Search

It's generally known that ocean stores abundant energy resources for the development and growth of human beings. Nowadays, the sustainable development of marine economy calls for precisely speculation of marine energy prices and efficiency. However, the traditional methods of measuring energy price and efficiency, for instance, the EROI (energy return on investment) model unable to define system boundaries and to calculate labor and physical costs, be it tidal energy or marine biomass energy. Thus, these methods may ignore as much as 50% of input energy consumption. Energy efficiency could be calculated by the ratio of average energy input cost to the average useable energy output cost while energy price could be measured by the ratio of the monetary input to the output. The principle above could be viewed as a check for energy return on investment as well as an elimination for a redundant process analysis. The results give us a chance to innovate traditional energy efficiency model by social and environmental factors which could be depicted through monetary terms. The precise estimation of marine energy efficiency could also help us make appropriate policies to combat global warming. [ABSTRACT FROM AUTHOR]

Rate of global eustatic sea-level rise during the Holocene Epoch has been identified as the principle cause of observed changes or inferred evolution of nontectonic coastal systems in mid- to low-latitude areas. The rate of rise is now three times faster than it was for the past several thousand years and similar to values associated with the middle Holocene marine transgression. This acceleration can be attributed to human-caused global warming. In this investigation, the effects of accelerating sea-level rise on coastal sedimentary environments of the SE Saline Everglades were quantified. The results reveal historic changes to coastal habitat, sedimentation, and stratigraphy that are transgressive. These changes initiated during the early 20th century and are attributed to accelerating sea-level rise. As this acceleration and the resulting geologic record is a suspected consequence of human-induced global warming, the paper concludes with a discussion of the relevance of these observations, in tandem with others, to the current debate over the utility and use of the proposed Anthropocene. [ABSTRACT FROM AUTHOR]

Li, Y.L., 2020. The influence of manufacturing export trade on marine ecological environment in China. In: Bai, X. and Zhou, H. (eds.), Advances in Water Resources, Environmental Protection, and Sustainable Development. Journal of Coastal Research, Special Issue No. 115, pp. 631-635. Coconut Creek (Florida), ISSN 0749-0208. With global warming, extreme climate and other environmental issues becoming increasingly prominent, the impact of import and export trade on Marine ecological environment has attracted more and more attention. Based on the current situation of China's manufacturing export, this paper discusses the deficiencies of China's current trade environment and its impact on the Marine ecological environment from the perspectives of policy norms, export structure, technology and concepts. The results show that China is at the low end of the global value chain, the role of processing and manufacturing makes China bear more pollution while becoming a manufacturing power, and taking labor-intensive and resource-intensive industries as China's comparative advantages to participate in the international division of labor will have a negative impact on China's Marine ecological environment. The low-end structure of exports, mainly manufactured goods, has further polluted China's Marine environment. [ABSTRACT FROM AUTHOR]

Li, Z. and Liu, Y., 2019. An improved model for marine energy price and efficiency assessment. In: Gong, D.; Zhu, H., and Liu, R. (eds.), Selected Topics in Coastal Research: Engineering, Industry, Economy, and Sustainable Development. Journal of Coastal Research, Special Issue No. 94, pp. 640–647. Coconut Creek (Florida), ISSN 0749-0208. It's generally known that ocean stores abundant energy resources for the development and growth of human beings. Nowadays, the sustainable development of marine economy calls for precisely speculation of marine energy prices and efficiency. However, the traditional methods of measuring energy price and efficiency, for instance, the EROI (energy return on investment) model unable to define system boundaries and to calculate labor and physical costs, be it tidal energy or marine biomass energy. Thus, these methods may ignore as much as 50% of input energy consumption. Energy efficiency could be calculated by the ratio of average energy input cost to the average useable energy output cost while energy price could be measured by the ratio of the monetary input to the output. The principle above could be viewed as a check for energy return on investment as well as an elimination for a redundant process analysis. The results give us a chance to innovate traditional energy efficiency model by social and environmental factors which could be depicted through monetary terms. The precise estimation of marine energy efficiency could also help us make appropriate policies to combat global warming. [ABSTRACT FROM AUTHOR]

Buzard, R.M.; Kinsman, N.E.M.; Maio, C.V.; Erikson, L.H.; Jones, B.M.; Anderson, S.; Glenn, R.J.T., and Overbeck, J.R., 2023. Barrier island reconfiguration leads to rapid erosion and relocation of a rural Alaska community. Journal of Coastal Research, 39(4), 625–642. Charlotte (North Carolina), ISSN 0749-0208. Coastal erosion is one of the foremost hazards that circumpolar communities face. Climate change and warming temperatures are anticipated to accelerate coastal change, increasing risk to coastal communities. Most erosion hazard studies for Alaska communities only consider linear erosion and do not anticipate coastal morphologic changes. This study showcases the possibility and consequence of accelerated erosion by examining a shift from stability to rapid erosion that forced the rural Alaska Native village of Meshik (now Port Heiden) to abandon the original town site and relocate inland. A combination of remote sensing, coastal surveys, and community-based monitoring are used to map coastal morphologic changes and identify erosion drivers. The community's shoreline was stable until a protective barrier island eroded away. The exposure to open ocean waves, coupled with unconsolidated, low-density sediments, led to rapid erosion rates averaging 5.8 ± 0.6 m/y from the 1970s to 2020s. The sudden and rapid erosion put great stress on Meshik residents and resulted in the loss of homes, erosion of a safe boat harbor, and pollution of the beach and bay. Erosion of the barrier island coincided with a period of greater storm activity and sea ice decline, but the exact cause could not be determined. Many polar communities are built on or behind barriers and are on erodible soils such as sands and thawing permafrost. This study highlights the need to study, monitor, and predict morphologic change and regime shifts that can bring catastrophic impacts to coastal communities. [ABSTRACT FROM AUTHOR]

Uranchimeg, S.; Kim, J-G.; Kim, J.-G.; Kwon, H.-H., and Lee, S.-O., 2018. A Bayesian Quantile Regression Approach for Nonstationary Frequency Analysis of Annual Maximum Sea Level in a Changing Climate. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 536–540. Coconut Creek (Florida), ISSN 0749-0208. Sea level rise is primarily caused by global warming and has been a key consideration in design practices in coastal engineering. The design of coastal structures is currently based on a frequency analysis of the local sea level under the stationary assumption, meaning that the maximum sea level will not vary significantly over time. However, the stationary assumption for sea levels might not be valid in a changing climate. In such a context, this study proposes a systematic approach to investigate nonstationarity in annual maximum sea levels (AMSLs) and offers estimates of design water levels for coastal structures using a non-crossing quantile regression-based nonstationary frequency analysis model within a fully Bayesian framework. The AMSLs for 20 tide gauge stations, each with more than 28 years of hourly records, are considered and compiled in this study. The nonstationarity in the AMSLs are explored by focusing on the change in the scale and location parameter of the probability distributions. The majority of the stations (three-fourths) are found to have an upward-convergent/divergent pattern in the distribution, and the distribution changes are confirmed by significance tests. This study determines an overly simple nonstationary frequency analysis (NSFA) approach with a time-dependent mean value might lead to underestimation of the AMSLs, which results in an increase the failure risk in coastal structures. A more detailed discussion of the characteristics of the distribution changes for the design water level is provided in the paper. [ABSTRACT FROM AUTHOR]

Lim, H.S.; Lee, H.J.; Kim, D., and Hong, S., 2023. Beach erosion along the eastern coast of Korea: A brief review. Journal of Coastal Research, 39(1), 181–190. Charlotte (North Carolina), ISSN 0749-0208. Most of the beaches on the eastern coast of Korea are eroding at an alarming rate, triggered by combined natural and artificial causes. In this review, each of the major causes of beach erosion is addressed briefly. A few protection measures such as breakwaters and nourishments are also discussed, with the emphasis on the unexpected or undesirable outcomes. Finally, some of the essential requirements for the field measurements in a beach are mentioned. Global warming has induced the chief natural causes of the beach erosion in Korea, including a gradual increase in wave energies and sea level. An estimation in this review suggests the rates of shoreline of 1 m/10 yrs on the eastern coast by sea-level rise alone. By comparison, artificial beach erosion is most likely to occur upon emplacing structures nearby. A variety of the artificially erosional cases by beach developments are described in the review. Storms and typhoons play a critical role in eroding beaches and changing local morphologies in a short period of time and thus should be observed hydrodynamically. However, the diminishing run-off of rivers and streams should be regarded as the primary reason for the nationwide artificial erosion of beaches. The scanty supply of stream sands to the beaches, together with the influence of global warming, would have the beaches eroded continuously without any coastal developments. [ABSTRACT FROM AUTHOR]

Jia, M.; Wang, Z.; Liu, D.; Ren, C.; Tang, X., and Dong, Z., 2015. Monitoring loss and recovery of salt marsh in the Liao River Delta, China. Coastal salt marsh plays an important role in the aquatic food web and the export of nutrients to coastal waters. The salt marshes in the Liao River Delta of China, dominated by Suaeda heteroptera, experienced a dramatic loss in the 1990s and then recovered in the 2000s. This study investigates these changes of salt marsh using a time series of Landsat Thematic Mapper (TM) images acquired in 1988, 1995, 2000, 2004, 2007, and 2009. The classification tree method was used on these TM images to extract S. heteroptera, and an interactive self-organizing data analysis algorithm was used to determine other land cover types. The conversions between salt marsh and other land cover types were described with conversion matrices. The classification results show that, during 1998-2004, salt marsh decreased dramatically at an average rate of 662.68 ha/y. However, during the period 2004-2009, salt marsh recovered gradually at a rate of 115.51 ha/y. The conversion matrix indicates that, from 1988 to 2004, a large area of former salt marsh was directly replaced by man-made landscape types, such as reed field (5111 ha), aquaculture pond (2655 ha), reservoir (1720 ha), and paddy field (729 ha). In contrast, the result for the period from 2004 to 2009 shows that salt marshes were recovered by the conversion of some areas of former barren beaches and river back to salt marsh. Driving forces analysis suggests that salt marsh dynamics were mainly caused by human activities, with the secondary drivers being climatic warming and dry conditions. [ABSTRACT FROM AUTHOR]

Mackey, R., 2007. Rhodes Fairbridge and the idea that the solar system regulates the Earth's climate. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 955 – 968. Gold Coast, Australia, ISSN 0749.0208 Rhodes Fairbridge died on 8th November, 2006. He was one of Australia's most accomplished scientists and has a special connection with Australia. In July, 1912 his father Kingsley established Fairbridge Village near Perth. It contains a chapel of elegant simplicity designed by one of the world's most famous architects of the time, Sir Herbert Baker, as a labour of love to commemorate Kingsley. Rhodes is one of the few scientists to research the sun/climate relationship in terms of the totality of the sun's impact on the earth (i.e. gravity, the electromagnetic force and output and their interaction). When the totality of the sun's impact is considered, having regard to the relevant research published over the last two decades, the influence of solar variability on the earth's climate is very strongly non-linear and stochastic. Rhodes also researched the idea that the planets might have a role in producing the sun's variable activity. If they do and if the sun's variable activity regulates climate, then ultimately the planets may regulate it. Recent research about the sun/climate relationship and the solar inertial motion (sim) hypothesis shows a large body of circumstantial evidence and several working hypotheses but no satisfactory account of a physical sim process. In 2007 Ulysses will send information about the solar poles. This could be decisive regarding the predictions about emergent Sunspot Cycle No 24, including the sim hypothesis. According to the sim hypothesis, this cycle should be like Sunspot Cycle No 14, and be followed by two that will create a brief ice age. During the 1920s and '30s Australia's Bureau of Meteorology published research about the sun/climate relationship, especially Sunspot Cycle No 14, showing that it probably caused the worst drought then on record. [ABSTRACT FROM AUTHOR]

Suh, S. and Kim, H., 2020. Extreme surge heights incorporating long-term tidal variation and sea-level rise. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1542–1546. Coconut Creek (Florida), ISSN 0749-0208. Global warming is a primary factor for acceleration of sea-level rise (SLR). Most previous studies have dealt only with mean SLR; however, in terms of storm surge inundation, not only the mean SLR, but also the summer seasonal SLR, which is locally almost 20 cm higher on the west coast of Korea because of thermal expansion and riverine runoff, must be considered. In addition, the nodal effects of the 18.6-year tidal variation should be considered for long-term (through 2100) surge hazard analyses. Tidal analyses were conducted at the Incheon station, which is located in the middle of the west coast of Korea, using records from 1960 to 2018. Peak M2 amplitudes varying from 2.96 to 3.02 m were obtained in 1979, 1997, and 2015, while the lowest value of 2.76 m was obtained in 1968, 1985 and 2006. The analysis predicted that the resulting tidal range, would show peak values this century in 2025, 2043, 2062, and 2099. To determine the extreme surge height (SH), this study generated synthetic storms. These storms were generated with a Perl script by adjusting typhoon parameters based data reported in the literature. Upon considering the nodal factor, the resulting SH in 100 years would vary from 1.18 to the 1.31 m mark on the west coast, while it would vary from 0.68 m to 0.71 m on the south coast of Korea. These extreme SHs are potentially hazardous to existing coastal infrastructure such as levees and dikes. This study is relevant to the mitigation of coastal hazards, incorporating not only extreme SH but also wave-induced overtopping hazards on artificial coasts where anthropogenic impacts were made without considering future sea-level changes. [ABSTRACT FROM AUTHOR]

Peterson, C.D.; Kingen, K.E.P.; Erlandson, J.M.; Kaijankoski, P.; Meyer, J., and Ryan, C., 2019. Widespread evidence of terminated marine transgressive sand supply and failing longshore sand transport to eroding coastal eolian sand ramps during the latest Holocene time in Oregon and California (Pacific Coast, USA). Journal of Coastal Research, 35(6), 1145–1163. Coconut Creek (Florida), ISSN 0749-0208. Holocene perched dunes and wave-truncated sand ramps were used to project paleoramp geometries and to estimate sand ramp erosion during the late Holocene in the U.S. Pacific Coast study area (1500 km in length). Both recently accreted sand ramp slopes (n = 24) and wave-truncated sand ramps (n = 59) in 11 sand ramp complexes (0.3–11.4 km in alongshore length) were profiled from areas of previously abundant dune sand supply. Modern sand ramp slopes (shore normal) ranged from 2 to 26°, with slope steepening resulting from upslope eolian deflation (10–20°) and downslope mass wasting by landslide (>20°). Paleoramp surface slopes at 10, 15, and 20° were projected seaward from truncated sand ramp tops (11–97 m in elevation) to intersect with projected basal ramp horizons (4-m elevation). Differences between the 10° slope paleoramps and the corresponding modern sea cliffs yield eroded ramp cross-sectional areas (78–16,770 m2). The eroded cross-sectional areas were multiplied by corresponding alongshore lengths to estimate truncated ramp complex erosion (1.29 × 105–6.41 × 107 m3, mean 12.62 × 106 m3). Modern beach sand volumes in shorelines fronting the 11 truncated ramp complexes are estimated to range from 1.05 × 105 to 1.47 × 106 m3. The average modern beach sand volume of 4.25 × 105 m3 represents only 3.4% of the average eroded ramp complex volume, as estimated from differencing the 10° projected slopes and the modern sea cliff profiles. Near-surface 14C ages of buried archaeological materials in the 11 truncated ramp complexes (932 ± 672 cal BP 1σ, n = 20) demonstrate terminal ramp accretion and associated ramp truncation by beach retreat during the latest Holocene time. The widespread sand ramp erosion, following 3.0 m of sea-level rise during the last 3.0 ka, serves as a warning for the U.S. Pacific Coast and other high–wave energy cliff-backed shorelines for potential beach response to near-future sea-level rise (1–3 m) predicted to occur from ongoing global warming. [ABSTRACT FROM AUTHOR]

Yang, Z.; Chen, D.; Huang, D., and Yang, Y., 2019. Prediction of coastal evolution in Puerto Cabello, Venezuela. In: Guido-Aldana, P.A. and Mulahasan, S. (eds.), Advances in Water Resources and Exploration. Journal of Coastal Research, Special Issue No. 93, pp. 16–21. Coconut Creek (Florida), ISSN 0749-0208. Coasts vary in their composition and the physical processes that affect them. However, their nature and behavior have similarities. Presently, the majority of coasts worldwide are eroding. The rapidly increasing threat of global warming and the resulting rise in sea level can accelerate coastal erosion. The nearly 2 km coastline in the port city of Puerto Cabello in Venezuela, to the west of the island Goaigoaza, was taken as a case study. The long-term state of the beach was assessed by considering the credits and debits of sand that pass through the coastal system. In the study, the net longshore sediment transport rate in the west of the salient was westward and Qin < Qout, denoting that beach erosion will occur in this particular area. Through field investigations and theoretical analysis, it can be preliminarily concluded that the beaches in the study area are slightly eroded. However, a long-term study on the current profile is essential to arrive at a decisive conclusion. [ABSTRACT FROM AUTHOR]

Coasts vary in their composition and the physical processes that affect them. However, their nature and behavior have similarities. Presently, the majority of coasts worldwide are eroding. The rapidly increasing threat of global warming and the resulting rise in sea level can accelerate coastal erosion. The nearly 2 km coastline in the port city of Puerto Cabello in Venezuela, to the west of the island Goaigoaza, was taken as a case study. The long-term state of the beach was assessed by considering the credits and debits of sand that pass through the coastal system. In the study, the net longshore sediment transport rate in the west of the salient was westward and Qin < Qout, denoting that beach erosion will occur in this particular area. Through field investigations and theoretical analysis, it can be preliminarily concluded that the beaches in the study area are slightly eroded. However, a long-term study on the current profile is essential to arrive at a decisive conclusion. [ABSTRACT FROM AUTHOR]

This study tests the effectiveness of physical barriers in blocking or reducing washover sedimentation in coastal marshes. It is widely assumed that natural and artificial physical barriers, such as foredunes and roads, block or reduce storm overwash. However, there appears to be little documented assessment of this effect. This topic has gained significance recently because of concerns over sea-level rise induced by global warming creating a larger potential threat from storm overwash. Nearshore physical barriers act to protect populations and infrastructure farther inland from storm surge, but they may also reduce sediment delivery to coastal marshlands, slowing their vertical accretion and contributing to their submergence by rising sea level. Consequently, there is a critical need for more information on the effect of physical barriers on marsh sedimentation. Washover sediment beds were examined along two transects across marshes in McFaddin National Wildlife Refuge in southeastern Texas, one in the lee of a higher and wider foredune barrier and one where foredunes are lower and narrower. Washover sediment beds deposited by Hurricanes Rita (2005) and Ike (2008) were found on both transects. Comparison of washover sedimentation along the two transects showed an average 40% reduction in sediment volume and an average reduction in inland extent of deposits of 505 m in the lee of the higher and wider barrier. These results show that even relatively subtle increases in barrier dimensions can cause substantial reductions in the magnitude of washover sedimentation in marshes. These findings have implications for paleotempestology studies that use the magnitude of washover sedimentation in the lee of dynamic coastal barriers as geologic proxies of storm intensity. Coastal management agencies contemplating the use of physical barriers to block storm surge should take into consideration the impact of such barriers on the sustainability of coastal marshes faced with rising sea level. [ABSTRACT FROM AUTHOR]

Oh, S.M.; Moon, I.-J., and Kwon, S.J., 2016. Increasing the highest storm surge in Busan harbor, In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 760-764. Coconut Creek (Florida), ISSN 0749-0208. One of the most pronounced effects of climate change in coastal regions is sea level rise and storm surges. Busan in particular, the fifth largest container handling port in the world, has suffered from serious storm surges and experienced a remarkable mean sea level (MSL) rise. This study investigates a long-term variation of annual maximum surge height (AMSH) using sea level data observed in Busan over 53 years (1962∼2014). The decomposition of astronomical tides and surge components shows that the AMSH has increased 18 cm over 53 years ( i.e., 3.5 mm/year), which is much larger than the MSL trend (2.5 mm/year) in Busan. This significant increase in AMSH is mostly explained by the increased intensity of landfall typhoons over the Korean peninsula (KP), which is associated with the increase of sea surface temperature and the decrease of vertical wind shear at mid-latitudes of the western North Pacific. In a projected future warming environment, the combination of an increasing MSL and AMSH will accelerate the occurrence of record-breaking extreme sea levels, which will be a potential threat in Busan harbor. [ABSTRACT FROM AUTHOR]

Yang, Z.; Chen, D.; Huang, D., and Yang, Y., 2019. Prediction of coastal evolution in Puerto Cabello, Venezuela. In: Guido-Aldana, P.A. and Mulahasan, S. (eds.), Advances in Water Resources and Exploration. Journal of Coastal Research, Special Issue No. 93, pp. 16–21. Coconut Creek (Florida), ISSN 0749-0208. Coasts vary in their composition and the physical processes that affect them. However, their nature and behavior have similarities. Presently, the majority of coasts worldwide are eroding. The rapidly increasing threat of global warming and the resulting rise in sea level can accelerate coastal erosion. The nearly 2 km coastline in the port city of Puerto Cabello in Venezuela, to the west of the island Goaigoaza, was taken as a case study. The long-term state of the beach was assessed by considering the credits and debits of sand that pass through the coastal system. In the study, the net longshore sediment transport rate in the west of the salient was westward and Qin < Qout, denoting that beach erosion will occur in this particular area. Through field investigations and theoretical analysis, it can be preliminarily concluded that the beaches in the study area are slightly eroded. However, a long-term study on the current profile is essential to arrive at a decisive conclusion. [ABSTRACT FROM AUTHOR]

A recent article published in the Journal of Coastal Research analysed a number of different sea-level records and reported that they found no acceleration of sea-level rise. We show that this is due to their focusing on records that are either too short or only regional in character, and on their specific focus on acceleration since the year 1930, which represents a unique minimum in the acceleration curve. We find that global sea-level rise is accelerating in a way strongly correlated with global temperature. This correlation also explains the acceleration minimum for time periods starting around 1930; it is due to the mid-twentieth-century plateau in global temperature. [ABSTRACT FROM AUTHOR]

A large database of deep water wave buoy measurements over a 24-year period is created for four regions comprising the West Coast of the United States. The regional monthly mean significant wave height (MMSWH) is selected as the defining wave climate parameter and averaging multiple data sources within a region is found to significantly reduce data gaps. Two 12-year periods are compared, showing significant temporal variability but high correlation between regions, allowing the further collapse of the data to a northern and a southern region. Correlations between MMSWH records with three global-scale climate indices are investigated and only the North Pacific Index (NPI), a measure of atmospheric pressure in the Gulf of Alaska, shows strong correlation. The Multivariate ENSO Index (MEI) is less correlated and the Pacific Decadal Index (PDO), which is a measure of ocean surface temperature, provides no significant correlation. A method for displaying multiple correlations is developed that shows the mean of all MMSWH records that occur at unique temporal combinations of two climate indices. The graphics depicting the mean wave height as a function of NPI and MEI for the two 12-year periods are shown to be very instructive in establishing why the two periods are so different. On the contrary, the same procedure with PDO substituted for MEI produces uniform distributions with little interpretive value. Century-scale variation in the climate indices is investigated, and significant linear trends are found for NPI and MEI, both consistent with causing increases in mean wave energy in these regions. Causal relationships for the observed correlations are discussed, and conclusions are reached indicating that global warming is a likely contributor to observed increases in wave intensity in the North Pacific. [ABSTRACT FROM AUTHOR]

Numerical modeling of dredged pits is conducted to investigate the hydrodynamic and morphodynamic interaction in offshore sand extractions. Based on an analytical formulation, a semianalytical numerical model (MEMPITS) has been developed to study the morphodynamic evolution of offshore (ho . 20 m) sand borrow areas. The numerical model has been applied to study the morphodynamic evolution of two offshore sand borrow areas in the Balearic Islands (Spain). Field data allowed a detailed characterization of the evolution of the sandpits. Time series of local hydrodynamics have been obtained using generation models (hindcast) combined with local wave and flow models. A verification of the simple model has been carried out using relatively slight adjustments to the calibration factors. The simple model provides good estimates of the infill rate and migration velocities of the offshore pits on the scale of years. This semianalytical tool allows a quick systematic investigation of the physical mechanisms as well as a etailed sensibility analysis regarding the pit design parameters. These parameters include location (water depth), pit length, width, depth, and orientation with respect to the mean flow. A nondimensional analysis based on the model is also carried out to explore the role of the different variables involved in the evolution of offshore sandpits. Based on the field data and the nondimensional analysis, some basic design recommendations for offshore sandpits are proposed. [ABSTRACT FROM AUTHOR]

Erosion along the West Coast of the United States is affected by climate controls that include a trend of increasing wave heights during at least the past 25 years that might be related to global warming and the El Niño Southern Oscillation (ENSO) range between El Niños and La Niñas that affects both annual wave conditions and monthly mean water levels that raise tidal elevations. These processes are analyzed for sites from Washington to south-central California, revealing a latitude dependence of the individual processes and how their combinations affect total water levels at the shore, which is important to beach and property erosion. Particularly significant on the coast of the Pacific Northwest (Washington and Oregon) has been the progressive decadal increases in deep-water wave heights and periods, which have increased breaker heights and elevated storm wave runup levels on beaches. Along the entire West Coast, the annual variations in wave conditions above and below any progressive decadal increase are controlled by the North Pacific index (NPI), the atmospheric pressure difference between the Hawaiian High and Aleutian Low, and the ENSO range, as demonstrated by a strong correlation with the multivariate ENSO index (MEl), with the highest wave conditions occurring during El Niños. In addition, the ENSO range is particularly important in controlling mean water levels, causing tides to reach their highest elevations during El Niños, again shown by correlations with MEIs along the entire West Coast. With El Niños producing increased deep-water wave heights, runup levels on beaches, and elevated tides, the total water levels at the shore from the combined processes are significantly higher compared with normal or La Niña years, resulting in episodes of major property erosion along the entire US West Coast. [ABSTRACT FROM AUTHOR]

This study deals with incorporating predictions of sea level rise into practical municipal planning. Predictions of global mean sea level rise can be made with more confidence than many other aspects of climate change science. The world has warmed in the past century, and as a result global mean sea level has risen and is expected to continue to rise. Even so, there are significant uncertainties regarding predictions of sea level. These arise from two main sources: the future amount of greenhouse gases in the atmosphere, and the ability of models to predict the impact of increasing concentrations of greenhouse gases. Current knowledge regarding the effect of global warming on sea level rise is reviewed. Global mean sea level is expected to rise by 3–30 cm by 2040, and 9–88 cm by 2100. An important remaining uncertainty is the future contribution of surface water storage (for example, lakes and reservoirs) to changes in sea level. In addition, there are also significant local sea level effects that need to be taken account in many regions of the globe, including isostatic and tectonic effects. The thermal expansion component of sea level rise is also likely to vary regionally, due to regional differences in the rate of downward mixing of heat and to changes in ocean currents. The current state of planning for sea level rise in Australia is reviewed. While not all coastal municipalities include sea level rise in their planning schemes, the recent adoption in a number of States of new planning schemes with statutory authority creates a changed planning environment for local government. Coastal urban planning needs to take sea level rise into account because its effects will be apparent during the typical replacement time of urban infrastructure such as buildings (before about 70 years). For local planning, ideally a risk assessment methodology may be employed to estimate the risk caused by sea level rise. In many locations, planning thresholds would also have to be considered in the light of possible changes in storm surge climatology due to changes in storm frequency and intensity, and (in some locations) changes to return periods of riverine flooding. In the medium term (decades), urban beaches will need beach re-nourishment and associated holding structures such as sea walls. Changes in storm and wave climatology are crucial factors for determining future coastal erosion. [ABSTRACT FROM AUTHOR]