and vertical tectonic motions in coastal flooding, Torres Islands (Vanuatu).

    Science.gov (United States)

    Ballu, Valérie; Bouin, Marie-Noëlle; Siméoni, Patricia; Crawford, Wayne C; Calmant, Stephane; Boré, Jean-Michel; Kanas, Tony; Pelletier, Bernard

    2011-08-09

    Since the late 1990s, rising sea levels around the Torres Islands (north Vanuatu, southwest Pacific) have caused strong local and international concern. In 2002-2004, a village was displaced due to increasing sea incursions, and in 2005 a United Nations Environment Programme press release referred to the displaced village as perhaps the world's first climate change "refugees." We show here that vertical motions of the Torres Islands themselves dominate the apparent sea-level rise observed on the islands. From 1997 to 2009, the absolute sea level rose by 150 + /-20 mm. But GPS data reveal that the islands subsided by 117 + /-30 mm over the same time period, almost doubling the apparent gradual sea-level rise. Moreover, large earthquakes that occurred just before and after this period caused several hundreds of mm of sudden vertical motion, generating larger apparent sea-level changes than those observed during the entire intervening period. Our results show that vertical ground motions must be accounted for when evaluating sea-level change hazards in active tectonic regions. These data are needed to help communities and governments understand environmental changes and make the best decisions for their future.

  13. Impact of sea-level rise on earthquake and landslide triggering offshore the Alentejo margin (SW Iberia)

    Science.gov (United States)

    Neves, M. C.; Roque, C.; Luttrell, K. M.; Vázquez, J. T.; Alonso, B.

    2016-12-01

    Earthquakes and submarine landslides are recurrent and widespread manifestations of fault activity offshore SW Iberia. The present work tests the effects of sea-level rise on offshore fault systems using Coulomb stress change calculations across the Alentejo margin. Large-scale faults capable of generating large earthquakes and tsunamis in the region, especially NE-SW trending thrusts and WNW-ESE trending dextral strike-slip faults imaged at basement depths, are either blocked or unaffected by flexural effects related to sea-level changes. Large-magnitude earthquakes occurring along these structures may, therefore, be less frequent during periods of sea-level rise. In contrast, sea-level rise promotes shallow fault ruptures within the sedimentary sequence along the continental slope and upper rise within distances of <100 km from the coast. The results suggest that the occurrence of continental slope failures may either increase (if triggered by shallow fault ruptures) or decrease (if triggered by deep fault ruptures) as a result of sea-level rise. Moreover, observations of slope failures affecting the area of the Sines contourite drift highlight the role of sediment properties as preconditioning factors in this region.

  14. Quantifying the effect of sea level rise and flood defence - a point process perspective on coastal flood damage

    Science.gov (United States)

    Boettle, M.; Rybski, D.; Kropp, J. P.

    2016-02-01

    In contrast to recent advances in projecting sea levels, estimations about the economic impact of sea level rise are vague. Nonetheless, they are of great importance for policy making with regard to adaptation and greenhouse-gas mitigation. Since the damage is mainly caused by extreme events, we propose a stochastic framework to estimate the monetary losses from coastal floods in a confined region. For this purpose, we follow a Peak-over-Threshold approach employing a Poisson point process and the Generalised Pareto Distribution. By considering the effect of sea level rise as well as potential adaptation scenarios on the involved parameters, we are able to study the development of the annual damage. An application to the city of Copenhagen shows that a doubling of losses can be expected from a mean sea level increase of only 11 cm. In general, we find that for varying parameters the expected losses can be well approximated by one of three analytical expressions depending on the extreme value parameters. These findings reveal the complex interplay of the involved parameters and allow conclusions of fundamental relevance. For instance, we show that the damage typically increases faster than the sea level rise itself. This in turn can be of great importance for the assessment of sea level rise impacts on the global scale. Our results are accompanied by an assessment of uncertainty, which reflects the stochastic nature of extreme events. While the absolute value of uncertainty about the flood damage increases with rising mean sea levels, we find that it decreases in relation to the expected damage.

  15. Detailed Flood Modeling and Hazard Assessment from Storm Tides, Rainfall and Sea Level Rise

    Science.gov (United States)

    Orton, P. M.; Hall, T. M.; Georgas, N.; Conticello, F.; Cioffi, F.; Lall, U.; Vinogradov, S. V.; Blumberg, A. F.

    2014-12-01

    A flood hazard assessment has been conducted for the Hudson River from New York City to Troy at the head of tide, using a three-dimensional hydrodynamic model and merging hydrologic inputs and storm tides from tropical and extra-tropical cyclones, as well as spring freshet floods. Our recent work showed that neglecting freshwater flows leads to underestimation of peak water levels at up-river sites and neglecting stratification (typical with two-dimensional modeling) leads to underestimation all along the Hudson. The hazard assessment framework utilizes a representative climatology of over 1000 synthetic tropical cyclones (TCs) derived from a statistical-stochastic TC model, and historical extra-tropical cyclones and freshets from 1950-present. Hydrodynamic modeling is applied with seasonal variations in mean sea level and ocean and estuary stratification. The model is the Stevens ECOM model and is separately used for operational ocean forecasts on the NYHOPS domain (http://stevens.edu/NYHOPS). For the synthetic TCs, an Artificial Neural Network/ Bayesian multivariate approach is used for rainfall-driven freshwater inputs to the Hudson, translating the TC attributes (e.g. track, SST, wind speed) directly into tributary stream flows (see separate presentation by Cioffi for details). Rainfall intensity has been rising in recent decades in this region, and here we will also examine the sensitivity of Hudson flooding to future climate warming-driven increases in storm precipitation. The hazard assessment is being repeated for several values of sea level, as projected for future decades by the New York City Panel on Climate Change. Recent studies have given widely varying estimates of the present-day 100-year flood at New York City, from 2.0 m to 3.5 m, and special emphasis will be placed on quantifying our study's uncertainty.

  16. Global DEM Errors Underpredict Coastal Vulnerability to Sea Level Rise and Flooding

    Science.gov (United States)

    Kulp, Scott; Strauss, Benjamin

    2016-04-01

    Elevation data based on NASA's Shuttle Radar Topography Mission (SRTM) have been widely used to evaluate threats from global sea level rise, storm surge, and coastal floods. However, SRTM data are known to include large vertical errors in densely urban or densely vegetated areas. The errors may propagate to derived land and population exposure assessments. We compare assessments based on SRTM data against references employing high-accuracy bare-earth elevation data generated from lidar data available for coastal areas of the United States. We find that both 1-arcsecond and 3-arcsecond horizontal resolution SRTM data systemically underestimate exposure across all assessed spatial scales and up to at least 10m above the high tide line. At 3m, 1-arcsecond SRTM underestimates U.S. population exposure by more than 60%, and under-predicts population exposure in 90% of coastal states, 87% of counties, and 83% of municipalities. These fractions increase with elevation, but error medians and variability fall to lower levels, with national exposure underestimated by just 24% at 10m. Results using 3-arcsecond SRTM are extremely similar. Coastal analyses based on SRTM data thus appear to greatly underestimate sea level and flood threats, especially at lower elevations. However, SRTM-based estimates may usefully be regarded as providing lower bounds to actual threats. We additionally assess the performance of NOAA's Global Land One-km Base Elevation Project (GLOBE), another publicly-available global DEM, but do not reach any definitive conclusion because of the spatial heterogeneity in its quality.

  17. Extreme floods in the Mekong River Delta under climate change: combined impacts of upstream hydrological changes and sea level rise

    Science.gov (United States)

    Hoang, Long; Nguyen Viet, Dung; Kummu, Matti; Lauri, Hannu; Koponen, Jorma; van Vliet, Michelle T. H.; Supit, Iwan; Leemans, Rik; Kabat, Pavel; Ludwig, Fulco

    2016-04-01

    Extreme floods cause huge damages to human lives and infrastructure, and hamper socio-economic development in the Mekong River Delta in Vietnam. Induced by climate change, upstream hydrological changes and sea level rise are expected to further exacerbate future flood hazard and thereby posing critical challenges for securing safety and sustainability. This paper provides a probabilistic quantification of future flood hazard for the Mekong Delta, focusing on extreme events under climate change. We developed a model chain to simulate separate and combined impacts of two drivers, namely upstream hydrological changes and sea level rise on flood magnitude and frequency. Simulation results show that upstream changes and sea level rise substantially increase flood hazard throughout the whole Mekong Delta. Due to differences in their nature, two drivers show different features in their impacts on floods. Impacts of upstream changes are more dominant in floodplains in the upper delta, causing an increase of up to +0.80 m in flood depth. Sea level rise introduces flood hazard to currently safe areas in the middle and coastal delta zones. A 0.6 m rise in relative sea level causes an increase in flood depth between 0.10 and 0.70 m, depending on location by 2050s. Upstream hydrological changes and sea level rise tend to intensify each other's impacts on floods, resulting in stronger combined impacts than linearly summed impacts of each individual driver. Substantial increase of future flood hazard strongly requires better flood protection and more flood resilient development for the Mekong Delta. Findings from this study can be used as quantified physical boundary conditions to develop flood management strategies and strategic delta management plans.

  18. Postglacial sea-level rise and its impact on the circum-arctic Holocene climate evolution

    Science.gov (United States)

    Bauch, Henning; Abramova, Ekaterina; Alenius, Teija; Saarnisto, Matti

    2016-04-01

    The global sea-level rise after the last glaciation not only affected the surface properties (circulation, T-S, sea ice seasonality) of the Arctic Ocean and nearby seas it also had a strong impact on the Holocene development of the shallow North Siberian shelf systems and the environmental evolution of the adjacent hinterland areas. In this region sea level reconstructions indicate the postglacial highstand occurred some time in the middle Holocene, between 6 to 5 ka (Klemann et al., 2015). After that time the sedimentary regime of the shelf seas stabilized as noted in a drastic decrease in sedimentation rates observed in all sediment cores taken from middle to outer shelf water depths of the Laptev Sea (Bauch et al. 2001). But, at water depths lower than 30 meters - i.e., in the inner shelf and nearer to the coasts - sedimentation continued at relatively higher rates, presumably due to input of terrigenous material from river runoff as well as coastal erosion. In relation to the latter process, the huge Lena Delta should comprise a region of sediment catchment where aggradation wins over erosion. However, little is known about the detailed history of this delta during the second half of the Holocene. We therefore have investigated three islands within the Lena Delta. All of these are comprised of massive peat of several meters in thickness. Picking discrete specimens of water mosses (Sphagnum) only, we have carefully dated these peat sections. The depth/age relation of the sampled profiles reflect the growth rate of peat, and thus, the islands. It shows that the islands' history above the present-day delta sea level is about 4000 yrs. old. Moreover, a significant change in peat growth is noted after 2500 yrs BP in both, accumulation and composition, and allows the conclusion of a major shift in Arctic environmental conditions since then. Thus, our results add further information also for other coastal studies, as the ongoing degradation of the rather vulnerable

  19. Integrated Modeling for the Assessment of Ecological Impacts of Sea Level Rise

    Science.gov (United States)

    Hagen, S. C.; Lewis, G.; Bartel, R.; Batten, B.; Huang, W.; Morris, J.; Slinn, D. N.; Sparks, J.; Walters, L.; Wang, D.; Weishampel, J.; Yeh, G.

    2010-12-01

    Sea level rise (SLR) has the potential to affect a variety of coastal habitats with a myriad of deleterious ecological effects and to overwhelm human settlements along the coast. SLR should be given serious consideration when more than half of the U.S. population lives within 50 miles of the coast. SLR effects will be felt along coastal beaches and in estuarine waters, with consequences to barrier islands, submerged aquatic vegetation beds, sand and mud flats, oyster reefs, and tidal and freshwater wetlands. Managers of these coastal resources must be aware of potential consequences of SLR and adjust their plans accordingly to protect and preserve the resources under their care. The Gulf Coast provides critical habitats for a majority of the commercially important species in the Gulf of Mexico, which depend on inshore waters for either permanent residence or nursery area. The ecosystem services provided by these coastal habitats are at risk from rising sea level. Our team will assess the risk to coasts and coastal habitats from SLR in a 5-year project. We will apply existing models of circulation and transport from the watershed to the sea. The ultimate prediction will be of sediment loadings to the estuary as a result of overland flow, shoreline and barrier island erosion, and salinity transport, all of which will be used to model the evolution of intertidal marshes (MEM II). Over the five-year course of our research we will be simulating hydrodynamics and transport for all three NERRS reserves, including: Apalachicola, Weeks Bay and Grand Bay. The project will result in products whereby managers will be able to assess marshes, oyster reefs, submerged aquatic vegetation, predict wetland stability and indentify restoration locations for marsh and oyster habitats. In addition, we will produce Decision Support tools that will enable managers to predict future coastal erosion rates for management-specified shorelines. Project outcomes will enable the management

  20. Supporting Coastal Management Decisions in the Face of Sea-Level Rise: Case Study for the Chesapeake Bay Region

    Science.gov (United States)

    Staudt, A. C.; Glick, P.; Clough, J. S.; Nunley, B.

    2008-12-01

    Sea-level rise needs to be a major consideration in regional coastal management and ecological restoration plans. The National Wildlife Federation has initiated a multi-pronged strategy for assisting decision makers at government agencies that manage near-shore ecosystems in several vulnerable coastal regions. Results from our work in the Chesapeake Bay region will be presented. This strategy involves: (1) Detailed modeling of how coastal habitats will migrate in response to a range of sea-level rise scenarios. For this work, we used the Sea Level Affecting Marshes Model (SLAMM), which simulates the dominant processes involved in wetland conversions and shoreline modifications during long-term sea-level rise and takes into consideration localized changes in land elevation due to geological and ecological factors. These model results provide specific information about the locations that are likely to experience shifts in coastal marshes, swamps, beaches, and other habitats due to sea-level rise at a scale that is relevant to regional decision making. (2) Extensive literature review and analysis of habitat, fish, and wildlife impacts potentially resulting from expected sea-level rise and other local climate changes. Synthesizing the available research is an important service for natural resource agencies that are only beginning to consider climate impacts on ecosystems and natural resources. (3) Analysis of government programs and policies relevant to coastal management and identification of opportunities to revise these policies in light of projected climate changes. An important aspect of this analysis is meeting with key decision makers at relevant state fish and wildlife agencies to better understand the factors that affect their abilities to effect policy changes. (4) Proactive campaign to share our results with diverse audiences. We have developed different research products, ranging from a technical report of the modeling results to short report briefs, to

  1. Apparent Sea Level Rise due to Loading of the Atlantic City Pier by Spectators Viewing (1929-1978) Diving Horses

    Science.gov (United States)

    Galvin, C.

    2012-12-01

    Cyril Galvin, Coastal Engineer Springfield, Virginia 22150 USA Since 1911, the Steel Pier at Atlantic City, New Jersey, has been the site of the Atlantic City tide gauge, except for two intervals: 1911-1921 when the gauge was at the Million Dollar Pier in Atlantic City, and 1985-1991 when the gauge was at the Ventnor Fishing Pier (see Table 2, Zervos, 2009). By design, the Steel Pier was an amusement pier, and its most famous amusement was the Diving Horses: they dove bareback with a woman rider from a platform about 40 feet above sea level. They did that between 1929 and 1978, except for seven years - a post-war period, 1945 to 1953, when diving was suspended. The popularity of the diving horses is recorded on photos of crowds which occupied the bleachers at the seaward end of the pier to view the diving horses. By my count, the crowd pictured in the end papers of the book by Steve Liebowitz (2009) was about 4000 people. Typically, there were multiple shows daily. The weight of the crowd, estimated from the count of the crowd, was about 150 tons. This weight was loaded down on the piles by the crowd of spectators, and unloaded between shows of the diving horses. Most of the piles supporting the pier deck were imbedded in sand newly deposited since 1850. Using Atlantic City sea levels from the PSMSL data base and historical facts from Liebowitz (2009), and beginning with a 1912 start of the tide gauge, the apparent sea level rose at a rate of 3.1mm/yr until 1929 when the horses began diving. With the 1929 start of diving, the apparent sea level rise tripled, averaging 9.4 mm/yr until the act was suspended in 1945. In the 1945-1953 interval, when the horses did not dive (no crowds on the pier), apparent sea level fell (sea level FELL) at a rate of -1.6 mm/yr. The horses resumed diving in 1953, when the apparent sea level resumed at a rate of 4.0mm/yr. This 4.0 mm/yr is identical to the longtime sea level trend (1911-2006) from Zervos (2009) of 3.99mm/yr The history

  2. Effects of elevated temperatures and rising sea level on Arctic Coast

    Science.gov (United States)

    Barnes, Peter W.

    1990-01-01

    Ice is a major agent on the inner shelf, gouging the bottom, increasing hydraulic scour, transporting sediment, and influencing river flood patterns. Rapid coastal retreat is common and low barrier islands and beaches are constantly changing due to the influence of permafrost, ice-push, waves, and currents. Coastal processes are presently a balance between the influence of ice and the action of waves and currents. Quantitative values for processes are poorly known, however our qualitative understanding is nearly complete. Climatic warming and rising sea levels would decrease the temporal and aerial extent of coastal ice thereby expanding the role of waves and currents. As a result, shoreline retreat rates would increase, producing a transgressive erosional surface on the low coastal plain. With increased wave activity, beaches and barrier islands presently nourished by ice push processes would decay and disappear. Increased sediment supply from a deeply thawed, active layer would release more sediments to rivers and coasts. Additional research should be focused on permafrost and sea ice processes active during freeze up and breakup; the two seasons of most vigorous activity and change.

  3. How Much Are Floridians Willing to Pay for Protecting Sea Turtles from Sea Level Rise?

    Science.gov (United States)

    Hamed, Ahmed; Madani, Kaveh; Von Holle, Betsy; Wright, James; Milon, J. Walter; Bossick, Matthew

    2016-01-01

    Sea level rise (SLR) is posing a great inundation risk to coastal areas. Some coastal nesting species, including sea turtle species, have experienced diminished habitat from SLR. Contingent valuation method (CVM) was used in an effort to assess the economic loss impacts of SLR on sea turtle nesting habitats for Florida coasts; and to elicit values of willingness to pay (WTP) of Central Florida residents to implement certain mitigation strategies, which would protect Florida's east coast sea turtle nesting areas. Using the open-ended and dichotomous choice CVM, we sampled residents of two Florida communities: Cocoa Beach and Oviedo. We estimated the WTP of households from these two cities to protect sea turtle habitat to be between 42 and 57 per year for 5 years. Additionally, we attempted to assess the impact of the both the respondents' demographics and their perception toward various situations on their WTP value. Findings include a negative correlation between the age of a respondent and the probability of an individual willing to pay the hypothetical WTP amount. We found that WTP of an individual was not dependent on prior knowledge of the effects of SLR on sea turtle habitat. The greatest indicators of whether or not an individual was willing to pay to protect sea turtle habitat were the respondents' perception regarding the trustworthiness and efficiency of the party which will implement the conservation measures and their confidence in the conservation methods used. Respondents who perceive sea turtles having an effect on their life were also more likely to pay.

  4. Migratory connectivity magnifies the consequences of habitat loss from sea-level rise for shorebird populations.

    Science.gov (United States)

    Iwamura, Takuya; Possingham, Hugh P; Chadès, Iadine; Minton, Clive; Murray, Nicholas J; Rogers, Danny I; Treml, Eric A; Fuller, Richard A

    2013-06-22

    Sea-level rise (SLR) will greatly alter littoral ecosystems, causing habitat change and loss for coastal species. Habitat loss is widely used as a measurement of the risk of extinction, but because many coastal species are migratory, the impact of habitat loss will depend not only on its extent, but also on where it occurs. Here, we develop a novel graph-theoretic approach to measure the vulnerability of a migratory network to the impact of habitat loss from SLR based on population flow through the network. We show that reductions in population flow far exceed the proportion of habitat lost for 10 long-distance migrant shorebirds using the East Asian-Australasian Flyway. We estimate that SLR will inundate 23-40% of intertidal habitat area along their migration routes, but cause a reduction in population flow of up to 72 per cent across the taxa. This magnifying effect was particularly strong for taxa whose migration routes contain bottlenecks-sites through which a large fraction of the population travels. We develop the bottleneck index, a new network metric that positively correlates with the predicted impacts of habitat loss on overall population flow. Our results indicate that migratory species are at greater risk than previously realized.

  5. A Climate Change Adaptation Planning Process for Low-Lying, Communities Vulnerable to Sea Level Rise

    Directory of Open Access Journals (Sweden)

    Kristi Tatebe

    2012-09-01

    Full Text Available While the province of British Columbia (BC, Canada, provides guidelines for flood risk management, it is local governments’ responsibility to delineate their own flood vulnerability, assess their risk, and integrate these with planning policies to implement adaptive action. However, barriers such as the lack of locally specific data and public perceptions about adaptation options mean that local governments must address the need for adaptation planning within a context of scientific uncertainty, while building public support for difficult choices on flood-related climate policy and action. This research demonstrates a process to model, visualize and evaluate potential flood impacts and adaptation options for the community of Delta, in Metro Vancouver, across economic, social and environmental perspectives. Visualizations in 2D and 3D, based on hydrological modeling of breach events for existing dike infrastructure, future sea level rise and storm surges, are generated collaboratively, together with future adaptation scenarios assessed against quantitative and qualitative indicators. This ‘visioning package’ is being used with staff and a citizens’ Working Group to assess the performance, policy implications and social acceptability of the adaptation strategies. Recommendations based on the experience of the initiative are provided that can facilitate sustainable future adaptation actions and decision-making in Delta and other jurisdictions.

  6. Uncertainties in Tidally Adjusted Estimates of Sea Level Rise Flooding (Bathtub Model for the Greater London

    Directory of Open Access Journals (Sweden)

    Ali P. Yunus

    2016-04-01

    Full Text Available Sea-level rise (SLR from global warming may have severe consequences for coastal cities, particularly when combined with predicted increases in the strength of tidal surges. Predicting the regional impact of SLR flooding is strongly dependent on the modelling approach and accuracy of topographic data. Here, the areas under risk of sea water flooding for London boroughs were quantified based on the projected SLR scenarios reported in Intergovernmental Panel on Climate Change (IPCC fifth assessment report (AR5 and UK climatic projections 2009 (UKCP09 using a tidally-adjusted bathtub modelling approach. Medium- to very high-resolution digital elevation models (DEMs are used to evaluate inundation extents as well as uncertainties. Depending on the SLR scenario and DEMs used, it is estimated that 3%–8% of the area of Greater London could be inundated by 2100. The boroughs with the largest areas at risk of flooding are Newham, Southwark, and Greenwich. The differences in inundation areas estimated from a digital terrain model and a digital surface model are much greater than the root mean square error differences observed between the two data types, which may be attributed to processing levels. Flood models from SRTM data underestimate the inundation extent, so their results may not be reliable for constructing flood risk maps. This analysis provides a broad-scale estimate of the potential consequences of SLR and uncertainties in the DEM-based bathtub type flood inundation modelling for London boroughs.

  7. Evaluation of dynamic coastal response to sea-level rise modifies inundation likelihood

    Science.gov (United States)

    Lentz, Erika E.; Thieler, E. Robert; Plant, Nathaniel G.; Stippa, Sawyer R.; Horton, Radley M.; Gesch, Dean B.

    2016-01-01

    Sea-level rise (SLR) poses a range of threats to natural and built environments1, 2, making assessments of SLR-induced hazards essential for informed decision making3. We develop a probabilistic model that evaluates the likelihood that an area will inundate (flood) or dynamically respond (adapt) to SLR. The broad-area applicability of the approach is demonstrated by producing 30 × 30 m resolution predictions for more than 38,000 km2 of diverse coastal landscape in the northeastern United States. Probabilistic SLR projections, coastal elevation and vertical land movement are used to estimate likely future inundation levels. Then, conditioned on future inundation levels and the current land-cover type, we evaluate the likelihood of dynamic response versus inundation. We find that nearly 70% of this coastal landscape has some capacity to respond dynamically to SLR, and we show that inundation models over-predict land likely to submerge. This approach is well suited to guiding coastal resource management decisions that weigh future SLR impacts and uncertainty against ecological targets and economic constraints.

  8. Evaluating Coastal Landscape Response to Sea-Level Rise in the Northeastern United States - Approach and Methods

    Science.gov (United States)

    Lentz, Erika E.; Stippa, Sawyer R.; Thieler, E. Robert; Plant, Nathaniel G.; Gesch, Dean B.; Horton, Radley M.

    2015-01-01

    The U.S. Geological Survey is examining effects of future sea-level rise on the coastal landscape from Maine to Virginia by producing spatially explicit, probabilistic predictions using sea-level projections, vertical land movement rates (due to isostacy), elevation data, and land-cover data. Sea-level-rise scenarios used as model inputs are generated by using multiple sources of information, including Coupled Model Intercomparison Project Phase 5 models following representative concentration pathways 4.5 and 8.5 in the Intergovernmental Panel on Climate Change Fifth Assessment Report. A Bayesian network is used to develop a predictive coastal response model that integrates the sea-level, elevation, and land-cover data with assigned probabilities that account for interactions with coastal geomorphology as well as the corresponding ecological and societal systems it supports. The effects of sea-level rise are presented as (1) level of landscape submergence and (2) coastal response type characterized as either static (that is, inundation) or dynamic (that is, landform or landscape change). Results are produced at a spatial scale of 30 meters for four decades (the 2020s, 2030s, 2050s, and 2080s). The probabilistic predictions can be applied to landscape management decisions based on sea-level-rise effects as well as on assessments of the prediction uncertainty and need for improved data or fundamental understanding. This report describes the methods used to produce predictions, including information on input datasets; the modeling approach; model outputs; data-quality-control procedures; and information on how to access the data and metadata online.

  9. Evaluating coastal landscape response to sea-level rise in the northeastern United States: approach and methods

    Science.gov (United States)

    Lentz, Erika E.; Stippa, Sawyer R.; Thieler, E. Robert; Plant, Nathaniel G.; Gesch, Dean B.; Horton, Radley M.

    2014-02-13

    The U.S. Geological Survey is examining effects of future sea-level rise on the coastal landscape from Maine to Virginia by producing spatially explicit, probabilistic predictions using sea-level projections, vertical land movement rates (due to isostacy), elevation data, and land-cover data. Sea-level-rise scenarios used as model inputs are generated by using multiple sources of information, including Coupled Model Intercomparison Project Phase 5 models following representative concentration pathways 4.5 and 8.5 in the Intergovernmental Panel on Climate Change Fifth Assessment Report. A Bayesian network is used to develop a predictive coastal response model that integrates the sea-level, elevation, and land-cover data with assigned probabilities that account for interactions with coastal geomorphology as well as the corresponding ecological and societal systems it supports. The effects of sea-level rise are presented as (1) level of landscape submergence and (2) coastal response type characterized as either static (that is, inundation) or dynamic (that is, landform or landscape change). Results are produced at a spatial scale of 30 meters for four decades (the 2020s, 2030s, 2050s, and 2080s). The probabilistic predictions can be applied to landscape management decisions based on sea-level-rise effects as well as on assessments of the prediction uncertainty and need for improved data or fundamental understanding. This report describes the methods used to produce predictions, including information on input datasets; the modeling approach; model outputs; data-quality-control procedures; and information on how to access the data and metadata online.

  10. Implications of sea level rise scenarios on land use /land cover classes of the coastal zones of Cochin, India.

    Science.gov (United States)

    Mani Murali, R; Dinesh Kumar, P K

    2015-01-15

    Physical responses of the coastal zones in the vicinity of Cochin, India due to sea level rise are investigated based on analysis of inundation scenarios. Quantification of potential habitat loss was made by merging the Land use/Land cover (LU/LC) prepared from the satellite imagery with the digital elevation model. Scenarios were generated for two different rates of sea level rise and responses of changes occurred were made to ascertain the vulnerability and loss in extent. LU/LC classes overlaid on 1 m and 2 m elevation showed that it was mostly covered by vegetation areas followed by water and urban zones. For the sea level rise scenarios of 1 m and 2 m, the total inundation zones were estimated to be 169.11 km(2) and 598.83 km(2) respectively using Geographic Information System (GIS). The losses of urban areas were estimated at 43 km(2) and 187 km(2) for the 1 m and 2 m sea level rise respectively which is alarming information for the most densely populated state of India. Quantitative comparison of other LU/LC classes showed significant changes under each of the inundation scenarios. The results obtained conclusively point that sea level rise scenarios will bring profound effects on the land use and land cover classes as well as on coastal landforms in the study region. Coastal inundation would leave ocean front and inland properties vulnerable. Increase in these water levels would alter the coastal drainage gradients. Reduction in these gradients would increase flooding attributable to rainstorms which could promote salt water intrusion into coastal aquifers and force water tables to rise. Changes in the coastal landforms associated with inundation generate concern in the background that the coastal region may continue to remain vulnerable in the coming decades due to population growth and development pressures.

  11. Reconsidering Melt-water Pulses 1A and 1B:Global Impacts of Rapid Sea-level Rise

    Institute of Scientific and Technical Information of China (English)

    J.Paul Liu; John D.Milliman

    2004-01-01

    Re-evaluation of the post-glacial sea level derived from the Barbados coral-reef borings suggests slightly revised depth ranges and timing of melt-water pulses MWP-1A(96-76 m, 14.3-14.0 ka cal BP)and 1B(58-45 m, 11.5-11.2 ka cal BP), respectively. Ages of non-reef sea-level indicators from the Sunda Shelf, the East China Sea and Yellow Sea for these two intervals are unreliable because of the well-documented radiocarbon(14C)plateau, but their vertical clustering corresponds closely with MWP-1A and 1B depth ranges. Close correlation of the revised sea-level curve with Greenland ice-core data suggests that the 14C plateau may be related to oceanographic-atmospheric changes due to rapid sea-level rise, fresh-water input, and impaired ocean circulation. MWP-1A appears to have occurred at the end of Blling Warm Transition, suggesting that the rapid sea-level rise may have resulted from lateral heat transport from low to high-latitude regions and subsequent abrupt ice-sheet collapses in both North America-Europe and Antarctica. An around 70 mm a-1 transgression during MWP-1A may have increased freshwater discharge to the North Atlantic by as much as an order of magnitude, thereby disturbing thermohaline circulation and initiating the Older Dryas global cooling.

  12. Sea Level Rise and Climate Change Effects on Marsh Plants Spartina Alterniflora and Typha Angustifolia Using Mesocosms

    Science.gov (United States)

    A four month experiment using greenhouse mesocosms was conducted to analyze the effect of sea level rise and climate change on salt marsh plants Spartina alterniflora (cordgrass) and Typha angustifolia (narrow-leaved cattail). Our goal was to examine the effects of three differen...

  13. Computing Risk to West Coast Intertidal Rocky Habitat due to Sea Level Rise using LiDAR Topobathy

    Science.gov (United States)

    Compared to marshes, little information is available on the potential for rocky intertidal habitats to migrate upward in response to sea level rise (SLR). To address this gap, we utilized topobathy LiDAR digital elevation models (DEMs) downloaded from NOAA’s Digital Coast G...

  14. Sediment and vegetation spatial dynamics facing sea-level rise in microtidal salt marshes: Insights from an ecogeomorphic model

    Science.gov (United States)

    Belliard, J.-P.; Di Marco, N.; Carniello, L.; Toffolon, M.

    2016-07-01

    Modeling efforts have considerably improved our understanding on the chief processes that govern the evolution of salt marshes under climate change. Yet the spatial dynamic response of salt marshes to sea-level rise that results from the interactions between the tidal landforms of interest and the presence of bio-geomorphic features has not been addressed explicitly. Accordingly, we use a modeling framework that integrates the co-evolution of the marsh platform and the embedded tidal networks to study sea-level rise effects on spatial sediment and vegetation dynamics in microtidal salt marshes considering different ecological scenarios. The analysis unveils mechanisms that drive spatial variations in sedimentation rates in ways that increase marsh resilience to rising sea-levels. In particular, marsh survival is related to the effectiveness of transport of sediments toward the interior marshland. This study hints at additional dynamics related to the modulation of channel cross-sections affecting sediment advection in the channels and subsequent delivery in the inner marsh, which should be definitely considered in the study of marsh adaptability to sea-level rise and posterior management.

  15. Plant growth under salinity and inundation stress: implications for sea-level rise on tidal wetland function

    Science.gov (United States)

    Climate change and sea-level rise (SLR) may increase salinity or inundation duration for tidal wetland organisms. To test the effects of these stressors on wetland productivity, we transplanted seedlings of seven common plant species to polyhaline, mesohaline and oligohaline tida...

  16. Global assessment of vulnerability to sea-level rise in topography-limited and recharge-limited coastal groundwater systems

    Science.gov (United States)

    Michael, Holly A.; Russoniello, Christopher J.; Byron, Lindsay A.

    2013-04-01

    Impacts of rising sea level on the hydraulic balance between aquifers and the ocean threaten fresh water resources and aquatic ecosystems along many world coastlines. Understanding the vulnerability of groundwater systems to these changes and the primary factors that determine the magnitude of system response is critical to developing effective management and adaptation plans in coastal zones. We assessed the vulnerability of two types of groundwater systems, recharge-limited and topography-limited, to changes caused by sea-level rise over a range of hydrogeologic settings. Vulnerability in this context is defined by the rate and magnitude of salinization of coastal aquifers and changes in groundwater flow to the sea. Two-dimensional variable-density groundwater flow and salt transport simulations indicate that the response of recharge-limited systems is largely minimal, whereas topography-limited systems are vulnerable for various combinations of permeability, vertical anisotropy in permeability, and recharge. World coastlines were classified according to system type as a vulnerability indicator. Results indicate that approximately 70% of world coastlines may be topography-limited, though variability in hydrogeologic conditions strongly affects classification. Future recharge and sea-level rise scenarios have much less influence on the proportion of vulnerable coastlines than differences in permeability, distance to a hydraulic divide, and recharge, indicating that hydrogeologic properties and setting are more important factors to consider in determining system type than uncertainties in the magnitude of sea-level rise and hydrologic shifts associated with future climate change.

  17. Final project memorandum: sea-level rise modeling handbook: resource guide for resource managers, engineers, and scientists

    Science.gov (United States)

    Doyle, Thomas W.

    2015-01-01

    Coastal wetlands of the Southeastern United States are undergoing retreat and migration from increasing tidal inundation and saltwater intrusion attributed to climate variability and sea-level rise. Much of the literature describing potential sea-level rise projections and modeling predictions are found in peer-reviewed academic journals or government technical reports largely suited to reading by other Ph.D. scientists who are more familiar or engaged in the climate change debate. Various sea-level rise and coastal wetland models have been developed and applied of different designs and scales of spatial and temporal complexity for predicting habitat and environmental change that have not heretofore been synthesized to aid natural resource managers of their utility and limitations. Training sessions were conducted with Federal land managers with U.S. Fish and Wildlife Service, National Park Service, and NOAA National Estuarine Research Reserves as well as state partners and nongovernmental organizations across the northern Gulf Coast from Florida to Texas to educate and to evaluate user needs and understanding of concepts, data, and modeling tools for projecting sea-level rise and its impact on coastal habitats and wildlife. As a result, this handbook was constructed from these training and feedback sessions with coastal managers and biologists of published decision-support tools and simulation models for sea-level rise and climate change assessments. A simplified tabular context was developed listing the various kinds of decision-support tools and ecological models along with criteria to distinguish the source, scale, and quality of information input and geographic data sets, physical and biological constraints and relationships, datum characteristics of water and land elevation components, utility options for setting sea-level rise and climate change scenarios, and ease or difficulty of storing, displaying, or interpreting model output. The handbook is designed

  18. Deviation of Baltic, Adriatic and Black Sea level from the global mean during the 20th century: analysis of the main factors involved and a high-end projection to the end of 21st century.

    Science.gov (United States)

    Scarascia, Luca; Lionello, Piero

    2016-04-01

    . Although a non-negligible fraction of past interannual variability of sea level remains to be explained in this study, a statistical model of basin sea level has been built. On the basis of an estimation obtained by forcing it with the outputs of ten CIMP5 models, it seems unlikely that local factors will be responsible for future large deviations of the regional sea level from the global mean until end of the 21st century. This study is part of the activities of RISES-AM project (FP7-EU-603396).

  19. Empirical Projection of Long-Term Coastal Erosion Hazards in Hawaii Under Rising Sea Levels: Preliminary Findings

    Science.gov (United States)

    Anderson, T. R.; Barbee, M.; Fletcher, C. H., II; Romine, B. M.; Lemmo, S.

    2014-12-01

    Chronic erosion dominates sandy beaches of Hawaii causing loss and beach narrowing; and damaging homes, infrastructure, and critical habitat. Increased rates of sea level rise (SLR) will likely exacerbate these problems. Shoreline managers and other stakeholders need guidance to support long-range planning and adaptation efforts. Despite recent advances in sophisticated numerical models, there remains a need for simple approaches to estimating land areas that are threatened by erosion on decadal-to-century time scales due to SLR. While not as detailed as numerical models, empirical approaches can provide a first-order approximation to shoreline change that may be useful for coastal management and planning. Shoreline managers in Hawaii commonly work with historical data to provide information on coastal erosion. Simple linear regression methods have been especially attractive in Hawaii, where complex reef topography can cause high spatial variability in sediment transport patterns. Yet, facing projected future increases in the rate of SLR, extrapolating historical trends is insufficient. Predictions of shoreline change with SLR commonly employ controversial geometric models (e.g., the Bruun Model) that do not account for sediment availability and alongshore variability captured in historical data. Furthermore, these two projections often produce conflicting results. We report here on the early results of mapping probability-based erosion hazard areas, determined by combining the extrapolated historical shoreline change model with a geometric model of shoreline response (Davidson-Arnott, 2005) to strictly accelerated SLR. A geographic information system is used to explore the intersection between potential erosion hazards, coastal geology, and development patterns. This approach is attractive because it is simple and utilizes existing datasets. Yet, its simplicity implies broad assumptions of the coastal system and leads to large uncertainty in projections. To

  20. Strategies for Sharing Scientific Research on Sea Level Rise: Suggestions from Stakeholder Focus Groups

    Science.gov (United States)

    DeLorme, D.; Hagen, S. C.; Stephens, S. H.

    2013-12-01

    This presentation reports results of focus groups with coastal resource managers on suggestions for effectively sharing sea level rise (SLR) scientific research with the public and other target audiences. The focus groups were conducted during three annual stakeholder workshops as an important and innovative component of an ongoing five-year multi-disciplinary NOAA-funded project, Ecological Effects of Sea Level Rise in the Northern Gulf of Mexico (EESLR-NGOM). The EESLR-NGOM project is assessing SLR risks to the natural and built environment along the Mississippi, Alabama, and Florida Panhandle coasts. The purpose was to engage stakeholders (e.g., coastal resource managers) in helping target, translate, and tailor the EESLR-NGOM project's scientific findings and emerging products so they are readily accessible, understandable, and useful. The focus groups provided insight into stakeholders' SLR informational and operational needs, solicited input on the project's products, and gathered suggestions for public communication and outreach. A total of three ninety-minute focus groups of between eight and thirteen participants each were conducted at annual workshops in Alabama, Florida, and Mississippi. The moderator asked a series of open-ended questions about SLR-related topics using an interview guide and encouraged participant interaction. All focus group audio-recordings were transcribed, and analyzed by carefully reading the 102 total pages of transcript data and identifying patterns and themes. Participants thought outreach about SLR impact and the EESLR-NGOM project scientific research/products was vital and acknowledged various communication challenges and opportunities. They identified three target audiences (local officials, general public, coastal resource managers themselves) that likely require different educational efforts and tools. Participants felt confident the EESLR-NGOM project products will benefit their resource planning and decision making and

  1. Assessing the impact of vertical land motion on twentieth century global mean sea level estimates

    Science.gov (United States)

    Hamlington, B. D.; Thompson, P.; Hammond, W. C.; Blewitt, G.; Ray, R. D.

    2016-07-01

    Near-global and continuous measurements from satellite altimetry have provided accurate estimates of global mean sea level in the past two decades. Extending these estimates further into the past is a challenge using the historical tide gauge records. Not only is sampling nonuniform in both space and time, but tide gauges are also affected by vertical land motion (VLM) that creates a relative sea level change not representative of ocean variability. To allow for comparisons to the satellite altimetry estimated global mean sea level (GMSL), typically the tide gauges are corrected using glacial isostatic adjustment (GIA) models. This approach, however, does not correct other sources of VLM that remain in the tide gauge record. Here we compare Global Positioning System (GPS) VLM estimates at the tide gauge locations to VLM estimates from GIA models, and assess the influence of non-GIA-related VLM on GMSL estimates. We find that the tide gauges, on average, are experiencing positive VLM (i.e., uplift) after removing the known effect of GIA, resulting in an increase of 0.24 ± 0.08 mm yr-1 in GMSL trend estimates from 1900 to present when using GPS-based corrections. While this result is likely dependent on the subset of tide gauges used and the actual corrections used, it does suggest that non-GIA VLM plays a significant role in twentieth century estimates of GMSL. Given the relatively short GPS records used to obtain these VLM estimates, we also estimate the uncertainty in the GMSL trend that results from limited knowledge of non-GIA-related VLM.

  2. Antarctic contribution to sea level rise observed by GRACE with improved GIA correction

    Science.gov (United States)

    Ivins, Erik R.; James, Thomas S.; Wahr, John; Schrama, Ernst J. O.; Landerer, Felix W.; Simon, Karen M.

    2013-06-01

    Antarctic volume changes during the past 21 thousand years are smaller than previously thought, and here we construct an ice sheet history that drives a forward model prediction of the glacial isostatic adjustment (GIA) gravity signal. The new model, in turn, should give predictions that are constrained with recent uplift data. The impact of the GIA signal on a Gravity Recovery and Climate Experiment (GRACE) Antarctic mass balance estimate depends on the specific GRACE analysis method used. For the method described in this paper, the GIA contribution to the apparent surface mass change is re-evaluated to be +55±13 Gt/yr by considering a revised ice history model and a parameter search for vertical motion predictions that best fit the GPS observations at 18 high-quality stations. Although the GIA model spans a range of possible Earth rheological structure values, the data are not yet sufficient for solving for a preferred value of upper and lower mantle viscosity nor for a preferred lithospheric thickness. GRACE monthly solutions from the Center for Space Research Release 04 (CSR-RL04) release time series from January 2003 to the beginning of January 2012, uncorrected for GIA, yield an ice mass rate of +2.9± 29 Gt/yr. The new GIA correction increases the solved-for ice mass imbalance of Antarctica to -57±34 Gt/yr. The revised GIA correction is smaller than past GRACE estimates by about 50 to 90 Gt/yr. The new upper bound to the sea level rise from the Antarctic ice sheet, averaged over the time span 2003.0-2012.0, is about 0.16±0.09 mm/yr.

  3. Tidal hydrodynamics under future sea level rise and coastal morphology in the Northern Gulf of Mexico

    Science.gov (United States)

    Passeri, Davina L.; Hagen, Scott C.; Plant, Nathaniel G.; Bilskie, Matthew V.; Medeiros, Stephen C.; Alizad, Karim

    2016-05-01

    This study examines the integrated influence of sea level rise (SLR) and future morphology on tidal hydrodynamics along the Northern Gulf of Mexico (NGOM) coast including seven embayments and three ecologically and economically significant estuaries. A large-domain hydrodynamic model was used to simulate astronomic tides for present and future conditions (circa 2050 and 2100). Future conditions were simulated by imposing four SLR scenarios to alter hydrodynamic boundary conditions and updating shoreline position and dune heights using a probabilistic model that is coupled to SLR. Under the highest SLR scenario, tidal amplitudes within the bays increased as much as 67% (10.0 cm) because of increases in the inlet cross-sectional area. Changes in harmonic constituent phases indicated that tidal propagation was faster in the future scenarios within most of the bays. Maximum tidal velocities increased in all of the bays, especially in Grand Bay where velocities doubled under the highest SLR scenario. In addition, the ratio of the maximum flood to maximum ebb velocity decreased in the future scenarios (i.e., currents became more ebb dominant) by as much as 26% and 39% in Weeks Bay and Apalachicola, respectively. In Grand Bay, the flood-ebb ratio increased (i.e., currents became more flood dominant) by 25% under the lower SLR scenarios, but decreased by 16% under the higher SLR as a result of the offshore barrier islands being overtopped, which altered the tidal prism. Results from this study can inform future storm surge and ecological assessments of SLR, and improve monitoring and management decisions within the NGOM.

  4. Coastal wetland response to sea-level rise in a fluvial estuarine system

    Science.gov (United States)

    Alizad, Karim; Hagen, Scott C.; Morris, James T.; Medeiros, Stephen C.; Bilskie, Matthew V.; Weishampel, John F.

    2016-11-01

    Coastal wetlands are likely to lose productivity under increasing rates of sea-level rise (SLR). This study assessed a fluvial estuarine salt marsh system using the Hydro-MEM model under four SLR scenarios. The Hydro-MEM model was developed to apply the dynamics of SLR as well as capture the effects associated with the rate of SLR in the simulation. Additionally, the model uses constants derived from a 2-year bioassay in the Apalachicola marsh system. In order to increase accuracy, the lidar-based marsh platform topography was adjusted using Real Time Kinematic survey data. A river inflow boundary condition was also imposed to simulate freshwater flows from the watershed. The biomass density results produced by the Hydro-MEM model were validated with satellite imagery. The results of the Hydro-MEM simulations showed greater variation of water levels in the low (20 cm) and intermediate-low (50 cm) SLR scenarios and lower variation with an extended bay under higher SLR scenarios. The low SLR scenario increased biomass density in some regions and created a more uniform marsh platform in others. Under intermediate-low SLR scenario, more flooded area and lower marsh productivity were projected. Higher SLR scenarios resulted in complete inundation of marsh areas with fringe migration of wetlands to higher land. This study demonstrated the capability of Hydro-MEM model to simulate coupled physical/biological processes across a large estuarine system with the ability to project marsh migration regions and produce results that can aid in coastal resource management, monitoring, and restoration efforts.

  5. Predicting Impacts of tropical cyclones and sea-Level rise on beach mouse habitat

    Science.gov (United States)

    Chen, Qin; Wang, Hongqing; Wang, Lixia; Tawes, Robert; Rollman, Drew

    2014-01-01

    Alabama beach mouse (ABM) (Peromyscus polionotus ammobates) is an important component of the coastal dune ecosystem along the Gulf of Mexico. Due to habitat loss and degradation, ABM is federally listed as an endangered species. In this study, we examined the impacts of storm surge and wind waves, which are induced by hurricanes and sea-level rise (SLR), on the ABM habitat on Fort Morgan Peninsula, Alabama, using advanced storm surge and wind wave models and spatial analysis tools in geographic information systems (GIS). Statistical analyses of the long-term historical data enabled us to predict the extreme values of winds, wind waves, and water levels in the study area at different return periods. We developed a series of nested domains for both wave and surge modeling and validated the models using field observations of surge hydrographs and high watermarks of Hurricane Ivan (2004). We then developed wave atlases and flood maps corresponding to the extreme wind, surge and waves without SLR and with a 0.5 m of SLR by coupling the wave and surge prediction models. The flood maps were then merged with a map of ABM habitat to determine the extent and location of habitat impacted by the 100-year storm with and without SLR. Simulation results indicate that more than 82% of ABM habitat would be inundated in such an extreme storm event, especially under SLR, making ABM populations more vulnerable to future storm damage. These results have aided biologists, community planners, and other stakeholders in the identification, restoration and protection of key beach mouse habitat in Alabama. Methods outlined in this paper could also be used to assist in the conservation and recovery of imperiled coastal species elsewhere.

  6. Optimal management of a multispecies shorebird flyway under sea-level rise.

    Science.gov (United States)

    Iwamura, Takuya; Fuller, Richard A; Possingham, Hugh P

    2014-12-01

    Every year, millions of migratory shorebirds fly through the East Asian-Australasian Flyway between their arctic breeding grounds and Australasia. This flyway includes numerous coastal wetlands in Asia and the Pacific that are used as stopover sites where birds rest and feed. Loss of a few important stopover sites through sea-level rise (SLR) could cause sudden population declines. We formulated and solved mathematically the problem of how to identify the most important stopover sites to minimize losses of bird populations across flyways by conserving land that facilitates upshore shifts of tidal flats in response to SLR. To guide conservation investment that minimizes losses of migratory bird populations during migration, we developed a spatially explicit flyway model coupled with a maximum flow algorithm. Migratory routes of 10 shorebird taxa were modeled in a graph theoretic framework by representing clusters of important wetlands as nodes and the number of birds flying between 2 nodes as edges. We also evaluated several resource allocation algorithms that required only partial information on flyway connectivity (node strategy, based on the impacts of SLR at nodes; habitat strategy, based on habitat change at sites; population strategy, based on population change at sites; and random investment). The resource allocation algorithms based on flyway information performed on average 15% better than simpler allocations based on patterns of habitat loss or local bird counts. The Yellow Sea region stood out as the most important priority for effective conservation of migratory shorebirds, but investment in this area alone will not ensure the persistence of species across the flyway. The spatial distribution of conservation investments differed enormously according to the severity of SLR and whether information about flyway connectivity was used to guide the prioritizations. With the rapid ongoing loss of coastal wetlands globally, our method provides insight into

  7. Sea-level rise and coastal groundwater inundation and shoaling at select sites in California, USA

    Science.gov (United States)

    Hoover, Daniel J.; Odigie, Kingsley; Swarzenski, Peter W.; Barnard, Patrick

    2016-01-01

    Study regionThe study region spans coastal California, USA, and focuses on three primary sites: Arcata, Stinson Beach, and Malibu Lagoon.Study focus1 m and 2 m sea-level rise (SLR) projections were used to assess vulnerability to SLR-driven groundwater emergence and shoaling at select low-lying, coastal sites in California. Separate and combined inundation scenarios for SLR and groundwater emergence were developed using digital elevation models of study site topography and groundwater surfaces constructed from well data or published groundwater level contours.New hydrological insights for the regionSLR impacts are a serious concern in coastal California which has a long (∼1800 km) and populous coastline. Information on the possible importance of SLR-driven groundwater inundation in California is limited. In this study, the potential for SLR-driven groundwater inundation at three sites (Arcata, Stinson Beach, and Malibu Lagoon) was investigated under 1 m and 2 m SLR scenarios. These sites provide insight into the vulnerability of Northern California coastal plains, coastal developments built on beach sand or sand spits, and developed areas around coastal lagoons associated with seasonal streams and berms. Northern California coastal plains with abundant shallow groundwater likely will see significant and widespread groundwater emergence, while impacts along the much drier central and southern California coast may be less severe due to the absence of shallow groundwater in many areas. Vulnerability analysis is hampered by the lack of data on shallow coastal aquifers, which commonly are not studied because they are not suitable for domestic or agricultural use. Shallow saline aquifers may be present in many areas along coastal California, which would dramatically increase vulnerability to SLR-driven groundwater emergence and shoaling. Improved understanding of the extent and response of California coastal aquifers to SLR will help in preparing for mitigation

  8. Salt marsh equilibrium states and transient dynamics in response to changing rates of sea level rise and sediment supply

    Science.gov (United States)

    D'Alpaos, A.; Mudd, S. M.; Carniello, L.

    2012-12-01

    Understanding and predicting the response of salt-marsh bio-geomorphic systems to changes in the rate of sea level rise and sediment supply is an issue of paramount importance due to the crucial role exerted by salt marshes within the tidal landscape. Salt-marsh platforms, in fact, buffer coastlines against storms, filter nutrients and pollutants from tidal waters, provide nursery areas for coastal biota, and serve as a sink for organic carbon. Observations of marsh degradation worldwide and the acceleration in the rate of global sea level rise highlight the importance of improving our understanding of the chief processes which control salt-marsh response to current natural climate changes and to the effects of variations in sediment supply. The results of our analytical model of salt-marsh bio-morphodynamic evolution in the vertical plane, accounting for two-way interactions between ecological and geomorphological processes, show that marshes are more resilient to a step decrease in the rate of relative sea level rise rather than to a step increase of the same magnitude. Interestingly, marshes respond more rapidly to an increase in sediment load or vegetation productivity, rather than to a decrease (of the same amount) in sediment load or vegetation productivity. Model results also suggest that marsh stability is positively correlated with tidal range: marshes with high tidal ranges respond more slowly to changes in the environmental forcings and therefore are less likely to be affected by perturbations than their counterparts in low tidal ranges. Finally, the model suggests that, in the case of a oscillating rate of sea level rise, marsh stratigraphy will be unable to fully record short term fluctuations in relative mean sea level, whereas it will be able to capture long term fluctuations particularly in sediment rich, microtidal settings.

  9. The Orinoco megadelta as a conservation target in the face of the ongoing and future sea level rise.

    Science.gov (United States)

    Vegas-Vilarrúbia, T; Hernández, E; Rull, Valentí; Rull Vegas, Elisa

    2015-05-15

    Currently, risk assessments related to rising sea levels and the adoption of defensive or adaptive measures to counter these sea level increases are underway for densely populated deltas where economic losses might be important, especially in the developed world. However, many underpopulated deltas harbouring high biological and cultural diversity are also at risk but will most likely continue to be ignored as conservation targets. In this study, we explore the potential effects of erosion, inundation and salinisation on one of the world's comparatively underpopulated megadeltas, the Orinoco Delta. With a 1 m sea level rise expected to occur by 2100, several models predict a moderate erosion of the delta's shorelines, migration or loss of mangroves, general inundation of the delta with an accompanying submersion of wetlands, and an increase in the distance to which sea water intrudes into streams, resulting in harm to the freshwater biota and resources. The Warao people are the indigenous inhabitants of the Orinoco Delta and currently are subject to various socioeconomic stressors. Changes due to sea level rise will occur extremely rapidly and cause abrupt shifts in the Warao's traditional environments and resources, resulting in migrations and abandonment of their ancestral territories. However, evidence indicates that deltaic aggradation/accretion processes at the Orinoco delta due to allochthonous sediment input and vegetation growth could be elevating the surface of the land, keeping pace with the local sea level rise. Other underpopulated and large deltas of the world also may risk immeasurable biodiversity and cultural losses and should not be forgotten as important conservation targets.

  10. Current Land Subsidence and Sea Level Rise along the North American Coastal Region: Observations from 10-Year (2005-2014) Closely-Spaced GPS and Tide Gauge Stations

    Science.gov (United States)

    Yang, L.; Yu, J.; Kearns, T.; Wang, G.

    2014-12-01

    Strong evidence has proved that the global sea-level is now rising at an increased rate and it is projected to continue to rise. However the rise of the sea-level is not uniform around the world. The local or relative sea-level rise will be of great concern to the coastal regions. The combination of the land subsidence and global sea-level rise causes the relative sea-level to rise. Relative sea-level rise increases the risk of flooding and wetland loss problems in near coastal areas, which in turn have important economic, environmental, and human health consequences for the heavily populated and ecologically important coastal region. However the role played by the coastal land subsidence is commonly absent during the discussion of sea-level rise problems. The sea-level can be measured in two ways: satellite altimetry and tide gauges. The sea-level measured by satellite is called the geocentric sea-level that is relative to earth center and the one measured by tide gauges is called local sea-level that is relative to the land. The tide gauge measurements of the local sea-level do not distinguish between whether the water is rising or the land is subsiding. In some coastal areas, land subsidence is occurring at a higher rate than the geocentric sea-level is rising. This can have a great local effect. GPS technology has proven to be efficient and accurate for measuring and tracking absolute land elevation change. There are about 300 publically available Continuously Operating Reference GPS Stations (CORS) within 15 km from the coastal line along North America. In this study, we use publicly available long-history (> 5 years) CORS data to derive current (2005-2014) coastal subsidence in North America. Absolute coastal sea-level rise will be determined by combing the land subsidence and relative sea-level measurements. This study shows that the relative sea-level of the Alaska area appears to be falling because the land is uplifting; this study also shows that the

  11. Sensitivity of Hurricane Storm Surge to Land Cover and Topography Under Various Sea Level Rise Scenarios Along the Mississippi Coast

    Science.gov (United States)

    Bilskie, M. V.; Hagen, S. C.; Medeiros, S. C.

    2013-12-01

    Major Gulf hurricanes have a high probability of impacting the northern Gulf of Mexico, especially coastal Mississippi (Resio, 2007). Due to the wide and flat continental shelf, this area provides near-perfect geometry for high water levels under tropical cyclone conditions. Literature suggests with 'very high confidence that global sea level will rise at least 0.2 m and no more than 2.0 m by 2011' (Donoghue, 2011; Parris et al., 2012). Further, it is recognized that the Mississippi barrier islands are highly susceptible to a westward migration and retreating shoreline. With predictions for less frequent, more intense tropical storms, rising sea levels, and a changing landscape, it is important to understand how these changes may affect inundation extent and flooding due to hurricane storm surge. A state-of-the-art SWAN+ADCIRC hydrodynamic model of coastal Mississippi was utilized to simulate Hurricane Katrina with present day sea level conditions. Using present day as a base scenario, past (1960) and future (2050) sea level changes were simulated. In addition to altering the initial sea state, land use land cover (LULC) was modified for 1960 and 2050 based on historic data and future projections. LULC datasets are used to derive surface roughness characteristics, such as Manning's n, and wind reduction factors. The topography along the barrier islands and near the Pascagoula River, MS was also altered to reflect the 1960 landscape. Storm surge sensitivity to topographic change were addressed by comparing model results between two 1960 storm surge simulations; one with current topography and a second with changes to the barrier islands. In addition, model responses to changes in LULC are compared. The results will be used to gain insight into adapting present day storm surge models for future conditions. References Donoghue, J. (2011). Sea level history of the northern Gulf of Mexico coast and sea level rise scenarios for the near future. Climatic Change, 107

  12. Vulnerability assessment of the coastal wetlands in the Yangtze Estuary, China to sea-level rise

    Science.gov (United States)

    Cui, Lifang; Ge, Zhenming; Yuan, Lin; Zhang, Liquan

    2015-04-01

    Sea-level rise (SLR) caused by global climate change will have significant impacts on the low-lying coastal zone. The coastal wetlands in the Yangtze Estuary, with their low elevation, are particularly sensitive to SLR. In this study, the potential impacts of SLR on the coastal wetlands in the Yangtze Estuary were analyzed by adopting the SPRC (Source-Pathway-Receptor-Consequence) model. Based on the SPRC model and IPCC vulnerability definition, an indicator system for vulnerability assessment on the coastal wetlands to SLR was developed, in which the rate of SLR, subsidence rate, habitat elevation, mean daily inundation duration of habitat and sedimentation rate were selected as the key indicators. A spatial assessment method based on a GIS platform was established by quantifying each indicator, calculating the vulnerability index and grading the vulnerability. Vulnerability assessment, based on the projection of SLR rates from the present trend (0.26 cm/yr) and IPCC's A1F1 scenario (0.59 cm/yr), were performed for three time periods: short-term (2030s), medium-term (2050s) and long-term (2100s). The results indicated that in the 2030s, 6.6% and 9.0% of the coastal wetlands were within the grade of low vulnerability under the scenarios of present trend and A1F1, respectively. In the 2050s, the percentage of coastal wetlands within the grades of low and moderate vulnerability increases to 9.8% and 0.2%, 9.5% and 1.0% under the scenarios of present trend and A1F1, respectively. In the 2100s, 8.1% and 3.0% of the coastal wetlands were within the grade of low vulnerability, 0.8% and 2.8% were within the grade of moderate vulnerability under the scenarios of present trend and A1F1, respectively. The percentage of coastal wetlands within the grade of high vulnerability increases significantly, amounting to 2.3% and 6.9% under the scenarios of present trend and A1F1, respectively. The application of the SPRC model, the methodology developed and the results could assist

  13. SEA LEVEL RISE AND ITS POTENTIAL IMPACTS ON COASTAL URBAN AREA: A CASE OF ETI-OSA, NIGERIA

    Directory of Open Access Journals (Sweden)

    Ayodele Michael AGBOOLA

    2016-10-01

    Full Text Available This study examines the spatial extent of coastal urban development and its potential sensitivity to sea-level rise. The main aim of the study is to critically examine the extent of growth in Eti-Osa over time, and the potential impacts of sea leve rise. Landsat Enhanced Thematic Mapper Plus (ETM+ imageries of years 2000 and 2015 were used to evaluate the different land use type identified. Post-classification change detection method was used to evaluate the output of the maximum likelihood supervised classification analysis done. This was also used to estimate the changes induces through urban development on the environment which accounts for the biodiversity loss. ASTER GDEM 2 imagery of 2011 was used to generate the elevation data used for the inundation analysis. Thus, both Land use map of Eti-Osa in 2015 and the down scaled Sea-level rise scenarios (at 0.5 to 15 meters were used for the inundation mapping. Results obtained from this research affirms that indeed EtiOsa has been subjected to gross urban expansion giving room for diverse forms of environmental degradation among which are huge replacement of natural land cover with built-up, reclamation of wetlands and sand filling of water bodies. This basically illustrates growth but also the risk that accompanies the advent of excessive alteration of natural ecosystem as Sea-level rise projections imply in this research.

  14. A probabilistic approach to 21st century regional sea-level projections using RCP and High-end scenarios

    Science.gov (United States)

    Jackson, Luke P.; Jevrejeva, Svetlana

    2016-11-01

    Sea-level change is an integrated climate system response due to changes in radiative forcing, anthropogenic land-water use and land-motion. Projecting sea-level at a global and regional scale requires a subset of projections - one for each sea-level component given a particular climate-change scenario. We construct relative sea-level projections through the 21st century for RCP 4.5, RCP 8.5 and High-end (RCP 8.5 with increased ice-sheet contribution) scenarios by aggregating spatial projections of individual sea-level components in a probabilistic manner. Most of the global oceans adhere to the projected global average sea level change within 5 cm throughout the century for all scenarios; however coastal regions experience localised effects due to the non-uniform spatial patterns of individual components. This can result in local projections that are 10‧s of centimetres different from the global average by 2100. Early in the century, RSL projections are consistent across all scenarios, however from the middle of the century the patterns of RSL for RCP scenarios deviate from the High-end where the contribution from Antarctica dominates. Similarly, the uncertainty in projected sea-level is dominated by an uncertain Antarctic fate. We also explore the effect upon projections of, treating CMIP5 model ensembles as normally distributed when they might not be, correcting CMIP5 model output for internal variability using different polynomials and using different unloading patterns of ice for the Greenland and Antarctic ice sheets.

  15. Relative sea-level rise around East Antarctica during Oligocene glaciation

    NARCIS (Netherlands)

    Stocchi, P.; Escutia, C.; Houben, A.J.P.; Vermeersen, B.L.A.; Bijl, P.K.; Brinkhuis, H.; Deconto, R.M.; Galeotti, S.; Passchier, S.; Pollard, D.

    2013-01-01

    During the middle and late Eocene (∼ 48-34 Myr ago), the Earth's climate cooled and an ice sheet built up on Antarctica. The stepwise expansion of ice on Antarctica induced crustal deformation and gravitational perturbations around the continent. Close to the ice sheet, sea level rose despite an ove

  16. Relative sea-level rise around East Antarctica during Oligocene glaciation

    NARCIS (Netherlands)

    Stocchi, P.; Escutia, C.; Houben, A.J.P.; Vermeersen, B.L.A.; Bijl, P.K.; Brinkhuis, H.; DeConto , R.M.; Galeotti, S.; Passchier, S.; Pollard, D.; IODP Expedition 318 Scientists; Houben, A.J.P.

    2013-01-01

    During the middle and late Eocene (similar to 48-34 Myr ago), the Earth's climate cooled(1,2) and an ice sheet built up on Antarctica. The stepwise expansion of ice on Antarctica(3,4) induced crustal deformation and gravitational perturbations around the continent. Close to the ice sheet, sea level

  17. North Indian Ocean warming and sea level rise in an OGCM

    Indian Academy of Sciences (India)

    Bijoy Thompson; C Gnanaseelan; Anant Parekh; P S Salvekar

    2008-04-01

    The variability in the long-term temperature and sea level over the north Indian Ocean during the period 1958–2000 has been investigated using an Ocean General Circulation Model, Modular Ocean Model version 4. The model simulated fields are compared with the sea level observations from tide-gauges, Topex/Poseidon (T/P) satellite, in situ temperature profile observations from WHOI moored buoy and sea surface temperature (SST) observations from DS1, DS3 and DS4 moored buoys. It is seen that the long (6–8 years) warming episodes in the SST over the north Indian Ocean are followed by short episodes (2–3 years) of cooling. The model temperature and sea level anomaly over the north Indian Ocean show an increasing trend in the study period. The model thermocline heat content per unit area shows a linear increasing trend (from 1958–2000) at the rate of 0.0018 × 1011J/m2 per year for north Indian Ocean. North Indian Ocean sea level anomaly (thermosteric component) also shows a linear increasing trend of 0.31mm/year during 1958–2000.

  18. Relative sea-level rise and the conterminous United States : Consequences of potential land inundation in terms of population at risk and GDP loss

    NARCIS (Netherlands)

    Haer, Toon; Kalnay, Eugenia; Kearney, Michael; Moll, Henk

    2013-01-01

    Global sea-level rise poses a significant threat not only for coastal communities as development continues but also for national economies. This paper presents estimates of how future changes in relative sea-level rise puts coastal populations at risk, as well as affect overall GDP in the contermino

  19. Combined effects of projected sea level rise, storm surge, and peak river flows on water levels in the Skagit Floodplain

    Science.gov (United States)

    Hamman, Josheph J; Hamlet, Alan F.; Fuller, Roger; Grossman, Eric

    2016-01-01

    Current understanding of the combined effects of sea level rise (SLR), storm surge, and changes in river flooding on near-coastal environments is very limited. This project uses a suite of numerical models to examine the combined effects of projected future climate change on flooding in the Skagit floodplain and estuary. Statistically and dynamically downscaled global climate model scenarios from the ECHAM-5 GCM were used as the climate forcings. Unregulated daily river flows were simulated using the VIC hydrology model, and regulated river flows were simulated using the SkagitSim reservoir operations model. Daily tidal anomalies (TA) were calculated using a regression approach based on ENSO and atmospheric pressure forcing simulated by the WRF regional climate model. A 2-D hydrodynamic model was used to estimate water surface elevations in the Skagit floodplain using resampled hourly hydrographs keyed to regulated daily flood flows produced by the reservoir simulation model, and tide predictions adjusted for SLR and TA. Combining peak annual TA with projected sea level rise, the historical (1970–1999) 100-yr peak high water level is exceeded essentially every year by the 2050s. The combination of projected sea level rise and larger floods by the 2080s yields both increased flood inundation area (+ 74%), and increased average water depth (+ 25 cm) in the Skagit floodplain during a 100-year flood. Adding sea level rise to the historical FEMA 100-year flood resulted in a 35% increase in inundation area by the 2040's, compared to a 57% increase when both SLR and projected changes in river flow were combined.

  20. The potential for sea-level-rise-induced barrier island loss: Insights from the Chandeleur Islands, Louisiana, USA

    Science.gov (United States)

    Moore, Laura J.; Patsch, Kiki; List, Jeffrey H.; Williams, S. Jeffress

    2014-01-01

    As sea level rises and hurricanes become more intense, barrier islands around the world become increasingly vulnerable to conversion from self-sustaining migrating landforms to submerging or subaqueous sand bodies. To explore the mechanism by which such state changes occur and to assess the factors leading to island disintegration, we develop a suite of numerical simulations for the Chandeleur Islands in Louisiana, U.S.A., which appear to be on the verge of this transition. Our results suggest that the Chandeleurs are likely poised to change state, leading to their demise, within decades depending on future storm history. Contributing factors include high rates of relative sea level rise, limited sediment supply, muddy substrate, current island position relative to former Mississippi River distributary channels, and the effects of changes in island morphology on sediment transport pathways. Although deltaic barrier islands are most sensitive to disintegration because of their muddy substrate, the importance of relative sea level rise rate in determining the timing of threshold crossing suggests that the conceptual models for deltaic barrier island formation and disintegration may apply more broadly in the future.

  1. Adapting to climate change despite scientific uncertainty: A case study of coastal protection from sea-level rise in Kiribati

    Science.gov (United States)

    Donner, S. D.

    2013-12-01

    Climate change adaptation is an increasing focus of international aid. At recent meetings of the parties to the United Nations Framework Convention on Climate Change (UNFCCC), the developed world agreed to rapidly increase international assistance to help developing countries, like the low-lying island nation of Kiribati, respond to the impacts of climate change. These emerging adaptation efforts must proceed despite the large and partially irreducible scientific uncertainty about the magnitude of those future climate impacts. In this study, we use the example of efforts to adapt to sea-level rise in Kiribati to document the challenges facing such internationally-funded climate change adaptation projects given the scientific uncertainty about climate impacts. Drawing on field and document research, we describe the scientific uncertainty about projected sea-level rise in Tarawa, the capital of Kiribati, how that uncertainty can create trade-offs between adaptation measures, and the social, political and economic context in which adaptation decisions must be made. The analysis shows there is no 'silver bullet' adaptation strategy in countries like Kiribati, given the long-term scientific uncertainty about sea-level rise and the environment of climate change aid. The existence of irreducible scientific uncertainty does not preclude effective climate change adaptation, but instead requires adaptation programs that embrace multiple strategies and planning horizons, and continually build on and re-adjust previous investments. This work highlights the importance of sustained international climate change financing, as proposed in UNFCCC negotiations.

  2. Accelerated relative sea-level rise and rapid coastal erosion: Testing a causal relationship for the Louisiana barrier islands

    Science.gov (United States)

    List, J.H.; Sallenger, A.H.; Hansen, M.E.; Jaffe, B.E.

    1997-01-01

    The role of relative sea-level rise as a cause for the rapid erosion of Louisiana's barrier island coast is investigated through a numerical implementation of a modified Bruun rule that accounts for the low percentage of sand-sized sediment in the eroding Louisiana shoreface. Shore-normal profiles from 150 km of coastline west of the Mississippi delta are derived from bathymetric surveys conducted during the 1880s. 1930s and 1980s. An RMS difference criterion is employed to test whether an equilibrium profile form is maintained between survey years. Only about half the studied profiles meet the equilibrium Criterion this represents a significant limitation on the potential applicability of the Bruun rule. The profiles meeting the equilibrium criterion, along with measured rates of relative sea-level rise, are used to hindcast shoreline retreat rates at 37 locations within the study area. Modeled and observed shoreline retreat rates show no significant correlation. Thus in terms of the Bruun approach relative sea-level rise has no power for hindcasting (and presumably forecasting) rates of coastal erosion for the Louisiana barrier islands.

  3. Impacts of sea-level rise on the Moroccan coastal zone: Quantifying coastal erosion and flooding in the Tangier Bay

    Science.gov (United States)

    Snoussi, Maria; Ouchani, Tachfine; Khouakhi, Abdou; Niang-Diop, Isabelle

    2009-06-01

    As part of a broad assessment of climate change impacts in Morocco, an assessment of vulnerability and adaptation of coastal zones to sea-level rise was conducted. Tangier Bay which is the most important socio-economic pole in Northern Morocco represents one of the cases studies. Using a GIS-based inundation analysis and an erosion modelling approach, the potential physical vulnerability to accelerated sea-level rise was investigated, and the most vulnerable socio-economic sectors were assessed. Results indicate that 10% and 24% of the area will be at risk of flooding respectively for minimum (4 m) and maximum (11 m) inundation levels. The most severely impacted sectors are expected to be the coastal defences and the port, the urban area, tourist coastal infrastructures, the railway, and the industrial area. Shoreline erosion would affect nearly 20% and 45% of the total beach areas respectively in 2050 and 2100. Potential response strategies and adaptation options identified include: sand dune fixation, beach nourishment and building of seawalls to protect the urban and industrial areas of high value. It was also recommended that an Integrated Coastal Zone Management Plan for the region, including upgrading awareness, building regulation and urban growth planning should be the most appropriate tool to ensure a long-term sustainable development, while addressing the vulnerability of the coast to future sea-level rise.

  4. Adapting to rates versus amounts of climate change: a case of adaptation to sea-level rise

    Science.gov (United States)

    Shayegh, Soheil; Moreno-Cruz, Juan; Caldeira, Ken

    2016-10-01

    Adaptation is the process of adjusting to climate change in order to moderate harm or exploit beneficial opportunities associated with it. Most adaptation strategies are designed to adjust to a new climate state. However, despite our best efforts to curtail greenhouse gas emissions, climate is likely to continue changing far into the future. Here, we show how considering rates of change affects the projected optimal adaptation strategy. We ground our discussion with an example of optimal investment in the face of continued sea-level rise, presenting a quantitative model that illustrates the interplay among physical and economic factors governing coastal development decisions such as rate of sea-level rise, land slope, discount rate, and depreciation rate. This model shows that the determination of optimal investment strategies depends on taking into account future rates of sea-level rise, as well as social and political constraints. This general approach also applies to the development of improved strategies to adapt to ongoing trends in temperature, precipitation, and other climate variables. Adaptation to some amount of change instead of adaptation to ongoing rates of change may produce inaccurate estimates of damages to the social systems and their ability to respond to external pressures.

  5. Impacts of Global Warming and Sea Level Rise on Service Life of Chloride-Exposed Concrete Structures

    Directory of Open Access Journals (Sweden)

    Xiao-Jian Gao

    2017-03-01

    Full Text Available Global warming will increase the rate of chloride ingress and the rate of steel corrosion of concrete structures. Furthermore, in coastal (atmospheric marine zones, sea level rise will reduce the distance of concrete structures from the coast and increase the surface chloride content. This study proposes a probabilistic model for analyzing the effects of global warming and sea level rise on the service life of coastal concrete structures. First, in the corrosion initiation stage, an improved chloride diffusion model is proposed to determine chloride concentration. The Monte Carlo method is employed to calculate the service life in the corrosion initiation stage; Second, in the corrosion propagation stage, a numerical model is proposed to calculate the rate of corrosion, probability of corrosion cracking, and service life. Third, overall service life is determined as the sum of service life in the corrosion initiation and corrosion propagation stages. After considering the impacts of global warming and sea level rise, the analysis results show that for concrete structures having a service life of 50 years, the service life decreases by about 5%.

  6. Tidal changes in the Yellow/East China Sea caused by the rapid sea-level rise during the Holocene

    Institute of Scientific and Technical Information of China (English)

    KatsutoUehara

    2001-01-01

    Two-dimensional numerical simulations of M2 and K1 tides were performed in order to assess the effect of the rapid sea level change occurring during the last 20000 years in the Yellow/East China Sea (YECS). Results were interpreted by utilizing the difference of the dynamical nature inherited in diurnal and semi-diurnal tides. M2 tides at the coastal region south of Korea exceeded 2 m in amplitude when the sea-level was low, and decreased as the water depth become larger. In the Yellow Sea, on the other hand, tidal amplitudes were small at the low sea-level stages and increased along with the sea-level rise. The way of the increase was not monotonic but with fluctuations, which was due to the movement of the standing wave nodes. An additional experiment with closing the Taiwan Strait revealed that changing the sill depth of the strait not only affects the M2 tides around the southeastern Chinese coast, but also modifies the tides around the southwestern coast of Korea. This result recall us the significa

  7. Protection versus retreat: the economic costs of sea-level rise

    OpenAIRE

    S Fankhauser

    1995-01-01

    The author analyses the relative role of protection (or damage mitigation) expenditures within the total costs associated with raised sea levels induced by climate change. A rule of thumb is derived to approximate the optimal level of protection. Economic efficiency requires that protection expenditures are designed such that the sum of protection costs plus remaining land-loss damage is minimised. The optimal protection level will depend on the relative importance of dryland loss compared wi...

  8. Assessing the Effects of Sea Level Rise on Plum Island Estuary Marshes Using a Hydrodynamic-marsh Modeling Tool

    Science.gov (United States)

    Demissie, H. K.; Bilskie, M. V.; Hagen, S. C.; Morris, J. T.; Alizad, K.

    2015-12-01

    Sea level rise (SLR) can significantly impact both human and ecological habitats in coastal and inland regions. Studies show that coastal estuaries and marsh systems are at the risk of losing their productivity under increasing rates of SLR (Donnelly and Bertness, 2001; Warren and Niering, 1993). The integrated hydrodynamic-marsh model (Hagen et al., 2013 & Alizad et al., 2015) uses a set of parameters and conditions to simulate tidal flow through the salt marsh of Plum Island Estuary, Massachusetts. The hydrodynamic model computes mean high water (MHW) and mean low water (MLW) and is coupled to the zero-dimensional Marsh Equilibrium Model (Morris et al. 2002) to estimate changes in biomass productivity and accretion. The coupled hydrodynamic-marsh model was used to examine the effects of different scenarios of SLR (Parris et al., 2012) on salt marsh productivity for the year 2100 in the Plum Island Estuary. In this particular study, responses of salt marsh production for different scenarios of SLR were compared. The study shows higher productivity of salt marsh under a low SLR scenario and lower productivity under the higher SLR. The study also demonstrates the migration of salt marshes under higher SLR scenarios. References: Alizad, K., S. C. Hagen, Morris, J.T., Bacopoulos, P., Bilskie, M.V., and John, F.W. 2015. A coupled, two-dimensional hydrodynamic-marsh model with biological feedback. Limnology and Oceanography, In review. Donnelly, J.P., and M.D. Bertness. 2001. Rapid shoreward encroachment of salt marsh cordgrass in response to accelerated sea-level rise. Proceedings of the National Academy of Sciences 98: 14218-14223.Hagen, S.C., J.T. Morris, P. Bacopoulos, and J. Weishampel. 2013. Sea-Level Rise Impact on a Salt Marsh System of the Lower St. Johns River. ASCE Journal of Waterway, Port, Coastal, and Ocean Engineering, Vol. 139, No. 2, March/April 2013, pp. 118-125.Morris, J.T., P.V. Sundareshwar, C.T. Nietch, B. Kjerfve, and D.R. Cahoon. 2002. Responses

  9. How a barrier island may react on a sea-level rise: The Holocene to Recent Rømø barrier island, Danish Wadden Sea

    DEFF Research Database (Denmark)

    Johannessen, Peter N.; Nielsen, Lars H.; Møller, Ingelise

    and related shoreface sand and lagoonal sediments are up to 20 m thick and overlie Weichselian fluvial sand. The first 5000 years the barrier island aggraded and the last 3000 years it prograded despite the relative rising sea level rise of c. 15 m during the last c. 8000 years. This shows......, that if there is a surplus of sand in a tidal area, barrier islands may aggrade even if there is a rise in sea level. If the rate of sea level rise decreases then the barrier island may prograded. With this unique dataset with extremely large amounts of OSL datings from core sediments it has been possible to construct...

  10. Rising sea level, temperature, and precipitation impact plant and ecosystem responses to elevated CO2 on a Chesapeake Bay wetland: review of a 28-year study.

    Science.gov (United States)

    Drake, Bert G

    2014-11-01

    An ongoing field study of the effects of elevated atmospheric CO2 on a brackish wetland on Chesapeake Bay, started in 1987, is unique as the longest continually running investigation of the effects of elevated CO2 on an ecosystem. Since the beginning of the study, atmospheric CO2 increased 18%, sea level rose 20 cm, and growing season temperature varied with approximately the same range as predicted for global warming in the 21st century. This review looks back at this study for clues about how the effects of rising sea level, temperature, and precipitation interact with high atmospheric CO2 to alter the physiology of C3 and C4 photosynthetic species, carbon assimilation, evapotranspiration, plant and ecosystem nitrogen, and distribution of plant communities in this brackish wetland. Rising sea level caused a shift to higher elevations in the Scirpus olneyi C3 populations on the wetland, displacing the Spartina patens C4 populations. Elevated CO2 stimulated carbon assimilation in the Scirpus C3 species measured by increased shoot and root density and biomass, net ecosystem production, dissolved organic and inorganic carbon, and methane production. But elevated CO2 also decreased biomass of the grass, S. patens C4. The elevated CO2 treatment reduced tissue nitrogen concentration in shoots, roots, and total canopy nitrogen, which was associated with reduced ecosystem respiration. Net ecosystem production was mediated by precipitation through soil salinity: high salinity reduced the CO2 effect on net ecosystem production, which was zero in years of severe drought. The elevated CO2 stimulation of shoot density in the Scirpus C3 species was sustained throughout the 28 years of the study. Results from this study suggest that rising CO2 can add substantial amounts of carbon to ecosystems through stimulation of carbon assimilation, increased root exudates to supply nitrogen fixation, reduced dark respiration, and improved water and nitrogen use efficiency.

  11. Sea-level-rise trends off the Indian coasts during the last two decades

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.; Nidheesh, A.G.; Lengaigne, M.

    ://www.cmar.csiro.au/sealevel/sl_data_ cmar.html). In this study, we used two types of sea-level data: (i) the data corrected for two major land and envi- ronmental effects, namely GIA (glacial isostatic adjust- ment) and IB (inverse barometer effect), and (ii) the uncorrected data. We.... The significance of this correlation was assessed on the basis of a two-sided t-distribution of linear correla- tion coefficients with effective degrees of freedom taken as the number of maximum yearly values that exist in each tide-gauge record reduced by 2. We...

  12. The role of local and external factors in determining the interannual sea level variability of the Adriatic and Black Seas during the 20th century.

    Science.gov (United States)

    Scarascia, Luca; Lionello, Piero

    2016-04-01

    The Adriatic Sea and the Black Sea are two semienclosed basins connected to the Mediterranean Sea by the Otranto and the Bosporus straits, respectively. This work aims to reconstruction the sea level for both basins in the 20th century and to investigate main sources of interannual variability. Using 7 tide gauge timeseries located along the Adriatic coast and 5 along the Black Sea coast, provided by the PSMSL (Permanent service of mean sea level), a seamless sea level timeseries (1900-2009) has been obtained for each basin on the basis of statistical procedure involving PCA and Least Square Method. The comparison with satellite data in the period 1993 - 2009 confirms that these are reliable representations of the observed sea level for the whole basin, showing a great agreement with a correlation value of 0.87 and 0.72 for Adriatic and Black Sea respectively. The sea level has been decomposed in various contributions in order to analyze the role of the factors responsible for its interannual variability. The annual cycles of the local effect of pressure (inverse barometer effect IB), of the steric effect due to temperature and salinity variation and of the wind effect have been computed. The largest contribute for the Adriatic Sea is due to the wind, whilst inverse barometer effect plays a minor role and the steric effect seems to be almost negligible. For the Black Sea, on the contrary, wind effect is negligible, and the largest source of variability is due to the Danube river, which is estimated from the available discharge data of Sulina (one of the exits of the Danube delta. Steric and IB effects play both a minor role in this basin. A linear regression model, built considering as predictor the SLP gradient identified at large scale after having carried out the correlation analysis, is capable to explain a further percentage of variability (about 20-25%) of the sea level after subtracting all the factors considered above. Finally, residual sea levels show a

  13. Threatened and endangered subspecies with vulnerable ecological traits Also have high susceptibility to sea level rise and habitat fragmentation

    Science.gov (United States)

    Benscoter, Allison M.; Reece, Joshua S.; Noss, Reed F.; Brandt, Laura B.; Mazzotti, Frank J.; Romañach, Stephanie S.; Watling, James I.

    2013-01-01

    The presence of multiple interacting threats to biodiversity and the increasing rate of species extinction make it critical to prioritize management efforts on species and communities that maximize conservation success. We implemented a multi-step approach that coupled vulnerability assessments evaluating threats to Florida taxa such as climate change, sea-level rise, and habitat fragmentation with in-depth literature surveys of taxon-specific ecological traits. The vulnerability, adaptive capacity, and ecological traits of 12 threatened and endangered subspecies were compared to non-listed subspecies of the same parent species. Overall, the threatened and endangered subspecies showed high vulnerability and low adaptive capacity, in particular to sea level rise and habitat fragmentation. They also exhibited larger home ranges and greater dispersal limitation compared to non-endangered subspecies, which may inhibit their ability to track changing climate in fragmented landscapes. There was evidence for lower reproductive capacity in some of the threatened or endangered taxa, but not for most. Taxa located in the Florida Keys or in other low coastal areas were most vulnerable to sea level rise, and also showed low levels of adaptive capacity, indicating they may have a lower probability of conservation success. Our analysis of at-risk subspecies and closely related non-endangered subspecies demonstrates that ecological traits help to explain observed differences in vulnerability and adaptive capacity. This study points to the importance of assessing the relative contributions of multiple threats and evaluating conservation value at the species (or subspecies) level when resources are limited and several factors affect conservation success.

  14. Threatened and endangered subspecies with vulnerable ecological traits also have high susceptibility to sea level rise and habitat fragmentation.

    Directory of Open Access Journals (Sweden)

    Allison M Benscoter

    Full Text Available The presence of multiple interacting threats to biodiversity and the increasing rate of species extinction make it critical to prioritize management efforts on species and communities that maximize conservation success. We implemented a multi-step approach that coupled vulnerability assessments evaluating threats to Florida taxa such as climate change, sea-level rise, and habitat fragmentation with in-depth literature surveys of taxon-specific ecological traits. The vulnerability, adaptive capacity, and ecological traits of 12 threatened and endangered subspecies were compared to non-listed subspecies of the same parent species. Overall, the threatened and endangered subspecies showed high vulnerability and low adaptive capacity, in particular to sea level rise and habitat fragmentation. They also exhibited larger home ranges and greater dispersal limitation compared to non-endangered subspecies, which may inhibit their ability to track changing climate in fragmented landscapes. There was evidence for lower reproductive capacity in some of the threatened or endangered taxa, but not for most. Taxa located in the Florida Keys or in other low coastal areas were most vulnerable to sea level rise, and also showed low levels of adaptive capacity, indicating they may have a lower probability of conservation success. Our analysis of at-risk subspecies and closely related non-endangered subspecies demonstrates that ecological traits help to explain observed differences in vulnerability and adaptive capacity. This study points to the importance of assessing the relative contributions of multiple threats and evaluating conservation value at the species (or subspecies level when resources are limited and several factors affect conservation success.

  15. Sea-level rise and refuge habitats for tidal marsh species: can artificial islands save the California Ridgway's rail?

    Science.gov (United States)

    Overton, Cory T.; Takekawa, John Y.; Casazza, Michael L.; Bui, Thuy-Vy D.; Holyoak, Marcel; Strong, Donald R.

    2014-01-01

    Terrestrial species living in intertidal habitats experience refuge limitation during periods of tidal inundation, which may be exacerbated by seasonal variation in vegetation structure, tidal cycles, and land-use change. Sea-level rise projections indicate the severity of refuge limitation may increase. Artificial habitats that provide escape cover during tidal inundation have been proposed as a temporary solution to alleviate these limitations. We tested for evidence of refuge habitat limitation in a population of endangered California Ridgway's rail (Rallus obsoletus obsoletus; hereafter California rail) through use of artificial floating island habitats provided during two winters. Previous studies demonstrated that California rail mortality was especially high during the winter and periods of increased tidal inundation, suggesting that tidal refuge habitat is critical to survival. In our study, California rail regularly used artificial islands during higher tides and daylight hours. When tide levels inundated the marsh plain, use of artificial islands was at least 300 times more frequent than would be expected if California rails used artificial habitats proportional to their availability (0.016%). Probability of use varied among islands, and low levels of use were observed at night. These patterns may result from anti-predator behaviors and heterogeneity in either rail density or availability of natural refuges. Endemic saltmarsh species are increasingly at risk from habitat change resulting from sea-level rise and development of adjacent uplands. Escape cover during tidal inundation may need to be supplemented if species are to survive. Artificial habitats may provide effective short-term mitigation for habitat change and sea-level rise in tidal marsh environments, particularly for conservation-reliant species such as California rails.

  16. Climate change under a scenario near 1.5 °C of global warming: monsoon intensification, ocean warming and steric sea level rise

    Directory of Open Access Journals (Sweden)

    M. Meinshausen

    2010-10-01

    Full Text Available We present climatic consequences of the Representative Concentration Pathways (RCPs using the coupled climate model CLIMBER-3α, which contains a statistical-dynamical atmosphere and a three-dimensional ocean model. We compare those with emulations of 19 state-of-the-art atmosphere-ocean general circulation models (AOGCM using MAGICC6. The RCPs are designed as standard scenarios for the forthcoming IPCC Fifth Assessment Report to span the full range of possible future greenhouse gas (GHG concentrations pathways. The lowest of the RCP scenarios, RCP3-PD, is projected in CLIMBER-3α to imply a maximal warming by the middle of the 21st century slightly above 1.5 °C and a slow decline of temperatures thereafter, approaching today's level by 2500. We identify two mechanisms that slow down global cooling after GHG concentrations peak: The known inertia induced by mixing-related oceanic heat uptake; and a change in oceanic convection that enhances ocean heat loss in high latitudes, reducing the surface cooling rate by almost 50%. Steric sea level rise under the RCP3-PD scenario continues for 200 years after the peak in surface air temperatures, stabilizing around 2250 at 30 cm. This contrasts with around 2 m of steric sea level rise by 2500 under the highest scenario, RCP8.5. Maximum oceanic warming at intermediate depth (300–800 m is found to exceed that of the sea surface by the second half of the 21st century under RCP3-PD. This intermediate-depth warming persists for centuries even after surface temperatures have returned to present-day values, with potential consequences for marine ecosystems, oceanic methane hydrates, and ice-shelf stability. Due to an enhanced land-ocean temperature contrast, all scenarios yield an intensification of monsoon rainfall under global warming.

  17. Climate change under a scenario near 1.5 °C of global warming: monsoon intensification, ocean warming and steric sea level rise

    Directory of Open Access Journals (Sweden)

    J. Schewe

    2011-03-01

    Full Text Available We present climatic consequences of the Representative Concentration Pathways (RCPs using the coupled climate model CLIMBER-3α, which contains a statistical-dynamical atmosphere and a three-dimensional ocean model. We compare those with emulations of 19 state-of-the-art atmosphere-ocean general circulation models (AOGCM using MAGICC6. The RCPs are designed as standard scenarios for the forthcoming IPCC Fifth Assessment Report to span the full range of future greenhouse gas (GHG concentrations pathways currently discussed. The lowest of the RCP scenarios, RCP3-PD, is projected in CLIMBER-3α to imply a maximal warming by the middle of the 21st century slightly above 1.5 °C and a slow decline of temperatures thereafter, approaching today's level by 2500. We identify two mechanisms that slow down global cooling after GHG concentrations peak: The known inertia induced by mixing-related oceanic heat uptake; and a change in oceanic convection that enhances ocean heat loss in high latitudes, reducing the surface cooling rate by almost 50%. Steric sea level rise under the RCP3-PD scenario continues for 200 years after the peak in surface air temperatures, stabilizing around 2250 at 30 cm. This contrasts with around 1.3 m of steric sea level rise by 2250, and 2 m by 2500, under the highest scenario, RCP8.5. Maximum oceanic warming at intermediate depth (300–800 m is found to exceed that of the sea surface by the second half of the 21st century under RCP3-PD. This intermediate-depth warming persists for centuries even after surface temperatures have returned to present-day values, with potential consequences for marine ecosystems, oceanic methane hydrates, and ice-shelf stability. Due to an enhanced land-ocean temperature contrast, all scenarios yield an intensification of monsoon rainfall under global warming.

  18. Coastal Flood Risks in the Bangkok Metropolitan Region, Thailand: Combined Impacts of Land Subsidence, Sea Level Rise and Storm Surge

    Science.gov (United States)

    Duangyiwa, C.; Yu, D.; Wilby, R.; Aobpaet, A.

    2015-12-01

    Due to the fast-changing climatic and anthropogenic conditions at coastal regions, many coastal mega-cities are becoming increasingly vulnerable to internal and external risks. The risk is particularly high for low-lying coastal cities in developing nations, with Southeast Asia recognized as a hotspot of vulnerability due to the increasing population density, rapid change of natural landscape associated with urbanization and intensified hydrological and atmospheric conditions at the coastal front in an uncertain climate future. The Bangkok Metropolitan Region is one of the largest coastal megacities in Southeast Asia that are challenged by the potential impacts due to climate change and anthropological variability in the coming decades. Climate-related risks in this region are associated with its relatively low-lying nature of the terrain and adjacency to the coast. Coastal inundation due to high tides from the sea occurs annually in the area close to the seashore. This is set to increase given a projected rising sea level and the sinking landscape due to groundwater extraction and urbanization. The aim of this research is, therefore, to evaluate the vulnerability of the city to sea level rise, land subsidence and storm surge. Distributed land subsidence rate, projected sea level rise and existing structural features such as flood defences are taken into account. The 2011 flood in Thailand is used as a baseline event. Scenarios were designed with projections of land subsidence and sea level rise to 2050s, 2080s, and 2100s. A two-dimensional flood inundation model (FloodMap, Yu and Lane 2006) is used to derive inundation depth and velocity associated with each scenario. The impacts of coastal flood risk on critical infrastructures (e.g. power supply, transportation network, rescue centers, hospitals, schools and key government buildings) are evaluated (e.g. Figure 1). Results suggest progressively increase but non-linear risks of coastal flooding to key coastal

  19. Grazing management can counteract the impacts of climate change-induced sea level rise on salt marsh-dependent waterbirds

    DEFF Research Database (Denmark)

    Clausen, Kevin Kuhlmann; Stjernholm, Michael; Clausen, Preben

    2013-01-01

    1) Climate change–induced rises in sea level threaten to drastically reduce the areal extent of important salt marsh habitats for large numbers of waterfowl and waders. Furthermore, recent changes in management practice have rendered existent salt marshes unfavourable to many birds, as lack of gr....... However, this may only be a temporary solution that will have to be supplemented by increased reintegration with the sea and managed retreat of seawalls or near-coastal agricultural areas to effectively safeguard the future salt marsh biome....

  20. Surface elevation change and susceptibility of different mangrove zones to sea-level rise on Pacific high islands of Micronesia

    Science.gov (United States)

    Krauss, K.W.; Cahoon, D.R.; Allen, J.A.; Ewel, K.C.; Lynch, J.C.; Cormier, N.

    2010-01-01

    Mangroves on Pacific high islands offer a number of important ecosystem services to both natural ecological communities and human societies. High islands are subjected to constant erosion over geologic time, which establishes an important source of terrigeneous sediment for nearby marine communities. Many of these sediments are deposited in mangrove forests and offer mangroves a potentially important means for adjusting surface elevation with rising sea level. In this study, we investigated sedimentation and elevation dynamics of mangrove forests in three hydrogeomorphic settings on the islands of Kosrae and Pohnpei, Federated States of Micronesia (FSM). Surface accretion rates ranged from 2.9 to 20.8 mm y-1, and are high for naturally occurring mangroves. Although mangrove forests in Micronesian high islands appear to have a strong capacity to offset elevation losses by way of sedimentation, elevation change over 61/2 years ranged from -3.2 to 4.1 mm y-1, depending on the location. Mangrove surface elevation change also varied by hydrogeomorphic setting and river, and suggested differential, and not uniformly bleak, susceptibilities among Pacific high island mangroves to sea-level rise. Fringe, riverine, and interior settings registered elevation changes of -1.30, 0.46, and 1.56 mm y-1, respectively, with the greatest elevation deficit (-3.2 mm y-1) from a fringe zone on Pohnpei and the highest rate of elevation gain (4.1 mm y-1) from an interior zone on Kosrae. Relative to sea-level rise estimates for FSM (0.8-1.8 mm y-1) and assuming a consistent linear trend in these estimates, soil elevations in mangroves on Kosrae and Pohnpei are experiencing between an annual deficit of 4.95 mm and an annual surplus of 3.28 mm. Although natural disturbances are important in mediating elevation gain in some situations, constant allochthonous sediment deposition probably matters most on these Pacific high islands, and is especially helpful in certain hydrogeomorphic zones

  1. Developing and managing transdisciplinary and transformative research on the coastal dynamics of sea level rise: Experiences and lessons learned

    Science.gov (United States)

    DeLorme, Denise E.; Kidwell, David; Hagen, Scott C.; Stephens, Sonia H.

    2016-05-01

    There is increasing emphasis from funding agencies on transdisciplinary approaches to integrate science and end-users. However, transdisciplinary research can be laborious and costly and knowledge of effective collaborative processes in these endeavors is incomplete. More guidance grounded in actual project experiences is needed. Thus, this article describes and examines the collaborative process of the Ecological Effects of Sea Level Rise in the Northern Gulf of Mexico transdisciplinary research project, including its development, implementation, and evaluation. Reflections, considerations, and lessons learned from firsthand experience are shared, supported with examples, and connected to relevant scholarly literature.

  2. Are sea-level-rise trends along the coasts of the north Indian Ocean consistent with global estimates?

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.; Shankar, D.

    the estuary (Hooghly), the value from the nearest point (Sagar) was taken. A linear correlation was performed for each Arabian-Sea record with that of Mumbai and for each Bay-of-Bengal record with that of Vishakhapatnam (Table 1); this includes stations... Change in the Era of the Recording Tide Gauge. In Sea Level Rise - History and Consequences. Ed Douglas, B.C. Kearney, M.S. Leatherman, S.P. Academic Press. 37-64. Goodbred, S.L., Kuel, S.A., 2000. The significance of large sediment supply, active...

  3. Implications of sea level rise scenarios on land use /land cover classes of the coastal zones of Cochin, India..

    Digital Repository Service at National Institute of Oceanography (India)

    ManiMurali, R.; DineshKumar, P.K.

    stream_size 35402 stream_content_type text/plain stream_name J_Environ_Manage_148_124a.pdf.txt stream_source_info J_Environ_Manage_148_124a.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 Author... Version: J. Environ. Manage., vol.148; 2015; 124-133. Implications of Sea Level Rise Scenarios on Land use /Land cover classes of the Coastal Zones of Cochin, India R.Mani Murali1, P.K.Dinesh Kumar2 1CSIR-National Institute of Oceanography, Dona...

  4. Sea-level rise and potential drowning of the Italian coastal plains: Flooding risk scenarios for 2100

    Science.gov (United States)

    Antonioli, F.; Anzidei, M.; Amorosi, A.; Lo Presti, V.; Mastronuzzi, G.; Deiana, G.; De Falco, G.; Fontana, A.; Fontolan, G.; Lisco, S.; Marsico, A.; Moretti, M.; Orrù, P. E.; Sannino, G. M.; Serpelloni, E.; Vecchio, A.

    2017-02-01

    We depict the relative sea-level rise scenarios for the year 2100 from four areas of the Italian peninsula. Our estimates are based on the Rahmstorf (2007) and IPCC-AR5 reports 2013 for the RCP-8.5 scenarios (http://www.ipcc.ch) The subsequent loss of land will impact the environment and local infrastructures, suggesting land planners and decision makers to take into account these scenarios for a cognizant coastal management. Our method developed for the Italian coast can be applied worldwide in other coastal areas expected to be affected by marine ingression due to global climate change.

  5. The hazard of Sea Level Rise (SLR) in Greece: from scientific knowledge towards risk awareness of main actors

    Science.gov (United States)

    Dandoulaki, Miranda; Karymbalis, Efthimios; Yorgos, Melissourgos; Skordili, Sophia; Valkanou, Kanella

    2014-05-01

    A natural hazard that is expected to affect coastal areas in the near future is Sea-Level Rise (SLR) due to climate change. According to recent reports the eustatic sea-level rise caused by global warming will reach approximately 18-59 cm by the year 2100. Potential impacts of future sea-level rise include coastal erosion, frequent and intensified cyclonic activity and associated storm surge flooding that may affect the coastal zones, saltwater intrusion into groundwater aquifers, the inundation of ecologically significant wetlands, and threats to cultural and historical resources, as well as to infrastructure. The identification of sensitive sections of coasts and the assessment of potential impacts of SLR on these is therefore a fundamental, yet initial, step towards their protection. Greece has the most extensive coastline among all Mediterranean countries with most of the socio-economic activities concentrated along the coastal zone. Almost all big urban centres are coastal ones and the same stands for a great part of infrastructure (ports, airports, roads, electricity and telecommunications network etc). As a result, the impacts of a potential rise of the sea level are expected to seriously affect the entire country. The paper examines the vulnerability to SLR of coastal zones in Greece; however its main focus is how knowledge can lead to policy making and the protection of coastal areas. The main actors in respect to protection from SLR in Greece are identified and there is an attempt to pin point how the knowledge is communicated and shared between them. Barriers, bridges and gaps are detected as regards how information and knowledge lead to risk awareness and finally to the implementation of protection policies. A main finding of the paper is that SLR risk is far from becoming a policy priority in Greece, although steps are taken for addressing impacts attributed to SLR such as coastal erosion. In order to address this risk, there are many potential

  6. Air pressure effects on sea level changes during the twentieth century

    Science.gov (United States)

    Piecuch, Christopher G.; Thompson, Philip R.; Donohue, Kathleen A.

    2016-10-01

    Interpretation of tide gauge data in terms sea level (η) and ocean dynamics requires estimates of air pressure (pa) to determine the ocean's isostatic response—the inverted barometer effect (ηib). Three gridded pa products (HadSLP2, NOAA-20CRv2, and ERA-20C) are used alongside meteorological station pa and tide gauge η records to evaluate the contribution of ηib to η changes over the twentieth century. Agreement between gridded products is better during more recent periods and over regions with good historical data coverage, whereas it is worse for earlier time periods or in ocean areas with poor observational data coverage. Comparison against station data reveals the presence of systematic errors in the gridded products, for example, such that uncertainties estimated through differencing the gridded products underestimate the true errors by roughly 40% on interannual and decadal time scales. Notwithstanding such correlated errors, gridded products are still useful for interpretation of tide gauge data. Removing gridded estimates of ηib from η records reduces spatial variance in centennial trends across tide gauges by 10-30%, formal errors in centennial trends from individual gauges by ˜5%, and the temporal variance in detrended records by 10-15% on average (depending on choice of gridded product). Results here advocate for making the ηib correction to tide gauge records in studies of ocean circulation and global η over long, multidecadal, and centennial time scales using an ensemble mean taken across several gridded ηib products.

  7. Mangrove expansion in the Gulf of Mexico with climate change: Implications for wetland health and resistance to rising sea levels

    Science.gov (United States)

    Comeaux, Rebecca S.; Allison, Mead A.; Bianchi, Thomas S.

    2012-01-01

    Black mangroves ( Avicennia spp.) are hypothesized to expand their latitudinal range with global climate change in the 21st century, induced by a reduction in the frequency and severity of coastal freezes, which are known to limit mangrove colony extent and individual tree size. The Gulf of Mexico is a prime candidate for population expansion to occur because it is located at the northward limit of black mangrove habitat. This may come at the expense of existing coastal saline wetlands that are dominantly Spartina spp. marsh grasses. The present study was conducted to focus on the implications of a marsh to mangrove transition in Gulf wetlands, specifically: (1) wetland resistance to accelerating eustatic sea level rise (ESLR) rates; (2) resistance to wave attack in large storms (increased cyclonic storm frequency/intensity is predicted with future climate warming); and (3) organic carbon sequestration and wetland soil geochemistry. Field sites of adjacent and inter-grown Avicennia germinans mangrove and Spartina marsh populations in similar geomorphological setting were selected in back-barrier areas near Port Aransas and Galveston, TX. Elevation surveys in the more mature Port Aransas site indicate mangrove vegetated areas are 4 cm higher in elevation than surrounding marsh on an average regional scale, and 1-2 cm higher at the individual mangrove scale. 210Pb and 137Cs accumulation rates and loss on ignition data indicate that mineral trapping is 4.1 times higher and sediment organics are 1.7 times lower in mangroves at Port Aransas. This additional mineral trapping does not differ in grain size character from marsh accumulation. Elevation change may also be effected by soil displacement of higher root volumes in mangrove cores. Port Aransas porosities are lower in mangrove rooted horizons, with a corresponding increase in sediment strength, suggesting mangrove intervals are more resistant to wave-induced erosion during storm events. Port Aransas mangroves

  8. A century-long simulation of terrestrial water storage change and its contribution to global sea-level

    Science.gov (United States)

    Bierkens, Marc F. P.; Bosmans, Joyce; de Graaf, Inge; Sutandjaja, Edwin; Schmitz, Oliver; Wada, Yoshihide; Wanders, Niko; van Beek, Ludovicus P. H.

    2016-04-01

    Although limited, the contribution of terrestrial water storage (TWS) change to sea-level change is significant enough to be taken into account in sea-level attribution studies. Thus, after being absent in a previous report, TWS was again one of the components taken into account in IPCC assessment report 5. TWS can be effectively observed by analysing gravity anomalies from the GRACE mission or by observing individual components with lidar (surface water level), geodetic surveys (groundwater) and space borne passive and active microwave sensors (soil moisture, snow water equivalent). However, these observation only yield time series of limited length making it difficult to estimate long term trends in TWS as multi-decadal variations. We present the results of a century-long (1900-2014) simulation of TWS change with PCR-GLOBWB 2.0 that is fully coupled with a global two-layer groundwater model. In this simulation we include the effects of land cover change, the building of reservoirs and human water use (abstraction from surface and groundwater, water consumption and return flows). The effects of wetland drainage and siltation of reservoirs is corrected for afterwards. We validate TWS estimates for the period 2003-2010 with GRACE estimates. Trends of TWS and its effects on sea-level change are estimated and the main contributions (humans and climate)identified. Similarly, we examine multi-year variability in TWS and sea-level change in relation to climate variability. Our results show a significant positive trend in TWS due to a trend in precipitation over the first half of the 20th century. In the second part of the 20th century trends in TWS due to dam impoundment and groundwater depletion are evident. Finally, large anomalies, in the order of 5 cm sea-level equivalent, can be seen as a result of interannual climate variability.

  9. Using a Bayesian Network to predict shore-line change vulnerability to sea-level rise for the coasts of the United States

    Science.gov (United States)

    Gutierrez, Benjamin T.; Plant, Nathaniel G.; Pendleton, Elizabeth A.; Thieler, E. Robert

    2014-01-01

    Sea-level rise is an ongoing phenomenon that is expected to continue and is projected to have a wide range of effects on coastal environments and infrastructure during the 21st century and beyond. Consequently, there is a need to assemble relevant datasets and to develop modeling or other analytical approaches to evaluate the likelihood of particular sea-level rise impacts, such as coastal erosion, and to inform coastal management decisions with this information. This report builds on previous work that compiled oceanographic and geomorphic data as part of the U.S. Geological Survey’s Coastal Vulnerability Index (CVI) for the U.S. Atlantic coast, and developed a Bayesian Network to predict shoreline-change rates based on sea-level rise plus variables that describe the hydrodynamic and geologic setting. This report extends the previous analysis to include the Gulf and Pacific coasts of the continental United States and Alaska and Hawaii, which required using methods applied to the USGS CVI dataset to extract data for these regions. The Bayesian Network converts inputs that include observations of local rates of relative sea-level change, mean wave height, mean tide range, a geomorphic classification, coastal slope, and observed shoreline-change rates to calculate the probability of the shoreline-erosion rate exceeding a threshold level of 1 meter per year for the coasts of the United States. The calculated probabilities were compared to the historical observations of shoreline change to evaluate the hindcast success rate of the most likely probability of shoreline change. Highest accuracy was determined for the coast of Hawaii (98 percent success rate) and lowest accuracy was determined for the Gulf of Mexico (34 percent success rate). The minimum success rate rose to nearly 80 percent (Atlantic and Gulf coasts) when success included shoreline-change outcomes that were adjacent to the most likely outcome. Additionally, the probabilistic approach determines the

  10. Consequences of climatic change, sea level rise and society evolution on the Kerkennah archipelago coast and sabkha

    Science.gov (United States)

    Lucile, Etienne; Gérard, Beltrando; Abdelkarim, Daoud

    2015-04-01

    Interaction between human activities, climate evolution and sea level can be summarised in a system where every element impacts the others. In the Kerkennah archipelago (Tunisia), recent observations have shown that the climate has become more arid, that the sea level is rising and that the society is modernizing at least since 1970. In our work we tried to understand the relations between the elements of the socio-ecosystem of Kerkennah to identify potential causes of the coastline movements and sabkhas extension (low and salty areas). Using photointerpretation (topographic map, Spot 5 image, aerial photographs) and remote sensing (2 landsat TM5 images), we detected and evaluated the movements of the coastline and of the sabkhas limits. Field data have also been added and all information has been used together in a GIS showing a significant retreat of the coastline (maximum of 41.2±6m in 47years) and an increase in the surface of sabkhas (+18%) between 1963 and 2010. The same dataset has been reanalysed at a much finer spatial scale to correlate observed changes to human pressure. This showed that coast erosion rates are more important where the coastline is partially artificialized or just after the end of a dam or a rockfill. Advances to the sea observed on some portions of the coast are always linked to human infrastructures. We conclude that the climatic change and the sea level rise increased the physical vulnerability of the archipelago and that the human installations near the coast amplify this vulnerability. Similarly, the extension of sabkha surfaces is global and most likely due to a natural perturbation of the seasonal cycle in the sabkhas by the sea level rise and by the stronger aridity in summer. However, discrepancies exist between individual areas and can be explained by the presence of active fault and/or by the evolution of agricultural practices. Indeed, frequent periods of drought and the political will for development of the Kerkennah

  11. Forecast effects of accelerating sea-level rise on the habitat of Atlantic Coast piping plovers and identify responsive conservation strategies

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This collaborative project will provide biologists and managers along the Atlantic coast with tools to predict effects of accelerating sea-level rise on the...

  12. Predicting the Impact of Storm Waves and Sea-Level Rise within the Papahānaumokuākea Marine National Monument (PMNM)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Recent storms and a tsunami (11 March 2011) have underscored the intrinsic potential for sea-level rise to damage wildlife populations and ecosystems of the...

  13. Integrated ecosystem services assessment: Valuation of changes due to sea level rise in Galveston Bay, Texas, USA.

    Science.gov (United States)

    Yoskowitz, David; Carollo, Cristina; Pollack, Jennifer Beseres; Santos, Carlota; Welder, Kathleen

    2017-03-01

    The goal of the present study was to identify the potential changes in ecosystem service values provided by wetlands in Galveston Bay, Texas, USA, under the Intergovernmental Panel on Climate Change (IPCC) A1B max (0.69 m) sea level rise scenario. Built exclusively upon the output produced during the Sea Level Affecting Marshes Model 6 (SLAMM 6) exercise for the Galveston Bay region, this study showed that fresh marsh and salt marsh present a steady decline from 2009 (initial condition) to 2100. Fresh marsh was projected to undergo the biggest changes, with the loss of approximately 21% of its extent between 2009 and 2100 under the A1B max scenario. The percentages of change for salt marsh were less prominent at approximately 12%. This trend was also shown in the values of selected ecosystem services (disturbance regulation, waste regulation, recreation, and aesthetics) provided by these habitats. An ordinary least squares regression was used to calculate the monetary value of the selected ecosystem services provided by salt marsh and fresh marsh in 2009, and in 2050 and 2100 under the A1B max scenario. The value of the selected services showed potential monetary losses in excess of US$40 million annually in 2100, compared to 2009 for fresh marsh and more than $11 million for salt marsh. The estimates provided here are only small portions of what can be lost due to the decrease in habitat extent, and they highlight the need for protecting not only built infrastructure but also natural resources from sea level rise. Integr Environ Assess Manag 2017;13:431-443. © 2016 SETAC.

  14. Biogeochemical analysis of ancient Pacific Cod bone suggests Hg bioaccumulation was linked to paleo sea level rise and climate change

    Directory of Open Access Journals (Sweden)

    Maribeth S. Murray

    2015-02-01

    Full Text Available Deglaciation at the end of the Pleistocene initiated major changes in ocean circulation and distribution. Within a brief geological time, large areas of land were inundated by sea-level rise and today global sea level is 120 m above its minimum stand during the last glacial maximum. This was the era of modern sea shelf formation; climate change caused coastal plain flooding and created broad continental shelves with innumerable consequences to marine and terrestrial ecosystems and human populations. In Alaska, the Bering Sea nearly doubled in size and stretches of coastline to the south were flooded, with regional variability in the timing and extent of submergence. Here we suggest how past climate change and coastal flooding are linked to mercury bioaccumulation that could have had profound impacts on past human populations and that, under conditions of continued climate warming, may have future impacts. Biogeochemical analysis of total mercury (tHg and 13C/15N ratios in the bone collagen of archaeologically recovered Pacific Cod (Gadus macrocephalus bone shows high levels of tHg during early/mid-Holocene. This pattern cannot be linked to anthropogenic activity or to food web trophic changes, but may result from natural phenomena such as increases in productivity, carbon supply and coastal flooding driven by glacial melting and sea-level rise. The coastal flooding could have led to increased methylation of Hg in newly submerged terrestrial land and vegetation. Methylmercury is bioaccumulated through aquatic food webs with attendant consequences for the health of fish and their consumers, including people. This is the first study of tHg levels in a marine species from the Gulf of Alaska to provide a time series spanning nearly the entire Holocene and we propose that past coastal flooding resulting from climate change had the potential to input significant quantities of Hg into marine food webs and subsequently to human consumers.

  15. Impacts of representing sea-level rise uncertainty on future flood risks: An example from San Francisco Bay

    Science.gov (United States)

    Oddo, Perry C.; Keller, Klaus

    2017-01-01

    Rising sea levels increase the probability of future coastal flooding. Many decision-makers use risk analyses to inform the design of sea-level rise (SLR) adaptation strategies. These analyses are often silent on potentially relevant uncertainties. For example, some previous risk analyses use the expected, best, or large quantile (i.e., 90%) estimate of future SLR. Here, we use a case study to quantify and illustrate how neglecting SLR uncertainties can bias risk projections. Specifically, we focus on the future 100-yr (1% annual exceedance probability) coastal flood height (storm surge including SLR) in the year 2100 in the San Francisco Bay area. We find that accounting for uncertainty in future SLR increases the return level (the height associated with a probability of occurrence) by half a meter from roughly 2.2 to 2.7 m, compared to using the mean sea-level projection. Accounting for this uncertainty also changes the shape of the relationship between the return period (the inverse probability that an event of interest will occur) and the return level. For instance, incorporating uncertainties shortens the return period associated with the 2.2 m return level from a 100-yr to roughly a 7-yr return period (∼15% probability). Additionally, accounting for this uncertainty doubles the area at risk of flooding (the area to be flooded under a certain height; e.g., the 100-yr flood height) in San Francisco. These results indicate that the method of accounting for future SLR can have considerable impacts on the design of flood risk management strategies. PMID:28350884

  16. Rates of sediment supply and sea-level rise in a large coastal lagoon

    Science.gov (United States)

    Morton, R.A.; Ward, G.H.; White, W.A.

    2000-01-01

    Laguna Madre, Texas, is 3-7 km wide and more than 190 km long, making it one of the longest lagoons in the world. The lagoon encompasses diverse geologic and climatic regions and it is an efficient sediment trap that accumulates clastic sediments from upland, interior, and oceanic sources. The semi-arid climate and frequent tropical cyclones historically have been responsible for the greatest volume of sediment influx. On an average annual basis, eolian transport, tidal exchange, storm washover, mainland runoff, interior shore erosion, and authigenic mineral production introduce approximately one million m3 of sediments into the lagoon. Analyses of these sediment transport mechanisms and associated line sources and point sources of sediment provide a basis for: (1) estimating the long-term average annual sediment supply to a large lagoon; (2) calculating the average net sedimentation rate; (3) comparing introduced sediment volumes and associated aggradation rates with observed relative sea-level change; and (4) predicting future conditions of the lagoon. This comparison indicates that the historical average annual accumulation rate in Laguna Madre (Laguna Madre is being submerged slowly and migrating westward rather than filling, as some have suggested.

  17. Assessment of island beach erosion due to sea level rise: the case of the Aegean archipelago (Eastern Mediterranean)

    Science.gov (United States)

    Monioudi, Isavela N.; Velegrakis, Adonis F.; Chatzipavlis, Antonis E.; Rigos, Anastasios; Karambas, Theophanis; Vousdoukas, Michalis I.; Hasiotis, Thomas; Koukourouvli, Nikoletta; Peduzzi, Pascal; Manoutsoglou, Eva; Poulos, Serafim E.; Collins, Michael B.

    2017-03-01

    The present contribution constitutes the first comprehensive attempt to (a) record the spatial characteristics of the beaches of the Aegean archipelago (Greece), a critical resource for both the local and national economy, and (b) provide a rapid assessment of the impacts of the long-term and episodic sea level rise (SLR) under different scenarios. Spatial information and other attributes (e.g., presence of coastal protection works and backshore development) of the beaches of the 58 largest islands of the archipelago were obtained on the basis of remote-sensed images available on the web. Ranges of SLR-induced beach retreats under different morphological, sedimentological and hydrodynamic forcing, and SLR scenarios were estimated using suitable ensembles of cross-shore (1-D) morphodynamic models. These ranges, combined with empirically derived estimations of wave run-up induced flooding, were then compared with the recorded maximum beach widths to provide ranges of retreat/erosion and flooding at the archipelago scale. The spatial information shows that the Aegean pocket beaches may be particularly vulnerable to mean sea level rise (MSLR) and episodic SLRs due to (i) their narrow widths (about 59 % of the beaches have maximum widths economic resource of the Aegean archipelago.

  18. How Shall We Tell Our People? The Art and Science of Communicating Sea-Level Rise to Coastal Audiences (Invited)

    Science.gov (United States)

    Moser, S. C.

    2010-12-01

    Improved sea-level rise projections and translation into decision-relevant information (e.g., changed flood frequencies and elevations, increased rates in coastal erosion, salinity changes in coastal aquifers) are critical for coastal managers, planners, and local elected officials to feel more confident in bringing climate change and its related coastal impacts to the attention of their communities. Those who have done so or are considering doing so, however, are not just concerned with “getting the science right” or getting the most credible and relevant information. They immediately, and sometimes primarily, are concerned with the reactions of coastal residents, developers, and business interests to the prospects of potentially difficult and substantial changes in coastal land use, their property rights, and the potential loss of their homes and establishments. How to engage the public constructively in developing adaptation strategies is a largely unmet challenge for most coastal managers. Similarly, they have not been trained in how to effectively communicate an issue that is ripe with the potential for loss, danger, and social and legal conflict - more so than they already face. Better physical science on sea-level rise alone will not meet these needs. Meanwhile, the social sciences have only begun to study public attitudes toward local impacts and adaptation responses. This paper will summarize key insights available at this time and point to important research and education/training needs to better assist practitioners faced with developing and implementing coastal adaptation strategies.

  19. Coastal Flooding in Florida's Big Bend Region with Application to Sea Level Rise Based on Synthetic Storms Analysis

    Directory of Open Access Journals (Sweden)

    Scott C. Hagen Peter Bacopoulos

    2012-01-01

    Full Text Available Flooding is examined by comparing maximum envelopes of water against the 0.2% (= 1-in-500-year return-period flooding surface generated as part of revising the Federal Emergency Management Agency¡¦s flood insurance rate maps for Franklin, Wakulla, and Jefferson counties in Florida¡¦s Big Bend Region. The analysis condenses the number of storms to a small fraction of the original 159 used in production. The analysis is performed by assessing which synthetic storms contributed to inundation extent (the extent of inundation into the floodplain, coverage (the overall surface area of the inundated floodplain and the spatially variable 0.2% flooding surface. The results are interpreted in terms of storm attributes (pressure deficit, radius to maximum winds, translation speed, storm heading, and landfall location and the physical processes occurring within the natural system (storms surge and waves; both are contextualized against existing and new hurricane scales. The approach identifies what types of storms and storm attributes lead to what types of inundation, as measured in terms of extent and coverage, in Florida¡¦s Big Bend Region and provides a basis in the identification of a select subset of synthetic storms for studying the impact of sea level rise. The sea level rise application provides a clear contrast between a dynamic approach versus that of a static approach.

  20. Using modelling to predict impacts of sea level rise and increased turbidity on seagrass distributions in estuarine embayments

    Science.gov (United States)

    Davis, Tom R.; Harasti, David; Smith, Stephen D. A.; Kelaher, Brendan P.

    2016-11-01

    Climate change induced sea level rise will affect shallow estuarine habitats, which are already under threat from multiple anthropogenic stressors. Here, we present the results of modelling to predict potential impacts of climate change associated processes on seagrass distributions. We use a novel application of relative environmental suitability (RES) modelling to examine relationships between variables of physiological importance to seagrasses (light availability, wave exposure, and current flow) and seagrass distributions within 5 estuarine embayments. Models were constructed separately for Posidonia australis and Zostera muelleri subsp. capricorni using seagrass data from Port Stephens estuary, New South Wales, Australia. Subsequent testing of models used independent datasets from four other estuarine embayments (Wallis Lake, Lake Illawarra, Merimbula Lake, and Pambula Lake) distributed along 570 km of the east Australian coast. Relative environmental suitability models provided adequate predictions for seagrass distributions within Port Stephens and the other estuarine embayments, indicating that they may have broad regional application. Under the predictions of RES models, both sea level rise and increased turbidity are predicted to cause substantial seagrass losses in deeper estuarine areas, resulting in a net shoreward movement of seagrass beds. Seagrass species distribution models developed in this study provide a valuable tool to predict future shifts in estuarine seagrass distributions, allowing identification of areas for protection, monitoring and rehabilitation.

  1. Interactions between barrier islands and backbarrier marshes affect island system response to sea level rise: Insights from a coupled model

    Science.gov (United States)

    Walters, David; Moore, Laura J.; Duran Vinent, Orencio; Fagherazzi, Sergio; Mariotti, Giulio

    2014-09-01

    Interactions between backbarrier marshes and barrier islands will likely play an important role in determining how low-lying coastal systems respond to sea level rise and changes in storminess in the future. To assess the role of couplings between marshes and barrier islands under changing conditions, we develop and apply a coupled barrier island-marsh model (GEOMBEST+) to assess the impact of overwash deposition on backbarrier marsh morphology and of marsh morphology on rates of island migration. Our model results suggest that backbarrier marsh width is in a constant state of change until either the backbarrier basin becomes completely filled or backbarrier marsh deposits have completely eroded away. Results also suggest that overwash deposition is an important source of sediment, which allows existing narrow marshes to be maintained in a long-lasting alternate state (~500 m wide in the Virginia Barrier Islands) within a range of conditions under which they would otherwise disappear. The existence of a narrow marsh state is supported by observations of backbarrier marshes along the eastern shore of Virginia. Additional results suggest that marshes reduce accommodation in the backbarrier bay, which, in turn, decreases island migration rate. As climate change results in sea level rise, and the increased potential for intense hurricanes resulting in overwash, it is likely that these couplings will become increasingly important in determining future system behavior.

  2. Global sea-level rise is recognised, but flooding from anthropogenic land subsidence is ignored around northern Manila Bay, Philippines.

    Science.gov (United States)

    Rodolfo, Kelvin S; Siringan, Fernando P

    2006-03-01

    Land subsidence resulting from excessive extraction of groundwater is particularly acute in East Asian countries. Some Philippine government sectors have begun to recognise that the sea-level rise of one to three millimetres per year due to global warming is a cause of worsening floods around Manila Bay, but are oblivious to, or ignore, the principal reason: excessive groundwater extraction is lowering the land surface by several centimetres to more than a decimetre per year. Such ignorance allows the government to treat flooding as a lesser problem that can be mitigated through large infrastructural projects that are both ineffective and vulnerable to corruption. Money would be better spent on preventing the subsidence by reducing groundwater pumping and moderating population growth and land use, but these approaches are politically and psychologically unacceptable. Even if groundwater use is greatly reduced and enlightened land-use practices are initiated, natural deltaic subsidence and global sea-level rise will continue to aggravate flooding, although at substantially lower rates.

  3. Coastal Flooding in Florida's Big Bend Region with Application to Sea Level Rise Based on Synthetic Storms Analysis

    Directory of Open Access Journals (Sweden)

    Scott C. Hagen and Peter Bacopoulos

    2012-01-01

    Full Text Available Flooding is examined by comparing maximum envelopes of water against the 0.2% (= 1-in-500-year return-period flooding surface generated as part of revising the Federal Emergency Management _ flood insurance rate maps for Franklin, Wakulla, and Jefferson counties in _ Big Bend Region. The analysis condenses the number of storms to a small fraction of the original 159 used in production. The analysis is performed by assessing which synthetic storms contributed to inundation extent (the extent of inundation into the floodplain, coverage (the overall surface area of the inundated floodplain and the spatially variable 0.2% flooding surface. The results are interpreted in terms of storm attributes (pressure deficit, radius to maximum winds, translation speed, storm heading, and landfall location and the physical processes occurring within the natural system (storms surge and waves; both are contextualized against existing and new hurricane scales. The approach identifies what types of storms and storm attributes lead to what types of inundation, as measured in terms of extent and coverage, in _ Big Bend Region and provides a basis in the identification of a select subset of synthetic storms for studying the impact of sea level rise. The sea level rise application provides a clear contrast between a dynamic approach versus that of a static approach.

  4. Salt marsh restoration as a community adaptation to climate change and sea level rise in Maritime Canada : workshop report

    Energy Technology Data Exchange (ETDEWEB)

    Singh, K. [Dalhousie Univ., Halifax, NS (Canada). Faculty of Management, School for Resource and Environmental Studies

    2007-01-17

    This workshop provided a multi-disciplinary perspective on salt marsh restoration as an adaptation strategy to climate change. It focused on the use of coastal salt marshes as an effective, low cost approach to coastal protection and adaptation to climate change and sea level rise. The purpose was to gain community feedback on many concerns such as land use conflicts regarding dykeland being used for transport infrastructure, agriculture production, and development; a lack of resources, education and money; community support; land ownership; and political barriers. The purpose of the workshop was to collect information and gain a better understanding of the viewpoints of different stakeholders, including all levels of government, First Nation groups, agricultural producers, non-governmental organizations and community groups. The vulnerability of Maritime Canada to climate change and sea-level rise was discussed along with the costs and benefits of restoring the salt marshes in the Maritimes which have been either significantly degraded or completely destroyed. 54 refs., 4 tabs., 6 figs., 4 appendices.

  5. Abrupt Bølling warming and ice saddle collapse contributions to the Meltwater Pulse 1a rapid sea level rise

    Science.gov (United States)

    Gregoire, Lauren J.; Otto-Bliesner, Bette; Valdes, Paul J.; Ivanovic, Ruza

    2016-09-01

    Elucidating the source(s) of Meltwater Pulse 1a, the largest rapid sea level rise caused by ice melt (14-18 m in less than 340 years, 14,600 years ago), is important for understanding mechanisms of rapid ice melt and the links with abrupt climate change. Here we quantify how much and by what mechanisms the North American ice sheet could have contributed to Meltwater Pulse 1a, by driving an ice sheet model with two transient climate simulations of the last 21,000 years. Ice sheet perturbed physics ensembles were run to account for model uncertainties, constraining ice extent and volume with reconstructions of 21,000 years ago to present. We determine that the North American ice sheet produced 3-4 m global mean sea level rise in 340 years due to the abrupt Bølling warming, but this response is amplified to 5-6 m when it triggers the ice sheet saddle collapse.

  6. A vulnerability assessment of 300 species in Florida: threats from sea level rise, land use, and climate change.

    Directory of Open Access Journals (Sweden)

    Joshua Steven Reece

    Full Text Available Species face many threats, including accelerated climate change, sea level rise, and conversion and degradation of habitat from human land uses. Vulnerability assessments and prioritization protocols have been proposed to assess these threats, often in combination with information such as species rarity; ecological, evolutionary or economic value; and likelihood of success. Nevertheless, few vulnerability assessments or prioritization protocols simultaneously account for multiple threats or conservation values. We applied a novel vulnerability assessment tool, the Standardized Index of Vulnerability and Value, to assess the conservation priority of 300 species of plants and animals in Florida given projections of climate change, human land-use patterns, and sea level rise by the year 2100. We account for multiple sources of uncertainty and prioritize species under five different systems of value, ranging from a primary emphasis on vulnerability to threats to an emphasis on metrics of conservation value such as phylogenetic distinctiveness. Our results reveal remarkable consistency in the prioritization of species across different conservation value systems. Species of high priority include the Miami blue butterfly (Cyclargus thomasi bethunebakeri, Key tree cactus (Pilosocereus robinii, Florida duskywing butterfly (Ephyriades brunnea floridensis, and Key deer (Odocoileus virginianus clavium. We also identify sources of uncertainty and the types of life history information consistently missing across taxonomic groups. This study characterizes the vulnerabilities to major threats of a broad swath of Florida's biodiversity and provides a system for prioritizing conservation efforts that is quantitative, flexible, and free from hidden value judgments.

  7. Beyond just sea-level rise: Considering macroclimatic drivers within coastal wetland vulnerability assessments to climate change

    Science.gov (United States)

    Osland, Michael J.; Enwright, Nicholas M.; Day, Richard H.; Gabler, Christopher A.; Stagg, Camille L.; Grace, James B.

    2016-01-01

    Due to their position at the land-sea interface, coastal wetlands are vulnerable to many aspects of climate change. However, climate change vulnerability assessments for coastal wetlands generally focus solely on sea-level rise without considering the effects of other facets of climate change. Across the globe and in all ecosystems, macroclimatic drivers (e.g., temperature and rainfall regimes) greatly influence ecosystem structure and function. Macroclimatic drivers have been the focus of climate-change related threat evaluations for terrestrial ecosystems, but largely ignored for coastal wetlands. In some coastal wetlands, changing macroclimatic conditions are expected to result in foundation plant species replacement, which would affect the supply of certain ecosystem goods and services and could affect ecosystem resilience. As examples, we highlight several ecological transition zones where small changes in macroclimatic conditions would result in comparatively large changes in coastal wetland ecosystem structure and function. Our intent in this communication is not to minimize the importance of sea-level rise. Rather, our overarching aim is to illustrate the need to also consider macroclimatic drivers within vulnerability assessments for coastal wetlands.

  8. COREDAR: COmmunicating Risk of sea level rise and Engaging stakeholDers in framing community based Adaptation stRategies

    Science.gov (United States)

    Amsad Ibrahim Khan, S. K.; Chen, R. S.; de Sherbinin, A. M.; Andimuthu, R.; Kandasamy, P.

    2015-12-01

    Accelerated sea-level rise (SLR) is a major long term outcome of climate change leading to increased inundation of low-lying areas. Particularly, global cities that are located on or near the coasts are often situated in low lying areas and these locations put global cities at greater risk to SLR. Localized flooding will profoundly impact vulnerable communities located in high-risk urban areas. Building community resilience and adapting to SLR is increasingly a high priority for cities. On the other hand, Article 6 of the United Nations Framework Convention on Climate Change addresses the importance of climate change communication and engaging stakeholders in decision making process. Importantly, Community Based Adaptation (CBA) experiences emphasize that it is important to understand a community's unique perceptions of their adaptive capacities to identify useful solutions and that scientific and technical information on anticipated coastal climate impacts needs to be translated into a suitable language and format that allows people to be able to participate in adaptation planning. To address this challenge, this study has put forth three research questions from the lens of urban community engagement in SLR adaptation, (1) What, if any, community engagement in addressing SLR occurring in urban areas; (2) What information do communities need and how does it need to be communicated, in order to be better prepared and have a greater sense of agency? and (3) How can government agencies from city to federal levels facilitate community engagement and action?. To answer these questions this study has evolved a framework "COREDAR" (COmmunicating Risk of sea level rise and Engaging stakeholDers in framing community based Adaptation StRategies) to communicate and transfer complex climate data and information such as projected SLR under different scenarios of IPCC AR5, predicted impact of SLR, prioritizing vulnerability, etc. to concerned stakeholders and local communities

  9. Vulnerability of topography-limited and recharge-limited groundwater systems to sea-level rise-induced salinization

    Science.gov (United States)

    Michael, H. A.; Byron, L. A.; Feinson, L. S.; Voss, C. I.; Russoniello, C. J.

    2012-12-01

    The effects of rising sea level on the hydraulic balance between aquifers and the ocean threaten freshwater resources and aquatic ecosystems along many world coastlines. Understanding both the vulnerability of groundwater systems to these changes and the primary factors that determine the magnitude of system response is critical to developing effective management plans in coastal zones. The rate and magnitude of salinization of fresh groundwater due to lateral seawater intrusion and changes in groundwater flow to the sea were assessed over a range of hydrogeologic settings. A primary factor affecting vulnerability is whether the system is recharge-limited or topography-limited. Results of two-dimensional variable-density groundwater-flow and salt-transport simulations indicate that the response of recharge-limited systems is largely minimal, whereas topography-limited systems are vulnerable for various combinations of permeability, vertical anisotropy in permeability, and recharge. World coastlines were classified according to system type as a vulnerability indicator. Results indicate that more than 50 percent of world coastlines are topography-limited over the range of cases tested. Central coastal Bangladesh is an example of a primarily topography-limited system that is highly vulnerable to impacts of sea-level rise as a result of its low elevation, dense population, and extensive groundwater use. Complexities of geologic heterogeneity and salinization processes, including storm-surge overtopping and accelerated salinization rates due to pumping, were considered. Results indicate that geologic heterogeneity has a strong control on the current and evolving pattern of salinity. The process of lateral intrusion can be slow, such that the current salinity distribution may still be changing in response to past sea-level rise. Vertical intrusion from above, where it occurs, is faster, and pumping can accelerate both mechanisms. Bangladesh vulnerability analyses are

  10. Responses of eastern Chinese coastal salt marshes to sea-level rise combined with vegetative and sedimentary processes

    Science.gov (United States)

    Ge, Zhen-Ming; Wang, Heng; Cao, Hao-Bin; Zhao, Bin; Zhou, Xiao; Peltola, Heli; Cui, Li-Fang; Li, Xiu-Zhen; Zhang, Li-Quan

    2016-06-01

    The impacts of sea-level rise (SLR) on coastal ecosystems have attracted worldwide attention in relation to global change. In this study, the salt marsh model for the Yangtze Estuary (SMM-YE, developed in China) and the Sea Level Affecting Marshes Model (SLAMM, developed in the U.S.) were used to simulate the effects of SLR on the coastal salt marshes in eastern China. The changes in the dominant species in the plant community were also considered. Predictions based on the SLAMM indicated a trend of habitat degradation up to 2100; total salt marsh habitat area continued to decline (4–16%) based on the low-level scenario, with greater losses (6–25%) predicted under the high-level scenario. The SMM-YE showed that the salt marshes could be resilient to threats of SLR through the processes of accretion of mudflats, vegetation expansion and sediment trapping by plants. This model predicted that salt marsh areas increased (3–6%) under the low-level scenario. The decrease in the total habitat area with the SMM-YE under the high-level scenario was much lower than the SLAMM prediction. Nevertheless, SLR might negatively affect the salt marsh species that are not adapted to prolonged inundation. An adaptive strategy for responding to changes in sediment resources is necessary in the Yangtze Estuary.

  11. Rapid changes in the seasonal sea level cycle along the US Gulf coast in the early 21st century

    Science.gov (United States)

    Wahl, T.; Calafat, F. M.; Luther, M. E.

    2013-12-01

    The seasonal cycle is an energetic component in the sea level spectrum and dominates the intra-annual sea level variability outside the semidiurnal and diurnal tidal bands in most regions. Changes in the annual or semi-annual amplitudes or phase lags have an immediate impact on marine coastal systems. Increases in the amplitudes or phase shifts towards the storm surge season may for instance exacerbate the risk of coastal flooding and/or beach erosion, and the ecological health of estuarine systems is also coupled to the seasonal sea level cycle. Here, we investigate the temporal variability of the seasonal harmonics along the US Gulf of Mexico (GOM) coastline using records from 13 tide gauges providing at least 30 years of data in total and at least 15 years for the period after 1990. The longest records go back to the early 20th century. Running Fourier analysis (with a window length of 5-years) is used to extract the seasonal harmonics from the observations. The resulting time series show a considerable decadal variability and no longer-term changes are found in the phase lags and the semi-annual amplitude. The amplitude of the dominating annual cycle in contrast shows a tendency towards higher values since the turn of the century at tide gauges in the eastern part of the GOM. This increase of up to more than 25% is found to be significant at the 90% confidence level for most tide gauges along the coastline of West Florida and at the 75% confidence level for virtually all stations in the eastern GOM (from Key West to Dauphin Island). Monthly mean sea level sub-series show that the changes are partly due to smaller values in the cold season but mostly a result of higher values in the warm season, i.e. sea levels tend to be higher during the hurricane season. We use information on the steric sea level component, sea surface and air temperature, wind forcing, precipitation, and sea level pressure to explain the mechanisms driving the decadal variability in the

  12. Ice Melt, Sea Level Rise and Superstorms: Evidence from Paleoclimate Data, Climate Modeling, and Modern Observations that 2C Global Warming Could Be Dangerous

    Science.gov (United States)

    Hansen, J.; Sato, Makiko; Hearty, Paul; Ruedy, Reto; Kelley, Maxwell; Masson-Delmotte, Valerie; Russell, Gary; Tselioudis, George; Cao, Junji; Rignot, Eric; Velicogna, Isabella; Tormey, Blair; Donovan, Bailey; Kandiano, Evgeniya; von Schuckmann, Karina; Kharecha, Pushker; Legrande, Allegra N.; Bauer, Michael; Lo, Kwok-Wai

    2016-01-01

    warmer than today. Ice melt cooling of the North Atlantic and Southern oceans increases atmospheric temperature gradients, eddy kinetic energy and baroclinicity, thus driving more powerful storms. The modeling, paleoclimate evidence, and ongoing observations together imply that 2 C global warming above the preindustrial level could be dangerous. Continued high fossil fuel emissions this century are predicted to yield (1) cooling of the Southern Ocean, especially in the Western Hemisphere; (2) slowing of the Southern Ocean overturning circulation, warming of the ice shelves, and growing ice sheet mass loss; (3) slowdown and eventual shutdown of the Atlantic overturning circulation with cooling of the North Atlantic region; (4) increasingly powerful storms; and (5) nonlinearly growing sea level rise, reaching several meters over a timescale of 50-150 years. These predictions, especially the cooling in the Southern Ocean and North Atlantic with markedly reduced warming or even cooling in Europe, differ fundamentally from existing climate change assessments. We discuss observations and modeling studies needed to refute or clarify these assertions.

  13. Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming could be dangerous

    Science.gov (United States)

    Hansen, James; Sato, Makiko; Hearty, Paul; Ruedy, Reto; Kelley, Maxwell; Masson-Delmotte, Valerie; Russell, Gary; Tselioudis, George; Cao, Junji; Rignot, Eric; Velicogna, Isabella; Tormey, Blair; Donovan, Bailey; Kandiano, Evgeniya; von Schuckmann, Karina; Kharecha, Pushker; Legrande, Allegra N.; Bauer, Michael; Lo, Kwok-Wai

    2016-03-01

    C warmer than today. Ice melt cooling of the North Atlantic and Southern oceans increases atmospheric temperature gradients, eddy kinetic energy and baroclinicity, thus driving more powerful storms. The modeling, paleoclimate evidence, and ongoing observations together imply that 2 °C global warming above the preindustrial level could be dangerous. Continued high fossil fuel emissions this century are predicted to yield (1) cooling of the Southern Ocean, especially in the Western Hemisphere; (2) slowing of the Southern Ocean overturning circulation, warming of the ice shelves, and growing ice sheet mass loss; (3) slowdown and eventual shutdown of the Atlantic overturning circulation with cooling of the North Atlantic region; (4) increasingly powerful storms; and (5) nonlinearly growing sea level rise, reaching several meters over a timescale of 50-150 years. These predictions, especially the cooling in the Southern Ocean and North Atlantic with markedly reduced warming or even cooling in Europe, differ fundamentally from existing climate change assessments. We discuss observations and modeling studies needed to refute or clarify these assertions.

  14. Ecological niche modeling of coastal dune plants and future potential distribution in response to climate change and sea level rise.

    Science.gov (United States)

    Mendoza-González, Gabriela; Martínez, M Luisa; Rojas-Soto, Octavio R; Vázquez, Gabriela; Gallego-Fernández, Juan B

    2013-08-01

    Climate change (CC) and sea level rise (SLR) are phenomena that could have severe impacts on the distribution of coastal dune vegetation. To explore this we modeled the climatic niches of six coastal dunes plant species that grow along the shoreline of the Gulf of Mexico and the Yucatan Peninsula, and projected climatic niches to future potential distributions based on two CC scenarios and SLR projections. Our analyses suggest that distribution of coastal plants will be severely limited, and more so in the case of local endemics (Chamaecrista chamaecristoides, Palafoxia lindenii, Cakile edentula). The possibilities of inland migration to the potential 'new shoreline' will be limited by human infrastructure and ecosystem alteration that will lead to a 'coastal squeeze' of the coastal habitats. Finally, we identified areas as future potential refuges for the six species in central Gulf of Mexico, and northern Yucatán Peninsula especially under CC and SLR scenarios.

  15. Impact of sea-level rise and coral mortality on the wave dynamics and wave forces on barrier reefs.

    Science.gov (United States)

    Baldock, T E; Golshani, A; Callaghan, D P; Saunders, M I; Mumby, P J

    2014-06-15

    A one-dimensional wave model was used to investigate the reef top wave dynamics across a large suite of idealized reef-lagoon profiles, representing barrier coral reef systems under different sea-level rise (SLR) scenarios. The modeling shows that the impacts of SLR vary spatially and are strongly influenced by the bathymetry of the reef and coral type. A complex response occurs for the wave orbital velocity and forces on corals, such that the changes in the wave dynamics vary reef by reef. Different wave loading regimes on massive and branching corals also leads to contrasting impacts from SLR. For many reef bathymetries, wave orbital velocities increase with SLR and cyclonic wave forces are reduced for certain coral species. These changes may be beneficial to coral health and colony resilience and imply that predicting SLR impacts on coral reefs requires careful consideration of the reef bathymetry and the mix of coral species.

  16. A probabilistic approach for assessing the vulnerability of transportation infrastructure to flooding from sea level rise and storm surge.

    Science.gov (United States)

    Douglas, E. M.; Kirshen, P. H.; Bosma, K.; Watson, C.; Miller, S.; McArthur, K.

    2015-12-01

    There now exists a plethora of information attesting to the reality of our changing climate and its impacts on both human and natural systems. There also exists a growing literature linking climate change impacts and transportation infrastructure (highways, bridges, tunnels, railway, shipping ports, etc.) which largely agrees that the nation's transportation systems are vulnerable. To assess this vulnerability along the coast, flooding due to sea level rise and storm surge has most commonly been evaluated by simply increasing the water surface elevation and then estimating flood depth by comparing the new water surface elevation with the topographic elevations of the land surface. While this rudimentary "bathtub" approach may provide a first order identification of potential areas of vulnerability, accurate assessment requires a high resolution, physically-based hydrodynamic model that can simulate inundation due to the combined effects of sea level rise, storm surge, tides and wave action for site-specific locations. Furthermore, neither the "bathtub" approach nor other scenario-based approaches can quantify the probability of flooding due to these impacts. We developed a high resolution coupled ocean circulation-wave model (ADCIRC/SWAN) that utilizes a Monte Carlo approach for predicting the depths and associated exceedance probabilities of flooding due to both tropical (hurricanes) and extra-tropical storms under current and future climate conditions. This required the development of an entirely new database of meteorological forcing (e.g. pressure, wind speed, etc.) for historical Nor'easters in the North Atlantic basin. Flooding due to hurricanes and Nor'easters was simulated separately and then composite flood probability distributions were developed. Model results were used to assess the vulnerability of the Central Artery/Tunnel system in Boston, Massachusetts to coastal flooding now and in the future. Local and regional adaptation strategies were

  17. Quantifying the patterns and dynamics of river deltas under conditions of steady forcing and relative sea level rise

    Science.gov (United States)

    Liang, Man; Van Dyk, Corey; Passalacqua, Paola

    2016-02-01

    Understanding deltaic channel dynamics is essential to acquiring knowledge on how deltas respond to environmental changes, as channels control the distribution of water, sediment, and nutrients. Channel-resolving morphodynamic models provide the basis for quantitative study of channel-scale dynamics, but they need to be properly assessed with a set of robust metrics able to quantitatively characterize delta patterns and dynamics before being used as predictive tools. In this work we use metrics developed in the context of delta formation, to assess the morphodynamic results of DeltaRCM, a parcel-based cellular model for delta formation and evolution. By comparing model results to theoretical predictions and field and experimental observations, we show that DeltaRCM captures the geometric growth characteristics of deltas such as fractality of channel network, spatial distribution of wet and dry surfaces, and temporal dynamics of channel-scale processes such as the decay of channel planform correlation. After evaluating the ability of DeltaRCM to produce delta patterns and dynamics at the scale of channel processes, we use the model to predict the deltaic response to relative sea level rise (RSLR). We show that uniform subsidence and absolute sea level rise have similar effects on delta evolution and cause intensified channel branching. Channel network fractality and channel mobility increase with higher-RSLR rates, while the spatial and temporal scales of avulsion events decrease, resulting in smaller sand bodies in the stratigraphy. Our modeling results provide the first set of quantitative predictions of the effects of RSLR on river deltas with a specific focus on the distributary channel network.

  18. Linking Historic Wetland Soil Accretion and Sea-Level Rise Data with Landcover Change in the US

    Science.gov (United States)

    Holmquist, J. R.; Brown, L. N.; MacDonald, G. M.

    2015-12-01

    Coastal marsh loss in the US due to sea-level rise and other anthropogenic factors has important ramifications for carbon sequestration, endangered species habitat, water quality, and myriad other ecosystem services. We compiled 486 reports of 137Cs dated cores from coastal marshes in North America and compared vertical accretion rates to relative sea-level rise (RSLR) from the nearest NOAA tide gauge between 1963 and the core collection year. There was a positive linear correlation between RSLR and vertical accretion. When RSLR was greater than 5 mm/yr RSLR outpaced accretion on average indicating a possible limitation to positive feedback within the system. We also calculated net-accretion (vertical accretion - RSLR) and summarized regional variation according to both coastal zone and watershed boundaries. From 1963 to present the West Coast has been the most historically resilient to RSLR, the Gulf Coast has been the most vulnerable, and the East Coast has been intermediate and variable. We compared regional trends in net-accretion to land cover change using 1996-2010 Coastal Change Analysis Program maps with freshwater wetland area constrained by tidal categories from the National Wetlands Inventory. Watersheds with historic net-accretion falling below -3.9 mm/yr in the Gulf Coast were much more likely to have massive losses of coastal wetland area from 1996-2010, up to 10% of 1996 wetland area in some cases. Areas with higher net-accretion did not show change, except for some gains in the San Francisco Bay. The Mississippi Delta mouth is a notable data anomaly with positive historical net-accretion as well as a net-loss of wetland surface to open water which may identify an important limitation of soil coring techniques in areas with dynamic sediment deposition.

  19. Future coastal population growth and exposure to sea-level rise and coastal flooding--a global assessment.

    Directory of Open Access Journals (Sweden)

    Barbara Neumann

    Full Text Available Coastal zones are exposed to a range of coastal hazards including sea-level rise with its related effects. At the same time, they are more densely populated than the hinterland and exhibit higher rates of population growth and urbanisation. As this trend is expected to continue into the future, we investigate how coastal populations will be affected by such impacts at global and regional scales by the years 2030 and 2060. Starting from baseline population estimates for the year 2000, we assess future population change in the low-elevation coastal zone and trends in exposure to 100-year coastal floods based on four different sea-level and socio-economic scenarios. Our method accounts for differential growth of coastal areas against the land-locked hinterland and for trends of urbanisation and expansive urban growth, as currently observed, but does not explicitly consider possible displacement or out-migration due to factors such as sea-level rise. We combine spatially explicit estimates of the baseline population with demographic data in order to derive scenario-driven projections of coastal population development. Our scenarios show that the number of people living in the low-elevation coastal zone, as well as the number of people exposed to flooding from 1-in-100 year storm surge events, is highest in Asia. China, India, Bangladesh, Indonesia and Viet Nam are estimated to have the highest total coastal population exposure in the baseline year and this ranking is expected to remain largely unchanged in the future. However, Africa is expected to experience the highest rates of population growth and urbanisation in the coastal zone, particularly in Egypt and sub-Saharan countries in Western and Eastern Africa. The results highlight countries and regions with a high degree of exposure to coastal flooding and help identifying regions where policies and adaptive planning for building resilient coastal communities are not only desirable but essential

  20. The combined impact on the flooding in Vietnam's Mekong River delta of local man-made structures, sea level rise, and dams upstream in the river catchment

    Science.gov (United States)

    Le, Thi Viet Hoa; Nguyen, Huu Nhan; Wolanski, Eric; Tran, Thanh Cong; Haruyama, Shigeko

    2007-01-01

    The Mekong River delta plays an important role in the Vietnamese economy and it has been severely impacted during this century by a series of unusually large floods. In the dry season the delta is also impacted by salinity intrusion and tides. These effects have caused severe human hardship. To mitigate these impacts, a large number of engineering structures, primarily dykes and weirs, have been built in the delta in recent years and are still being built, mainly to control floods and saltwater intrusion. These control measures are still being upgraded. A GIS-linked numerical model shows that the flood levels in the delta depend on the combined impacts of high river flows in the Mekong River, storm surges, sea level rise, and the likely, future siltation of the Mekong Estuary resulting from the construction of dams in China as well as many other dams proposed throughout the remaining river catchment. The model suggests that the engineering structures in the delta increase the flow velocities in the rivers and canals, increasing bank erosion, and cause the water to be deeper in the rivers and canals. This increases flooding in the non-protected areas of the delta and increases the risk of catastrophic failure of the dykes in the protected areas. The model also predicts that a sea level rise induced by global warming will enhance flooding in the Mekong River delta in Vietnam, and that flooding may worsen in the long term as a result of estuarine siltation resulting from the construction of dams. At the scale of the Mekong River basin, a multinational water resources management plan is needed that includes the hydrological needs of the delta. At the scale of the delta, a compromise is needed between allowing some flooding necessary for agriculture and preventing catastrophic flooding to alleviate human suffering.

  1. The role of surface and subsurface processes in keeping pace with sea level rise in intertidal wetlands of Moreton Bay, Queensland, Australia

    Science.gov (United States)

    Lovelock, Catherine E.; Bennion, Vicki; Grinham, Alistair; Cahoon, Donald R.

    2011-01-01

    Increases in the elevation of the soil surfaces of mangroves and salt marshes are key to the maintenance of these habitats with accelerating sea level rise. Understanding the processes that give rise to increases in soil surface elevation provides science for management of landscapes for sustainable coastal wetlands. Here, we tested whether the soil surface elevation of mangroves and salt marshes in Moreton Bay is keeping up with local rates of sea level rise (2.358 mm y-1) and whether accretion on the soil surface was the most important process for keeping up with sea level rise. We found variability in surface elevation gains, with sandy areas in the eastern bay having the highest surface elevation gains in both mangrove and salt marsh (5.9 and 1.9 mm y-1) whereas in the muddier western bay rates of surface elevation gain were lower (1.4 and -0.3 mm y-1 in mangrove and salt marsh, respectively). Both sides of the bay had similar rates of surface accretion (~7–9 mm y-1 in the mangrove and 1–3 mm y-1 in the salt marsh), but mangrove soils in the western bay were subsiding at a rate of approximately 8 mm y-1, possibly due to compaction of organic sediments. Over the study surface elevation increments were sensitive to position in the intertidal zone (higher when lower in the intertidal) and also to variation in mean sea level (higher at high sea level). Although surface accretion was the most important process for keeping up with sea level rise in the eastern bay, subsidence largely negated gains made through surface accretion in the western bay indicating a high vulnerability to sea level rise in these forests.

  2. Impacts of sea level rise and climate change on coastal plant species in the central California coast

    Directory of Open Access Journals (Sweden)

    Kendra L. Garner

    2015-05-01

    Full Text Available Local increases in sea level caused by global climate change pose a significant threat to the persistence of many coastal plant species through exacerbating inundation, flooding, and erosion. In addition to sea level rise (SLR, climate changes in the form of air temperature and precipitation regimes will also alter habitats of coastal plant species. Although numerous studies have analyzed the effect of climate change on future habitats through species distribution models (SDMs, none have incorporated the threat of exposure to SLR. We developed a model that quantified the effect of both SLR and climate change on habitat for 88 rare coastal plant species in San Luis Obispo, Santa Barbara, and Ventura Counties, California, USA (an area of 23,948 km2. Our SLR model projects that by the year 2100, 60 of the 88 species will be threatened by SLR. We found that the probability of being threatened by SLR strongly correlates with a species’ area, elevation, and distance from the coast, and that 10 species could lose their entire current habitat in the study region. We modeled the habitat suitability of these 10 species under future climate using a species distribution model (SDM. Our SDM projects that 4 of the 10 species will lose all suitable current habitats in the region as a result of climate change. While SLR accounts for up to 9.2 km2 loss in habitat, climate change accounts for habitat suitability changes ranging from a loss of 1,439 km2 for one species to a gain of 9,795 km2 for another species. For three species, SLR is projected to reduce future suitable area by as much as 28% of total area. This suggests that while SLR poses a higher risk, climate changes in precipitation and air temperature represents a lesser known but potentially larger risk and a small cumulative effect from both.

  3. Modeled Sea Level Rise Impacts on Coastal Ecosystems at Six Major Estuaries on Florida's Gulf Coast: Implications for Adaptation Planning.

    Science.gov (United States)

    Geselbracht, Laura L; Freeman, Kathleen; Birch, Anne P; Brenner, Jorge; Gordon, Doria R

    2015-01-01

    The Sea Level Affecting Marshes Model (SLAMM) was applied at six major estuaries along Florida's Gulf Coast (Pensacola Bay, St. Andrews/Choctawhatchee Bays, Apalachicola Bay, Southern Big Bend, Tampa Bay and Charlotte Harbor) to provide quantitative and spatial information on how coastal ecosystems may change with sea level rise (SLR) and to identify how this information can be used to inform adaption planning. High resolution LiDAR-derived elevation data was utilized under three SLR scenarios: 0.7 m, 1 m and 2 m through the year 2100 and uncertainty analyses were conducted on selected input parameters at three sites. Results indicate that the extent, spatial orientation and relative composition of coastal ecosystems at the study areas may substantially change with SLR. Under the 1 m SLR scenario, total predicted impacts for all study areas indicate that coastal forest (-69,308 ha; -18%), undeveloped dry land (-28,444 ha; -2%) and tidal flat (-25,556 ha; -47%) will likely face the greatest loss in cover by the year 2100. The largest potential gains in cover were predicted for saltmarsh (+32,922 ha; +88%), transitional saltmarsh (+23,645 ha; na) and mangrove forest (+12,583 ha; +40%). The Charlotte Harbor and Tampa Bay study areas were predicted to experience the greatest net loss in coastal wetlands The uncertainty analyses revealed low to moderate changes in results when some numerical SLAMM input parameters were varied highlighting the value of collecting long-term sedimentation, accretion and erosion data to improve SLAMM precision. The changes predicted by SLAMM will affect exposure of adjacent human communities to coastal hazards and ecosystem functions potentially resulting in impacts to property values, infrastructure investment and insurance rates. The results and process presented here can be used as a guide for communities vulnerable to SLR to identify and prioritize adaptation strategies that slow and/or accommodate the changes underway.

  4. Modeled Sea Level Rise Impacts on Coastal Ecosystems at Six Major Estuaries on Florida's Gulf Coast: Implications for Adaptation Planning.

    Directory of Open Access Journals (Sweden)

    Laura L Geselbracht

    Full Text Available The Sea Level Affecting Marshes Model (SLAMM was applied at six major estuaries along Florida's Gulf Coast (Pensacola Bay, St. Andrews/Choctawhatchee Bays, Apalachicola Bay, Southern Big Bend, Tampa Bay and Charlotte Harbor to provide quantitative and spatial information on how coastal ecosystems may change with sea level rise (SLR and to identify how this information can be used to inform adaption planning. High resolution LiDAR-derived elevation data was utilized under three SLR scenarios: 0.7 m, 1 m and 2 m through the year 2100 and uncertainty analyses were conducted on selected input parameters at three sites. Results indicate that the extent, spatial orientation and relative composition of coastal ecosystems at the study areas may substantially change with SLR. Under the 1 m SLR scenario, total predicted impacts for all study areas indicate that coastal forest (-69,308 ha; -18%, undeveloped dry land (-28,444 ha; -2% and tidal flat (-25,556 ha; -47% will likely face the greatest loss in cover by the year 2100. The largest potential gains in cover were predicted for saltmarsh (+32,922 ha; +88%, transitional saltmarsh (+23,645 ha; na and mangrove forest (+12,583 ha; +40%. The Charlotte Harbor and Tampa Bay study areas were predicted to experience the greatest net loss in coastal wetlands The uncertainty analyses revealed low to moderate changes in results when some numerical SLAMM input parameters were varied highlighting the value of collecting long-term sedimentation, accretion and erosion data to improve SLAMM precision. The changes predicted by SLAMM will affect exposure of adjacent human communities to coastal hazards and ecosystem functions potentially resulting in impacts to property values, infrastructure investment and insurance rates. The results and process presented here can be used as a guide for communities vulnerable to SLR to identify and prioritize adaptation strategies that slow and/or accommodate the changes underway.

  5. The conservation value of elevation data accuracy and model sophistication in reserve design under sea-level rise.

    Science.gov (United States)

    Zhu, Mingjian; Hoctor, Tom; Volk, Mike; Frank, Kathryn; Linhoss, Anna

    2015-10-01

    Many studies have explored the value of using more sophisticated coastal impact models and higher resolution elevation data in sea-level rise (SLR) adaptation planning. However, we know little about to what extent the improved models and data could actually lead to better conservation outcomes under SLR. This is important to know because high-resolution data are likely to not be available in some data-poor coastal areas in the world and running more complicated coastal impact models is relatively time-consuming, expensive, and requires assistance by qualified experts and technicians. We address this research question in the context of identifying conservation priorities in response to SLR. Specifically, we investigated the conservation value of using more accurate light detection and ranging (Lidar)-based digital elevation data and process-based coastal land-cover change models (Sea Level Affecting Marshes Model, SLAMM) to identify conservation priorities versus simple "bathtub" models based on the relatively coarse National Elevation Dataset (NED) in a coastal region of northeast Florida. We compared conservation outcomes identified by reserve design software (Zonation) using three different model dataset combinations (Bathtub-NED, Bathtub-Lidar, and SLAMM-Lidar). The comparisons show that the conservation priorities are significantly different with different combinations of coastal impact models and elevation dataset inputs. The research suggests that it is valuable to invest in more accurate coastal impact models and elevation datasets in SLR adaptive conservation planning because this model-dataset combination could improve conservation outcomes under SLR. Less accurate coastal impact models, including ones created using coarser Digital Elevation Model (DEM) data can still be useful when better data and models are not available or feasible, but results need to be appropriately assessed and communicated. A future research priority is to investigate how

  6. Birth of the modern Chesapeake Bay estuary between 7.4 and 8.2 ka and implications for global sea-level rise

    Science.gov (United States)

    Bratton, John F.; Colman, Steven M.; Thieler, E. Robert; Seal, Robert R.

    2002-12-01

    Two major pulses of sea-level rise are thought to have taken place since the last glacial maximum — meltwater pulses (mwp) 1A (12 cal ka) and 1B (9.5 cal ka). Between mwp 1B and about 6 cal ka, many of the complex coastal ecosystems which ring the world's oceans began to form. Here we report data for rhenium, carbon isotopes, total organic carbon, and fossil oysters from Chesapeake Bay which span the transition from fresh to brackish water conditions in the bay in the mid-Holocene. These data constrain sea-level change and resulting environmental change in the bay. They indicate that the transition was rapid, and that it was produced by (1) a third pulse of rapid eustatic sea-level rise, or (2) a geometry of the prehistoric Chesapeake Bay basin which predisposed it to a nonlinear response to a steadily rising sea level. Similar nonlinear changes in vulnerable coastal environments are likely to take place in the future due to polar warming, regardless of the timing or rate of sea-level rise.

  7. Coastal vulnerability to sea-level rise: a preliminary database for the U.S. Atlantic, Pacific, and Gulf of Mexico coasts

    Science.gov (United States)

    Hammar-Klose, Erika S.; Thieler, E. Robert

    2001-01-01

    The prediction of coastal evolution is not straightforward. There is no standard methodology, and even the kind of data required to make such predictions are the subject of much scientific debate. Since a viable, quantitative predictive model for coastal evolution is not available. The relative susceptibility of the Nation's coastline to sea-level rise is quantified here at a regional to national scale using basic information on coastal geomorphology, rate of sea-level rise, past shoreline evolution and other factors. This approach combines the coastal system's susceptibility to change with its natural ability to adapt to changing environmental and conditions, and yields a relative measure of the system's natural vulnerability to the effects of sea-level rise. This information has immediate application to many of the decisions our society will be making regarding coastal development in both the short- and long-term.

  8. Sea level rise and inundation of island interiors: Assessing impacts of lake formation and evaporation on water resources in arid climates

    Science.gov (United States)

    Gulley, J. D.; Mayer, A. S.; Martin, J. B.; Bedekar, V.

    2016-09-01

    Coasts of many low-lying islands will be inundated should sea level rise by 1 m by 2100 as projected, thereby decreasing water resources through aquifer salinization. A lesser known impact occurs if rising sea level elevates water tables above interior topographic lows to form lakes. Impacts of lake formation on water resources, however, remain unquantified. Here we use hydrological models, based on islands in the Bahamian archipelago, to demonstrate that on islands with negative water budgets, evaporation following lake inundation can cause more than twice the loss of fresh groundwater resources relative to an equivalent amount of coastal inundation. This result implies that in dry climates, low-lying islands with inland depressions could face substantially greater threats to their water resources from sea level rise than previously considered.

  9. Use of a Florida Gulf Coast Barrier Island by Spring Trans-Gulf Migrants and the Projected Effects of Sea Level Rise on Habitat Availability.

    Directory of Open Access Journals (Sweden)

    Lori A Lester

    Full Text Available Barrier islands on the north coast of the Gulf of Mexico are an internationally important coastal resource. Each spring hundreds of thousands of Nearctic-Neotropical songbirds crossing the Gulf of Mexico during spring migration use these islands because they provide the first landfall for individuals following a trans-Gulf migratory route. The effects of climate change, particularly sea level rise, may negatively impact habitat availability for migrants on barrier islands. Our objectives were (1 to confirm the use of St. George Island, Florida by trans-Gulf migrants and (2 to determine whether forested stopover habitat will be available for migrants on St. George Island following sea level rise. We used avian transect data, geographic information systems, remote sensing, and simulation modelling to investigate the potential effects of three different sea level rise scenarios (0.28 m, 0.82 m, and 2 m on habitat availability for trans-Gulf migrants. We found considerable use of the island by spring trans-Gulf migrants. Migrants were most abundant in areas with low elevation, high canopy height, and high coverage of forests and scrub/shrub. A substantial percentage of forest (44% will be lost by 2100 assuming moderate sea level rise (0.82 m. Thus, as sea level rise progresses, less forests will be available for migrants during stopover. Many migratory bird species' populations are declining, and degradation of barrier island stopover habitat may further increase the cost of migration for many individuals. To preserve this coastal resource, conservation and wise management of migratory stopover areas, especially near ecological barriers like the Gulf of Mexico, will be essential as sea levels rise.

  10. A geospatial dataset for U.S. hurricane storm surge and sea-level rise vulnerability: Development and case study applications

    Directory of Open Access Journals (Sweden)

    Megan C. Maloney

    2014-01-01

    Full Text Available The consequences of future sea-level rise for coastal communities are a priority concern arising from anthropogenic climate change. Here, previously published methods are scaled up in order to undertake a first pass assessment of exposure to hurricane storm surge and sea-level rise for the U.S. Gulf of Mexico and Atlantic coasts. Sea-level rise scenarios ranging from +0.50 to +0.82 m by 2100 increased estimates of the area exposed to inundation by 4–13% and 7–20%, respectively, among different Saffir-Simpson hurricane intensity categories. Potential applications of these hazard layers for vulnerability assessment are demonstrated with two contrasting case studies: potential exposure of current energy infrastructure in the U.S. Southeast and exposure of current and future housing along both the Gulf and Atlantic Coasts. Estimates of the number of Southeast electricity generation facilities potentially exposed to hurricane storm surge ranged from 69 to 291 for category 1 and category 5 storms, respectively. Sea-level rise increased the number of exposed facilities by 6–60%, depending on the sea-level rise scenario and the intensity of the hurricane under consideration. Meanwhile, estimates of the number of housing units currently exposed to hurricane storm surge ranged from 4.1 to 9.4 million for category 1 and category 4 storms, respectively, while exposure for category 5 storms was estimated at 7.1 million due to the absence of landfalling category 5 hurricanes in the New England region. Housing exposure was projected to increase 83–230% by 2100 among different sea-level rise and housing scenarios, with the majority of this increase attributed to future housing development. These case studies highlight the utility of geospatial hazard information for national-scale coastal exposure or vulnerability assessment as well as the importance of future socioeconomic development in the assessment of coastal vulnerability.

  11. Adapting to Sea Level Rise and Storms: Missed Opportunities and Continuing Development (case studies from USA and Bulgaria)

    Science.gov (United States)

    Young, Robert; Stancheva, Margarita; Stanchev, Hristo; Palazov, Atanas; Peek, Katie; Coburn, Andrew; Griffith, Adam

    2014-05-01

    Over the last several years, there have been significant discussions within the global scientific and coastal zone management communities about the need to adapt to the realities of long-term sea level rise and to make coastal development more "resilient" to hazards and climate change. With all of the talk, publications, and recognition of the problem, you would think that we had made significant progress, but this is not the case. Once again, the USA has experienced the impact of a significant coastal storm, Hurricane Sandy. There were initially some serious post-Sandy discussions regarding the need to ensure that we simply don't "just put everything back were it was." Almost a year later, there have been few substantive moves to relocate property away from coastal hazards or to change the footprint of vulnerable coastal communities. This is particularly true of coastal resort communities in New York and New Jersey. Some communities have initiated large-scale efforts to elevate (in situ) infrastructure and private property. Raising buildings is only a workable solution if you also commit to holding all the beaches in place . . . forever. This is what the federal government has done for New Jersey and New York. The U. S. Army Corps of Engineers will be spending upward of US5 billion on shore protection projects following Hurricane Sandy. The vast majority of these funds will be spent pumping sand onto beaches from Delaware to Connecticut. The amount of sand they will move is staggering, approaching 25 to 35 million cubic meters. This is an adaptation model that cannot be exported to the rest of the USA. Nor can it be maintained for an extended period of time. Along the Black Sea Coast of Bulgaria the risk of storms is not as great as that of the US East Coast, but long-term sea level rise is still a threat. In Bulgaria, most coastal development problems occur simply because people continue to build in areas that are too close to the coast or in very high hazard

  12. Predicted eelgrass response to sea level rise and its availability to foraging Black Brant in Pacific coast estuaries

    Science.gov (United States)

    Shaughnessy, Frank J.; Gilkerson, Whelan; Black, Jeffrey M.; Ward, David H.; Petrie, Mark

    2012-01-01

    Managers need to predict how animals will respond to habitat redistributions caused by climate change. Our objective was to model the effects of sea level rise on total eelgrass (Zostera marina) habitat area and on the amount of that area that is accessible to Brant geese (Branta bernicla), specialist grazers of eelgrass. Digital elevation models were developed for seven estuaries from Alaska, Washington, California (USA), and Mexico. Scenarios of future total eelgrass area were derived from combinations of estuarine specific sediment and tectonic rates (i.e., bottom change rate) with three rates of eustatic sea level rise (ESLR). Percentages of total eelgrass areas that were accessible to foraging Brant were determined for December when the birds overwinter at more southerly sites and in April as they move north to sites where they build body stores on their way to nesting areas in Alaska. The modeling showed that accessible eelgrass area could be lower than total area due to how daytime low-tide height, eelgrass shoot length, and the upper elevation of eelgrass determined Brant-reaching depth. Projections of future eelgrass area indicated that present-day ESLR (2.8 mm/yr) and bottom change rates should sustain the current pattern of estuarine use by Brant except in Morro Bay, where use should decrease because eelgrass is being ejected from this estuary by a positive bottom change rate. Higher ESLR rates (6.3 and 12.7 mm/yr) should result in less Brant use of estuaries at the northern and southern ends of the flyway, particularly during the winter, but more use of mid-latitude estuaries. The capacity of mid-latitude estuaries to function as Brant feeding refugia, or for these estuaries and Izembek Lagoon to provide drift rather than attached leaves, is eventually limited by the decrease in total eelgrass area, which is a result of a light extinction affect on the eelgrass, or the habitat being pushed out of the estuary by positive tectonic rates. Management

  13. How a barrier island may react on a sea-level rise: The Holocene to Recent Rømø barrier island, Danish Wadden Sea

    DEFF Research Database (Denmark)

    Johannessen, Peter N.; Nielsen, Lars H.; Møller, Ingelise

    of c. 15 m and a resolution of c. 20–30 cm (Nielsen et al., 2009), and dating of 70 core samples using optically stimulated luminescence (OSL). The area has experienced a relative sea-level rise of c. 15 m during the last c. 8000 years. The Recent tidal amplitude reaches c. 1.8 m. During strong wind...... and related shoreface sand and lagoonal sediments are up to 20 m thick and overlie Weichselian fluvial sand. The first 5000 years the barrier island aggraded and the last 3000 years it prograded despite the relative rising sea level rise of c. 15 m during the last c. 8000 years. This shows......, that if there is a surplus of sand in a tidal area, barrier islands may aggrade even if there is a rise in sea level. If the rate of sea level rise decreases then the barrier island may prograded. With this unique dataset with extremely large amounts of OSL datings from core sediments it has been possible to construct...

  14. On the Coastal Dynamics of Sea Level Rise: A case study in the Northern Gulf of Mexico

    Science.gov (United States)

    Hagen, S. C.

    2012-12-01

    One of the most prominent aspects of global climate change is sea level rise (SLR). With over half of the U.S. population living within 50 miles of the coast, SLR has the potential to considerably impact both human and ecological habitats. Effects of SLR will be felt along coastal beaches, estuarine waters, barrier islands, submerged aquatic vegetation beds, sand and mud flats, oyster reefs and tidal and freshwater wetlands. The Gulf of Mexico coast sustains a diverse habitat including delta marshes, lower river floodplain forests, and oyster reefs, which provide critical habitats for many commercially important species. How we choose to study these complex processes and the adaptation tools that we develop may determine our ability to sustain the human and ecological habitats. The purpose of this presentation is to examine the dynamic effects of SLR to the coasts and coastal habitats of the Northern Gulf of Mexico and to compare and contrast those results with a simpler bathtub model (static) approach. Dynamic assessments will be presented through integrated models representing wave, tidal, overland, bay and biological processes. The models are applied to regions of the Northern Gulf to simulate hydrodynamic properties including waves, tides, and surge, and to estimate impacts to coastal marshes, wetlands and estuaries. Results strongly indicate the importance of simulating the dynamical processes.

  15. Potential effects of sea-level rise on the depth to saturated sediments of the Sagamore and Monomoy flow lenses on Cape Cod, Massachusetts

    Science.gov (United States)

    Walter, Donald A.; McCobb, Timothy D.; Masterson, John P.; Fienen, Michael N.

    2016-05-25

    In 2014, the U.S. Geological Survey, in cooperation with the Association to Preserve Cape Cod, the Cape Cod Commission, and the Massachusetts Environmental Trust, began an evaluation of the potential effects of sea-level rise on water table altitudes and depths to water on central and western Cape Cod, Massachusetts. Increases in atmospheric and oceanic temperatures arising, in part, from the release of greenhouse gases likely will result in higher sea levels globally. Increasing water table altitudes in shallow, unconfined coastal aquifer systems could adversely affect infrastructure—roads, utilities, basements, and septic systems—particularly in low-lying urbanized areas. The Sagamore and Monomoy flow lenses on Cape Cod are the largest and most populous of the six flow lenses that comprise the region’s aquifer system, the Cape Cod glacial aquifer. The potential effects of sea-level rise on water table altitude and depths to water were evaluated by use of numerical models of the region. The Sagamore and Monomoy flow lenses have a number of large surface water drainages that receive a substantial amount of groundwater discharge, 47 and 29 percent of the total, respectively. The median increase in the simulated water table altitude following a 6-foot sea-level rise across both flow lenses was 2.11 feet, or 35 percent when expressed as a percentage of the total sea-level rise. The response is nearly the same as the sea-level rise (6 feet) in some coastal areas and less than 0.1 foot near some large inland streams. Median water table responses differ substantially between the Sagamore and Monomoy flow lenses—at 29 and 49 percent, respectively—because larger surface water discharge on the Sagamore flow lens results in increased dampening of the water table response than in the Monomoy flow lens. Surface waters dampen water table altitude increases because streams are fixed-altitude boundaries that cause hydraulic gradients and streamflow to increase as sea-level

  16. Impacts of Sea Level Rise and Morphological Changes on Tidal Hydrodynamics in the Northern Gulf of Mexico

    Science.gov (United States)

    Passeri, D. L.; Hagen, S. C.; Plant, N. G.; Bilskie, M. V.

    2014-12-01

    Sea level rise (SLR) threatens coastal environments with increased erosion, inundation of wetlands, and changes in hydrodynamic patterns. Planning for the effects of SLR requires understanding the coupled response of SLR, geomorphic and hydrodynamic processes; this will provide crucial information for managers to make informed decisions for human and natural communities. Evaluating changes in tidal hydrodynamics under future scenarios is a key aspect for understanding the effects of SLR on coastal systems; tidal hydrodynamics influence inundation, circulation patterns, sediment transport processes, shoreline erosion, and productivity of marshes and other species. This study evaluates the dynamic effects of SLR and morphologic change on tidal hydrodynamics along the Northern Gulf of Mexico (NGOM) coast from Mississippi to the Florida panhandle. A large-scale hydrodynamic model is used to simulate astronomic tides under present (circa 2005), and future conditions (circa 2050 and 2100). The model is modified with specific SLR scenarios, morphology, and shorelines that represent the conditions at each of the time periods. Future sea levels for the years 2050 and 2100 are determined using the Parris et al. (2012) projections. To make projections of future morphology, a Bayesian Network (BN) is implemented. The BN is used to define relationships between forcing mechanisms and coastal responses based on long-term relative SLR, mean wave height, long-term shoreline change rates, mean tidal range, geomorphic setting and coastal slope. Probabilistic predictions of future shoreline positions and dune heights are developed for each SLR scenario for the years 2050 and 2100. The Digital Elevation Model (DEM) is then updated to reflect the future morphologic changes. Comparison of present and future conditions illustrates the hydrodynamic response of the system to the changing landscape. Changes in variables such as harmonic tidal constituents, tidal range, tidal prism, tidal

  17. Spatial patterns of composition in tidal wetland plant and algal assemblages in Oregon: Implications for wetland vulnerability to sea-level rise

    Science.gov (United States)

    Plants and algae mediate important ecosystem processes in coastal marshes and swamps. These assemblages are structured in part by estuarine environmental gradients such as tidal elevation and salinity. Such gradients are likely to change with sea-level rise (SLR) due to global cl...

  18. Late Holocene sea-level rise in Tampa Bay: Integrated reconstruction using biomarkers, pollen, organic-walled dinoflagellate cysts, and diatoms

    NARCIS (Netherlands)

    Soelen, E.E. van; Lammertsma, E.I.; Cremer, H.; Donders, T.H.; Sangiorgi, F.; Brooks, G.R.; Larson, R.A.; Sinninghe Damsté, J.S.; Wagner-Cremer, F.; Reichart, G.J.

    2010-01-01

    A suite of organic geochemical, micropaleontological and palynological proxies was applied to sediments from Southwest Florida, to study the Holocene environmental changes associated with sea-level rise. Sediments were recovered from Hillsborough Bay, part of Tampa Bay, and studied using biomarkers,

  19. Exploring high-end scenarios for local sea level rise to develop flood protection strategies for a lowlying delta-the Netherlands as an example

    NARCIS (Netherlands)

    Katsman, C.A.; Sterl, A.; Beersma, H.W.; Brink, van den H.W.; Church, J.A.; Hazeleger, W.; Kopp, R.E.; Kroon, D.; Kwadijk, J.; Lammersen, R.; Lowe, J.; Oppenheimer, M.; Plag, H.P.; Ridley, J.; Storch, von H.; Vaughan, D.G.; Vellinga, P.; Vermeersen, L.L.A.; Wal, R.S.W.; Weise, R.

    2011-01-01

    Sea level rise, especially combined with possible changes in storm surges and increased river discharge resulting from climate change, poses a major threat in low-lying river deltas. In this study we focus on a specific example of such a delta: the Netherlands. To evaluate whether the country’s floo

  20. Keeping your seed head above water - EPA's research on the effects of sea level rise on sea grasses and emergent marshes in the Pacific Northwest

    Science.gov (United States)

    Global climate change, including sea-level rise (SLR), will have profound effects on estuarine fish, shellfish, and wildlife populations and their habitats. To develop an understanding of these potential impacts, the U.S. EPA at Newport, Oregon is participating in a joint researc...

  1. Sea level rise drives increased tidal flooding frequency at tide gauges along the U.S. East and Gulf Coasts: Projections for 2030 and 2045

    Science.gov (United States)

    Fitzpatrick, Melanie F.; Spanger-Siegfried, Erika

    2017-01-01

    Tidal flooding is among the most tangible present-day effects of global sea level rise. Here, we utilize a set of NOAA tide gauges along the U.S. East and Gulf Coasts to evaluate the potential impact of future sea level rise on the frequency and severity of tidal flooding. Using the 2001–2015 time period as a baseline, we first determine how often tidal flooding currently occurs. Using localized sea level rise projections based on the Intermediate-Low, Intermediate-High, and Highest projections from the U.S. National Climate Assessment, we then determine the frequency and extent of such flooding at these locations for two near-term time horizons: 2030 and 2045. We show that increases in tidal flooding will be substantial and nearly universal at the 52 locations included in our analysis. Long before areas are permanently inundated, the steady creep of sea level rise will force many communities to grapple with chronic high tide flooding in the next 15 to 30 years. PMID:28158209

  2. Estimating Greenland ice sheet surface mass balance contribution to future sea level rise using the regional atmospheric climate model MAR

    Directory of Open Access Journals (Sweden)

    X. Fettweis

    2012-08-01

    Full Text Available We report future projections of Surface Mass Balance (SMB over the Greenland ice sheet (GrIS obtained with the regional climate model MAR, forced by the outputs of three CMIP5 General Circulation Models (GCMs when considering two different warming scenarios (RCP 4.5 and RCP 8.5. The GCMs selected in this study have been chosen according to their ability to simulate the current climate over Greenland. Our results indicate that in a warmer climate (i the mass gained due to increased precipitation over GrIS does not compensate the mass lost through increased run-off; (ii the surface melt increases non-linearly with rising temperatures due to the positive feedback between surface albedo and melt, associated with the expansion of bare ice zones which, in addition, decreases the ice sheet refreezing capacity; (iii most of the precipitation is expected to fall as rainfall in summer, which further increases surface melt; (iv no considerable change is expected on the length of the melting season, since heavier winter snowfall dampens the melt increase at the end of spring; (v the increase of meltwater run-off versus temperature anomalies is dependent of the GCM-forced MAR ability to simulate the current climate; (vi the MAR-simulated SMB changes can be approximated using the annual accumulated snowfall and summer 600 hPa temperature increase simulated by the forcing GCMs. In view of the large range in the CMIP5 future projections for the same future scenario, the GCM-based SMB approximations allow us to estimate what future projections are most likely within the CMIP5 multi-model ensemble. In 2100, the ensemble mean projects a sea level rise, resulting from a GrIS SMB decrease, estimated to be +4 ± 2 cm and +9 ± 4 cm for the RCP 4.5 and RCP 8.5 scenarios, respectively. The GrIS SMB should remain positive with respect to RCP 4.5 scenario and becomes negative around 2070 in the case of the RCP 8.5 scenario since a global warming >+3 °C is needed

  3. Effects of Sea-Level Rise and Anthropogenic Development on Priority Bird Species Habitats in Coastal Georgia, USA

    Science.gov (United States)

    Brittain, Ross A.; Craft, Christopher B.

    2012-02-01

    We modeled changes in area of five habitats, tidal-freshwater forest, salt marsh, maritime shrub-scrub (shrub), maritime broadleaf forest (oak) and maritime narrowleaf (pine) forest, in coastal Georgia, USA, to evaluate how simultaneous habitat loss due to predicted changes in sea level rise (SLR) and urban development will affect priority bird species of the south Atlantic coastal plain by 2100. Development rates, based on regional growth plans, were modeled at 1% and 2.5% annual urban growth, while SLR rates, based on the Intergovernmental Panel on Climate Change's A1B mean and maximum scenarios, were modeled at 52 cm and 82 cm, respectively. SLR most greatly affected the shrub habitat with predicted losses of 35-43%. Salt marsh and tidal forest also were predicted to lose considerable area to SLR (20-45 and 23-35%, respectively), whereas oak and pine forests had lesser impact from SLR, 18-22% and 11-15%, respectively. Urban development resulted in losses of considerable pine (48-49%) and oak (53-55%) habitat with lesser loss of shrub habitat (21-24%). Under maximum SLR and urban growth, shrub habitat may lose up to 59-64% compared to as much as 62-65% pine forest and 74-75% oak forest. Conservation efforts should focus on protection of shrub habitat because of its small area relative to other terrestrial habitats and use by Painted Buntings ( Passerina ciris), a Partners In Flight (PIF) extremely high priority species. Tidal forests also deserve protection because they are a likely refuge for forest species, such as Northern Parula and Acadian Flycatcher, with the decline of oak and pine forests due to urban development.

  4. Beyond the Dams: Linking Rural Smallholder Soil and Water Management Practices in Tropical Deltas to Sea Level Rise Vulnerability

    Science.gov (United States)

    Rogers, K. G.; Syvitski, J. P.; Brondizio, E. S.

    2014-12-01

    The increased vulnerability of deltaic communities to coastal flooding as a result of upstream engineering has been acknowledged for decades. What has received less attention is the sensitivity of deltas to the interactions of river basin modifications and cultivation and irrigation in their coastal regions, particularly in tropical deltas. Embanking, tilling, and crop or stock choice all affect the movement of sediment and water on deltas. Combined with reduced river and sediment discharge, soil and water management practices in coastal areas may in fact exacerbate the risk of tidal flooding, erosion of arable land, and salinization of soils and groundwater associated with sea level rise. Thus exists a cruel irony to smallholder subsistence farmers whose priorities are food, water and economic security, rather than sustainability of the regional environment. Such issues challenge disciplinary approaches and require integrated social-biophysical models able to understand and diagnose these complex relationships. The complementary Institutional Analysis and Development and SocioEcological Systems frameworks are applied to the southwestern Bengal Delta (Bangladesh). The method helps to define the relevant social and physical units operating on the common pool of environmental resources, those of climate, water and sediment. The conceptual frameworks are designed to inform development of a nested geospatial analysis and a dynamic coupled model to identify the social-biophysical feedbacks associated with smallholder soil and water management practices, coastal dynamics, and climate vulnerability in rural Bangladesh. Our presentation will discuss components of the conceptual frameworks and will introduce a bi-directional pilot study designed for obtaining and disseminating information about environmental change to farmers in southwest Bangladesh with potential application to rural farming communities in other tropical deltas.

  5. Architecture analysis of a river flood-dominated delta during an overall sea-level rise (early Pliocene, SE Spain)

    Science.gov (United States)

    García-García, F.; Corbí, H.; Soria, J. M.; Viseras, C.

    2011-05-01

    The sedimentary record of delta-front to prodelta transition that developed during the early Pliocene (Bajo Segura Basin, peri-Mediterranean Betic Cordillera Basin) represents an unusual infilling of an incised valley cutting downwards into late Messinian pelagic marls. The complete delta succession, less than 65 m thick, consists of four upwardly fining and thinning sequences several metres thick. Each sequence consists of basal conglomeratic and coarse-grained sandstone beds (delta-front deposits) evolving upwards to alternating sandstones and silty-marl beds (prodelta deposits). The retrogradational stratal succession pattern is interpreted as having been deposited during an overall sea-level rise. Facies association is characterised by quasi- to planar-laminated sandstones and pebbly sandstones alternating with clast-supported boulders to pebbles, sheet-like climbing cross-laminated sandstones with abundant plant remains, and epsilon cross-stratified and channelized gravels and sandstones. These are interpreted as having been deposited by highly concentrated flows interpreted as hyperpycnal turbidity flows from high (cohesionless debris flows and sinuous submarine channels) to moderate (sheet-like climbing cross-laminated sandstones) discharge river-flood events. Slabs of sediment from unstable banks, outsized clasts which roll onto thin beds from channel mouths, slumps and intraformational breccias in delta front are other signatures (including a lack of bored clasts) which indicate high-energy and rapid deposition at the river mouth, encouraging the delta-front gravitational instability failures. Major changes in the discharge of the river-fed delta could have been caused by brief catastrophic, heavy-precipitation events coupled with quasi-stationary convective orographic rainfall typical of the modern Mediterranean.

  6. Linking River Basin Modifications and Rural Soil and Water Management Practices in Tropical Deltas to Sea Level Rise Vulnerability

    Science.gov (United States)

    Rogers, K. G.; Brondizio, E.; Roy, K.; Syvitski, J. P.

    2015-12-01

    The increased vulnerability of deltaic communities to coastal flooding as a result of upstream engineering has been acknowledged for decades. What has received less attention is the sensitivity of deltas to the interactions between river basin modifications and local scale cultivation and irrigation. Combined with reduced river and sediment discharge, soil and water management practices in coastal areas may exacerbate the risk of tidal flooding, erosion of arable land, and salinization of soils and groundwater associated with sea level rise. This represents a cruel irony to smallholder subsistence farmers whose priorities are food, water and economic security, rather than sustainability of the environment. Such issues challenge disciplinary approaches and require integrated social-biophysical models able to understand and diagnose these complex relationships. This study applies a new conceptual framework to define the relevant social and physical units operating on the common pool resources of climate, water and sediment in the Bengal Delta (Bangladesh). The new framework will inform development of a nested geospatial analysis and a coupled model to identify multi-scale social-biophysical feedbacks associated with smallholder soil and water management practices, coastal dynamics, basin modification, and climate vulnerability in tropical deltas. The framework was used to create household surveys for collecting data on climate perceptions, land and water management, and governance. Test surveys were administered to rural farmers in 14 villages during a reconnaissance visit to coastal Bangladesh. Initial results demonstrate complexity and heterogeneity at the local scale in both biophysical conditions and decision-making. More importantly, the results illuminate how national and geopolitical-level policies scale down to impact local-level environmental and social stability in communities already vulnerable to coastal flooding. Here, we will discuss components of the

  7. Reconstructing the contribution of the Weddell Sea sector, Antarctica, to sea level rise since the last glacial maximum, using numerical modelling constrained by field evidence.

    Science.gov (United States)

    Le Brocq, A.; Bentley, M.; Hubbard, A.; Fogwill, C.; Sugden, D.

    2008-12-01

    A numerical ice sheet model constrained by recent field evidence is employed to reconstruct the Last Glacial Maximum (LGM) ice sheet in the Weddell Sea Embayment (WSE). Previous modelling attempts have predicted an extensive grounding line advance (to the continental shelf break) in the WSE, leading to a large equivalent sea level contribution for the sector. The sector has therefore been considered as a potential source for a period of rapid sea level rise (MWP1a, 20 m rise in ~500 years). Recent field evidence suggests that the elevation change in the Ellsworth mountains at the LGM is lower than previously thought (~400 m). The numerical model applied in this paper suggests that a 400 m thicker ice sheet at the LGM does not support such an extensive grounding line advance. A range of ice sheet surfaces, resulting from different grounding line locations, lead to an equivalent sea level estimate of 1 - 3 m for this sector. It is therefore unlikely that the sector made a significant contribution to sea level rise since the LGM, and in particular to MWP1a. The reduced ice sheet size also has implications for the correction of GRACE data, from which Antarctic mass balance calculations have been derived.

  8. Phase I for the Use of TOPEX-Poseidon and Jason-1 Radar Altimetry to Monitor Coastal Wetland Inundation and Sea Level Rise in Coastal Louisiana

    Science.gov (United States)

    Brozen, Madeline; Batina, Matthew; Parker, Stephen; Brooks, Christopher

    2010-01-01

    The objective of the first phase of this project was to determine the feasibility of applying satellite altimetry data to monitor sea level rise and inundation within coastal Louisiana. Global sea level is rising, and coastal Louisiana is subsiding. Therefore, there is a need to monitor these trends over time for coastal restoration and hazard mitigation efforts. TOPEX/POSEIDON and Jason-data are used for global sea level estimates and have also been demonstrated successfully in water level studies of lakes, river basins, and floodplains throughout the world. To employ TOPEX/POSEIDON and Jason-1 data in coastal regions, the numerous steps involved in processing the data over non-open ocean areas must be assessed. This project outlined the appropriate methodology for processing non-open ocean data, including retracking and atmospheric corrections. It also inventoried the many factors in coastal land loss including subsidence, sea level rise, coastal geomorphology, and salinity levels, among others, through a review of remote sensing and field methods. In addition, the project analyzed the socioeconomic factors within the Coastal Zone as compared to the rest of Louisiana. While sensor data uncertainty must be addressed, it was determined that it is feasible to apply radar altimetry data from TOPEX/POSEIDON and Jason 1 to see trends in change within Coastal Louisiana since

  9. Estimating the Greenland ice sheet surface mass balance contribution to future sea level rise using the regional atmospheric climate model MAR

    Directory of Open Access Journals (Sweden)

    X. Fettweis

    2013-03-01

    Full Text Available To estimate the sea level rise (SLR originating from changes in surface mass balance (SMB of the Greenland ice sheet (GrIS, we present 21st century climate projections obtained with the regional climate model MAR (Modèle Atmosphérique Régional, forced by output of three CMIP5 (Coupled Model Intercomparison Project Phase 5 general circulation models (GCMs. Our results indicate that in a warmer climate, mass gain from increased winter snowfall over the GrIS does not compensate mass loss through increased meltwater run-off in summer. Despite the large spread in the projected near-surface warming, all the MAR projections show similar non-linear increase of GrIS surface melt volume because no change is projected in the general atmospheric circulation over Greenland. By coarsely estimating the GrIS SMB changes from GCM output, we show that the uncertainty from the GCM-based forcing represents about half of the projected SMB changes. In 2100, the CMIP5 ensemble mean projects a GrIS SMB decrease equivalent to a mean SLR of +4 ± 2 cm and +9 ± 4 cm for the RCP (Representative Concentration Pathways 4.5 and RCP 8.5 scenarios respectively. These estimates do not consider the positive melt–elevation feedback, although sensitivity experiments using perturbed ice sheet topographies consistent with the projected SMB changes demonstrate that this is a significant feedback, and highlight the importance of coupling regional climate models to an ice sheet model. Such a coupling will allow the assessment of future response of both surface processes and ice-dynamic changes to rising temperatures, as well as their mutual feedbacks.

  10. Salt Marsh Zonal Migration and Ecosystem Service Change in Response to Global Sea Level Rise: A Case Study from an Urban Region

    Directory of Open Access Journals (Sweden)

    Rusty A. Feagin

    2010-12-01

    Full Text Available Coastal wetland plants are expected to respond to global sea level rise by migrating toward higher elevations. Housing, infrastructure, and other anthropogenic modifications are expected to limit the space available for this potential migration. Here, we explore the ecological and economic effects of projected Intergovernmental Panel on Climate Change (IPCC 2007 report sea level changes at the plant community scale using the highest horizontal (1 m and vertical (0.01 m resolution data available, using a 6 x 6 km area as an example. Our findings show that salt marshes do not always lose land with increasing rates of sea level rise. We found that the lower bound of the IPCC 2007 potential rise (0.18 m by 2095 actually increased the total marsh area. This low rise scenario resulted in a net gain in ecosystem service values on public property, whereas market-based economic losses were predicted for private property. The upper rise scenario (0.59 m by 2095 resulted in both public and private economic losses for this same area. Our work highlights the trade-offs between public and privately held value under the various IPCC 2007 climate change scenarios. We conclude that as wetlands migrate inland into urbanized regions, their survival is likely to be dependent on the rate of return on property and housing investments.

  11. The importance of land hydrology changes in sea level rise on decadal time scales: results from 2002-2014 using GRACE

    Science.gov (United States)

    Reager, John; Gardner, Alex; Famiglietti, James; Wiese, David; Eicker, Annette; Lo, Min-Hui

    2016-04-01

    Climate-driven changes in land hydrology and their contributions to sea level rise have been absent from IPCC sea level budgets owing to challenges in observing global land water storage. In a review of recent and ongoing work, we show that recent advances in the measurement of time variable gravity from space using Gravity Recovery and Climate Experiment (GRACE) mission observations, combined with reconciled global glacier loss estimates, enable a disaggregation of continental water mass trends and a quantification of this climate-driven term. We find that between 2002 and 2014, can additional 3200 +/- 900 Gt of water was stored on land in snow, soils and groundwater, likely due to climate variability. This gain partially offset water losses from ice sheets, glaciers, and groundwater pumping, slowing the rate of sea level rise by 0.71 +/- 0.20 mm yr-1, and consistent with observations of slowing over the recent decade. We also discuss possible causes and contributors to these trends and their implications for decadal variability. These findings highlight the importance of climate-driven changes in hydrology when assigning attribution to decadal changes in sea level.

  12. Forecasting the impact of storm waves and sea-level rise on Midway Atoll and Laysan Island within the Papahānaumokuākea Marine National Monument—a comparison of passive versus dynamic inundation models

    Science.gov (United States)

    Storlazzi, Curt D.; Berkowitz, Paul; Reynolds, Michelle H.; Logan, Joshua B.

    2013-01-01

    Two inundation events in 2011 underscored the potential for elevated water levels to damage infrastructure and affect terrestrial ecosystems on the low-lying Northwestern Hawaiian Islands in the Papahānaumokuākea Marine National Monument. The goal of this study was to compare passive "bathtub" inundation models based on geographic information systems (GIS) to those that include dynamic water levels caused by wave-induced set-up and run-up for two end-member island morphologies: Midway, a classic atoll with islands on the shallow (2-8 m) atoll rim and a deep, central lagoon; and Laysan, which is characterized by a deep (20-30 m) atoll rim and an island at the center of the atoll. Vulnerability to elevated water levels was assessed using hindcast wind and wave data to drive coupled physics-based numerical wave, current, and water-level models for the atolls. The resulting model data were then used to compute run-up elevations using a parametric run-up equation under both present conditions and future sea-level-rise scenarios. In both geomorphologies, wave heights and wavelengths adjacent to the island shorelines increased more than three times and four times, respectively, with increasing values of sea-level rise, as more deep-water wave energy could propagate over the atoll rim and larger wind-driven waves could develop on the atoll. Although these increases in water depth resulted in decreased set-up along the islands’ shorelines, the larger wave heights and longer wavelengths due to sea-level rise increased the resulting wave-induced run-up. Run-up values were spatially heterogeneous and dependent on the direction of incident wave direction, bathymetry, and island configuration. Island inundation was modeled to increase substantially when wave-driven effects were included, suggesting that inundation and impacts to infrastructure and terrestrial habitats will occur at lower values of predicted sea-level rise, and thus sooner in the 21st century, than suggested