Showing papers in "Journal of Coastal Research in 2011"
TL;DR: Klemmas et al. as mentioned in this paper reviewed and compared wetland remote sensing techniques that are cost-effective and practical and illustrate their use through two case studies, showing that analysis of satellite and aircraft imagery, combined with on-the-ground observations, allows researchers to effectively determine long-term trends and short-term changes of wetland vegetation and hydrology.
Abstract: KLEMAS, V., 2011. Remote sensing of wetlands: case studies comparing practical techniques. Journal of Coastal Research, 27(3), 418–427. West Palm Beach (Florida), ISSN 0749-0208. To plan for wetland protection and sensible coastal development, scientists and managers need to monitor the changes in coastal wetlands as the sea level continues to rise and the coastal population keeps expanding. Advances in sensor design and data analysis techniques are making remote sensing systems practical and attractive for monitoring natural and man-induced wetland changes. The objective of this paper is to review and compare wetland remote sensing techniques that are cost-effective and practical and to illustrate their use through two case studies. The results of the case studies show that analysis of satellite and aircraft imagery, combined with on-the-ground observations, allows researchers to effectively determine long-term trends and short-term changes of wetland vegetation and hydrology.
180 citations
TL;DR: Klemmas et al. as discussed by the authors presented an overview of practical remote sensing techniques that can be used in studies of coastal ecosystems, such as wetlands, estuaries, and coral reefs.
Abstract: KLEMAS, V., 2011. Remote sensing techniques for studying coastal ecosystems: an overview. Journal of Coastal Research, 27(1), 2–17. West Palm Beach (Florida), ISSN 0749-0208. Advances in sensor design and data analysis techniques are making remote sensing systems practical and attractive for use in research and management of coastal ecosystems, such as wetlands, estuaries, and coral reefs. Multispectral and hyperspectral imagers are available for mapping coastal land cover, concentrations of organic/inorganic suspended particles, and dissolved substances in coastal waters. Thermal infrared scanners can map sea surface temperatures accurately and chart coastal currents, while microwave radiometers can measure ocean salinity, soil moisture, and other hydrologic parameters. Radar imagers, scatterometers, and altimeters provide information on ocean waves, ocean winds, sea surface height, and coastal currents, which strongly influence coastal ecosystems. Using airborne light detecting and ranging systems, one can produce bathymetric maps, even in moderately turbid coastal waters. Since coastal ecosystems have high spatial complexity and temporal variability, they frequently have to be observed from both satellite and aircraft in order to obtain the required spatial, spectral, and temporal resolutions. A reliable field data collection approach using ships, buoys, and field instruments with a valid sampling scheme is required to calibrate and validate the remotely sensed information. The objective of this paper is to present an overview of practical remote sensing techniques that can be used in studies of coastal ecosystems.
170 citations
TL;DR: In this article, the authors analyzed monthly-averaged records for 57 U.S. tide gauges in the Permanent Service for Mean Sea Level (PSMSL) data base that have lengths of 60-156 years.
Abstract: HOUSTON, J.R. and DEAN, R.G., 2011. Sea-level acceleration based on U.S. tide gauges and extensions of previous global-gauge analyses. Journal of Coastal Research, 27(3), 409–417. West Palm Beach (Florida), ISSN 0749-0208. Without sea-level acceleration, the 20th-century sea-level trend of 1.7 mm/y would produce a rise of only approximately 0.15 m from 2010 to 2100; therefore, sea-level acceleration is a critical component of projected sea-level rise. To determine this acceleration, we analyze monthly-averaged records for 57 U.S. tide gauges in the Permanent Service for Mean Sea Level (PSMSL) data base that have lengths of 60–156 years. Least-squares quadratic analysis of each of the 57 records are performed to quantify accelerations, and 25 gauge records having data spanning from 1930 to 2010 are analyzed. In both cases we obtain small average sea-level decelerations. To compare these results with worldwide data, we extend the analysis of Douglas (1992) by an additional 25 years and analyze revised data of Church and White (2006) from 1930 to 2007 and also obtain small sea-level decelerations similar to those we obtain from U.S. gauge records.
168 citations
TL;DR: In this paper, a satellite-based inventory of barrier islands was used to study the influence of depositional setting, climate, and tide regime on island distribution and morphology, finding that the distribution of barrier island morphology is strongly related to sea level history and tectonic setting.
Abstract: STUTZ, M.L. and PILKEY, O.H., 2011. Open-ocean barrier islands: global influence of climatic, oceanographic, and depositional settings. Journal of Coastal Research, 27(2), 207–222. West Palm Beach (Florida), ISSN 0749-0208. A satellite-based inventory of barrier islands was used to study the influence of depositional setting, climate, and tide regime on island distribution and morphology. The survey reveals 20,783 km of shoreline occupied by 2149 barrier islands worldwide. Their distribution is strongly related to sea level history in addition to the influence of tectonic setting. Rising sea level in the late Holocene (5000 YBP–present) is associated with greatest island abundance, especially on North Atlantic and Arctic coastal plains. Stable or falling sea level in the same time frame, a pattern typical of the Southern Hemisphere, is associated with a lower abundance of islands and a higher percentage of islands along deltas rather than coastal plains. Both coastal plain and deltaic island morphology are sensitive to the wave–tide regime; however, island length is 40% greater along coastal plains whereas inlet width is 40% greater on deltas. Island morphology is also fundamentally affected by climate. Island lengths in the Arctic are on average (5 km) only half the global average (10 km) because of the effect of sea ice on fetch and thus wave energy. Storm frequency in the high and middle latitudes is suggested to result in shorter and narrower islands relative to those on swell-dominated low-latitude coasts. The ratio of storm wave height to annual mean wave height is a good indicator of the degree of storm influence on island evolution. The potential for significant climate and sea level change this century underscores the need to improve understanding of the fundamental roles that these two factors have played historically in island evolution in order to predict their future impacts on the islands.
164 citations
TL;DR: The diagnostic morphological wetland features are products of the coupling of high-velocity wind and storm-surge water and their interaction with the underlying, variably resistant, wetland vegetation and soils as discussed by the authors.
Abstract: Temporally and spatially repeated patterns of wetland erosion, deformation, and deposition are observed on remotely sensed images and in the field after hurricanes cross the coast of Louisiana. The diagnostic morphological wetland features are products of the coupling of high-velocity wind and storm-surge water and their interaction with the underlying, variably resistant, wetland vegetation and soils. Erosional signatures include construction of orthogonal-elongate ponds and amorphous ponds, pond expansion, plucked marsh, marsh denudation, and shoreline erosion. Post-storm gravity reflux of floodwater draining from the wetlands forms dendritic incisions around the pond margins and locally integrates drainage pathways forming braided channels. Depositional signatures include emplacement of broad zones of organic wrack on topographic highs and inorganic deposits of variable thicknesses and lateral extents in the form of shore-parallel sandy washover terraces and interior-marsh mud blankets. Deform...
141 citations
TL;DR: Schmid et al. as discussed by the authors applied the minimum bin technique to the bare-earth classified LIDAR data, and the overall bias in the resultant surface was reduced by 12 cm and the vertical accuracy was improved by 8 cm when compared with the "as-received" data.
Abstract: SCHMID, K.A.; HADLEY, B.C., and WIJEKOON, N., 2011. Vertical accuracy and use of topographic LIDAR data in coastal marshes. Journal of Coastal Research, 27(6A), 116–132. West Palm Beach (Florida), ISSN 0749-0208. Coastal marsh habitat and its associated vegetation are strongly linked to substrate elevation and local drainage patterns. As such, accurate representations of both the vegetation height and the surface elevations are requisite components for systematic analysis and temporal monitoring of the habitat. Topographic Light Detection and Ranging (LIDAR) data can provide high-resolution, high-accuracy elevation measurements of features both aboveground and at the surface. However, because of poor penetration of the laser pulse through the marsh vegetation, bare-earth LIDAR elevations can be markedly less accurate when compared with adjacent upland habitats. Consequently, LIDAR groundelevation errors (i.e., standard deviation [SD] and bias) can vary significantly from the standard upland land-cover classes quoted in a typical data provider’s quality-assurance report. Custom digital elevation model (DEM) generation techniques and point classification processes can be used to improve estimates of ground elevations in coastal marshes. The simplest of these methods is minimum bin gridding, which extracts the lowest elevation value included within a user-specified search window and assigns that value to the appropriate DEM grid cell. More complex point-to-point classification can be accomplished by enforcing stricter slope limits and increasing the level of smoothing. Despite lowering the spatial resolution of the DEM, the application of these techniques significantly improves the vertical accuracy of the LIDAR-derived bare-earth surfaces. By employing the minimum bin technique to the bare-earth classified LIDAR data, the overall bias in the resultant surface was reduced by 12 cm, and the vertical accuracy was improved by 8 cm when compared with the ‘‘as-received’’ data. www.JCRonline.org
129 citations
TL;DR: Watson et al. as discussed by the authors investigated whether there is evidence that the rise in mean sea level is accelerating over the longer term at these locations in line with various global average sea level time-series reconstructions and found a consistent trend of weak deceleration at each of these gauge sites throughout Australasia over the period from 1940 to 2000.
Abstract: WATSON, P.J., 2011. Is there evidence yet of acceleration in mean sea level rise around mainland Australia? Journal of Coastal Research, 27(2), 368–377. West Palm Beach (Florida), ISSN 0749-0208. As an island nation with some 85% of the population residing within 50 km of the coast, Australia faces significant threats into the future from sea level rise. Further, with over 710,000 addresses within 3 km of the coast and below 6-m elevation, the implication of a projected global rise in mean sea level of up to 100 cm over the 21st century will have profound economic, social, environmental, and planning consequences. In this context, it is becoming increasingly important to monitor trends emerging from local (regional) records to augment global average measurements and future projections. The Australasian region has four very long, continuous tide gauge records, at Fremantle (1897), Auckland (1903), Fort Denison (1914), and Newcastle (1925), which are invaluable for considering whether there is evidence that the rise in mean sea level is accelerating over the longer term at these locations in line with various global average sea level time-series reconstructions. These long records have been converted to relative 20-year moving average water level time series and fitted to second-order polynomial functions to consider trends of acceleration in mean sea level over time. The analysis reveals a consistent trend of weak deceleration at each of these gauge sites throughout Australasia over the period from 1940 to 2000. Short period trends of acceleration in mean sea level after 1990 are evident at each site, although these are not abnormal or higher than other short-term rates measured throughout the historical record.
104 citations
TL;DR: In this article, light detection and ranging (LIDAR) techniques, combined with Global Positioning Systems (GPSs), make it possible to obtain accurate topographical and bathymetric maps, including maps of s...
Abstract: Light detection and ranging (LIDAR) techniques, combined with Global Positioning Systems (GPSs), make it possible to obtain accurate topographical and bathymetric maps, including maps of s...
77 citations
TL;DR: In this article, the authors used the EFDC (Environmental Fluid Dynamics Code) with a coupled dye module to investigate the flow field and average residence time for water in Jiaozhou Bay.
Abstract: The tidal-driven flow field and average residence time for water in Jiaozhou Bay in the years 1966, 1988, 2000, and 2008 were investigated using the EFDC (Environmental Fluid Dynamics Code) with a coupled dye module. Jiaozhou Bay (JZB) in northeastern China is a semi-enclosed shallow bay that has undergone large-scale land reclamation over the last four decades, especially over the extensive intertidal flats. Data from field observations were used to calibrate and verify the EFDC model for JZB. The verified JZB model was used to study spatial variations of flow field and water exchanges from 1966 to 2008. The overwhelming influence of human activities, especially land reclamation, is the main cause of the significant changes in hydrodynamic conditions and water exchange in JZB. The human-induced changes of the coastline position-configuration and nearshore bathymetry have resulted in substantial changes in the residual current patterns, especially in Qianwan Bay, Haixi Bay, and northeastern Jiaoz...
74 citations
TL;DR: In this paper, an analysis of the progressive multidecadal trends and climate-controlled annual variations in mean sea levels is presented for nine tide-gauge stations along the coast of the U.S. Pacific Northwest: Washington, Oregon and Northern California.
Abstract: Analyses of the progressive multidecadal trends and climate-controlled annual variations in mean sea levels are presented for nine tide-gauge stations along the coast of the U.S. Pacific Northwest: Washington, Oregon, and Northern California. The trends in relative sea levels are strongly affected by the tectonics of this region, characterized by significant alongcoast variations in changing land elevations measured by benchmarks and global positioning system data. These combined data sets document the existence of both submergent and emergent stretches of shore. The Pacific Northwest sea levels are also affected by variations in the monthly mean seasonal cycles, with its extreme water levels occurring in the winter during strong El Ninos. To quantify this climate control and to derive improved multidecadal sea-level trends, separate evaluations of the winter and summer-averaged measured water levels have been undertaken. The resulting pair of linear regressions for each tide gauge shows a consis...
70 citations
TL;DR: In this paper, the authors compare microseismic ground movements resulting from wave impacts to the occurrence of rockfalls from a section of cliffs on the North Yorkshire, United Kingdom, coastline.
Abstract: The influence of waves and tides on the development of coastal cliffs has long been recognised as an important contributor to long-term coastline evolution. However, the relationship between the assailing force of waves and the resistance afforded by foreshore and cliff material that governs the processes through which cliff change occurs remains inadequately quantified and poorly understood. This is further confounded by a limited appreciation of the interplay between the coastal landforms and the range of processes that control their evolution. To explore this, we compare microseismic ground movements resulting from wave impacts to the occurrence of rockfalls from a section of cliffs on the North Yorkshire, United Kingdom, coastline. The results indicate that critical tide levels exist at which waves, in combination with wind directions coinciding with the greatest fetch, generate notably higher levels of energy delivery to the cliff face and that these levels, in turn, correspond to increased ...
TL;DR: In this article, the authors describe the development, behaviour, and application of a mesoscale numerical geomorphological model of eroding soft rock and beach shores, SCAPE (Soft-Cliff and Platform Erosion), which is a suitable tool for testing management strategies.
Abstract: This paper describes the development, behaviour, and application of a mesoscale numerical geomorphological model of eroding soft rock and beach shores. The model, SCAPE (Soft-Cliff and Platform Erosion), describes coastal processes and engineering interventions and is a suitable tool for testing management strategies. The mesoscale capability of SCAPE arises because it includes a broad system: its principal modules describe wave transformation, platform erosion, and a (one-line) beach. Feedback within and between the modules regulates their behaviour, brings long-term (dynamic) stability, and allows quantified representation of qualitatively different shore behaviours. SCAPE is demonstrated through the construction of a model of more than 30 km of the North Norfolk coast. A precalibration initialisation phase is required to allow dynamic equilibrium to emerge. Once initialised, calibrated, and validated against an 87-year record, the model is used to explore the development of the North Norfolk c...
TL;DR: In this paper, the sensitivity of coastal flood risk mapping to future uncertainties was investigated by propagating ranges of plausible parameters through a LISFLOOD inundation model of a significant historic flood event to the North Somerset (U.K.) coast.
Abstract: Future sea-level rise will increase coastal flood risk in the U.K., yet the hazard uncertainties associated with such future risk estimates have not been fully explored. The sensitivity of coastal flood-risk mapping to future uncertainties was investigated by propagating ranges of plausible parameters through a LISFLOOD inundation model of a significant historic flood event to the North Somerset (U.K.) coast. Mean sea-level rise (including land movement) was found to have the greatest effect on the extent of flood inundation. Analysis of the latest research into the future storm-surge climate of the U.K. indicates no change above natural variability, thus, future, extreme water-level estimates (for the U.K.) should be based on observations and not Regional Circulation Models until research indicates otherwise. Evidence suggests that the current approach of forcing the inundation model with an extreme water level of a constant return period is incorrect. This uncertainty of the peak storm tide hei...
TL;DR: GIRI et al. as discussed by the authors proposed an operational methodology based on remote sensing (Landsat, Advanced Spaceborne Thermal Emission and Reflection Radiometer [ASTER], hyperspectral, light detection and ranging [LIDAR], aerial photographs, and field inventory data) to monitor the existing and emerging mangrove areas and their disturbance and regrowth patterns.
Abstract: GIRI, C.; LONG, J., and TIESZEN, L., 2011. Mapping and monitoring Louisiana’s mangroves in the aftermath of the 2010 Gulf of Mexico oil spill. Journal of Coastal Research, 27(6), 1059–1064. West Palm Beach (Florida), ISSN 0749-0208. Information regarding the present condition, historical status, and dynamics of mangrove forests is needed to study the impacts of the Gulf of Mexico oil spill and other stressors affecting mangrove ecosystems. Such information is unavailable for Louisiana at sufficient spatial and thematic detail. We prepared mangrove forest distribution maps of Louisiana (prior to the oil spill) at 1 m and 30 m spatial resolution using aerial photographs and Landsat satellite data, respectively. Image classification was performed using a decision-tree classification approach. We also prepared land-cover change pairs for 1983, 1984, and every 2 y from 1984 to 2010 depicting ‘‘ecosystem shifts’’ (e.g., expansion, retraction, and disappearance). This new spatiotemporal information could be used to assess short-term and long-term impacts of the oil spill on mangroves. Finally, we propose an operational methodology based on remote sensing (Landsat, Advanced Spaceborne Thermal Emission and Reflection Radiometer [ASTER], hyperspectral, light detection and ranging [LIDAR], aerial photographs, and field inventory data) to monitor the existing and emerging mangrove areas and their disturbance and regrowth patterns. Several parameters such as spatial distribution, ecosystem shifts, species composition, and tree height/biomass could be measured to assess the impact of the oil spill and mangrove recovery and restoration. Future research priorities will be to quantify the impacts and recovery of mangroves considering multiple stressors and perturbations, including oil spill, winter freeze, sea-level rise, land subsidence, and land-use/land-cover change for the entire Gulf Coast. www.JCRonline.org
TL;DR: In this article, the results of field experiments designed to compare four types of aeolian saltation sensors: the Safire, the Wenglor® Particle Counter, the Miniphone, and the Buzzer Disc are reported.
Abstract: We report the results of field experiments designed to compare four types of aeolian saltation sensors: the Safire; the Wenglor® Particle Counter; the Miniphone; and the Buzzer Disc. Sets of sensors were deployed in tight spatial arrays and sampled at rates as fast as 20 kHz. In two of the three trials, the data from the sensors are compared to data obtained from sand traps. The Miniphone and the Buzzer Disc, based on microphone and piezoelectric technologies, respectively, produced grain impact counts comparable to those derived from the trap data. The Safire and the Wenglor® Particle Counter produce count rates that were an order of magnitude too slow. Safires undercount because of their large momentum threshold and because its signal is saturated at relatively slow transport rates. We conclude that the Miniphone and the Buzzer Disc are appropriate for deployment as grain counters because their small size allows them to be installed in closely-spaced sets.
TL;DR: In this paper, the authors used the Salinity, Temperature, and Roughness Remote Scanner (STARRS) and the European Soil Moisture and Ocean Salinity Satellite (ESO SALINV) to estimate the sea surface salinity (SSS).
Abstract: Sea surface salinity (SSS) is critical for studying biological and physical processes in the ocean, such as the global water balance, ocean currents, and evaporation rates. The water and heat fluxes associated with precipitation and evaporation over global oceans are fundamental in regulating climate and weather. Yet measurements of global SSSs are sparse and do not show the required temporal and spatial variability of SSS distributions. Airborne microwave radiometers, such as the Scanning Low-Frequency Microwave Radiometer (SLFMR) and the Salinity, Temperature, and Roughness Remote Scanner (STARRS), have been used successfully to map SSS and its variability, but only in estuaries and coastal waters. Since 2009, SSS has been measured from satellite orbit by the European Soil Moisture and Ocean Salinity satellite, which is designed to provide synthesized SSS maps with a high accuracy. Other salinity-related satellites are being developed, such as Aquarius, which will provide the global view of sal...
TL;DR: In this article, a nearshore spectral wave transformation numerical model called CMS-Wave has been developed to address the needs of U.S. Army Corps of Engineers (USACE) navigation projects.
Abstract: The Coastal Inlets Research Program (CIRP) of the U.S. Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory (CHL) has developed a nearshore spectral wave transformation numerical model to address needs of the U.S. Army Corps of Engineers (USACE) navigation projects. The model is called CMS-Wave and is part of Coastal Modeling System (CMS) for wave estimates in the vicinity of coastal and estuarine navigation channels. It can simulate important wave processes at coastal inlets including wave diffraction, refraction, reflection, wave breaking and dissipation mechanisms, wave-current interaction, and wave generation and growth. This paper describes recent improvements in CMS-Wave that include semi-empirical estimates of wave run-up and overtopping, nonlinear wave-wave interactions, and wave dissipation over muddy bottoms. CMS-Wave may be used with nested grids and variable rectangular cells in a rapid mode to assimilate full-plane wave generation for circulation an...
TL;DR: In this paper, the authors defined land uses, delimited subwatersheds emptying into GSB, and estimated nitrogen loads to subwaterheds and from these to receiving waters.
Abstract: Biogeochemical couplings between land and coastal waters are increasingly altered by land cover changes forced by accumulation of human uses of watersheds. In particular, human activities increase nitrogen loads to receiving waters. Definitions of forcings require estimation of external nitrogen sources and evaluation of the effects on the roles of different land covers, retention within watersheds, and net exports to the sea. One powerful example of change in N loads is the effect of urban development on the watershed and concentrations of inorganic nitrogen in the water of Great South Bay (GSB), New York. We defined land uses, delimited subwatersheds emptying into GSB, and estimated nitrogen loads to subwatersheds and from these to receiving waters. Wastewater-derived nitrogen was the dominant source to watershed surfaces (55%), with lesser amounts added by atmospheric deposition to land (31%) and fertilizer use (15%). About 77% of nitrogen entering the watershed was retained within the watersh...
TL;DR: In this paper, daily flow data from four central wastewater treatment systems in coastal North Carolina were examined for responses to rainfall, tide level, and other environmental variables during the period January 2005 through December 2008.
Abstract: Daily flow data from four central wastewater treatment systems in coastal North Carolina were examined for responses to rainfall, tide level, and other environmental variables during the period January 2005 through December 2008. Flow data revealed substantial variation at several timescales, indicating external effects on flow volumes, most likely through inflow and infiltration (I&I). Daily flow volumes were strongly influenced by short-term rainfall quantities, as expected, but other factors contribute on a longer-term basis. The portion of total flow attributable to I&I varied from 100% of base flow. Multiple regression analysis showed that infiltration, defined in this analysis as flow responses to rainfall integrated over 3 day or longer periods, contributed the majority of increased flow. Significant infiltration effects indicate that collection systems are leaky and that elevated groundwater levels drive increased influent flows through central treatment systems. Sea-level variat...
TL;DR: The humped-back relationship in species diversity during succession was tested using vegetation in a coastal sand dune system of the German Wadden Sea island of Spiekeroog.
Abstract: The humped-back relationship in species diversity during succession was tested using vegetation in a coastal sand dune system of the German Wadden Sea island of Spiekeroog. Permanent plots were studied over 15 years along a spatial chronosequence from young grey dunes to old brown dunes. Species diversity, succession rate, and environmental indicator value were used to evaluate multitemporal dynamics of the ecosystem. Long-term development of the dune vegetation was reflected along the chronosequence, whereas fluctuations of plant communities were analyzed by short-term changes of each permanent plot. The study confirmed the intermediate stress theory, whereas highest species diversity was reached at the transition zone of the environmental gradients. Total species richness showed humped-back relations along the xerosere. Hotspots in species diversity varied with the life form group. Highest richness of herbaceous plants was reached in semidynamic young grey dunes, whereas highest richness of bry...
TL;DR: In this paper, the uncertainty of NGS' LIDAR-derived shoreline is assessed using an empirical (ground-based) approach and a stochastic (MSE) approach.
Abstract: The National Oceanic and Atmospheric Administration's (NOAA) National Geodetic Survey (NGS) is mandated to map the national shoreline, which is depicted on NOAA nautical charts, serves as an important source in determining territorial limits, and is widely used in various coastal science and management applications. The National Geodetic Survey's primary method of mapping the national shoreline is through stereo compilation from tide-coordinated aerial photography. However, over the past decade, NGS has conducted several phases of research to develop, test, and refine light detection and ranging (LIDAR)–based shoreline mapping procedures. Although important, reliable estimates of uncertainty of these products have, unfortunately, lagged behind in development. We attempt here to outline possible solutions to this lack. Specifically, this study presents and compares two new methods of assessing the uncertainty of NGS' LIDAR-derived shoreline: an empirical (ground-based) approach and a stochastic (M...
Journal Article•
TL;DR: In this article, a numerical model of storm-driven sediment redistributions within the shoreface/island/back-barrier system and human rearrangements of sediment within the subaerial barrier island was used to explore how the behavior of a natural barrier island differs from one in which humans are dynamic system constituents.
Abstract: Interactions between human manipulations and landscape processes can form a dynamically coupled system because landscape-forming processes affect humans, and humans increasingly manipulate landscape-forming processes. Despite the dynamic nature of sandy barrier islands, economic incentive and recreational opportunities attract humans and development. Storm-driven sediment-transport events that build barrier islands constitute hazards to humans and infrastructure, and manipulations aimed at preventing or mitigating such events link human actions and long-term island morphodynamics. To explore how the behavior of a natural barrier island differs from one in which humans are dynamic system constituents, we use a numerical model of storm-driven sediment redistributions within the shoreface/island/back-barrier system and human rearrangements of sediment within the subaerial barrier island. In a modeled natural system, periods of dune growth and island stability, initiated by stochastic lulls in storm ...
TL;DR: In this paper, the short-term effect of freshly deposited wrack on aeolian transport and surface elevation changes on the backshore and foredune of a barrier island at Avalon, New Jersey, USA was identified.
Abstract: This field study identifies the short-term (hours) effect of freshly deposited wrack on aeolian transport and surface elevation changes on the backshore and foredune of a barrier island at Avalon, New Jersey, USA. Storm wave uprush reached the dune toe on 21 October 2008 and deposited a line of vegetative wrack about 2 m wide (cross-shore) and 70 mm high near the dune toe (upper wrack) and a line about 0.3–0.5 m wide and 30 mm high about 5 m from the dune toe (lower wrack). Fourteen cylindrical sediment traps were deployed 23 October 2008 when the wind blew onshore at an angle of 8 deg to the trend of the dune. Wind speed at 1 m elevation at the dune toe averaged 6.3 m s−1. The lower wrack line was nearly covered with sand about an hour after initiation of transport, diminishing its effect as a barrier to cross-shore transport. The upper wrack line caused greater reduction in trapping rates, with downwind traps collecting only 3.2% and 12.7% of upwind amounts. Data from erosion pins revealed the ...
TL;DR: There are good prospects for safe and effective biological control of these invasive species in Florida and Australian surveys for potential biological control agents began in 2004, resulting in the discovery of several promising candidates.
Abstract: The Casuarina spp. are invasive plants in Florida that threaten biological diversity and beach integrity of coastal habitats. The trees include three species and their hybrids that aggressively invade riverine and coastal areas. Of the three species, C. equisetifolia and C. glauca are highly salt tolerant and widespread in coastal areas. The third species, C. cunninghamiana, invades riverine habitats. These species pose dangers to both the environment and public safety. The environmental damage includes interfering with nesting by endangered sea turtles, American crocodiles, and the rare swallow-tailed kite. Additionally, allelochemical leachates reduce germination and establishment of native vegetation. Casuarina-infested beaches are more prone to sand loss and erosion. Moreover, with shallow roots and tall canopies, they are among the first trees to fall in high winds and as such restrict evacuation efforts during hurricanes. Control of these species is mostly with herbicides, requiring repeate...
TL;DR: In this article, Micallef et al. estimate the coastal vulnerability on a stretch of coastline by using two different methodologies and to check if both methodologies give rise to similar results or if notably dissimilar assessments are obtained.
Abstract: DI PAOLA, G., IGLESIAS, J., RODRIGUEZ, G., BENASSAI, G., AUCELLI, P and PAPPONE, G., 2011. Estimating Coastal Vulnerability in a Meso-Tidal Beach by Means of Quantitative and Semi-Quantitative Methodologies. In: Micallef, A. (ed.), MCRR3-2010 Conference Proceedings, Journal of Coastal Research, Special Issue, No. 61, pp. 303–308. Grosseto, Tuscany, Italy, ISSN 0749-0208. The main goal of this study is to estimate the coastal vulnerability on a stretch of coastline by using two different methodologies and to check if both methodologies give rise to similar results or if notably dissimilar assessments are obtained. To reach the above mentioned objective, a new experimental methodology (Benassai et al, 2009) based on inundation of the inshore land and the well known USGS methodology (Gornitz et al, 1994) are applied and compared. In the first approach, a new parameter, named as impact index, is calculated by using wave climate and geomorphologic data. In general, impact index depends on run-up heigh...
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TL;DR: In this article, a depth-averaged sediment transport model with emphasis on morphodynamic processes near coastal inlets and navigation channels is presented, considering bed material hiding and exposure, avalanching and sediment transport over hard bottoms.
Abstract: This paper presents a depth-averaged sediment transport model with emphasis on morphodynamic processes near coastal inlets and navigation channels. The model solves the depth-averaged two-dimensional non-equilibrium transport equation of total-load sediment, considering bed-material hiding and exposure, avalanching and sediment transport over hard bottoms. The model is coupled with a depth-averaged circulation model and a spectral wave transformation model. Predicted bed changes are compared with measurements for two laboratory experiments of channel infilling and in a field study at Shinnecock Inlet, Long Island, NY. The results indicate that the model is capable of predicting the general trends of morphology change and provides a useful tool for engineering applications such as coastal sediment management, navigation channel maintenance, and beach erosion protection.
TL;DR: Bethel et al. as mentioned in this paper investigated the feasibility and benefits of integrating geospatial technology with the traditional ecological knowledge (TEK) of an indigenous Louisiana coastal population to assess the impacts of current and historical ecosystem change on community viability.
Abstract: BETHEL, M.B.; BRIEN, L.F.; DANIELSON, E.J.; LASKA, S.B.; TROUTMAN, J.P.; BOSHART, W.M.; GIARDINO, M.J., and PHILLIPS, M.A., 2011. Blending geospatial technology and traditional ecological knowledge to enhance restoration decision-support processes in coastal Louisiana. Journal of Coastal Research, 27(3), 555-571. West Palm Beach (Florida), ISSN 0749-0208. More informed coastal restoration decisions have become increasingly important given limited resources available for restoration projects and the increasing magnitude of marsh degradation and loss across the Gulf Coast. This research investigated the feasibility and benefits of integrating geospatial technology with the traditional ecological knowledge (TEK) of an indigenous Louisiana coastal population to assess the impacts of current and historical ecosystem change on community viability. The primary goal was to provide coastal resource managers with a decision-support tool that allows for a more comprehensive method of assessing localized ecological change in the Gulf Coast region, which can also benefit human community sustainability. Using remote sensing (RS) and geographic information systems (GIS) mapping products, integrated with a coastal community's TEK to achieve this goal, the research team determined a method for producing vulnerability/sustainability mapping products for an ecosystem-dependent livelihood base of a coastal population based on information derived from RS imagery prioritized with TEK. This study also demonstrates how such an approach can engage affected community residents who are interested in determining and addressing the causes and mitigating the decline of marsh habitat. Historical image data sets of the study area were acquired to understand evolution of land change to current conditions and project future vulnerability. Image-processing procedures were developed and applied to produce maps that detail land change in the study area at time intervals from 1968 to 2009. This information was combined in a GIS with acquired TEK and scientific data sets relating to marsh vegetation health and vulnerability characteristics to produce mapping products that provide new information for use in the coastal restoration decision-making process. This information includes: (1) marsh areas that are most vulnerable; and (2) the areas that are most significant to community sustainability.
TL;DR: In this paper, the authors estimate the impacts of surge flooding, sea-level rise, and erosion on barrier islands, the lengths and areas of barrier islands and population living there were quantified using high-resolution satellite imagery from Google Earth and 1990-2000 census block data.
Abstract: Barrier islands, the dominant geomorphic features along the U.S. Atlantic and Gulf Coasts, are a favorite place for living and visiting. Unfortunately, barrier islands are vulnerable to storm-surge flooding and erosion because of low elevations and the movement of sand by waves and tides. In order to estimate the impacts of surge flooding, sea-level rise, and erosion on barrier islands, the lengths and areas of barrier islands and population living there were quantified using high-resolution satellite imagery from Google Earth and 1990–2000 census block data. The total length and area of barrier islands spanning 18 states along the U.S. Atlantic and Gulf Coasts are about 3700 km and 6800 km2, respectively. There are approximately 1.4 million people living on barrier islands, half of which are in Florida according to 2000 census data. The population densities of barrier islands are three times those of coastal states on average, and the population increased 14% from 1990 to 2000. The collision cou...