WorldWideScience

Sample records for point shoreline erosion

  1. Regional shoreline change and coastal erosion hazards in Arctic Alaska

    Science.gov (United States)

    Gibbs, Ann E.; Richmond, Bruce M.; Erikson, Li H.; Harden, E. Lynne; Wallendorf, Louise

    2011-01-01

    Historical shoreline positions along the mainland Beaufort Sea coast of Alaska were digitized and analyzed to determine the long-term rate of change. Average shoreline change rates and ranges from 1947 to the mid-2000s were determined every 50 meters between Barrow and Demarcation Point, at the U.S.-Canadian border. Results show that shoreline change rates are highly variable along the coast, with an average regional shoreline change rate of-2.0 m/yr and localized rates of up to -19 m/yr. The highest erosion rates were observed at headlands, points, and associated with breached thermokarst lakes. Areas of accretion were limited, and generally associated with spit extension and minor beach accretion. In general, erosion rates increase from east to west, with overall higher rates east of Harrison Bay.

  2. Soil erosion and deposition in the new shorelines of the Three Gorges Reservoir.

    Science.gov (United States)

    Su, Xiaolei; Nilsson, Christer; Pilotto, Francesca; Liu, Songping; Shi, Shaohua; Zeng, Bo

    2017-12-01

    During the last few decades, the construction of storage reservoirs worldwide has led to the formation of many new shorelines in former upland areas. After the formation of such shorelines, a dynamic phase of soil erosion and deposition follows. We explored the factors regulating soil dynamics in the shorelines of the Three Gorges Reservoir (TGR) on the Yangtze River in China. We selected four study sites on the main stem and three on the tributaries in the upstream parts of the reservoir, and evaluated whether the sites close to the backwater tail (the point at which the river meets the reservoir) had more soil deposition than the sites far from the backwater tail. We also tested whether soil erosion differed between the main stem and the tributaries and across shorelines. We found that soil deposition in the new shorelines was higher close to the backwater tail and decreased downstream. Soil erosion was higher in the main stem than in the tributaries and higher at lower compared to higher shoreline altitudes. In the tributaries, erosion did not differ between higher and lower shoreline levels. Erosion increased with increasing fetch length, inundation duration and distance from the backwater tail, and decreased with increasing soil particle fineness. Our results provide a basis for identifying shorelines in need of restorative or protective measures. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. 15 CFR 923.25 - Shoreline erosion/mitigation planning.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Shoreline erosion/mitigation planning... erosion/mitigation planning. (a) The management program must include a planning process for assessing the... planning process may be within the broader context of coastal hazard mitigation planning. (b) The basic...

  4. Impacts of shoreline erosion on coastal ecosystems in Songkhla Province

    Directory of Open Access Journals (Sweden)

    Nipaporn Chusrinuan

    2009-07-01

    Full Text Available Songkhla Province is located on the eastern coast of the southern Thai Peninsula, bordering the Gulf of Thailand for approximately 107 km. Most of the basin’s foreshores have been extensively developed for housing, tourism and shrimp farming. The beaches are under deteriorating impacts, often causing sediment transport which leads to an unnaturally high erosion rate. This natural phenomenon is considered to be a critical problem in the coastal areas affected by the hazard of coastal infrastructure and reduced beach esthetics for recreation. In this study, shoreline changes were compared between 1975 and 2006 using aerial photographs and Landsat imageries using Geographic Information System (GIS. The results revealed that 18.5 km2 of the coastal areas were altered during the period. Of this, 17.3 km2 suffered erosion and 1.2 km2were subjected to accretion. The most significant changes occurred between 1975-2006. Shoreline erosion was found at Ban Paktrae, Ranot District, with an average erosion rate of 5.3 m/year, while accretion occurred at Laem Samila, MuangSongkhla District with an average accretion rate of 2.04 m/year. The occurrences of shoreline erosion have contributed to the degradation of coastal soil and water quality, destruction of beach and mangrove forests, loss of human settlements and livelihood.These processes have led to deterioration of the quality of life of the residents. Prevention and mitigation measures to lessen economic and social impacts due to shoreline erosion are discussed.

  5. Development of Biotechnical Methods to Control Shoreline Erosion

    National Research Council Canada - National Science Library

    Mays, D

    1999-01-01

    .... Coconut fiber logs, straw bales wrapped in poultry netting, large round hay bales, and bundled logs anchored to the shoreline were all evaluated for their potential to control wave damage to the shoreline...

  6. Sedimentation and erosion in Lake Diefenbaker, Canada: solutions for shoreline retreat monitoring.

    Science.gov (United States)

    Sadeghian, Amir; de Boer, Dirk; Lindenschmidt, Karl-Erich

    2017-09-15

    This study looks into sedimentation and erosion rates in Lake Diefenbaker, a prairie reservoir, in Saskatchewan, Canada, which has been in operation since 1968. First, we looked at the historical data in all different formats over the last 70 years, which includes data from more than 20 years before the formation of the lake. The field observations indicate high rates of shoreline erosion, especially in the upstream portion as a potential region for shoreline retreat. Because of the great importance of this waterbody to the province, monitoring sedimentation and erosion rates is necessary for maintaining the quality of water especially after severe floods which are more common due to climate change effects. Second, we used Google Maps Elevation API, a new tool from Google that provides elevation data for cross sections drawn between two points, by drawing 24 cross sections in the upstream area extending 250 m from each bank. This feature from Google can be used as an easy and fast monitoring tool, is free of charge, and provides excellent control capabilities for monitoring changes in cross-sectional profiles.

  7. Effects of shoreline erosion on infrastructure development along the ...

    African Journals Online (AJOL)

    ... coastal environment and affected the socio-economic life of local populations, threatened cultural heritage and hindered coastal tourism development. This paper assessed the extent of shoreline recession and its effects on buildings and infrastructure along Ghana's coastline through a study of the Nkontompo Community ...

  8. Effects of erosion control structures along a portion of the northern Chesapeake Bay shoreline

    Science.gov (United States)

    Zabawa, C.F.; Kerhin, R.T.; Bayley, S.

    1981-01-01

    A 6.500-meter reach of western Chesapeake Bay shoreline (lower Mayo Peninsula) lost about 1.1??106 cubic meters of sediment (equivalent to 170 cubic meters lost per meter of shoreline) between 1846 and 1932, when the first aerial photographs show the shoreline already substantially protected by a system of groins and intermittent bulkheading. These structures have eliminated the fastland as a source of erodable material, and have starved the supply of sand for littoral drift, thus limiting the extent of the beaches to the remaining groin fields. Volumes of sediment involved in these impacts are small in the overall sediment budget. Bulkheads produce no deficit in the budget since scouring of the beaches on their seaward sides makes up for the decreased erosion of protected fastland. Groins trap little of the potential littoral drift (computed to be about 104 cubic meters per meter of shoreline per year). The sand supply in the remaining beaches is nearly equivalent to the annual loss of sediment from the entire shoreline system due to the long-term rate of erosion of the shoreline and nearshore between 1846 and 1932. ?? 1981 Springer-Verlag New York Inc.

  9. Shoreline Erosion and Proposed Control at Experimental Facility 15-Spesutie Island

    Science.gov (United States)

    2017-09-01

    distribution is unlimited. 1 1. Introduction Coastal erosion is the wearing away of land and the removal of beach or dune sediments by wave action...the land , air, and water defines the wetted perimeter where land use and clearing practices have taken on an adversarial role with regard to the...stand with approximately 30–40 ft of manicured lawn to the shoreline. There are no trees on the range proper, with only a smattering of indigenous

  10. Effects of oil on the rate and trajectory of Louisiana marsh shoreline erosion

    International Nuclear Information System (INIS)

    McClenachan, Giovanna; Eugene Turner, R; Tweel, Andrew W

    2013-01-01

    Oil can have long-term detrimental effects on marsh plant health, both above- and belowground. However, there are few data available that quantify the accelerated rate of erosion that oil may cause to marshes and the trajectory of change. Between November 2010 and August 2012, we collected data on shoreline erosion, soil strength, per cent cover of Spartina alterniflora, and marsh edge overhang at 30 closely spaced low oil and high oil sites in Bay Batiste, Louisiana. Surface oil samples were taken one meter into the marsh in February 2011. All high oiled sites in Bay Batiste were contaminated with Macondo 252 oil (oil from the Deepwater Horizon oil spill, 20 April–15 July 2010). The results suggest that there is a threshold where soil parameters change dramatically with a relatively small increase in oil concentration in the soil. Heavy oiling weakens the soil, creating a deeper undercut of the upper 50 cm of the marsh edge, and causing an accelerated rate of erosion that cascades along the shoreline. Our results demonstrate that it could take at least 2 yr to document the effects heavy oiling has had on the marsh shoreline. The presence of aboveground vegetation alone may not be an appropriate indicator of recovery. (letter)

  11. Archaeological Site Vulnerability Modelling: The Influence of High Impact Storm Events on Models of Shoreline Erosion in the Western Canadian Arctic

    Directory of Open Access Journals (Sweden)

    O’Rourke Michael J. E.

    2017-01-01

    Full Text Available Much of the Inuvialuit archaeological record is situated along shorelines of the western Canadian Arctic. These coastal sites are at substantial risk of damage due to a number of geomorphological processes at work in the region. The identification of threatened heritage remains is critical in the Mackenzie Delta, where landscape changes are taking place at an increasingly rapid pace. This paper outlines some preliminary observations from a research program directed toward identifying vulnerable archaeological remains within the Inuvialuit Settlement Region. Coastal erosion rates have been calculated for over 280 km of the Kugmallit Bay shoreline, extending along the eastern extent of Richards Island and neighbouring areas of the Tuktoyaktuk Peninsula. Helicopter surveys conducted during the 2014 field season confirmed that areas exposed to heavy erosive forces in the past continue to erode at alarming rates. Some of the calculated rates, however, have proven far too conservative. An extreme period of erosion at Toker Point in the autumn of 2013 has yielded a prime example of how increasingly volatile weather patterns can influence shoreline erosion models. It has also provided a case with which to demonstrate the value of using more recent, shorter time-interval imagery in assessing impacts to cultural landscapes.

  12. Shoreline erosion and decadal sediment accumulation in the Tar-Pamlico estuary, North Carolina, USA: A source-to-sink analysis

    Science.gov (United States)

    Eulie, Devon O.; Corbett, D. Reide; Walsh, J. P.

    2018-03-01

    Estuaries contain vital habitats and it is important to understand how these areas respond to human activities and natural processes such as sea-level rise and wave attack. As estuarine shorelines erode or become modified with hard structures, there is potential for significantly altering the availability of sediment and the filling of coastal systems. This study used a source-to-sink approach and quantified rates of shoreline erosion in the Tar-Pamlico sub-estuary, a tributary of the larger Albemarle-Pamlico Estuarine System (APES). The average shoreline change rate (SCR) determined using an end-point method was -0.5 ± 0.9 m yr-1 for the Tar-Pamlico. Incorporating bulk density estimates, this contributes 0.6 × 105 tons of fine sediment to the system annually, or after accounting for fluvial input, about 40% of the total sediment supply to the sub-estuary. The role of the Tar-Pamlico as a sink for these sediments was addressed using the radionuclide tracers 210Pb and 137Cs. Radionuclide activities and sediment accumulation rates identified several depositional regions, in particular in the middle of the estuary. Linear sediment accumulation rates ranged from 0.10 ± 0.02 to 0.38 ± 0.02 g cm-2 yr-1, and total storage of fine sediment in the system was 1.6 × 105 t yr-1. It was not possible to confidently discern a change in the rate of shoreline erosion or seabed accumulation. A preliminary budget for fine sediments (grain-size <63 μm) was then calculated to compare erosional sources with sedimentary sinks. Almost all (∼93.0%) of the fine sediment entering the system was accumulated and stored, while only about 7.0% was exported to Pamlico Sound.

  13. Role of Erosion in Shaping Point Bars

    Science.gov (United States)

    Moody, J.; Meade, R.

    2012-04-01

    A powerful metaphor in fluvial geomorphology has been that depositional features such as point bars (and other floodplain features) constitute the river's historical memory in the form of uniformly thick sedimentary deposits waiting for the geomorphologist to dissect and interpret the past. For the past three decades, along the channel of Powder River (Montana USA) we have documented (with annual cross-sectional surveys and pit trenches) the evolution of the shape of three point bars that were created when an extreme flood in 1978 cut new channels across the necks of two former meander bends and radically shifted the location of a third bend. Subsequent erosion has substantially reshaped, at different time scales, the relic sediment deposits of varying age. At the weekly to monthly time scale (i.e., floods from snowmelt or floods from convective or cyclonic storms), the maximum scour depth was computed (by using a numerical model) at locations spaced 1 m apart across the entire point bar for a couple of the largest floods. The maximum predicted scour is about 0.22 m. At the annual time scale, repeated cross-section topographic surveys (25 during 32 years) indicate that net annual erosion at a single location can be as great as 0.5 m, and that the net erosion is greater than net deposition during 8, 16, and 32% of the years for the three point bars. On average, the median annual net erosion was 21, 36, and 51% of the net deposition. At the decadal time scale, an index of point bar preservation often referred to as completeness was defined for each cross section as the percentage of the initial deposit (older than 10 years) that was still remaining in 2011; computations indicate that 19, 41, and 36% of the initial deposits of sediment were eroded. Initial deposits were not uniform in thickness and often represented thicker pods of sediment connected by thin layers of sediment or even isolated pods at different elevations across the point bar in response to multiple

  14. Process-based coastal erosion modeling for Drew Point (North Slope, Alaska)

    Science.gov (United States)

    Ravens, Thomas M.; Jones, Benjamin M.; Zhang, Jinlin; Arp, Christopher D.; Schmutz, Joel A.

    2012-01-01

    A predictive, coastal erosion/shoreline change model has been developed for a small coastal segment near Drew Point, Beaufort Sea, Alaska. This coastal setting has experienced a dramatic increase in erosion since the early 2000’s. The bluffs at this site are 3-4 m tall and consist of ice-wedge bounded blocks of fine-grained sediments cemented by ice-rich permafrost and capped with a thin organic layer. The bluffs are typically fronted by a narrow (∼ 5  m wide) beach or none at all. During a storm surge, the sea contacts the base of the bluff and a niche is formed through thermal and mechanical erosion. The niche grows both vertically and laterally and eventually undermines the bluff, leading to block failure or collapse. The fallen block is then eroded both thermally and mechanically by waves and currents, which must occur before a new niche forming episode may begin. The erosion model explicitly accounts for and integrates a number of these processes including: (1) storm surge generation resulting from wind and atmospheric forcing, (2) erosional niche growth resulting from wave-induced turbulent heat transfer and sediment transport (using the Kobayashi niche erosion model), and (3) thermal and mechanical erosion of the fallen block. The model was calibrated with historic shoreline change data for one time period (1979-2002), and validated with a later time period (2002-2007).

  15. Rapid shoreline erosion induced by human impacts in a tropical muddy coast context, an example from western French Guiana.

    Science.gov (United States)

    Brunier, Guillaume; Anthony, Edward; Gardel, Antoine

    2015-04-01

    The Guyanas coast (French Guiana, Surinam and Guiana) is the longest muddy coast in the world (1500 km). It is under the influence of mud banks in transit from the Amazon delta in Brazil to the Orinoco delta in Venezuela. This westward mud bank migration induces a strong geomorphic control on the shoreline which can be summarized in terms of "bank" (shoreline advance and wave energy dissipation) and "inter-bank" phases (erosion of shoreline by waves). Our study site, rice polders close to Mana city (western French Guiana), is a fine example of the exacerbation, by human activities, of the erosional dynamics on this muddy coast during an "inter-bank" phase. The polders cover 50,000 ha, in 200 x 600 m compartments flanked by earth dikes and canals. They were built in the muddy Holocene coastal plain in the 1980s and are rapidly eroding. Waves (mean significant height = 1.5 m height) comprise Atlantic swell and local trade wind-waves, and the tidal context is semi-diurnal and meso-tidal. We determined historical shoreline evolution from satellite (Landsat & SPOT) and orthophotography images, and conducted four field campaigns between October 2013 and October 2014, comprising topographic (RTK-DGPS) and hydrodynamic (pressure sensors) measurements. The results show intense erosion of 150 m/year affecting the polders since 2001, and lesser retreat (30 to 100 m/year) of the adjacent sectors colonized by mangrove forests. The erosive shoreface shows the same structure in each polder compartment: a chenier beach which freely retreats backwards under the influence of wave overwash. The chenier retreat rate is 100 m/year and it appears to be more intense (net retreat of 45 m) during the high wave-energy season (December to March), which generates more overwashing. In front of the chenier, we observed a large (50 m) inter-tidal mud bed showing different levels of induration and bioturbation by mangrove roots. The mud shorefaces exhibit an erosion rate of 100 m/year on average

  16. Shoreline Erosion and Slope Failure Detection over Southwest Lakeshore Michigan using Temporal Radar and Digital Elevation Model

    Science.gov (United States)

    Sataer, G.; Sultan, M.; Yellich, J. A.; Becker, R.; Emil, M. K.; Palaseanu, M.

    2017-12-01

    Throughout the 20th century and into the 21st century, significant losses of residential, commercial and governmental property were reported along the shores of the Great Lakes region due to one or more of the following factors: high lake levels, wave actions, groundwater discharge. A collaborative effort (Western Michigan University, University of Toledo, Michigan Geological Survey [MGS], United States Geological Survey [USGS], National Oceanographic and Atmospheric Administration [NOAA]) is underway to examine the temporal topographic variations along the shoreline and the adjacent bluff extending from the City of South Haven in the south to the City of Saugatuck in the north within the Allegan County. Our objectives include two main tasks: (1) identification of the timing of, and the areas, witnessing slope failure and shoreline erosion, and (2) investigating the factors causing the observed failures and erosion. This is being accomplished over the study area by: (1) detecting and measuring slope subsidence rates (velocities along line of site) and failures using radar interferometric persistent scatter (PS) techniques applied to ESA's European Remote Sensing (ERS) satellites, ERS-1 and -2 (spatial resolution: 25 m) that were acquired in 1995 to 2007, (2) extracting temporal high resolution (20 cm) digital elevation models (DEM) for the study area from temporal imagery acquired by Unmanned Aerial Vehicles (UAVs), and applying change detection techniques to the extracted DEMs, (3) detecting change in elevation and slope profiles extracted from two LIDAR Coastal National Elevation Database (CoNED) DEMs (spatial resolution: 0.5m), acquired on 2008 and 2012, and (4) spatial and temporal correlation of the detected changes in elevation with relevant data sets (e.g., lake levels, precipitation, groundwater levels) in search of causal effects.

  17. The national assessment of shoreline change: a GIS compilation of vector cliff edges and associated cliff erosion data for the California coast

    Science.gov (United States)

    Hapke, Cheryl; Reid, David; Borrelli, Mark

    2007-01-01

    The U.S. Geological Survey has generated a comprehensive data clearinghouse of digital vector cliff edges and associated rates of cliff retreat along the open-ocean California coast. These data, which are presented herein, were compiled as part of the U.S. Geological Survey's National Assessment of Shoreline Change Project. Cliff erosion is a chronic problem along many coastlines of the United States. As coastal populations continue to grow and community infrastructures are threatened by erosion, there is increased demand for accurate information including rates and trends of coastal cliff retreat. There is also a critical need for these data to be consistent from one region to another. One objective of this work is to a develop standard, repeatable methodology for mapping and analyzing cliff edge retreat so that periodic, systematic, and internally consistent updates of cliff edge position and associated rates of erosion can be made at a national scale. This data compilation for open-ocean cliff edges for the California coast is a separate, yet related study to Hapke and others, 2006 documenting shoreline change along sandy shorelines of the California coast, which is itself one in a series that includes the Gulf of Mexico and the Southeast Atlantic coast (Morton and others, 2004; Morton and Miller, 2005). Future reports and data compilations will include coverage of the Northeast U.S., the Great Lakes, Hawaii and Alaska. Cliff edge change is determined by comparing the positions of one historical cliff edge digitized from maps with a modern cliff edge derived from topographic LIDAR (light detection and ranging) surveys. Historical cliff edges for the California coast represent the 1920s-1930s time-period; the most recent cliff edge was delineated using data collected between 1998 and 2002. End-point rate calculations were used to evaluate rates of erosion between the two cliff edges. Please refer to our full report on cliff edge erosion along the California

  18. Multidecadal shoreline changes in Denmark

    DEFF Research Database (Denmark)

    Kabuth, Alina Kristin; Kroon, Aart; Pedersen, Jørn Bjarke Torp

    2014-01-01

    Multidecadal shoreline changes along ca. 7000 km coastline around Denmark were computed for the time interval between 1862 AD and 2005 AD and were connected with a geomorphological coastal classification. The shoreline data set was based on shoreline positions from historical and modern topograph...... shoreline changes around Denmark, the mapping can contribute to enhanced adaptation and mitigation strategies in response to increased risks of erosion and flooding under a changing climate....

  19. River delta shoreline reworking and erosion in the Mediterranean and Black Seas: the potential roles of fluvial sediment starvation and other factors

    Directory of Open Access Journals (Sweden)

    Manon Besset

    2017-09-01

    Full Text Available The Mediterranean basin (including the Black Sea is characterized by a plethora of deltas that have developed in a wave-influenced setting. Many of these deltas are sourced in sediments by river catchments that have been variably dammed. The vulnerability status of a selection of ten deltas subject to different levels of reduction in fluvial sediment supply following damming was analysed by quantifying changes in delta protrusion area and protrusion angle over the last 30 years. The rationale for choosing these two metrics, which do not require tricky calculations of longshore bedload transport volumes and river ‘influence’, is that as sediment supply wanes, increasing relative efficiency of waves leads to longshore redistribution of reworked sediments and progressive ‘flattening’ of the delta protrusion. The results show that eight of the ten deltas (Nile, Rhône, Ebro, Ceyhan, Arno, Ombrone, Moulouya, Medjerda are in erosion, whereas two (Danube, Po show stability, but the statistical relationship between change in delta protrusion area and sediment flux reduction is poor, thus suggesting that the role of dams in causing delta shoreline erosion may have been over-estimated. But this poor relationship could also be due to a long temporal lag between dam construction and bedload removal and transport to the coast downstream of dams, and, where the delta protrusion is being eroded, to bedload trapping by shoreline engineering structures and by elongating delta-flank spits. Other potential influential factors in shoreline change include subsidence, sea-level rise, storminess, exceptional river floods, and managed sediment releases downstream of dams. A longer observation period and high-resolution sediment-budget studies will be necessary to determine more definitively to which extent continued trapping of sediment behind dams will impact overall delta stability in the Mediterranean and Black Seas. Mitigation of delta erosion is likely to

  20. The National Assessment of Shoreline Change: a GIS compilation of vector shorelines and associated shoreline change data for the U.S. southeast Atlantic coast

    Science.gov (United States)

    Miller, Tara L.; Morton, Robert A.; Sallenger, Asbury H.

    2006-01-01

    The Coastal and Marine Geology Program of the U.S. Geological Survey has generated a comprehensive database of digital vector shorelines and shoreline change rates for the U.S. Southeast Atlantic Coast (Florida, Georgia, South Carolina, North Carolina). These data, which are presented herein, were compiled as part of the U.S. Geological Survey's National Assessment of Shoreline Change Project. Beach erosion is a chronic problem along most open-ocean shores of the United States. As coastal populations continue to grow and community infrastructures are threatened by erosion, there is increased demand for accurate information including rates and trends of shoreline migration. There is also a critical need for shoreline change data that is consistent from one coastal region to another. One purpose of this work is to develop standard repeatable methods for mapping and analyzing shoreline movement so that periodic updates of shorelines and shoreline change rates can be made nationally that are systematic and internally consistent. This data compilation for open-ocean, sandy shorelines of the U.S. Southeast Atlantic Coast is the second in a series that already includes the Gulf of Mexico, and will eventually include the Pacific Coast, and parts of Hawaii and Alaska. Short- and long-term shoreline change evaluations are based on merging three historical shorelines with a modern shoreline derived from lidar (light detection and ranging) topographic surveys. Historical shorelines generally represent the following time periods: 1800s, 1920s-1930s, and 1970s. The most recent shoreline is derived from data collected over the period of 1997-2002. Long-term rates of change are calculated by linear regression using all four shorelines. Short-term rates of change are simple end-point rate calculations using the two most recent shorelines. Please refer to our full report on shoreline change for the U.S. Southeast Atlantic Coast at http://pubs.usgs.gov/of/2005/1401/ to get additional

  1. The National Assessment of Shoreline Change:A GIS Compilation of Vector Shorelines and Associated Shoreline Change Data for the Sandy Shorelines of the California Coast

    Science.gov (United States)

    Hapke, Cheryl J.; Reid, David

    2006-01-01

    Introduction The Coastal and Marine Geology Program of the U.S. Geological Survey has generated a comprehensive data clearinghouse of digital vector shorelines and shoreline change rates for the sandy shoreline along the California open coast. These data, which are presented herein, were compiled as part of the U.S. Geological Survey's National Assessment of Shoreline Change Project. Beach erosion is a chronic problem along many open-ocean shores of the United States. As coastal populations continue to grow and community infrastructures are threatened by erosion, there is increased demand for accurate information including rates and trends of shoreline migration. There is also a critical need for shoreline change data that is consistent from one coastal region to another. One purpose of this work is to develop standard, repeatable methods for mapping and analyzing shoreline movement so that periodic, systematic, and internally consistent updates of shorelines and shoreline change rates can be made at a National Scale. This data compilation for open-ocean, sandy shorelines of the California coast is one in a series that already includes the Gulf of Mexico and the Southeast Atlantic Coast (Morton et al., 2004; Morton et al., 2005) and will eventually cover Washington, Oregon, and parts of Hawaii and Alaska. Short- and long-term shoreline change evaluations are determined by comparing the positions of three historical shorelines digitized from maps, with a modern shoreline derived from LIDAR (light detection and ranging) topographic surveys. Historical shorelines generally represent the following time-periods: 1850s-1880s, 1920s-1930s, and late 1940s-1970s. The most recent shoreline is from data collected between 1997 and 2002. Long-term rates of change are calculated by linear regression using all four shorelines. Short-term rates of change are end-point rate calculations using the two most recent shorelines. Please refer to our full report on shoreline change of the

  2. Buhne Point Shoreline Erosion Demonstration Project. Volume 1. Appendices A-D.

    Science.gov (United States)

    1987-08-01

    discussion, ;rojected costs are based on S.C rcr hour for latrers an’ S17 per hour for supervisors. These firures arc assumed to cover on!y waces and...in Phase Two, and simple " " economies of scale for the larger planting. The average dune grass planting labor in the Phase One project was 38 to 64...attributed to economies of scale, but may be attributed to greater crew efficiency. Other planting-related activities such as orientation, tool and

  3. Fast shoreline erosion induced by ship wakes in a coastal lagoon: Field evidence and remote sensing analysis.

    Directory of Open Access Journals (Sweden)

    Luca Zaggia

    Full Text Available An investigation based on in-situ surveys combined with remote sensing and GIS analysis revealed fast shoreline retreat on the side of a major waterway, the Malamocco Marghera Channel, in the Lagoon of Venice, Italy. Monthly and long-term regression rates caused by ship wakes in a reclaimed industrial area were considered. The short-term analysis, based on field surveys carried out between April 2014 and January 2015, revealed that the speed of shoreline regression was insignificantly dependent on the distance from the navigation channel, but was not constant through time. Periods of high water levels due to tidal forcing or storm surges, more common in the winter season, are characterized by faster regression rates. The retreat is a discontinuous process in time and space depending on the morpho-stratigraphy and the vegetation cover of the artificial deposits. A GIS analysis performed with the available imagery shows an average retreat of 3-4 m/yr in the period between 1974 and 2015. Digitization of historical maps and bathymetric surveys made in April 2015 enabled the construction of two digital terrain models for both past and present situations. The two models have been used to calculate the total volume of sediment lost during the period 1968-2015 (1.19×106 m3. The results show that in the presence of heavy ship traffic, ship-channel interactions can dominate the morphodynamics of a waterway and its margins. The analysis enables a better understanding of how shallow-water systems react to the human activities in the post-industrial period. An adequate evaluation of the temporal and spatial variation of shoreline position is also crucial for the development of future scenarios and for the sustainable management port traffic worldwide.

  4. Fast shoreline erosion induced by ship wakes in a coastal lagoon: Field evidence and remote sensing analysis.

    Science.gov (United States)

    Zaggia, Luca; Lorenzetti, Giuliano; Manfé, Giorgia; Scarpa, Gian Marco; Molinaroli, Emanuela; Parnell, Kevin Ellis; Rapaglia, John Paul; Gionta, Maria; Soomere, Tarmo

    2017-01-01

    An investigation based on in-situ surveys combined with remote sensing and GIS analysis revealed fast shoreline retreat on the side of a major waterway, the Malamocco Marghera Channel, in the Lagoon of Venice, Italy. Monthly and long-term regression rates caused by ship wakes in a reclaimed industrial area were considered. The short-term analysis, based on field surveys carried out between April 2014 and January 2015, revealed that the speed of shoreline regression was insignificantly dependent on the distance from the navigation channel, but was not constant through time. Periods of high water levels due to tidal forcing or storm surges, more common in the winter season, are characterized by faster regression rates. The retreat is a discontinuous process in time and space depending on the morpho-stratigraphy and the vegetation cover of the artificial deposits. A GIS analysis performed with the available imagery shows an average retreat of 3-4 m/yr in the period between 1974 and 2015. Digitization of historical maps and bathymetric surveys made in April 2015 enabled the construction of two digital terrain models for both past and present situations. The two models have been used to calculate the total volume of sediment lost during the period 1968-2015 (1.19×106 m3). The results show that in the presence of heavy ship traffic, ship-channel interactions can dominate the morphodynamics of a waterway and its margins. The analysis enables a better understanding of how shallow-water systems react to the human activities in the post-industrial period. An adequate evaluation of the temporal and spatial variation of shoreline position is also crucial for the development of future scenarios and for the sustainable management port traffic worldwide.

  5. The National Assessment of Shoreline Change: A GIS Compilation of Vector Shorelines and Associated Shoreline Change Data for the U.S. Gulf of Mexico

    Science.gov (United States)

    Miller, Tara L.; Morton, Robert A.; Sallenger, Asbury H.; Moore, Laura J.

    2004-01-01

    Introduction The Coastal and Marine Geology Program of the U.S. Geological Survey has generated a comprehensive database of digital vector shorelines and shoreline change rates for the U.S. Gulf of Mexico. These data, which are presented herein, were compiled as part of the U.S. Geological Survey's National Assessment of Shoreline Change Project. Beach erosion is a chronic problem along most open-ocean shores of the United States. As coastal populations continue to grow and community infrastructures are threatened by erosion, there is increased demand for accurate information including rates and trends of shoreline migration. There is also a critical need for shoreline change data that is consistent from one coastal region to another. One purpose of this work is to develop standard repeatable methods for mapping and analyzing shoreline movement so that periodic updates regarding coastal erosion and land loss can be made nationally that are systematic and internally consistent. This data compilation for open-ocean, sandy shorelines of the Gulf of Mexico is the first in a series that will eventually include the Atlantic Coast, Pacific Coast, and parts of Hawaii and Alaska. Short- and long-term shoreline change evaluations are based on merging three historical shorelines with a modern shoreline derived from lidar (light detection and ranging) topographic surveys. Historical shorelines generally represent the following time periods: 1800s, 1920s-1930s, and 1970s. The most recent shoreline is derived from data collected over the period of 1998-2002. Long-term rates of change are calculated by linear regression using all four shorelines. Short-term rates of change are simple end-point rate calculations using the two most recent shorelines. Please refer to our full report on shoreline change in the Gulf of Mexico, National Assessment of Shoreline Change: Part 1, Historical Shoreline Changes and Associated Coastal Land Loss Along the U.S. Gulf of Mexico (USGS Open File

  6. Instantaneous Shoreline Extraction Utilizing Integrated Spectrum and Shadow Analysis From LiDAR Data and High-resolution Satellite Imagery

    Science.gov (United States)

    Lee, I.-Chieh

    manually connected, for its length was less than 3% of the total shoreline length in our dataset. Secondly, the parameters for satellite image classification needed to be manually determined. The need for manpower was significantly less compared to the ground surveying or aerial photogrammetry. The first phase of shoreline extraction was to utilize Normalized Difference Vegetation Index (NDVI), Mean-Shift segmentation on the coordinate (X, Y, Z), and attributes (multispectral bands from satellite images) of the LiDAR points to classify each LiDAR point into land or water surface. Boundary of the land points were then traced to create the shoreline. The second phase of shoreline extraction solely from satellite images utilized spectrum, NDVI, and shadow analysis to classify the satellite images into classes. These classes were then refined by mean-shift segmentation on the panchromatic band. By tracing the boundary of the water surface, the shoreline can be created. Since these two shorelines may represent different shoreline instances in time, evaluating the changes of shoreline was the first to be done. Then an independent scenario analysis and a procedure are performed for the shoreline of each of the three conditions: in the process of erosion, in the process of accession, and remaining the same. With these three conditions, we could analysis the actual terrain type and correct the classification errors to obtain a more accurate shoreline. Meanwhile, methods of evaluating the quality of shorelines had also been discussed. The experiment showed that there were three indicators could best represent the quality of the shoreline. These indicators were: (1) shoreline accuracy, (2) land area difference between extracted shoreline and ground truth shoreline, and (3) bias factor from shoreline quality metrics.

  7. A tectonically uplifted marine shoreline deposit, Knights Point, Westland, New Zealand

    International Nuclear Information System (INIS)

    Cooper, A.F.; Kostro, F.

    2006-01-01

    An 11 m thick subhorizontal beach deposit rests on steeply dipping Cretaceous bedrock. Sediments, ranging from a basal boulder bed to upper sands, are poorly sorted and negatively skewed, indicating pronounced winnowing of fine material. Impact features on quartz grain surfaces attest to high-energy turbulent environments, and are similar to those found on clasts from modern nearby beaches. The Haast River was source to some of the sand and gravel. Heavy minerals from the Dun Mountain Ophiolite Belt were transported 85 km by fluvial/glacial and longshore drift processes, necessitating caution when using apparent lateral separation of source material for estimating strike-slip displacement rates on the Alpine Fault. An optical luminescence age estimate of 123 ± 7 ka for Knights Point beach sands dates to the last interglacial (MIS 5e). A shore-platform altitude of 113 m a.s.l. requires tectonic uplift of the Australian plate of 0.86 mm/yr, an order of magnitude less than the nearby Pacific plate. (author). 66 refs., 6 figs., 3 tabs

  8. The Influence of Shoreline Curvature on Rates of Shoreline Change on Sandy Coasts

    Science.gov (United States)

    Murray, A. B.; Lauzon, R.; Cheng, S.; Liu, J.; Lazarus, E.

    2017-12-01

    The sandy, low-lying barrier islands which characterize much of the US East and Gulf coasts are popular spots to live and vacation, and are often heavily developed. However, sandy shorelines and barriers are also naturally mobile landforms, which are vulnerable to sea level rise and storms and can experience high rates of shoreline change. Many previous studies have attempted to understand and quantify the factors that contribute to those rates of shoreline change, such as grain size, underlying geology, sea level rise, and anthropogenic modification. Shoreline curvature has not been considered in such analyses, but previous research has demonstrated that subtle coastline curvature (and therefore alongshore variation in relative offshore wave angle) can result in gradients in net alongshore transport that cause significant shoreline erosion or accretion. Here we present the results of a spatially extensive analysis of the correlation between shoreline curvature and shoreline change rates for the sandy shorelines of the US East and Gulf coasts. We find that, for wave-dominated sandy coasts where nourishment and shoreline stabilization do not dominate the shoreline change signal (such as parts of Texas, North Carolina, and Florida), there is a significant negative correlation between shoreline curvature and shoreline change rates over 1 - 5 km and decadal to centurial space and time scales. This correlation indicates that a portion of the coastal erosion (and accretion) observed in these areas can be explained by the smoothing of subtle coastline curvature by gradients in alongshore transport, and suggests that shoreline curvature should be included in future attempts to understand historical and future rates of shoreline change. Shoreline stabilization, especially through beach nourishment, complicates the relationship between curvature and shoreline change. Beach construction during nourishment creates a seaward convex curvature in the part of the shoreline moves

  9. Massachusetts Shoreline Change Mapping and Analysis Project, 2013 Update

    Science.gov (United States)

    Thieler, E. Robert; Smith, Theresa L.; Knisel, Julia M.; Sampson, Daniel W.

    2013-01-01

    Information on rates and trends of shoreline change can be used to improve the understanding of the underlying causes and potential effects of coastal erosion on coastal populations and infrastructure and can support informed coastal management decisions. In this report, we summarize the changes in the historical positions of the shoreline of the Massachusetts coast for the 165 years from 1844 through 2009. The study area includes the Massachusetts coastal region from Salisbury to Westport, including Cape Cod, as well as Martha’s Vineyard, Nantucket, and the Elizabeth Islands. New statewide shoreline data were developed for approximately 1,804 kilometers (1,121 miles) of shoreline using color aerial orthoimagery from 2008 and 2009 and topographic lidar from 2007. The shoreline data were integrated with existing historical shoreline data from the U.S. Geological Survey (USGS) and Massachusetts Office of Coastal Zone Management (CZM) to compute long- (about 150 years) and short-term (about 30 years) rates of shoreline change. A linear regression method was used to calculate long- and short-term rates of shoreline change at 26,510 transects along the Massachusetts coast. In locations where shoreline data were insufficient to use the linear regression method, short-term rates were calculated using an end-point method. Long-term rates of shoreline change are calculated with (LTw) and without (LTwo) shorelines from the 1970s and 1994 to examine the effect of removing these data on measured rates of change. Regionally averaged rates are used to assess the general characteristics of the two-rate computations, and we find that (1) the rates of change for both LTw and LTwo are essentially the same; (2) including more data slightly reduces the uncertainty of the rate, which is expected as the number of shorelines increases; and (3) the data for the shorelines from the 1970s and 1994 are not outliers with respect to the long-term trend. These findings are true for regional

  10. High and low frequency erosive and constructive cycles in estuarine beaches: an example from Garcez Point, Bahia/Brazil

    Directory of Open Access Journals (Sweden)

    ABÍLIO C.S.P. BITTENCOURT

    2001-12-01

    Full Text Available Monitoring of the morphodynamic variations of the beaches associated with an estuary contiguous with Garcez Point, Bahia, Brazil, and the superposition of aerial photographs from the region, show the presence of distinctive erosive and constructive cycles of low and high frequencies. Between 1959 and 1989, one event of shoreline erosion and progradation was recognized on the oceanic beaches just outside the estuary. Inside the estuary, an erosion phase at the southern margin coincides with a constructive phase at the other side, and vice-versa. On the southern estuarine beach, low-frequency cycles of erosion and progradation are also perceived, but with the inverse trend when compared to the contiguous oceanic beach. During the beach monitoring period (February/1991 to July/1992, the oceanic beach showed retreat rates varying from 23.7m/year, at the channel entrance, to 1.0m/year, three kilometers away from it. During the same period, the estuarine beach advanced at a rate of 60.3m/year. The long-term dynamics of the shoreline position in both sides of the estuarine entrance appears to be related to the position of the channel in the ebb-tidal delta.O monitoramento das variações morfodinâmicas das praias associadas com um estuário contíguo à Ponta dos Garvez, Bahia, Brasil, e a superposição de fotos aéreas da região, mostram a presença de distintos ciclos erosivos e construtivos, de baixa e alta freqüências. Entre 1959 e 1989, um evento de erosão e progradação da linha de costa foi reconhecido nas praias oceânicas fora do estuário. Dentro do estuário, uma fase erosiva na margem sul, coincide com uma fase construtiva no outro lado, e vice-versa. Na margem estuarina sul, são também percebidos ciclos de erosão e progradação de baixa freqüência, porém com um sentido inverso quando comparados aos da praia oceânica contígua. Durante o período de monitoramento das praias (fevereiro de 1991 a julho de 1992, a praia oce

  11. Massachusetts shoreline change project: a GIS compilation of vector shorelines and associated shoreline change data for the 2013 update

    Science.gov (United States)

    Smith, Theresa L.; Himmelstoss, Emily A.; Thieler, E. Robert

    2013-01-01

    Identifying the rates and trends associated with the position of the shoreline through time presents vital information on potential impacts these changes may have on coastal populations and infrastructure, and supports informed coastal management decisions. This report publishes the historical shoreline data used to assess the scale and timing of erosion and accretion along the Massachusetts coast from New Hampshire to Rhode Island including all of Cape Cod, Martha’s Vineyard, Nantucket and the Elizabeth Islands. This data is an update to the Massachusetts Office of Coastal Zone Management Shoreline Change Project. Shoreline positions from the past 164 years (1845 to 2009) were used to compute the shoreline change rates. These data include a combined length of 1,804 kilometers of new shoreline data derived from color orthophoto imagery collected in 2008 and 2009, and topographic lidar collected in 2007. These new shorelines have been added to previously published historic shoreline data from the Massachusetts Office of Coastal Zone Management and the U.S. Geological Survey. A detailed report containing a discussion of the shoreline change data presented here and a summary of the resulting rates is available and cited at the end of the Introduction section of this report.

  12. Sand spit and shoreline dynamics near Terekhol river mouth, Goa, India

    Digital Repository Service at National Institute of Oceanography (India)

    Rajasekaran, C.; Jayakumar, S.; Gowthaman, R.; Jishad, M.; Yadhunath, E.M.; Pednekar, P.S.

    Evolution of shoreline and sand spit at the mouth of the Terekhol River, near Keri beach, located in the Indian state of Goa has been investigated From the analysis of the data collected, the shoreline oscillation (accretion & erosion) is seasonal...

  13. Shoreline change due to coastal structures of power plants

    International Nuclear Information System (INIS)

    Kang, K. S.; Lee, T. S.; Kim, Y. I.

    2001-01-01

    Characteristics of shoreline change at the coastal area near power plant were analyzed. For a nuclear power plant located in the east coast of Korean peninsula, remote-sensing data, i.e.airborne images and satellite images are acquired and shoreline data were extracted. Recession and davance of shoreline due to coastal structures of powder plant and land reclamation was showed. 1-line numerical shoreline change model was established for simulating the response of shoreline to construction of coastal structures. The model uses curvilinear coordinates that follow the shoreline and is capable of handling the formation of tombolos as well as the growth of salients in the vicinity of coastal structures. The model predicted significant erosion of beach in case breakwaters were extended. Offshore breakwaters were suggested as a countermeasure to shoreline change

  14. Semi-automated procedures for shoreline extraction using single RADARSAT-1 SAR image

    Science.gov (United States)

    Al Fugura, A.'kif; Billa, Lawal; Pradhan, Biswajeet

    2011-12-01

    Coastline identification is important for surveying and mapping reasons. Coastline serves as the basic point of reference and is used on nautical charts for navigation purposes. Its delineation has become crucial and more important in the wake of the many recent earthquakes and tsunamis resulting in complete change and redraw of some shorelines. In a tropical country like Malaysia, presence of cloud cover hinders the application of optical remote sensing data. In this study a semi-automated technique and procedures are presented for shoreline delineation from RADARSAT-1 image. A scene of RADARSAT-1 satellite image was processed using enhanced filtering technique to identify and extract the shoreline coast of Kuala Terengganu, Malaysia. RADSARSAT image has many advantages over the optical data because of its ability to penetrate cloud cover and its night sensing capabilities. At first, speckles were removed from the image by using Lee sigma filter which was used to reduce random noise and to enhance the image and discriminate the boundary between land and water. The results showed an accurate and improved extraction and delineation of the entire coastline of Kuala Terrenganu. The study demonstrated the reliability of the image averaging filter in reducing random noise over the sea surface especially near the shoreline. It enhanced land-water boundary differentiation, enabling better delineation of the shoreline. Overall, the developed techniques showed the potential of radar imagery for accurate shoreline mapping and will be useful for monitoring shoreline changes during high and low tides as well as shoreline erosion in a tropical country like Malaysia.

  15. High and Increasing Shoreline Erosion Rates of Thermokarst Lakes Set in Ice-Rich Permafrost Terrain of the Arctic Coastal Plain of Alaska

    Science.gov (United States)

    Bondurant, A. C.; Arp, C. D.; Jones, B. M.; Shur, Y.; Daanen, R. P.

    2017-12-01

    Thermokarst lakes are a dominant landform shaping landscapes and impacting permafrost on the Arctic Coastal Plain (ACP) of northern Alaska, a region of continuous permafrost. Here lakes cover greater than 20% of the landscape and drained lake basins cover an additional 50 to 60% of the landscape. The formation, expansion, and drainage of thaw lakes has been described by some researchers as part of a natural cycle that has reworked the ACP landscape during the Holocene. Yet the factors and processes controlling contemporary thermokarst lake expansion remain poorly described. This study focuses on the factors controlling expansion rates of thermokarst lakes in three ACP regions that vary in landscape history, ground-ice content, and lake morphology (i.e. size and depth), as well as evaluating changes through time. Through the use of historical aerial imagery, satellite imagery, and field observations, this study identifies the controlling factors at multiple spatial and temporal scales to better understand the processes relating to thermokarst lake expansion. Studies of 35 lakes across the ACP shows regional differences in expansion rate related to permafrost ice content ranging from an average expansion rate of 0.62 m/yr where ice content is highest ( 86%) to 0.16 m/yr where ice content is lowest (45%-71%). A subset of these lakes analyzed over multiple time periods show increasing rates of erosion, with average rates being 37% higher over the period 1979-2002 (0.73 m/yr) compared to 1948-1979 (0.53 m/yr). These increased rates of erosion have important implications for the regional hydrologic cycle and localized permafrost degradation. Predicting how thermokarst lakes will behave locally and on a landscape scale is increasingly important for managing habitat and water resources and informing models of land-climate interactions in the Arctic.

  16. Automatic Detection of Decadal Shoreline Change on Northern Coastal of Gresik, East Java - Indonesia

    Science.gov (United States)

    Fuad, M. A. Z.; A, M. Fais D.

    2017-12-01

    The Coastal zone is a dynamic region that has high environmental and economic values. This present research focuses on the analyzing the rate of shoreline change using multi-temporal Landsat Imagery and Digital Shoreline Analysis Systems (DSAS) along the northern part of Gresik coastal area, East Java Indonesia. Five village were selected for analysis; Campurejo, Dalegan, Prupuh, Ngemboh, and Banyuurip. Erosion and Accretion were observed and detected on Multi-temporal satellite Images along the area of interest from 1972 - 2016. Landsat Images were radiometrically and geometrically corrected before using for analysis. Coastline delineation for each Landsat image was performed by MNDWI method before digitized for quantitative shoreline change analysis. DSAS was performed for quantitative analysis of Net Shoreline Movement (NSM) and End Point Rate (EPR). The results indicate that in the study area accretion and abrasion was occurred, but overall abrasion was dominated than accretion. The remarkable shoreline changes were observed in the entire region. The highest abrasion area was occurred in Ngemboh village. From 1972 to 2016, coastline was retreat 242.56 meter to the land and the rate of movement was -5.54m/yr. In contrast, Campurejo area was relatively stable due to the introduction of manmade structure, i.e. Jetty and Groin. The Shoreline movement and the rate of movement in this area were -6.11m and -0.12 m/yr respectively. The research represents an important step in understanding the dynamics of coastal area in this area. By identification and analysis of coastline evolution, the stake holder could perform a scenario for reducing the risk of coastal erosion and minimize the social and economic lost.

  17. Application of remote sensing and GIS for detection of long-term mangrove shoreline changes in Ca Mau, Vietnam

    Science.gov (United States)

    Tran Thi, V.; Phan Nguyen, H.; Tien Thi Xuan, A.; Dahdouh-Guebas, F.; Koedam, N.

    2013-12-01

    Ca Mau at the southern tip of Vietnam supports a large area of mangroves and has a high value for biodiversity and scenic beauty. This area is affected by erosion along the East Sea and accretion along the Gulf of Thailand, leading to the loss of huge stretches of mangroves along the East Sea and, in some cases, loss of ecosystems services provided by mangroves. In this study, we used remotely sensed aerial (1953), Landsat (1979, 1988, and 2000) and SPOT (1992, 1995, 2004, 2008 and 2009, and 2011) images and the Digital Shoreline Analysis System (DSAS) to quantify the rate of mangrove shoreline change for a 58 yr period. There were 1129 transects sampled at 100 m intervals along the mangrove shoreline and two statistical methods, namely End Point Rate (EPR) and Linear Regression Rate (LRR), were used to calculate the rate of change of mangrove shorelines and distance from 1953 to 2011. The study confirms erosion and accretion respectively are significant at the Eastern and Western Sea sides of the Ca Mau tip. The East Sea side had a mean erosion LRR of 33.24 m yr-1. For the accretion trend at the Gulf of Thailand side averaged at rate of 40.65 m yr-1. The results are important in predicting changes of coastal ecosystem boundaries and enable advanced planning for specific sections of coastline, to minimize or neutralize losses, to inform provincial rehabilitation efforts and reduce threats to coastal development and human safety.

  18. Application of remote sensing and GIS for detection of long-term mangrove shoreline changes in Mui Ca Mau, Vietnam

    Science.gov (United States)

    Tran Thi, V.; Tien Thi Xuan, A.; Phan Nguyen, H.; Dahdouh-Guebas, F.; Koedam, N.

    2014-07-01

    Mui Ca Mau at the southern tip of Vietnam supports a large area of mangroves and has a high value for biodiversity and scenic beauty. This area is affected by erosion along the East Sea and accretion along the Gulf of Thailand, leading to the loss of huge stretches of mangroves along the East Sea and, in some cases, loss of environmental and ecosystem services provided by mangroves. In this study, we used remotely sensed aerial (1953), Landsat (1979, 1988 and 2000) and SPOT (1992, 1995, 2004, 2008, 2009 and 2011) images and the Digital Shoreline Analysis System (DSAS) to quantify the rate of mangrove shoreline change for a 58 yr period. There were 1129 transects sampled at 100 m intervals along the mangrove shoreline and two statistical methods, namely end point rate (EPR) and linear regression rate (LRR), were used to calculate the rate of change of mangrove shorelines and distance from 1953 to 2011. The study confirms that erosion and accretion, respectively, are significant at the East Sea and Gulf of Thailand sides of Mui Ca Mau. The East Sea side had a mean erosion LRR of 33.24 m yr-1. The accretion trend at the Gulf of Thailand side had an average rate of 40.65 m yr-1. The results are important in predicting changes of coastal ecosystem boundaries and enable advanced planning for specific sections of coastline, to minimize or neutralize losses, to inform provincial rehabilitation efforts and reduce threats to coastal development and human safety.

  19. Living Shorelines: Coastal Resilience with a Blue Carbon Benefit.

    Science.gov (United States)

    Davis, Jenny L; Currin, Carolyn A; O'Brien, Colleen; Raffenburg, Craig; Davis, Amanda

    2015-01-01

    Living shorelines are a type of estuarine shoreline erosion control that incorporates native vegetation and preserves native habitats. Because they provide the ecosystem services associated with natural coastal wetlands while also increasing shoreline resilience, living shorelines are part of the natural and hybrid infrastructure approach to coastal resiliency. Marshes created as living shorelines are typically narrow (erosion control and habitat for estuarine organisms has been documented but their capacity for carbon sequestration has not. We measured carbon sequestration rates in living shorelines and sandy transplanted Spartina alterniflora marshes in the Newport River Estuary, North Carolina. The marshes sampled here range in age from 12 to 38 years and represent a continuum of soil development. Carbon sequestration rates ranged from 58 to 283 g C m-2 yr-1 and decreased with marsh age. The pattern of lower sequestration rates in older marshes is hypothesized to be the result of a relative enrichment of labile organic matter in younger sites and illustrates the importance of choosing mature marshes for determination of long-term carbon sequestration potential. The data presented here are within the range of published carbon sequestration rates for S. alterniflora marshes and suggest that wide-scale use of the living shoreline approach to shoreline management may come with a substantial carbon benefit.

  20. UAV survey of a Thyrrenian micro-tidal beach for shoreline evolution update

    Science.gov (United States)

    Benassai, Guido; Pugliano, Giovanni; Di Paola, Gianluigi; Mucerino, Luigi

    2015-04-01

    Coastal geomorphology requires increasingly accurate topographic information of the beach systems to perform reliable simulation of coastal erosion, flooding phenomena, and coastal vulnerability assessment. Among the range of terrestrial and aerial methods available to produce such a dataset, this study tests the utility of low-altitude aerial imageries collected by Unmanned Aerial Vehicle (UAV). The image-based approach was selected whilst searching for a rapid, inexpensive, and highly automated method, able to produce 3D information from unstructured aerial images. In particular, it was used to generate a high-resolution Digital Surface Model (DSM) of the micro-tidal beach of Serapo - Gaeta (LT) in order to obtain recent update of erosional/accretional trends already established through historical shoreline evolution. A UAV exacopter (fig. 1a) was used, weighing about 2500g, carrying on board a GPS and multi-directional accelerometer to ensure a recovery of the beach features (fig. 1b) through a sweep with constant speed, direction and altitude. The on-board camera was a Canon 16M pixels, with fixed and constant focal takeoff in order to perform the 3D cloud points. Six adjacent strips were performed for the survey realization with pictures taken every second in sequence, in order to allow a minimum 80% overlap. A direct on site survey was also carried out with a DGPS for the placement of GPS markers and the geo-referencing of the final product (fig. 1c). Each flight with constant speed, direction and altitude recorded from 500 to 800 shots. The height of flight was dictated by the scale of the final report, an altitude of 100m was used for the beach survey. The topographic survey on the ground for the placement of the control points was performed with the Trimble R6 DGPS in RTK mode. The long-term shoreline evolution was obtained by a sixty-year historical shoreline time-series, through the analysis of a number of aerial photographs dating from 1954 to 2013. The

  1. National assessment of shoreline change: historical shoreline change along the Pacific Northwest coast

    Science.gov (United States)

    Ruggerio, Peter; Kratzmann, Meredith G.; Himmelstoss, Emily A.; Reid, David; Allan, Jonathan; Kaminsky, George

    2013-01-01

    Beach erosion is a chronic problem along most open ocean shores of the United States. As coastal populations continue to increase and infrastructure is threatened by erosion, there is increased demand for accurate information regarding past and present trends and rates of shoreline movement. There is also a need for a comprehensive analysis of shoreline movement that is consistent from one coastal region to another. To meet these national needs, the U.S. Geological Survey (USGS) is conducting an analysis of historical shoreline changes along the open-ocean sandy shores of the conterminous United States and parts of Hawaii, Alaska, and the Great Lakes. One purpose of this work is to develop standard, repeatable methods for mapping and analyzing shoreline movement so that periodic, systematic, and internally consistent updates regarding coastal erosion and land loss can be made nationally. In the case of the analysis of shoreline change in the Pacific Northwest (PNW), the shoreline is the interpreted boundary between the ocean water surface and the sandy beach. This report on the PNW coasts of Oregon and Washington is the seventh in a series of regionally focused reports on historical shoreline change. Previous investigations include analyses and descriptive reports of the U.S. Gulf of Mexico (Morton and others, 2004), the southeastern Atlantic (Morton and Miller, 2005), the sandy shorelines (Hapke and others, 2006) and coastal cliffs (Hapke and Reid, 2007) of California, the New England and mid-Atlantic coasts (Hapke and others, 2011), and parts of the Hawaii coast (Fletcher and others, 2012). Like the earlier reports in this series, this report summarizes the methods of analysis, interprets the results of the analysis, provides explanations regarding long- and short-term trends and rates of shoreline change, and describes how different coastal communities are responding to coastal erosion. This report differs from the early USGS reports in the series in that those

  2. Living Shorelines: Assessing Geomorphic Change and Water Quality in an Urban Waterway

    Science.gov (United States)

    Huggins, A.; Schwartz, M. C.; Schmutz, P. P.

    2017-12-01

    In recent years, alternative strategies for shoreline armoring have become increasingly popular with coastal property owners. In Northwest Florida, local agencies implemented plans to attenuate wave action and reduce landward shore recession in an urban bayou by installing living shorelines. Living shorelines are constructed in the inter-tidal zones and incorporate both hard and soft structured stabilization. Generally, the hard component is fossilized oyster shells and the soft component is planted intertidal vegetation, such as Spartina alterniflora (Smooth cordgrass) and Juncus roemererianus (Black needlerush). Living shorelines were intended to comprise both ecological and societal implications by significantly slowing erosion processes for property owners, by utilizing oyster beds to improve water quality, and by fostering new ecological habitats in the marsh grasses. The issue presented with living shoreline management is long-term studies have not been carried out on these engineered systems. For this study, geospatial technology was utilized to create 3D images of terrain by interpolation of data points using a TotalStation to compute geomorphic change. Additionally, water samples were analyzed using traditional wet chemistry laboratory methods to determine total oxidized nitrogen (TON), ammonium, and orthophosphate content in water. Over a short three-month preliminary study, sediment accretion was observed primarily within the vegetation with the bulk of the erosion occurring around the oyster beds. TON was detected at levels between 10 µM and 30 µM, ammonium up to 5 µM, and orthophosphate was only detected in very low levels, consistently quality data will be used to establish baseline data for future research to determine volumetric geomorphic change,and to set a standard for water quality trends, surrounding oyster beds and vegetation in response to climatic events.

  3. National assessment of shoreline change: Historical shoreline change in the Hawaiian Islands

    Science.gov (United States)

    Fletcher, Charles H.; Romine, Bradley M.; Genz, Ayesha S.; Barbee, Matthew M.; Dyer, Matthew; Anderson, Tiffany R.; Lim, S. Chyn; Vitousek, Sean; Bochicchio, Christopher; Richmond, Bruce M.

    2012-01-01

    Sandy beaches of the United States are some of the most popular tourist and recreational destinations. Coastal property constitutes some of the most valuable real estate in the country. Beaches are an ephemeral environment between water and land with unique and fragile natural ecosystems that have evolved in equilibrium with the ever-changing winds, waves, and water levels. Beachfront lands are the site of intense residential and commercial development even though they are highly vulnerable to several natural hazards, including marine inundation, flooding and drainage problems, effects of storms, sea-level rise, and coastal erosion. Because the U.S. population continues to shift toward the coast where valuable coastal property is vulnerable to erosion, the U.S. Geological Survey (USGS) is conducting a national assessment of coastal change. One aspect of this effort, the National Assessment of Shoreline Change, uses shoreline position as a proxy for coastal change because shoreline position is one of the most commonly monitored indicators of environmental change (for example, Fletcher, 1992; Dolan and others, 1991; Douglas and others, 1998; Galgano and others, 1998). Additionally, the National Research Council (1990) recommended the use of historical shoreline analysis in the absence of a widely accepted model of shoreline change.

  4. Analysis of Decadal-Scale Shoreline Change along the Hamlet of Paulatuk (Canadian Arctic), using Landsat Satellite Imagery and GIS techniques from 1984 to 2014.

    Science.gov (United States)

    Sankar, R. D.; Murray, M. S.; Wells, P.

    2016-12-01

    Increased accuracy in estimating coastal change along localized segments of the Canadian Arctic coast is essential, in order to identify plausible adaptation initiatives to deal with the effects of climate change. This paper quantifies rates of shoreline movement along an 11 km segment of the Hamlet of Paulatuk (Northwest Territories, Canada), using an innovative modelling technique - Analyzing Moving Boundaries Using R (AMBUR). Approximately two dozen shorelines, obtained from high-resolution Landsat satellite imagery were analyzed. Shorelines were extracted using the band ratio method and compiled in ArcMapTM to determine decadal trends of coastal change. The unique geometry of Paulatuk facilitated an independent analysis of the western and eastern sections of the study area. Long-term (1984-2014) and short-term (1984-2003) erosion and accretion rates were calculated using the Linear Regression and End Point Rate methods respectively. Results reveal an elevated rate of erosion for the western section of the hamlet over the long-term (-1.1 m/yr), compared to the eastern portion (-0.92 m/yr). The study indicates a significant alongshore increase in the rates of erosion on both portions of the study area, over the short-term period 1984 to 2003. Mean annual erosion rates increased over the short-term along the western segment (-1.4 m/yr), while the eastern shoreline retreated at a rate of -1.3 m/yr over the same period. The analysis indicates that an amalgamation of factors may be responsible for the patterns of land loss experienced along Paulatuk. These include increased sea-surface temperature coupled with dwindling arctic ice and elevated storm hydrodynamics. The analysis further reveals that the coastline along the eastern portion of the hamlet, where the majority of the population reside, is vulnerable to a high rate of shoreline erosion.

  5. Living Shorelines: Coastal Resilience with a Blue Carbon Benefit.

    Directory of Open Access Journals (Sweden)

    Jenny L Davis

    Full Text Available Living shorelines are a type of estuarine shoreline erosion control that incorporates native vegetation and preserves native habitats. Because they provide the ecosystem services associated with natural coastal wetlands while also increasing shoreline resilience, living shorelines are part of the natural and hybrid infrastructure approach to coastal resiliency. Marshes created as living shorelines are typically narrow (< 30 m fringing marshes with sandy substrates that are well flushed by tides. These characteristics distinguish living shorelines from the larger meadow marshes in which most of the current knowledge about created marshes was developed. The value of living shorelines for providing both erosion control and habitat for estuarine organisms has been documented but their capacity for carbon sequestration has not. We measured carbon sequestration rates in living shorelines and sandy transplanted Spartina alterniflora marshes in the Newport River Estuary, North Carolina. The marshes sampled here range in age from 12 to 38 years and represent a continuum of soil development. Carbon sequestration rates ranged from 58 to 283 g C m-2 yr-1 and decreased with marsh age. The pattern of lower sequestration rates in older marshes is hypothesized to be the result of a relative enrichment of labile organic matter in younger sites and illustrates the importance of choosing mature marshes for determination of long-term carbon sequestration potential. The data presented here are within the range of published carbon sequestration rates for S. alterniflora marshes and suggest that wide-scale use of the living shoreline approach to shoreline management may come with a substantial carbon benefit.

  6. Reservoir shorelines : a methodology for evaluating operational impacts

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, M.; Braund-Read, J.; Musgrave, B. [BC Hydro, Burnaby, BC (Canada)

    2009-07-01

    BC Hydro has been operating hydroelectric facilities for over a century in British Columbia. The integrity and stability of the shorelines and slopes bordering hydroelectric reservoirs is affected by changing water levels in the reservoir, natural processes of flooding, wind and wave action and modification of groundwater levels. Establishing setbacks landward of the shoreline are needed in order to protect useable shoreline property that may be at risk of flooding, erosion or instability due to reservoir operations. Many of the reservoirs in British Columbia are situated in steep, glaciated valleys with diverse geological, geomorphological and climatic conditions and a variety of eroding shorelines. As such, geotechnical studies are needed to determine the operational impacts on reservoir shorelines. Since the 1960s BC Hydro has been developing a methodology for evaluating reservoir impacts and determining the land around the reservoir perimeter that should remain as a right of way for operations while safeguarding waterfront development. The methodology was modified in the 1990s to include geomorphological and geological processes. However, uncertainties in the methodology still exist due to limited understanding of key issues such as rates of erosion and shoreline regression, immaturity of present day reservoir shorelines and impacts of climate change. 11 refs., 1 tab., 7 figs.

  7. Cuspate Shoreline Morphology

    National Research Council Canada - National Science Library

    McWilliams, Brandon

    2005-01-01

    Large beach cusps with wavelengths O(200m), sometimes termed mega-cusps, were measured along 18km of the Southern Monterey Bay coastline from October 2004 to April 2005 to investigate the cuspate shoreline response to rip current systems...

  8. Decoupling processes and scales of shoreline morphodynamics

    Science.gov (United States)

    Hapke, Cheryl J.; Plant, Nathaniel G.; Henderson, Rachel E.; Schwab, William C.; Nelson, Timothy R.

    2016-01-01

    Behavior of coastal systems on time scales ranging from single storm events to years and decades is controlled by both small-scale sediment transport processes and large-scale geologic, oceanographic, and morphologic processes. Improved understanding of coastal behavior at multiple time scales is required for refining models that predict potential erosion hazards and for coastal management planning and decision-making. Here we investigate the primary controls on shoreline response along a geologically-variable barrier island on time scales resolving extreme storms and decadal variations over a period of nearly one century. An empirical orthogonal function analysis is applied to a time series of shoreline positions at Fire Island, NY to identify patterns of shoreline variance along the length of the island. We establish that there are separable patterns of shoreline behavior that represent response to oceanographic forcing as well as patterns that are not explained by this forcing. The dominant shoreline behavior occurs over large length scales in the form of alternating episodes of shoreline retreat and advance, presumably in response to storms cycles. Two secondary responses include long-term response that is correlated to known geologic variations of the island and the other reflects geomorphic patterns with medium length scale. Our study also includes the response to Hurricane Sandy and a period of post-storm recovery. It was expected that the impacts from Hurricane Sandy would disrupt long-term trends and spatial patterns. We found that the response to Sandy at Fire Island is not notable or distinguishable from several other large storms of the prior decade.

  9. Monitoring shoreline environment of Paradip, east coast of India using remote sensing

    Digital Repository Service at National Institute of Oceanography (India)

    ManiMurali, R.; Shrivastava, D.; Vethamony, P.

    -raey et al. 8 used remote sensing for detecting beach erosion and ac- cretion along Damietta Port, Egypt. Narayana and Priju 9 studied the shoreline changes along the central Kerala coast using satellite images. Shoreline-change mapping was carried... and detecting long-term change in the entire coastline. Meijerink 11 and Rao 12 studied the dynamic geomor- phology of Mahanadi delta and problems of coastal dyna- mics and shoreline changes which arose after the construction of Paradip port. Rupali 13...

  10. Investigating Coastal Processes Responsible for Large-Scale Shoreline Responses to Human Shoreline Stabilization

    Science.gov (United States)

    Slott, J. M.; Murray, A. B.; Ashton, A. D.

    2006-12-01

    Human shoreline stabilization practices, such as beach nourishment (i.e. placing sand on an eroding beach), have become more prevalent as erosion threatens coastal communities. On sandy shorelines, recent experiments with a numerical model of shoreline change (Slott, et al., in press) indicate that moderate shifts in storminess patterns, one possible outcome of global warming, may accelerate the rate at which shorelines erode or accrete, by altering the angular distribution of approaching waves (the `wave climate'). Accelerated erosion would undoubtedly place greater demands on stabilization. Scientists and coastal engineers have typically only considered the site-specific consequences of shoreline stabilization; here we explore the coastal processes responsible for large-scale (10's kms) and long-term (decades) effects using a numerical model developed by Ashton, et al. (2001). In this numerical model, waves breaking at oblique angles drive a flux of sediment along the shoreline, where gradients in this flux can shape the coastline into surprisingly complex forms (e.g. cuspate-capes found on the Carolina coast). Wave "shadowing" plays a major role in shoreline evolution, whereby coastline features may block incoming waves from reaching distant parts. In this work, we include beach nourishment in the Ashton, et al. (2001) model. Using a cuspate-cape shoreline as our initial model condition, we conducted pairs of experiments and varied the wave-climate forcing across each pair, each representing different storminess scenarios. Here we report on one scenario featuring increased extra-tropical storm influence. For each experiment-pair we ran a control experiment with no shoreline stabilization and a second where a beach nourishment project stabilized a cape tip. By comparing the results of these two parallel runs, we isolate the tendency of the shoreline to migrate landward or seaward along the domain due solely to beach nourishment. Significant effects from beach

  11. Multidecadal shoreline changes of atoll islands in the Marshall Islands

    Science.gov (United States)

    Ford, M.

    2012-12-01

    Atoll islands are considered highly vulnerable to the impacts of continued sea level rise. One of the most commonly predicted outcomes of continued sea level rise is widespread and chronic shoreline erosion. Despite the widespread implications of predicted erosion, the decadal scale changes of atoll island shorelines are poorly resolved. The Marshall Islands is one of only four countries where the majority of inhabited land is comprised of reef and atoll islands. Consisting of 29 atolls and 5 mid-ocean reef islands, the Marshall Islands are considered highly vulnerable to the impacts of sea level rise. A detailed analysis of shoreline change on over 300 islands on 10 atolls was undertaken using historic aerial photos (1945-1978) and modern high resolution satellite imagery (2004-2012). Results highlight the complex and dynamic nature of atoll islands, with significant shifts in shoreline position observed over the period of analysis. Results suggest shoreline accretion is the dominant mode of change on the islands studied, often associated with a net increase in vegetated island area. However, considerable inter- and intra-atoll variability exists with regards to shoreline stability. Findings are discussed with respect to island morphodynamics and potential hazard mitigation and planning responses within atoll settings.

  12. Driftcretions: The legacy impacts of driftwood on shoreline morphology

    Science.gov (United States)

    Kramer, Natalie; Wohl, Ellen

    2015-07-01

    This research demonstrates how vegetation interacts with physical processes to govern landscape development. We quantify and describe interactions among driftwood, sedimentation, and vegetation for Great Slave Lake, which is used as proxy for shoreline dynamics and landforms before deforestation and wood removal along major waterways. We introduce driftcretion to describe large, persistent concentrations of driftwood that interact with vegetation and sedimentation to influence shoreline evolution. We report the volume and distribution of driftwood along shorelines, the morphological impacts of driftwood delivery throughout the Holocene, and rates of driftwood accretion. Driftcretions facilitate the formation of complex, diverse morphologies that increase biological productivity and organic carbon capture and buffer against erosion. Driftcretions should be common on shorelines receiving a large wood supply and with processes which store wood permanently. We encourage others to work in these depositional zones to understand the physical and biological impacts of large wood export from river basins.

  13. Numerical Modeling of Shoreline Undulations

    DEFF Research Database (Denmark)

    Kærgaard, Kasper Hauberg

    model has been developed which describes the longshore sediment transport along arbitrarily shaped shorelines. The numerical model is based on a spectral wave model, a depth integrated flow model, a wave-phase resolving sediment transport description and a one-line shoreline model. First the theoretical...... of the feature and under predicts the migration speeds of the features. On the second shoreline, the shoreline model predicts undulations lengths which are longer than the observed undulations. Lastly the thesis considers field measurements of undulations of the bottom bathymetry along an otherwise straight...... length of the shoreline undulations is determined in the linear regime using a shoreline stability analysis based on the numerical model. The analysis shows that the length of the undulations in the linear regime depends on the incoming wave conditions and on the coastal profile. For larger waves...

  14. Drivers of coastal shoreline change: case study of hon dat coast, Kien Giang, Vietnam.

    Science.gov (United States)

    Nguyen, Hai-Hoa; McAlpine, Clive; Pullar, David; Leisz, Stephen Joseph; Galina, Gramotnev

    2015-05-01

    Coastal shorelines are naturally dynamic, shifting in response to coastal geomorphological processes. Globally, land use change associated with coastal urban development and growing human population pressures is accelerating coastal shoreline change. In southern Vietnam, coastal erosion currently is posing considerable risks to shoreline land use and coastal inhabitants. The aim of this paper is to quantify historical shoreline changes along the Hon Dat coast between 1995 and 2009, and to document the relationships between coastal mangrove composition, width and density, and rates of shoreline change. The generalized linear mixed-effects models were used to quantify the major biophysical and land-use factors influencing shoreline change rates. Most significant drivers of the rates of change are cutting of mangroves, the dominant mangrove genus, changes in adjacent shoreline land use, changes of shoreline land cover, and width of fringing mangroves. We suggest that a possible and inexpensive strategy for robust mangrove shoreline defense is direct mangrove planting to promote mangrove density with the presence of breakwater structures. In the shorter term, construction of coastal barriers such as fence-structured melaleuca poles in combination with mangrove restoration schemes could help retain coastal sediments and increase the elevation of the accretion zone, thereby helping to stabilize eroding fringe shorelines. It also is recommended that implementation of a system of payments for mangrove ecosystem services and the stronger regulation of mangrove cutting and unsustainable land-use change to strengthen the effectiveness of mangrove conservation programs and coastal land-use management.

  15. Drivers of Coastal Shoreline Change: Case Study of Hon Dat Coast, Kien Giang, Vietnam

    Science.gov (United States)

    Nguyen, Hai-Hoa; McAlpine, Clive; Pullar, David; Leisz, Stephen Joseph; Galina, Gramotnev

    2015-05-01

    Coastal shorelines are naturally dynamic, shifting in response to coastal geomorphological processes. Globally, land use change associated with coastal urban development and growing human population pressures is accelerating coastal shoreline change. In southern Vietnam, coastal erosion currently is posing considerable risks to shoreline land use and coastal inhabitants. The aim of this paper is to quantify historical shoreline changes along the Hon Dat coast between 1995 and 2009, and to document the relationships between coastal mangrove composition, width and density, and rates of shoreline change. The generalized linear mixed-effects models were used to quantify the major biophysical and land-use factors influencing shoreline change rates. Most significant drivers of the rates of change are cutting of mangroves, the dominant mangrove genus, changes in adjacent shoreline land use, changes of shoreline land cover, and width of fringing mangroves. We suggest that a possible and inexpensive strategy for robust mangrove shoreline defense is direct mangrove planting to promote mangrove density with the presence of breakwater structures. In the shorter term, construction of coastal barriers such as fence-structured melaleuca poles in combination with mangrove restoration schemes could help retain coastal sediments and increase the elevation of the accretion zone, thereby helping to stabilize eroding fringe shorelines. It also is recommended that implementation of a system of payments for mangrove ecosystem services and the stronger regulation of mangrove cutting and unsustainable land-use change to strengthen the effectiveness of mangrove conservation programs and coastal land-use management.

  16. Overview of shoreline cleaning agents

    International Nuclear Information System (INIS)

    Clayton, J.

    1992-01-01

    Chemical cleaning agents may be used to promote release of stranded oil from shorelines for reasons including biological sensitivity of indigenous fauna and flora to the oil, amenity considerations of the shoreline, or concern about refloating of the oil and subsequent stranding on adjacent shorelines. While use of chemical cleaning agents may be appropriate under proper toxic responses in circumstances, certain limitations should be recognized. The potential for toxic responses in indigenous fauna and flora to the cleaning agents must be considered. Enhanced penetration of oil into permeable shorelines following treatment with chemical cleaning agents also is not desirable. However, if conditions related to toxicity and substrate permeability are determined to be acceptable, the use of chemical cleaning agents for treatment of stranded oil can be considered. Chemical agents for cleaning oiled shorelines can be grouped into three categories: (1) non-surfactant-based solvents, (2) chemical dispersants, and (3) formulations especially designed to release stranded oil from shoreline substrates (i.e., shoreline-cleaning-agents). Depending on the specific circumstances present on an oiled shoreline, it is generally desirable that chemical agents used for cleaning will release oil from shoreline substrate(s) to surface waters. Recovery of the oil can then be accomplished by mechanical procedures such as booming and skimming operations

  17. Coastal erosion management in Accra: Combining local knowledge and empirical research

    Directory of Open Access Journals (Sweden)

    Kwasi Appeaning Addo

    2016-11-01

    Full Text Available Coastal erosion along the Accra coast has become a chronic phenomenon that threatens both life and property. The issue has assumed a centre stage of national debate in recent times because of its impact on the coastal communities. Lack of reliable geospatial data hinders effective scientific investigations into the changing trends in the shoreline position. However, knowledge about coastal erosion, by the local people, and how far the shoreline has migrated inland over time is high in the coastal communities in Accra. This opens a new chapter in coastal erosion research to include local knowledge of the local settlers in developing sustainable coastal management. This article adopted a scientific approach to estimate rate of erosion and tested the results against perceived erosion trend by the local settlers. The study used a 1974 digital topographic map and 1996 aerial photographs. The end point rate statistical method in DSAS was used to compute the rates of change. The short-term rate of change for the 22-year period under study was estimated as -0.91 m/annum ± 0.49 m/annum. It was revealed that about 79% of the shoreline is eroding, while the remaining 21% is either stabilised or accreting. It emerged, from semi-structured interviews with inhabitants in the Accra coastal communities, that an average of about 30 m of coastal lands are perceived to have been lost to erosion for a period of about 20 years. This translates to a historic rate of change of about 1.5 m/year, which corroborates the results of the scientific study. Again this study has established that the local knowledge of the inhabitants, about coastal erosion, can serve as reliable information under scarcity of scientific data for coastal erosion analyses in developing countries.

  18. Recent shoreline changes in the Volta River delta, West Africa: the ...

    African Journals Online (AJOL)

    Spit growth has been accompanied by a wave of erosion over the last century of the immediate downdrift sector of the bight coast, endangering the town of Keta. Erosion since the 1960s may have been aggravated by the construction of the Akosombo hydropower dam. The tip of the spit has recently welded to the shoreline, ...

  19. National Assessment Of Shoreline Change: Part 2, Historical Shoreline Changes And Associated Coastal Land Loss Along The U.S. Southeast Atlantic Coast

    Science.gov (United States)

    Morton, Robert A.; Miller, Tara L.

    2005-01-01

    EXECUTIVE SUMMARY Beach erosion is a chronic problem along most open-ocean shores of the United States. As coastal populations continue to grow and community infrastructures are threatened by erosion, there is increased demand for accurate information regarding past and present trends and rates of shoreline movement. There is also a need for a comprehensive analysis of shoreline movement that is consistent from one coastal region to another. To meet these national needs, the U.S. Geological Survey is conducting an analysis of historical shoreline changes along open-ocean sandy shores of the conterminous United States and parts of Hawaii and Alaska. One purpose of this work is to develop standard repeatable methods for mapping and analyzing shoreline movement so that periodic updates regarding coastal erosion and land loss can be made nationally that are systematic and internally consistent. This report on states comprising the Southeast Atlantic Coast (east Florida, Georgia, South Carolina, North Carolina) represents the second in a series that already includes the Gulf of Mexico and will eventually include the Northeast Atlantic Coast, Pacific Coast, and parts of Hawaii and Alaska. The report summarizes the methods of analysis, interprets the results, provides explanations regarding the historical and present trends and rates of change, and describes how different coastal communities are responding to coastal erosion. Shoreline change evaluations are based on comparing three historical shorelines with a recent shoreline derived from lidar (Light Detection and Ranging) topographic surveys. The historical shorelines generally represent the following periods: 1800s, 1920s-1930s, and 1970s, whereas the lidar shoreline is 1998-2002. Long-term rates of change are calculated using four shorelines (1800s to lidar shoreline), whereas short-term rates of change are calculated for the most recent period (1970s to lidar shoreline). The historical rates of change presented in

  20. National Assessment of Shoreline Change: Part 1, Historical Shoreline Changes and Associated Coastal Land Loss Along the U.S. Gulf of Mexico

    Science.gov (United States)

    Morton, Robert A.; Miller, Tara L.; Moore, Laura J.

    2004-01-01

    EXECUTIVE SUMMARY Beach erosion is a chronic problem along most open-ocean shores of the United States. As coastal populations continue to grow and community infrastructures are threatened by erosion, there is increased demand for accurate information regarding past and present trends and rates of shoreline movement. There is also a need for a comprehensive analysis of shoreline movement that is consistent from one coastal region to another. To meet these national needs, the U.S. Geological Survey is conducting an analysis of historical shoreline changes along open-ocean sandy shores of the conterminous United States and parts of Hawaii and Alaska. One purpose of this work is to develop standard repeatable methods for mapping and analyzing shoreline movement so that periodic updates regarding coastal erosion and land loss can be made nationally that are systematic and internally consistent. This report on states bordering the Gulf of Mexico (Florida, Alabama, Mississippi, Louisiana, and Texas) represents the first in a series that will eventually include the Atlantic Coast, Pacific Coast, and parts of Hawaii and Alaska. The report summarizes the methods of analysis, interprets the results, provides explanations regarding the historical and present trends and rates of change, and describes how different coastal communities are responding to coastal erosion. Shoreline change evaluations are based on comparing three historical shorelines with a recent shoreline derived from lidar (Light Detection and Ranging) topographic surveys. The historical shorelines generally represent the following periods: 1800s, 1920s-1930s, and 1970s, whereas the lidar shoreline is 1998-2002. Long-term rates of change are calculated using all four shorelines (1800s to lidar shoreline), whereas short-term rates of change are calculated for the most recent period (1970s to lidar shoreline). The historical rates of change presented in this report represent past conditions and therefore are not

  1. 2002 Upper Texas Coast Lidar Point Data, Gulf of Mexico Shoreline in the Northeast 3.75-Minute Quadrant of the Lake Como 7.5-Minute Quadrangle: Post Fay Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains elevation data derived from a lidar survey approximately 300m wide of the Gulf of Mexico shoreline in the Northeast Lake Como...

  2. Modeling of Shoreline Changes of Tulamben Coast, Bali Indonesia

    Science.gov (United States)

    Yuanita, Nita; Pratama, Roka; Husrin, Semeidi

    2015-04-01

    Modeling of Shoreline Changes of Tulamben Coast, Bali Indonesia Tulamben coast is located in Lombok Strait on the northeastern coast of Bali island, Indonesia, as part of Karang Asem district. Severe erosion along the coastline has long been occurred in Karang Asem area and threatening houses, religious buildings (Hindu temples), and a national heritage site. As one of most popular diving site in Bali Island, Tulamben attracted many local and international tourist since 1980. The main attraction of Tulamben diving site is the USAT Liberty ship that was shipwrecked in Tulamben beach in 1942, after attacked by Japanese torpedo in Lombok Strait. Currently about 150 diver visit Tulamben per day. Due to physical changes of coastal environmental such as coastal erosion, sliding, and scouring, the shipwreck is vulnerable. It had been slipped off the beach several times and is predicted would be moved to deeper offshore floor if it is not protected. Coastal erosion in Karang Asem district is occurred probably due to interaction between cross-shore and long-shore wave-generated current and river sand supply decreasing after sand mining activities. In this study, the effect of cross-shore and longshore transport to coastal erosion in Tulamben is analyzed by doing numerical model. Numerical simulation of shoreline changes is performed by using Beach Processes Module of CEDAS (Coastal Engineering Design and Analysis System) consists of SBEACH and GENESIS. The model domain is covered Karang Asem coastline about 60 km length and wave data is calculated from hourly wind data (10 years). Simulated shoreline is calibrated using shoreline data from 1972 to 2013. Using calibrated model, then the simulation is performed from 2003 - 2013. From the simulation it is determined that longshore current and longshore sediment contribute to coastal erosion in Tulamben. Based on model results, several alternatives of general layout and configuration of coastal protection structures is proposed

  3. Effect of farmyard manure rate on water erosion of a Mediterranean soil: determination of the critical point of inefficacy

    Science.gov (United States)

    Annabi, Mohamed; Bahri, Haithem; Cheick M'Hamed, Hatem; Hermessi, Taoufik

    2016-04-01

    Intensive cultivation of soils, using multiple soil tillage, led to the decrease of their organic matter content and structural stability in several cultivated area of the Mediterranean countries. In these degraded soils, the addition of organic products, traditionally the animal manure, should improve soil health among them the resistance of soil to water erosion. The aim of this study was to evaluate after 1 year of the addition to a cambisoil different doses of farmyard manure on soil organic matter content, on microbial activity and on aggregate stability (proxy to soil resistance to water erosion). The statistical process (bilinear model) was used to found a point at which the addition of the organic product no longer influences the soil resistance to erosion. The farmyard manure issued from a cow breeding was composted passively during 4 months and used to amend a small plots of a cultivated cambisol (silty-clay texture, 0.9% TOC) located in the northeast of Tunisia (Morneg region). The manure was intimately incorporate to the soil. The manure organic matter content was 31%, and its isohumic coefficient was 49%. Twelve dose of manure were tested: from 0 to 220 t C.ha-1. The experiment was started on September 2011. In November 2012, soil sampling was done and soil organic carbon content (Walkley-Black method) and soil aggregate stability (wet method of Le Bissonnais) were assessed. A laboratory incubations of soil+manure mixtures, with the same proportions as tested in the field conditions, was carried at 28°C and at 75% of the mixture field capacity water retention. Carbon mineralization was monitored during three months incubation. Results show that the addition of farmyard manure stimulated the microbial activity proportionally to the added dose. This activation is due to the presence of easily biodegradable carbon in the manure, which increases with increasing manure dose. On the other hand, the addition of manure increased the aggregate stability with

  4. Dynamic control of low-Z material deposition and tungsten erosion by strike point sweeping on DIII-D

    Directory of Open Access Journals (Sweden)

    J. Guterl

    2017-08-01

    Full Text Available Carbon deposition on tungsten between ELMs was investigated in DIII-D in semi-attached/detached H-mode plasma conditions using fixed outer strike point (OSP positions. Carbon deposition during plasma exposure of tungsten was monitored in-situ by measuring the reflectivity of the tungsten sample surface. No significant carbon deposition, i.e., without strong variations of the reflectivity, was observed during these experiments including discharges at high densities. In contrast, ERO modeling predicts a significant carbon deposition on the tungsten surface for those high density plasma conditions. The surface reflectivity decreases with methane injection, consistent with increased carbon coverage, as expected. The sweeping of OSP leads to a pronounced increase of the surface reflectivity, suggesting that the strike point sweeping may provide an effective means to remove carbon coating from tungsten surface. The ERO modeling however predicts again a regime of carbon deposition for these experiments. The discrepancies between carbon deposition regime predicted by the ERO model and the experimental observations suggest that carbon erosion during ELMs may significantly affect carbon deposition on tungsten.

  5. National Assessment of Shoreline Change; historical shoreline change along the New England and Mid-Atlantic coasts

    Science.gov (United States)

    Hapke, Cheryl J.; Himmelstoss, Emily A.; Kratzmann, Meredith G.; List, Jeffrey H.; Thieler, E. Robert

    2011-01-01

    Beach erosion is a chronic problem along many open-ocean shores of the United States. As coastal populations continue to grow and community infrastructures are threatened by erosion, there is increased demand for accurate information regarding past and present trends and rates of shoreline movement. There is also a need for a comprehensive analysis of shoreline movement that is consistent from one coastal region to another. To meet these national needs, the U.S. Geological Survey (USGS) is conducting an analysis of historical shoreline changes along open-ocean sandy shores of the conterminous United States and parts of Hawaii, Alaska, and the Great Lakes. One purpose of this work is to develop standard, repeatable methods for mapping and analyzing shoreline movement so that periodic, systematic, internally consistent updates regarding coastal erosion and land loss can be made nationally. In the case of this study, the shoreline is the interpreted boundary between the ocean water surface and the sandy beach. This report on the New England and Mid-Atlantic coasts is the fifth in a series of reports on historical shoreline change. Previous investigations include analyses and descriptive reports of the Gulf of Mexico, the Southeast Atlantic, and, for California, the sandy shoreline and the coastal cliffs. The rates of change presented in this report represent conditions up to the date of the most recent shoreline data and therefore are not intended for predicting future shoreline positions or rates of change. Because of the geomorphology of the New England and Mid-Atlantic (rocky coastlines, large embayments and beaches) as well as data gaps in some areas, this report presents beach erosion rates for 78 percent of the 1,360 kilometers of the New England and Mid-Atlantic coasts. The New England and Mid-Atlantic shores were subdivided into a total of 10 analysis regions for the purpose of reporting regional trends in shoreline change rates. The average rate of long

  6. Living shorelines enhanced the resilience of saltmarshes to Hurricane Matthew (2016).

    Science.gov (United States)

    Smith, Carter S; Puckett, Brandon; Gittman, Rachel K; Peterson, Charles H

    2018-06-01

    Nature-based solutions, such as living shorelines, have the potential to restore critical ecosystems, enhance coastal sustainability, and increase resilience to natural disasters; however, their efficacy during storm events compared to traditional hardened shorelines is largely untested. This is a major impediment to their implementation and promotion to policy-makers and homeowners. To address this knowledge gap, we evaluated rock sill living shorelines as compared to natural marshes and hardened shorelines (i.e., bulkheads) in North Carolina, USA for changes in surface elevation, Spartina alterniflora stem density, and structural damage from 2015 to 2017, including before and after Hurricane Matthew (2016). Our results show that living shorelines exhibited better resistance to landward erosion during Hurricane Matthew than bulkheads and natural marshes. Additionally, living shorelines were more resilient than hardened shorelines, as they maintained landward elevation over the two-year study period without requiring any repair. Finally, rock sill living shorelines were able to enhance S. alterniflora stem densities over time when compared to natural marshes. Our results suggest that living shorelines have the potential to improve coastal resilience while supporting important coastal ecosystems. © 2018 by the Ecological Society of America.

  7. ERO and PIC simulations of gross and net erosion of tungsten in the outer strike-point region of ASDEX Upgrade

    Directory of Open Access Journals (Sweden)

    A. Hakola

    2017-08-01

    Full Text Available We have modelled net and gross erosion of W in low-density l-mode plasmas in the low-field side strike point region of ASDEX Upgrade by ERO and Particle-in-Cell (PIC simulations. The observed net-erosion peak at the strike point was mainly due to the light impurities present in the plasma while the noticeable net-deposition regions surrounding the erosion maximum could be attributed to the strong E ×B drift and the magnetic field bringing eroded particles from a distance of several meters towards the private flux region. Our results also imply that the role of cross-field diffusion is very small in the studied plasmas. The simulations indicate net/gross erosion ratio of 0.2–0.6, which is in line with the literature data and what was determined spectroscopically. The deviations from the estimates extracted from post-exposure ion-beam-analysis data (∼0.6–0.7 are most likely due to the measured re-deposition patterns showing the outcomes of multiple erosion-deposition cycles.

  8. Shoreline change and potential sea level rise impacts in a climate hazardous location in southeast coast of India.

    Science.gov (United States)

    Jayanthi, Marappan; Thirumurthy, Selvasekar; Samynathan, Muthusamy; Duraisamy, Muthusamy; Muralidhar, Moturi; Ashokkumar, Jangam; Vijayan, Koyadan Kizhakkedath

    2017-12-28

    Climate change impact on the environment makes the coastal areas vulnerable and demands the evaluation of such susceptibility. Historical changes in the shoreline positions and inundation based on projected sea-level scenarios of 0.5 and 1 m were assessed for Nagapattinam District, a low-lying coastal area in the southeast coast of India, using high-resolution Shuttle Radar Topography Mission data; multi-dated Landsat satellite images of 1978, 1991, 2003, and 2015; and census data of 2011. Image processing, geographical information system, and digital shoreline analysis system methods were used in the study. The shoreline variation indicated that erosion rate varied at different time scales. The end point rate indicated the highest mean erosion of - 3.12 m/year, occurred in 73% of coast between 1978 and 1991. Weighted linear regression analysis revealed that the coast length of 83% was under erosion at a mean rate of - 2.11 m/year from 1978 to 2015. Sea level rise (SLR) impact indicated that the coastal area of about 14,122 ha from 225 villages and 31,318 ha from 272 villages would be permanently inundated for the SLR of 0.5 and 1 m, respectively, which includes agriculture, mangroves, wetlands, aquaculture, and forest lands. The loss of coastal wetlands and its associated productivity will severely threaten more than half the coastal population. Adaptation measures in people participatory mode, integrated into coastal zone management with a focus on sub-regional coastal activities, are needed to respond to the consequences of climate change.

  9. Timing of oceans on Mars from shoreline deformation.

    Science.gov (United States)

    Citron, Robert I; Manga, Michael; Hemingway, Douglas J

    2018-03-29

    Widespread evidence points to the existence of an ancient Martian ocean. Most compelling are the putative ancient shorelines in the northern plains. However, these shorelines fail to follow an equipotential surface, and this has been used to challenge the notion that they formed via an early ocean and hence to question the existence of such an ocean. The shorelines' deviation from a constant elevation can be explained by true polar wander occurring after the formation of Tharsis, a volcanic province that dominates the gravity and topography of Mars. However, surface loading from the oceans can drive polar wander only if Tharsis formed far from the equator, and most evidence indicates that Tharsis formed near the equator, meaning that there is no current explanation for the shorelines' deviation from an equipotential that is consistent with our geophysical understanding of Mars. Here we show that variations in shoreline topography can be explained by deformation caused by the emplacement of Tharsis. We find that the shorelines must have formed before and during the emplacement of Tharsis, instead of afterwards, as previously assumed. Our results imply that oceans on Mars formed early, concurrent with the valley networks, and point to a close relationship between the evolution of oceans on Mars and the initiation and decline of Tharsis volcanism, with broad implications for the geology, hydrological cycle and climate of early Mars.

  10. County Boundaries with Shorelines (National)

    Data.gov (United States)

    Department of Transportation — County boundaries with shorelines cut in (NTAD). The TIGER/Line Files are shapefiles and related database files (.dbf) that are an extract of selected geographic and...

  11. NOAA Coastal Mapping Shoreline Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Mapping Shoreline Products from the Remote Sensing Division are primarily for application to the nautical charts produced by NOAA's Office of Coast...

  12. Wetland shoreline recession in the Mississippi River Delta from petroleum oiling and cyclonic storms

    Science.gov (United States)

    Rangoonwala, Amina; Jones, Cathleen E.; Ramsey, Elijah W.

    2016-01-01

    We evaluate the relative impact of petroleum spill and storm surge on near-shore wetland loss by quantifying the lateral movement of coastal shores in upper Barataria Bay, Louisiana (USA), between June 2009 and October 2012, a study period that extends from the year prior to the Deepwater Horizon spill to 2.5 years following the spill. We document a distinctly different pattern of shoreline loss in the 2 years following the spill, both from that observed in the year prior to the spill, during which there was no major cyclonic storm, and from change related to Hurricane Isaac, which made landfall in August 2012. Shoreline erosion following oiling was far more spatially extensive and included loss in areas protected from wave-induced erosion. We conclude that petroleum exposure can substantially increase shoreline recession particularly in areas protected from storm-induced degradation and disproportionally alters small oil-exposed barrier islands relative to natural erosion.

  13. Digital shoreline analysis system-based change detection along the highly eroding Krishna-Godavari delta front

    Science.gov (United States)

    Kallepalli, Akhil; Kakani, Nageswara Rao; James, David B.; Richardson, Mark A.

    2017-07-01

    Coastal regions are highly vulnerable to rising sea levels due to global warming. Previous Intergovernmental Panel on Climate Change (2013) predictions of 26 to 82 cm global sea level rise are now considered conservative. Subsequent investigations predict much higher levels which would displace 10% of the world's population living less than 10 m above sea level. Remote sensing and GIS technologies form the mainstay of models on coastal retreat and inundation to future sea-level rise. This study estimates the varying trends along the Krishna-Godavari (K-G) delta region. The rate of shoreline shift along the 330-km long K-G delta coast was estimated using satellite images between 1977 and 2008. With reference to a selected baseline from along an inland position, end point rate and net shoreline movement were calculated using a GIS-based digital shoreline analysis system. The results indicated a net loss of about 42.1 km2 area during this 31-year period, which is in agreement with previous literature. Considering the nature of landforms and EPR, the future hazard line (or coastline) is predicted for the area; the predication indicates a net erosion of about 57.6 km2 along the K-G delta coast by 2050 AD.

  14. USGS science for the Nation's changing coasts; shoreline change assessment

    Science.gov (United States)

    Thieler, E. Robert; Hapke, Cheryl J.

    2011-01-01

    The coastline of the United States features some of the most popular tourist and recreational destinations in the world and is the site of intense residential, commercial, and industrial development. The coastal zone also has extensive and pristine natural areas, with diverse ecosystems providing essential habitat and resources that support wildlife, fish, and human use. Coastal erosion is a widespread process along most open-ocean shores of the United States that affects both developed and natural coastlines. As the coast changes, there are a wide range of ways that change can affect coastal communities, habitats, and the physical characteristics of the coast?including beach erosion, shoreline retreat, land loss, and damage to infrastructure. Global climate change will likely increase the rate of coastal change. A recent study of the U.S. Mid-Atlantic coast, for example, found that it is virtually certain that sandy beaches will erode faster in the future as sea level rises because of climate change. The U.S. Geological Survey (USGS) is responsible for conducting research on coastal change hazards, understanding the processes that cause coastal change, and developing models to predict future change. To understand and adapt to shoreline change, accurate information regarding the past and present configurations of the shoreline is essential. A comprehensive, nationally consistent analysis of shoreline movement is needed. To meet this national need, the USGS is conducting an analysis of historical shoreline changes along open-ocean coasts of the conterminous United States and parts of Alaska and Hawaii, as well as the coasts of the Great Lakes.

  15. COMPARISON OF TWO SIMPLIFICATION METHODS FOR SHORELINE EXTRACTION FROM DIGITAL ORTHOPHOTO IMAGES

    Directory of Open Access Journals (Sweden)

    B. Bayram

    2017-11-01

    Full Text Available The coastal ecosystems are very sensitive to external influences. Coastal resources such as sand dunes, coral reefs and mangroves has vital importance to prevent coastal erosion. Human based effects also threats the coastal areas. Therefore, the change of coastal areas should be monitored. Up-to-date, accurate shoreline information is indispensable for coastal managers and decision makers. Remote sensing and image processing techniques give a big opportunity to obtain reliable shoreline information. In the presented study, NIR bands of seven 1:5000 scaled digital orthophoto images of Riga Bay-Latvia have been used. The Object-oriented Simple Linear Clustering method has been utilized to extract shoreline of Riga Bay. Bend and Douglas-Peucker methods have been used to simplify the extracted shoreline to test the effect of both methods. Photogrammetrically digitized shoreline has been taken as reference data to compare obtained results. The accuracy assessment has been realised by Digital Shoreline Analysis tool. As a result, the achieved shoreline by the Bend method has been found closer to the extracted shoreline with Simple Linear Clustering method.

  16. Comparison of Two Simplification Methods for Shoreline Extraction from Digital Orthophoto Images

    Science.gov (United States)

    Bayram, B.; Sen, A.; Selbesoglu, M. O.; Vārna, I.; Petersons, P.; Aykut, N. O.; Seker, D. Z.

    2017-11-01

    The coastal ecosystems are very sensitive to external influences. Coastal resources such as sand dunes, coral reefs and mangroves has vital importance to prevent coastal erosion. Human based effects also threats the coastal areas. Therefore, the change of coastal areas should be monitored. Up-to-date, accurate shoreline information is indispensable for coastal managers and decision makers. Remote sensing and image processing techniques give a big opportunity to obtain reliable shoreline information. In the presented study, NIR bands of seven 1:5000 scaled digital orthophoto images of Riga Bay-Latvia have been used. The Object-oriented Simple Linear Clustering method has been utilized to extract shoreline of Riga Bay. Bend and Douglas-Peucker methods have been used to simplify the extracted shoreline to test the effect of both methods. Photogrammetrically digitized shoreline has been taken as reference data to compare obtained results. The accuracy assessment has been realised by Digital Shoreline Analysis tool. As a result, the achieved shoreline by the Bend method has been found closer to the extracted shoreline with Simple Linear Clustering method.

  17. Integrated Shoreline Extraction Approach with Use of Rasat MS and SENTINEL-1A SAR Images

    Science.gov (United States)

    Demir, N.; Oy, S.; Erdem, F.; Şeker, D. Z.; Bayram, B.

    2017-09-01

    Shorelines are complex ecosystems and highly important socio-economic environments. They may change rapidly due to both natural and human-induced effects. Determination of movements along the shoreline and monitoring of the changes are essential for coastline management, modeling of sediment transportation and decision support systems. Remote sensing provides an opportunity to obtain rapid, up-to-date and reliable information for monitoring of shoreline. In this study, approximately 120 km of Antalya-Kemer shoreline which is under the threat of erosion, deposition, increasing of inhabitants and urbanization and touristic hotels, has been selected as the study area. In the study, RASAT pansharpened and SENTINEL-1A SAR images have been used to implement proposed shoreline extraction methods. The main motivation of this study is to combine the land/water body segmentation results of both RASAT MS and SENTINEL-1A SAR images to improve the quality of the results. The initial land/water body segmentation has been obtained using RASAT image by means of Random Forest classification method. This result has been used as training data set to define fuzzy parameters for shoreline extraction from SENTINEL-1A SAR image. Obtained results have been compared with the manually digitized shoreline. The accuracy assessment has been performed by calculating perpendicular distances between reference data and extracted shoreline by proposed method. As a result, the mean difference has been calculated around 1 pixel.

  18. NOAA Composite Shoreline - Vectorized Shoreline Derived From NOAA-NOS Coastal Survey Maps and Aerial Photographs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Composite Shoreline is primarily intended for high-resolution cartographic representation of the shoreline. It is a high-resolution vector shoreline based...

  19. Power Scaling of the Mainland Shoreline of the Atlantic Coast of the United States

    Science.gov (United States)

    Vasko, E.; Barton, C. C.; Geise, G. R.; Rizki, M. M.

    2017-12-01

    The fractal dimension of the mainland shoreline of the Atlantic coast of the United Stated from Maine to Homestead, FL has been measured in 1000 km increments using the box-counting method. The shoreline analyzed is the NOAA Medium Resolution Shoreline (https://shoreline.noaa.gov/data/datasheets/medres.html). The shoreline was reconstituted into sequentially numbered X-Y coordinate points in UTM Zone 18N which are spaced 50 meters apart, as measured continuously along the shoreline. We created a MATLAB computer code to measure the fractal dimension by box counting while "walking" along the shoreline. The range of box sizes is 0.7 to 450 km. The fractal dimension ranges from 1.0 to1.5 along the mainland shoreline of the Atlantic coast. The fractal dimension is compared with beach particle sizes (bedrock outcrop, cobbles, pebbles, sand, clay), tidal range, rate of sea level rise, rate and direction of vertical crustal movement, and wave energy, looking for correlation with the measured fractal dimensions. The results show a correlation between high fractal dimensions (1.3 - 1.4) and tectonically emergent coasts, and low fractal dimensions (1.0 - 1.2) along submergent and stable coastal regions. Fractal dimension averages 1.3 along shorelines with shoreline protection structures such as seawalls, jetties, and groins.

  20. Runoff erosion

    OpenAIRE

    Evelpidou, Niki (Ed.); Cordier, Stephane (Ed.); Merino, Agustin (Ed.); Figueiredo, Tomás de (Ed.); Centeri, Csaba (Ed.)

    2013-01-01

    Table of Contents PART I – THEORY OF RUNOFF EROSION CHAPTER 1 - RUNOFF EROSION – THE MECHANISMS CHAPTER 2 - LARGE SCALE APPROACHES OF RUNOFF EROSION CHAPTER 3 - MEASURING PRESENT RUNOFF EROSION CHAPTER 4 - MODELLING RUNOFF EROSION CHAPTER 5 - RUNOFF EROSION AND HUMAN SOCIETIES: THE INFLUENCE OF LAND USE AND MANAGEMENT PRACTICES ON SOIL EROSION PART II - CASE STUDIES CASE STUDIES – INTRODUCTION: RUNOFF EROSION IN MEDITERRANEAN AREA CASE STUDY 1: Soil Erosion Risk...

  1. A numerical shoreline model for shorelines with large curvature

    DEFF Research Database (Denmark)

    Kærgaard, Kasper Hauberg; Fredsøe, Jørgen

    2013-01-01

    orthogonal horizontal directions are used. The volume error in the sediment continuity equation which is thereby introduced is removed through an iterative procedure. The model treats the shoreline changes by computing the sediment transport in a 2D coastal area model, and then integrating the sediment...

  2. Interactions between Point Bar Growth and Bank Erosion on a Low Sinuosity Meander Bend in an Ephemeral Channel: Insights from Repeat Topographic Surveys and Numerical Modeling

    Science.gov (United States)

    Ursic, M.; Langendoen, E. J.

    2017-12-01

    Interactions between point bar growth, bank migration, and hydraulics on meandering rivers are complicated and not well understood. For ephemeral streams, rapid fluctuations in flow further complicate studying and understanding these interactions. This study seeks to answer the following `cause-and-effect' question: Does point bar morphologic adjustment determine where bank erosion occurs (for example, through topographic steering of the flow), or does local bank retreat determine where accretion/erosion occurs on the point bar, or do bank erosion and point bar morphologic adjustment co-evolve? Further, is there a response time between the `cause-and-effect' processes and what variables determine its magnitude and duration? In an effort to answer these questions for an ephemeral stream, a dataset of forty-eight repeat topographic surveys over a ten-year period (1996-2006) of a low sinuosity bend within the Goodwin Creek Experimental Watershed, located near Batesville, MS, were utilized in conjunction with continuous discharge measurements to correlate flow variability and erosional and depositional zones, spatially and temporally. Hydraulically, the bend is located immediately downstream of a confluence with a major tributary. Supercritical flumes on both the primary and tributary channels just upstream of the confluence provide continuous measured discharges to the bend over the survey period. In addition, water surface elevations were continuously measured at the upstream and downstream ends of the bend. No spatial correlation trends could be discerned between reach-scale bank retreat, point bar morphologic adjustment, and flow discharge. Because detailed flow patterns were not available, the two-dimensional computer model Telemac2D was used to provide these details. The model was calibrated and validated for a set of runoff events for which more detailed flow data were available. Telemac2D simulations were created for each topographic survey period. Flows

  3. Variability and correlations of shoreline and dunes on the southern Baltic coast (CRS Lubiatowo, Poland

    Directory of Open Access Journals (Sweden)

    Zbigniew Pruszak

    2011-03-01

    Full Text Available The paper analyses the results of field investigations into the evolution of the shoreline and dune toe positions in a multi-bar,dissipative coastal zone. The correlations between the changes in the shoreline and the dune toe range from -0.4 to 0.8. It is most often the case that the dune toe is stable while the shoreline moves. Consistent cross-shore migration is slightly more likelyto happen than the divergent or convergent movements of both lines. Shoreline retreat and advance attain respective rates of 0.7 m day-1 and 0.4 m day-1. Deep-water wave energy of about 50 kJ m-1 constitutes the boundary between shore accumulation and erosion.

  4. A Collaborative Geospatial Shoreline Inventory Tool to Guide Coastal Development and Habitat Conservation

    Directory of Open Access Journals (Sweden)

    Peter Gies

    2013-05-01

    Full Text Available We are developing a geospatial inventory tool that will guide habitat conservation, restoration and coastal development and benefit several stakeholders who seek mitigation and adaptation strategies to shoreline changes resulting from erosion and sea level rise. The ESRI Geoportal Server, which is a type of web portal used to find and access geospatial information in a central repository, is customized by adding a Geoinventory tool capability that allows any shoreline related data to be searched, displayed and analyzed on a map viewer. Users will be able to select sections of the shoreline and generate statistical reports in the map viewer to allow for comparisons. The tool will also facilitate map-based discussion forums and creation of user groups to encourage citizen participation in decisions regarding shoreline stabilization and restoration, thereby promoting sustainable coastal development.

  5. Natural shorelines promote the stability of fish communities in an urbanized coastal system.

    Directory of Open Access Journals (Sweden)

    Steven B Scyphers

    Full Text Available Habitat loss and fragmentation are leading causes of species extinctions in terrestrial, aquatic and marine systems. Along coastlines, natural habitats support high biodiversity and valuable ecosystem services but are often replaced with engineered structures for coastal protection or erosion control. We coupled high-resolution shoreline condition data with an eleven-year time series of fish community structure to examine how coastal protection structures impact community stability. Our analyses revealed that the most stable fish communities were nearest natural shorelines. Structurally complex engineered shorelines appeared to promote greater stability than simpler alternatives as communities nearest vertical walls, which are among the most prevalent structures, were most dissimilar from natural shorelines and had the lowest stability. We conclude that conserving and restoring natural habitats is essential for promoting ecological stability. However, in scenarios when natural habitats are not viable, engineered landscapes designed to mimic the complexity of natural habitats may provide similar ecological functions.

  6. Enhanced sediment loading facilitates point bar growth and accelerates bank erosion along a modelled meander bend on the Sacramento River, USA

    Science.gov (United States)

    Ahmed, J.; Constantine, J. A.; Hales, T. C.

    2017-12-01

    Meandering channels provide a conduit through which sediment and water is routed from the uplands to the sea. Alluvial material is periodically stored and transported through the channel network as permitted by the prevailing hydrologic conditions. The lowlands are typically characterised by accumulations of sediment attached to the inner banks of meander bends (point bars). These bedforms have been identified as important for facilitating a link between in-stream sediment supplies and channel dynamism. A 2D curvilinear hydrodynamic model (MIKE 21C) was used to perform a number of experiments in which the sediment load was adjusted to investigate how changes in alluvial material fluxes affect the development of point bars and the resultant patterns of bank erosion. A doubling of the sediment load caused a longitudinal increase in the bar in the upstream direction and caused a coeval doubling of the transverse channel slope at the meander apex. The upstream growth of the point bar was accompanied by an increase in length over which lateral migration took place at the outer bank. The magnitude of outer bank erosion was 9-times greater for the high-sediment simulation. These results suggest that enhanced sediment loads (potentially the result of changes in land use or climate) can trigger greater rates of bank erosion and channel change through the sequestration of alluvial material on point bars, which encourage high-velocity fluid deflection towards the outer bank of the meander. This controls riparian habitat development and exchanges of sediment and nutrients across the channel-floodplain interface.

  7. Decadal shoreline assessment using remote sensing along the central Odisha coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    ManiMurali, R.; Dhiman, R.; Choudhary, R.; Jayakumar, S.; Ilangovan, D.; Vethamony, P.

    sensing data (Landsat and IRS P6) were used in the study. Digital shoreline analysis system discovered the eroded and accreted parts of the study area. Gahirmatha and coast above Devi River experienced heavy erosion during 2000–2012 compared with 1990...

  8. Runoff experiment and adapted SfM photogrammetry to assess rill erosion in Mediterranean agricultural fields from a holistic point of view

    Science.gov (United States)

    Gronz, Oliver; Rodrigo-Comino, Jesús; Seeger, Manuel

    2017-04-01

    In Mediterranean agricultural fields, more research is needed to quantify soil loss and to assess runoff generation caused by unsuitable land management strategies (García-Díaz et al., 2017; Keesstra et al., 2016). Nowadays, farmers are increasing the generation of rills and, consequently, enhancing several sub-processes related to soil erosion by water such as headcut retreats, piping or cracks joint to mass movements (Marzolff and Poesen, 2009; Poesen et al., 2003; Rodrigo Comino et al., 2015). This complex problem under different spatiotemporal scales hinders a reliable forecasting of its final consequences (Prasuhn, 2011; Salome et al., 2014). Several researchers pay more attention to point observations, but no to general and connected overviews of processes related to forms and the quantitative functioning of all elements. Therefore, the main goal of this study is to characterize and quantify the rill erosion generated by these degradation processes. To achieve this goal, two runoff experiments were carried out with two repetitions (dry and wet conditions) under extreme conditions (Wirtz et al., 2013, 2012, 2010): a motor driven pump discharged a water inflow up to ˜4.2 l s-1 maintained during between 4 and 6 minutes (≈1000 litres). Additionally, a 3D-captation of the rill by an adapted SfM photogrammetry was performed to assess: i) clear visible zonation of geomorphological (structural) connectivity features; ii) runoff and sediment productions close to the catchment outlet under actual conditions; iii) topsoil-subsoil interaction and crusting crucial for runoff generation; and, iv) the area with evidence of (former) high erosion intensity now stable, but with remnant. García-Díaz, A., Bienes, R., Sastre, B., Novara, A., Gristina, L., Cerdà, A., 2017. Nitrogen losses in vineyards under different types of soil groundcover. A field runoff simulator approach in central Spain. Agric. Ecosyst. Environ. 236, 256-267. doi:10.1016/j.agee.2016.12.013 Keesstra

  9. Projected atoll shoreline and run-up changes in response to sea-level rise and varying large wave conditions at Wake and Midway Atolls, Northwestern Hawaiian Islands

    Science.gov (United States)

    Shope, James B.; Storlazzi, Curt D.; Hoeke, Ron K.

    2017-10-01

    Atoll islands are dynamic features that respond to seasonal alterations in wave conditions and sea level. It is unclear how shoreline wave run-up and erosion patterns along these low elevation islands will respond to projected sea-level rise (SLR) and changes in wave climate over the next century, hindering communities' preparation for the future. To elucidate how these processes may respond to climate change, extreme boreal winter and summer wave conditions under future sea-level rise (SLR) and wave climate scenarios were simulated at two atolls, Wake and Midway, using a shallow-water hydrodynamic model. Nearshore wave conditions were used to compute the potential longshore sediment flux along island shorelines via the CERC empirical formula and wave-driven erosion was calculated as the divergence of the longshore drift; run-up and the locations where the run-up exceed the berm elevation were also determined. SLR is projected to predominantly drive future island morphological change and flooding. Seaward shorelines (i.e., ocean fronted shorelines directly facing incident wave energy) were projected to experience greater erosion and flooding with SLR and in hypothetical scenarios where changes to deep water wave directions were altered, as informed by previous climate change forced Pacific wave modeling efforts. These changes caused nearshore waves to become more shore-normal, increasing wave attack along previously protected shorelines. With SLR, leeward shorelines (i.e., an ocean facing shoreline but sheltered from incident wave energy) became more accretive on windward islands and marginally more erosive along leeward islands. These shorelines became more accretionary and subject to more flooding with nearshore waves becoming more shore-normal. Lagoon shorelines demonstrated the greatest SLR-driven increase in erosion and run-up. They exhibited the greatest relative change with increasing wave heights where both erosion and run-up magnitudes increased. Wider

  10. Projected atoll shoreline and run-up changes in response to sea-level rise and varying large wave conditions at Wake and Midway Atolls, Northwestern Hawaiian Islands

    Science.gov (United States)

    Shope, James B.; Storlazzi, Curt; Hoeke, Ron

    2017-01-01

    Atoll islands are dynamic features that respond to seasonal alterations in wave conditions and sea level. It is unclear how shoreline wave run-up and erosion patterns along these low elevation islands will respond to projected sea-level rise (SLR) and changes in wave climate over the next century, hindering communities' preparation for the future. To elucidate how these processes may respond to climate change, extreme boreal winter and summer wave conditions under future sea-level rise (SLR) and wave climate scenarios were simulated at two atolls, Wake and Midway, using a shallow-water hydrodynamic model. Nearshore wave conditions were used to compute the potential longshore sediment flux along island shorelines via the CERC empirical formula and wave-driven erosion was calculated as the divergence of the longshore drift; run-up and the locations where the run-up exceed the berm elevation were also determined. SLR is projected to predominantly drive future island morphological change and flooding. Seaward shorelines (i.e., ocean fronted shorelines directly facing incident wave energy) were projected to experience greater erosion and flooding with SLR and in hypothetical scenarios where changes to deep water wave directions were altered, as informed by previous climate change forced Pacific wave modeling efforts. These changes caused nearshore waves to become more shore-normal, increasing wave attack along previously protected shorelines. With SLR, leeward shorelines (i.e., an ocean facing shoreline but sheltered from incident wave energy) became more accretive on windward islands and marginally more erosive along leeward islands. These shorelines became more accretionary and subject to more flooding with nearshore waves becoming more shore-normal. Lagoon shorelines demonstrated the greatest SLR-driven increase in erosion and run-up. They exhibited the greatest relative change with increasing wave heights where both erosion and run-up magnitudes increased. Wider

  11. Oyster reefs as natural breakwaters mitigate shoreline loss and facilitate fisheries.

    Directory of Open Access Journals (Sweden)

    Steven B Scyphers

    Full Text Available Shorelines at the interface of marine, estuarine and terrestrial biomes are among the most degraded and threatened habitats in the coastal zone because of their sensitivity to sea level rise, storms and increased human utilization. Previous efforts to protect shorelines have largely involved constructing bulkheads and seawalls which can detrimentally affect nearshore habitats. Recently, efforts have shifted towards "living shoreline" approaches that include biogenic breakwater reefs. Our study experimentally tested the efficacy of breakwater reefs constructed of oyster shell for protecting eroding coastal shorelines and their effect on nearshore fish and shellfish communities. Along two different stretches of eroding shoreline, we created replicated pairs of subtidal breakwater reefs and established unaltered reference areas as controls. At both sites we measured shoreline and bathymetric change and quantified oyster recruitment, fish and mobile macro-invertebrate abundances. Breakwater reef treatments mitigated shoreline retreat by more than 40% at one site, but overall vegetation retreat and erosion rates were high across all treatments and at both sites. Oyster settlement and subsequent survival were observed at both sites, with mean adult densities reaching more than eighty oysters m(-2 at one site. We found the corridor between intertidal marsh and oyster reef breakwaters supported higher abundances and different communities of fishes than control plots without oyster reef habitat. Among the fishes and mobile invertebrates that appeared to be strongly enhanced were several economically-important species. Blue crabs (Callinectes sapidus were the most clearly enhanced (+297% by the presence of breakwater reefs, while red drum (Sciaenops ocellatus (+108%, spotted seatrout (Cynoscion nebulosus (+88% and flounder (Paralichthys sp. (+79% also benefited. Although the vertical relief of the breakwater reefs was reduced over the course of our study

  12. A METHOD OF EXTRACTING SHORELINE BASED ON SEMANTIC INFORMATION USING DUAL-LENGTH LiDAR DATA

    Directory of Open Access Journals (Sweden)

    C. Yao

    2017-09-01

    Full Text Available Shoreline is a spatial varying separation between water and land. By utilizing dual-wavelength LiDAR point data together with semantic information that shoreline often appears beyond water surface profile and is observable on the beach, the paper generates the shoreline and the details are as follows: (1 Gain the water surface profile: first we obtain water surface by roughly selecting water points based on several features of water body, then apply least square fitting method to get the whole water trend surface. Then we get the ground surface connecting the under -water surface by both TIN progressive filtering method and surface interpolation method. After that, we have two fitting surfaces intersected to get water surface profile of the island. (2 Gain the sandy beach: we grid all points and select the water surface profile grids points as seeds, then extract sandy beach points based on eight-neighborhood method and features, then we get all sandy beaches. (3 Get the island shoreline: first we get the sandy beach shoreline based on intensity information, then we get a threshold value to distinguish wet area and dry area, therefore we get the shoreline of several sandy beaches. In some extent, the shoreline has the same height values within a small area, by using all the sandy shoreline points to fit a plane P, and the intersection line of the ground surface and the shoreline plane P can be regarded as the island shoreline. By comparing with the surveying shoreline, the results show that the proposed method can successfully extract shoreline.

  13. Timing of oceans on Mars from shoreline deformation

    Science.gov (United States)

    Citron, Robert I.; Manga, Michael; Hemingway, Douglas J.

    2018-03-01

    Widespread evidence points to the existence of an ancient Martian ocean. Most compelling are the putative ancient shorelines in the northern plains. However, these shorelines fail to follow an equipotential surface, and this has been used to challenge the notion that they formed via an early ocean and hence to question the existence of such an ocean. The shorelines’ deviation from a constant elevation can be explained by true polar wander occurring after the formation of Tharsis, a volcanic province that dominates the gravity and topography of Mars. However, surface loading from the oceans can drive polar wander only if Tharsis formed far from the equator, and most evidence indicates that Tharsis formed near the equator, meaning that there is no current explanation for the shorelines’ deviation from an equipotential that is consistent with our geophysical understanding of Mars. Here we show that variations in shoreline topography can be explained by deformation caused by the emplacement of Tharsis. We find that the shorelines must have formed before and during the emplacement of Tharsis, instead of afterwards, as previously assumed. Our results imply that oceans on Mars formed early, concurrent with the valley networks, and point to a close relationship between the evolution of oceans on Mars and the initiation and decline of Tharsis volcanism, with broad implications for the geology, hydrological cycle and climate of early Mars.

  14. Shoreline Changes at New Mangalore Port, India in the past and over future

    Science.gov (United States)

    Bharathan Radhamma, R.; Deo, M. C.

    2016-12-01

    The New Mangalore port is one of the major ports along the west coast of India. It is of artificial type with a pair of breakwaters constructed in phases from the year 1974 to 1996. The studies indicating the impact of constructing the breakwaters on adjacent shorelines after 1996 are difficult to find. The present work is aimed in this direction. For a 10 km stretch of the coast lying on both sides of the breakwaters 35 transects were constructed and shorelines were delineated from 4 satellite imageries that were recorded over the past 36 years at around 12 years' interval. Over each transect the rate of change of shoreline was calculated using linear regression and its adequacy was checked using the error statistics of R2 and RMSE. After such satisfactory cross-check, shorelines were predicted over the 12 and 36 years in future, i. e., in the years: 2028 and 2051. The patches undergoing erosion as well as accretion were identified. It was found that the rate of shoreline shifts fluctuated from -1.69 ± 0.45 m/year to 2.56 ± 0.45 m/year and about 52.28 % of the study area underwent substantial erosion. Most of the transects located toward north of the northern breakwater saw pro-gradation while those sited at south of the southern breakwater exhibited chronic erosion. The human interventions and presence of artificial structures accelerated the changes in the shoreline and also gave rise to higher uncertainties. The paper will present full details of the methodology, results and their interpretation.

  15. The Efficiency of Random Forest Method for Shoreline Extraction from LANDSAT-8 and GOKTURK-2 Imageries

    Science.gov (United States)

    Bayram, B.; Erdem, F.; Akpinar, B.; Ince, A. K.; Bozkurt, S.; Catal Reis, H.; Seker, D. Z.

    2017-11-01

    Coastal monitoring plays a vital role in environmental planning and hazard management related issues. Since shorelines are fundamental data for environment management, disaster management, coastal erosion studies, modelling of sediment transport and coastal morphodynamics, various techniques have been developed to extract shorelines. Random Forest is one of these techniques which is used in this study for shoreline extraction.. This algorithm is a machine learning method based on decision trees. Decision trees analyse classes of training data creates rules for classification. In this study, Terkos region has been chosen for the proposed method within the scope of "TUBITAK Project (Project No: 115Y718) titled "Integration of Unmanned Aerial Vehicles for Sustainable Coastal Zone Monitoring Model - Three-Dimensional Automatic Coastline Extraction and Analysis: Istanbul-Terkos Example". Random Forest algorithm has been implemented to extract the shoreline of the Black Sea where near the lake from LANDSAT-8 and GOKTURK-2 satellite imageries taken in 2015. The MATLAB environment was used for classification. To obtain land and water-body classes, the Random Forest method has been applied to NIR bands of LANDSAT-8 (5th band) and GOKTURK-2 (4th band) imageries. Each image has been digitized manually and shorelines obtained for accuracy assessment. According to accuracy assessment results, Random Forest method is efficient for both medium and high resolution images for shoreline extraction studies.

  16. THE EFFICIENCY OF RANDOM FOREST METHOD FOR SHORELINE EXTRACTION FROM LANDSAT-8 AND GOKTURK-2 IMAGERIES

    Directory of Open Access Journals (Sweden)

    B. Bayram

    2017-11-01

    Full Text Available Coastal monitoring plays a vital role in environmental planning and hazard management related issues. Since shorelines are fundamental data for environment management, disaster management, coastal erosion studies, modelling of sediment transport and coastal morphodynamics, various techniques have been developed to extract shorelines. Random Forest is one of these techniques which is used in this study for shoreline extraction.. This algorithm is a machine learning method based on decision trees. Decision trees analyse classes of training data creates rules for classification. In this study, Terkos region has been chosen for the proposed method within the scope of "TUBITAK Project (Project No: 115Y718 titled "Integration of Unmanned Aerial Vehicles for Sustainable Coastal Zone Monitoring Model – Three-Dimensional Automatic Coastline Extraction and Analysis: Istanbul-Terkos Example". Random Forest algorithm has been implemented to extract the shoreline of the Black Sea where near the lake from LANDSAT-8 and GOKTURK-2 satellite imageries taken in 2015. The MATLAB environment was used for classification. To obtain land and water-body classes, the Random Forest method has been applied to NIR bands of LANDSAT-8 (5th band and GOKTURK-2 (4th band imageries. Each image has been digitized manually and shorelines obtained for accuracy assessment. According to accuracy assessment results, Random Forest method is efficient for both medium and high resolution images for shoreline extraction studies.

  17. Historical sediment budget and present-day catchment-shoreline coupling at Twofold Bay, southeastern Australia

    Science.gov (United States)

    Tamura, T.; Oliver, T.; Hudson, J.; Woodroffe, C. D.

    2017-12-01

    Considering projected impacts of sea-level rise in the 21st century on sandy shorelines, an understanding of long-term sediment budget for individual beaches or coastal compartments supports assessments of shoreline stability. We examined a low-lying coastal beach-ridge barrier in Twofold Bay using optically stimulated luminescence (OSL) dating , airborne LiDAR, sedimentological analysis and seismic data to assess changes in rates of sediment supply to this shoreline through time. Calculations of barrier volume, Twofold Bay bay-floor sediment volume and estimates of sediment delivery from a proximal river system provide a broad-scale assessment of past-sediment budget. Between ca. 7500 years ago and 1500 years ago, sources of sediment for shoreline progradation at Boydtown were bay-floor sediments either inherited or moved into the embayment during late-stage transgression. Progradation rate between ca. 7500-1500 years ago was 0.16 m/yr with subaerial barrier volume accumulating at 0.46 m3/m/yr. Between ca. 1500 years and present day, the Towamba River to the south has delivered additional sediment to the Boydtown shoreline more than doubling shoreline progradation rate to 0.65 m/yr and subaerial barrier accumulation has risen to 1.83 m3/m/yr. The delivery of fluvial sediment from the Towamba River was restricted to the past ca. 1500 years as prior to this, estuary infilling prevented floods delivering sediments to the bay. This recent historical coupling of river sand supply and shoreline progradation rate implies that anthropogenic modifications to the Towamba River catchment such as river damming, or climatic changes reducing rainfall or runoff, would negatively impact the Boydtown Beach shoreline. Conversely increased rainfall or deforestation may increase sediment discharge due to upstream erosion. The Boydtown shoreline within Twofold Bay may be able to maintain its current position in the coming century if fluvial sediment delivery continues. The fact that

  18. The present and future role of coastal wetland vegetation in protecting shorelines: Answering recent challenges to the paradigm

    Science.gov (United States)

    Gedan, Keryn B.; Kirwan, Matthew L.; Wolanski, Eric; Barbier, Edward B.; Silliman, Brian R.

    2011-01-01

    For more than a century, coastal wetlands have been recognized for their ability to stabilize shorelines and protect coastal communities. However, this paradigm has recently been called into question by small-scale experimental evidence. Here, we conduct a literature review and a small meta-analysis of wave attenuation data, and we find overwhelming evidence in support of established theory. Our review suggests that mangrove and salt marsh vegetation afford context-dependent protection from erosion, storm surge, and potentially small tsunami waves. In biophysical models, field tests, and natural experiments, the presence of wetlands reduces wave heights, property damage, and human deaths. Meta-analysis of wave attenuation by vegetated and unvegetated wetland sites highlights the critical role of vegetation in attenuating waves. Although we find coastal wetland vegetation to be an effective shoreline buffer, wetlands cannot protect shorelines in all locations or scenarios; indeed large-scale regional erosion, river meandering, and large tsunami waves and storm surges can overwhelm the attenuation effect of vegetation. However, due to a nonlinear relationship between wave attenuation and wetland size, even small wetlands afford substantial protection from waves. Combining man-made structures with wetlands in ways that mimic nature is likely to increase coastal protection. Oyster domes, for example, can be used in combination with natural wetlands to protect shorelines and restore critical fishery habitat. Finally, coastal wetland vegetation modifies shorelines in ways (e.g. peat accretion) that increase shoreline integrity over long timescales and thus provides a lasting coastal adaptation measure that can protect shorelines against accelerated sea level rise and more frequent storm inundation. We conclude that the shoreline protection paradigm still stands, but that gaps remain in our knowledge about the mechanistic and context-dependent aspects of shoreline

  19. Erosion and erosion-corrosion

    International Nuclear Information System (INIS)

    Isomoto, Yoshinori

    2008-01-01

    It is very difficult to interpret the technical term of erosion-corrosion' which is sometimes encountered in piping systems of power plants, because of complicated mechanisms and several confusing definitions of erosion-corrosion phenomena. 'FAC (flow accelerated corrosion)' is recently introduced as wall thinning of materials in power plant systems, as a representative of 'erosion-corrosion'. FAC is, however, not necessarily well understood and compared with erosion-corrosion. This paper describes firstly the origin, definition and fundamental understandings of erosion and erosion-corrosion, in order to reconsider and reconfirm the phenomena of erosion, erosion-corrosion and FAC. Next, typical mapping of erosion, corrosion, erosion-corrosion and FAC are introduced in flow velocity and environmental corrosiveness axes. The concept of damage rate in erosion-corrosion is finally discussed, connecting dissolution rate, mass transfer of metal ions in a metal oxide film and film growth. (author)

  20. Dynamics of the spatial structure of pulsed discharges in dense gases in point cathode−plane anode gaps and their erosion effect on the plane electrode surface

    International Nuclear Information System (INIS)

    Baksht, E. Kh.; Blinova, O. M.; Erofeev, M. V.; Karelin, V. I.; Ripenko, V. S.; Tarasenko, V. F.; Trenkin, A. A.; Shibitov, Yu. M.; Shulepov, M. A.

    2016-01-01

    The dynamics of the spatial structure of the plasma of pulsed discharges in air and nitrogen in a nonuniform electric field and their erosion effect on the plane anode surface were studied experimentally. It is established that, at a nanosecond front of the voltage pulse, a diffuse discharge forms in the point cathode–plane anode gap due to the ionization wave propagating from the cathode. As the gap length decreases, the diffuse discharge transforms into a spark. A bright spot on the anode appears during the diffuse discharge, while the spark channel forms in the later discharge stage. The microstructure of autographs of anode spots and spark channels in discharges with durations of several nanoseconds is revealed. The autographs consist of up to 100 and more microcraters 5–100 μm in diameter. It is shown that, due to the short duration of the voltage pulse, a diffuse discharge can be implemented, several pulses of which do not produce appreciable erosion on the plane anode or the soot coating deposited on it.

  1. 55-year (1960-2015) spatiotemporal shoreline change analysis using historical DISP and Landsat time series data in Shanghai

    Science.gov (United States)

    Qiao, Gang; Mi, Huan; Wang, Weian; Tong, Xiaohua; Li, Zhongbin; Li, Tan; Liu, Shijie; Hong, Yang

    2018-06-01

    Shoreline change has been an increasing concern for low-lying and vulnerable coastal zones worldwide, especially in estuarine delta regions, which generally have significant economic development, large human settlements and infrastructures. Thus, long time-series shoreline change data are useful for understanding how shorelines respond to natural and anthropogenic activities, as well as for providing greater insights into coastal protection and sustainable development in the future. For the first time, this study analyzes 55 years of spatiotemporal shoreline changes in Shanghai, China, by integrating the historical Declassified Intelligence Satellite Photography (DISP) and Landsat time series data at five-year intervals from 1960 to 2015. Twelve shorelines were interpreted from DISP and Landsat images. The spatiotemporal changes in the shorelines were explored at five-year intervals within the study period for the Shanghai mainland and islands. The results indicate that shorelines in Shanghai accreted significantly over the last 55 years, but different accretion patterns were observed in Chongming Dongtan. The rate of shoreline change varied in different areas, and the most noticeable expansions were Chongming Beitan, Chongming Dongtan, Hengsha Dongtan, and Nanhuizui. The length of the entire shoreline increased by 25.7% from 472.6 km in 1960 to 594.2 km in 2015. Due to the shoreline changes, the Shanghai area expanded by 1,192.5 km2 by 2015, which was an increase of 19.9% relative to its 1960 area. The Digital Shoreline Analysis System (DSAS) was used to compute rate-of-change statistics. Between 1960 and 2015, 10.6% of the total transects exceeded 3 km of Net Shoreline Movement (NSM), with a maximum value of approximately 20 km at eastern Hengsha Island. The average Weighted Linear Regression Rate (WLR) of the Shanghai shoreline was 52.2 m/yr from 1960 to 2015; there was 94.1% accretion, 3.1% erosion, and 2.8% with no significant change. In addition, the driving

  2. Coastal Erosion Control Methods

    Science.gov (United States)

    Greene, V.

    2016-12-01

    Coastal erosion is bad because the ecosystem there will be washed away and the animals could drown or be displaced and have to adapt to a new ecosystem that they are not prepared for. I'm interested in this problem because if there aren't beaches when I grow up I won't be able to do the things I would really like to do. I would like to be a marine biologist. Secondly, I don't want to see beach houses washed away. I would like to see people live in harmony with their environment. So, to study ways in which to preserve beaches I will make and use models that test different erosion controls. Two different ideas for erosion control I tested are using seaweed or a rock berm. I think the rock berm will work better than the model of seaweed because the seaweed is under water and the waves can carry the sand over the seaweed, and the rock berm will work better because the rocks will help break the waves up before they reach the shore and the waves can not carry the sand over the rocks that are above the water. To investigate this I got a container to use to model the Gulf of Mexico coastline. I performed several test runs using sand and water in the container to mimic the beach and waves from the Gulf of Mexico hitting the shoreline. I did three trials for the control (no erosion control), seaweed and a rock berm. Rock berms are a border of a raised area of rock. The model for seaweed that I used was plastic shopping bags cut into strips and glued to the bottom of my container to mimic seaweed. My results were that the control had the most erosion which ranged from 2.75 - 3 inches over 3 trials. The seaweed was a little better than the control but was very variable and ranged from 1.5 - 3 inches over 3 trials. The rock berm worked the best out of all at controlling erosion with erosion ranging from 1.5 - 2 inches. My hypothesis was correct because the rock berm did best to control erosion compared to the control which had no erosion control and the model with seaweed.

  3. Performance of a process-based hydrodynamic model in predicting shoreline change

    Science.gov (United States)

    Safak, I.; Warner, J. C.; List, J. H.

    2012-12-01

    Shoreline change is controlled by a complex combination of processes that include waves, currents, sediment characteristics and availability, geologic framework, human interventions, and sea level rise. A comprehensive data set of shoreline position (14 shorelines between 1978-2002) along the continuous and relatively non-interrupted North Carolina Coast from Oregon Inlet to Cape Hatteras (65 km) reveals a spatial pattern of alternating erosion and accretion, with an erosional average shoreline change rate of -1.6 m/yr and up to -8 m/yr in some locations. This data set gives a unique opportunity to study long-term shoreline change in an area hit by frequent storm events while relatively uninfluenced by human interventions and the effects of tidal inlets. Accurate predictions of long-term shoreline change may require a model that accurately resolves surf zone processes and sediment transport patterns. Conventional methods for predicting shoreline change such as one-line models and regression of shoreline positions have been designed for computational efficiency. These methods, however, not only have several underlying restrictions (validity for small angle of wave approach, assuming bottom contours and shoreline to be parallel, depth of closure, etc.) but also their empirical estimates of sediment transport rates in the surf zone have been shown to vary greatly from the calculations of process-based hydrodynamic models. We focus on hind-casting long-term shoreline change using components of the process-based, three-dimensional coupled-ocean-atmosphere-wave-sediment transport modeling system (COAWST). COAWST is forced with historical predictions of atmospheric and oceanographic data from public-domain global models. Through a method of coupled concurrent grid-refinement approach in COAWST, the finest grid with resolution of O(10 m) that covers the surf zone along the section of interest is forced at its spatial boundaries with waves and currents computed on the grids

  4. Positional Accuracy Assessment for Effective Shoreline Change ...

    African Journals Online (AJOL)

    Michael

    2016-06-01

    Jun 1, 2016 ... as backdrop in GIS environment. Positional error of ... integrated dataset obviously bore the cumulative effect of the input datasets. ... change. The shoreline, which is the interface between land ... modelling, which enables future shoreline change trend to ..... as gaps due to cloud cover and limitation of the.

  5. Positional Accuracy Assessment for Effective Shoreline Change ...

    African Journals Online (AJOL)

    Ghana Mining Journal ... Data quality may be expressed in terms of several indicators such as attributes, temporal or positional accuracies. ... It is concluded that for the purpose of shoreline change analysis, such as shoreline change trends, large scale data sources should be used where possible for accurate ...

  6. Shoreline response to detached breakwaters in prototype

    NARCIS (Netherlands)

    Khuong, T.C.

    2016-01-01

    An accurate prediction of shoreline changes behind detached breakwaters is, in regard to the adjustment to the environmental impact, still a challenge for designers and coastal managers. This research is expected to fill the gaps in the estimation of shoreline changes by developing new and

  7. Uncertainties in sandy shorelines evolution under the Bruun rule assumption

    Directory of Open Access Journals (Sweden)

    Gonéri eLe Cozannet

    2016-04-01

    Full Text Available In the current practice of sandy shoreline change assessments, the local sedimentary budget is evaluated using the sediment balance equation, that is, by summing the contributions of longshore and cross-shore processes. The contribution of future sea-level-rise induced by climate change is usually obtained using the Bruun rule, which assumes that the shoreline retreat is equal to the change of sea-level divided by the slope of the upper shoreface. However, it remains unsure that this approach is appropriate to account for the impacts of future sea-level rise. This is due to the lack of relevant observations to validate the Bruun rule under the expected sea-level rise rates. To address this issue, this article estimates the coastal settings and period of time under which the use of the Bruun rule could be (invalidated, in the case of wave-exposed gently-sloping sandy beaches. Using the sedimentary budgets of Stive (2004 and probabilistic sea-level rise scenarios based on IPCC, we provide shoreline change projections that account for all uncertain hydrosedimentary processes affecting idealized coasts (impacts of sea-level rise, storms and other cross-shore and longshore processes. We evaluate the relative importance of each source of uncertainties in the sediment balance equation using a global sensitivity analysis. For scenario RCP 6.0 and 8.5 and in the absence of coastal defences, the model predicts a perceivable shift toward generalized beach erosion by the middle of the 21st century. In contrast, the model predictions are unlikely to differ from the current situation in case of scenario RCP 2.6. Finally, the contribution of sea-level rise and climate change scenarios to sandy shoreline change projections uncertainties increases with time during the 21st century. Our results have three primary implications for coastal settings similar to those provided described in Stive (2004 : first, the validation of the Bruun rule will not necessarily be

  8. Spatio-temporal evolution of shoreline changes along the coast between sousse- Monastir (Eastearn of Tunisia)

    Science.gov (United States)

    Fathallah, S.; Ben Amor, R.; Gueddari, M.

    2009-04-01

    Spatio-temporal evolution of shoreline Changes along the coast between Sousse-Monastir (Eastern of Tunisia). Safa Fathallah*, Rim Ben Amor and Moncef Gueddari Unit of Research of Geochemistry and Environmental Geology. Faculty of Science of Tunis, University of Tunis El Manar, 2092. (*) Corresponding author: safa_fathallah@yahoo.fr The coast of Sousse-Monastir in eastern of Tunisia, has undergone great changes, due to natural and anthropic factors. Increasing human use, the construction of two ports and coastal urbanization (hotels and industries) has accelerated the erosion process. The coastal defense structures (breakwaters and enrockment), built to protect the most eroded zone are efficient, but eroded zones appeared in the southern part of breakwaters. Recent and historic aerial photography was used to estimate, observe, and analyze past shoreline and bathymetric positions and trends involving shore evolution for Sousse-Monastir coast. All of the photographs were calibrated and mosaicked by Arc Map Gis 9.1, the years used are 1925, 1962, 1988, 1996, and 2001 for shoreline change analysis and 1884 and 2001 for bathymetric changes. The analyze of this photographs show that the zone located at the south of breakwater are mostly eroded with high speed process (2m/year). Another zone appears as eroded at the south part of Hamdoun River, with 1,5m/year erosion speed . Keywords: Shoreline evolution, defense structures, Sousse-Monastir coast, Tunisia.

  9. Quantifying the effectiveness of shoreline armoring removal on coastal biota of Puget Sound.

    Science.gov (United States)

    Lee, Timothy S; Toft, Jason D; Cordell, Jeffery R; Dethier, Megan N; Adams, Jeffrey W; Kelly, Ryan P

    2018-01-01

    Shoreline armoring is prevalent around the world with unprecedented human population growth and urbanization along coastal habitats. Armoring structures, such as riprap and bulkheads, that are built to prevent beach erosion and protect coastal infrastructure from storms and flooding can cause deterioration of habitats for migratory fish species, disrupt aquatic-terrestrial connectivity, and reduce overall coastal ecosystem health. Relative to armored shorelines, natural shorelines retain valuable habitats for macroinvertebrates and other coastal biota. One question is whether the impacts of armoring are reversible, allowing restoration via armoring removal and related actions of sediment nourishment and replanting of native riparian vegetation. Armoring removal is targeted as a viable option for restoring some habitat functions, but few assessments of coastal biota response exist. Here, we use opportunistic sampling of pre- and post-restoration data for five biotic measures (wrack % cover, saltmarsh % cover, number of logs, and macroinvertebrate abundance and richness) from a set of six restored sites in Puget Sound, WA, USA. This broad suite of ecosystem metrics responded strongly and positively to armor removal, and these results were evident after less than one year. Restoration responses remained positive and statistically significant across different shoreline elevations and temporal trajectories. This analysis shows that removing shoreline armoring is effective for restoration projects aimed at improving the health and productivity of coastal ecosystems, and these results may be widely applicable.

  10. Quantifying the effectiveness of shoreline armoring removal on coastal biota of Puget Sound

    Directory of Open Access Journals (Sweden)

    Timothy S. Lee

    2018-02-01

    Full Text Available Shoreline armoring is prevalent around the world with unprecedented human population growth and urbanization along coastal habitats. Armoring structures, such as riprap and bulkheads, that are built to prevent beach erosion and protect coastal infrastructure from storms and flooding can cause deterioration of habitats for migratory fish species, disrupt aquatic–terrestrial connectivity, and reduce overall coastal ecosystem health. Relative to armored shorelines, natural shorelines retain valuable habitats for macroinvertebrates and other coastal biota. One question is whether the impacts of armoring are reversible, allowing restoration via armoring removal and related actions of sediment nourishment and replanting of native riparian vegetation. Armoring removal is targeted as a viable option for restoring some habitat functions, but few assessments of coastal biota response exist. Here, we use opportunistic sampling of pre- and post-restoration data for five biotic measures (wrack % cover, saltmarsh % cover, number of logs, and macroinvertebrate abundance and richness from a set of six restored sites in Puget Sound, WA, USA. This broad suite of ecosystem metrics responded strongly and positively to armor removal, and these results were evident after less than one year. Restoration responses remained positive and statistically significant across different shoreline elevations and temporal trajectories. This analysis shows that removing shoreline armoring is effective for restoration projects aimed at improving the health and productivity of coastal ecosystems, and these results may be widely applicable.

  11. Medium-term shoreline evolution of the mediterranean coast of Andalusia (SW Spain)

    Science.gov (United States)

    Liguori, Vincenzo; Manno, Giorgio; Messina, Enrica; Anfuso, Giorgio; Suffo, Miguel

    2015-04-01

    Coastal environment is a dynamic system in which numerous natural processes are continuously actuating and interacting among them. As a result, geomorphologic, physical and biological characteristics of coastal environments are constantly changing. Such dynamic balance is nowadays seriously threatened by the strong and increasing anthropic pressure that favors erosion processes, and the associated loss of environmental, ecologic and economic aspects. Sandy beaches are the most vulnerable environments in coastal areas. The aim of this work was to reconstruct the historical evolution of the Mediterranean coastline of Andalusia, Spain. The investigated area is about 500 km in length and includes the provinces of Cadiz, Malaga, Granada and Almeria. It is essentially composed by cliffed sectors with sand and gravel pocket beaches constituting independent morphological cells of different dimensions. This study was based on the analysis of aerial photos and satellite images covering a period of 55 years, between 1956 and 2011. Aerial photos were scanned and geo-referenced in order to solve scale and distortion problems. The shoreline was considered and mapped through the identification of the wet / dry sand limit which coincides with the line of maximum run-up; this indicator - representing the shoreline at the moment of the photo - is the most easily identifiable and representative one in microtidal coastal environments. Since shoreline position is linked to beach profile characteristics and to waves, tide and wind conditions at the moment of the photo, such parameters were taken into account in the calculation of shoreline position and changes. Specifically, retreat/accretion changes were reconstructed applying the DSAS method (Digital Shoreline Analysis System) proposed by the US Geological Survey. Significant beach accretion was observed at Playa La Mamola (Granada), with +1 m/y, because the construction of five breakwaters, and at Playa El Cantal (Almeria) and close

  12. Numerical prediction of shoreline adjacent to breakwater

    Digital Repository Service at National Institute of Oceanography (India)

    Mahadevan, R.; Chandramohan, P.; Nayak, B.U.

    Existing mathematical models for prediction of shoreline changes in the vicinity of a breakwater were reviewed The analytical and numerical results obtained from these models have been compared Under the numerical approach, two different implicit...

  13. Historical Shoreline for Louisiana, Geographic NAD83, NOAA (2001) [shoreline_la_NOAA_1986

    Data.gov (United States)

    Louisiana Geographic Information Center — These data were automated to provide a suitable geographic information system (GIS) data layer depicting the historical shoreline for Louisiana. These data are...

  14. Decadal changes in the land use/land cover and shoreline along the coastal districts of southern Gujarat, India.

    Science.gov (United States)

    Misra, A; Balaji, R

    2015-07-01

    The coastal zone along the districts of Surat, Navsari, and Valsad in southern Gujarat, India, is reported to be facing serious environmental challenges in the form of shoreline erosion, wetland loss, and man-made encroachments. This study assesses the decadal land use/ land cover (LULC) changes in these three districts for the years 1990, 2001, and 2014 using satellite datasets of Landsat TM, ETM, and OLI. The LULC changes are identified by using band ratios as a pre-classification step, followed by implementation of hybrid classification (a combination of supervised and unsupervised classification). An accuracy assessment is carried out for each dataset, and the overall accuracy ranges from 90 to 95%. It is observed that the spatial extents of aquaculture, urban built-up, and barren classes have appreciated over time, whereas the coverage of mudflats has depreciated due to rapid urbanization. The changes in the shoreline of these districts have also been analyzed for the same years, and significant changes are found in the form of shoreline erosion. The LULC maps prepared as well as the shoreline change analysis done for this study area will enable the local decision makers to adopt better land-use planning and shoreline protection measures, which will further aid in sustainable future developments in this region.

  15. Exploring the Dominant Modes of Shoreline Change Along the Central Florida Atlantic Coast

    Science.gov (United States)

    Conlin, M. P.; Adams, P. N.; Jaeger, J. M.; MacKenzie, R.

    2017-12-01

    Geomorphic change within the littoral zone can place communities, ecosystems, and critical infrastructure at risk as the coastal environment responds to changes in sea level, sediment supply, and wave climate. At NASA's Kennedy Space Center near Cape Canaveral, Florida, chronic shoreline retreat currently threatens critical launch infrastructure, but the spatial (alongshore) pattern of this hazard has not been well documented. During a 5-year monitoring campaign (2009-2014), 86 monthly and rapid-response RTK GPS surveys were completed along this 11 km-long coastal reach in order to monitor and characterize shoreline change and identify links between ocean forcing and beach morphology. Results indicate that the study area can be divided into four behaviorally-distinct alongshore regions based on seasonal variability in shoreline change, mediated by the complex offshore bathymetry of the Cape Canaveral shoals. In addition, seasonal erosion/accretion cycles are regularly interrupted by large erosive storm events, especially during the anomalous wave climates produced during winter Nor'Easter storms. An effective tool for analyzing multidimensional datasets like this one is Empirical Orthogonal Function (EOF) analysis, a technique to determine the dominant spatial and temporal signals within a dataset. Using this approach, it is possible to identify the main time and space scales (modes) along which coastal changes are occurring. Through correlation of these changes with oceanographic forcing mechanisms, we are enabled to infer the principal drivers of shoreline change at this site. Here, we document the results of EOF analysis applied to the Cape Canaveral shoreline change dataset, and further correlate the results of this analysis with oceanographic forcings in order to reveal the dominant modes as well as drivers of coastal variability along the central Atlantic coast of Florida. This EOF-based analysis, which is the first such analysis in the region, is shedding

  16. Correlation between land use changes and shoreline changes around THE Nakdong River in Korea using landsat images.

    Science.gov (United States)

    Kwon, J. S.; Lim, C.; Baek, S. G.; Shin, S.

    2015-12-01

    Coastal erosion has badly affected the marine environment, as well as the safety of various coastal structures. In order to monitor shoreline changes due to coastal erosion, remote sensing techniques are being utilized. The land-cover map classifies the physical material on the surface of the earth, and it can be utilized in establishing eco-policy and land-use policy. In this study, we analyzed the correlation between land-use changes around the Nakdong River and shoreline changes at Busan Dadaepo Beach adjacent to the river. We produced the land-cover map based on the guidelines published by the Ministry of Environment Korea, using eight Landsat satellite images obtained from 1984 to 2015. To observe land use changes around the Nakdong River, the study site was set to include the surroundings areas of the Busan Dadaepo Beach, the Nakdong River as well as its estuary, and also Busan New Port. For the land-use classification of the study site, we also produced a land-cover map divided into seven categories according to the Ministry of Environment, Korea guidelines and using the most accurate Maximum Likelihood Method (MLM). Land use changes inland, at 500m from the shoreline, were excluded for the correlation analysis between land use changes and shoreline changes. The other categories, except for the water category, were transformed into numerical values and the land-use classifications, using all other categories, were analyzed. Shoreline changes were observed by setting the base-line and three cut-lines. We assumed that longshore bars around the Nakdong River and the shoreline of the Busan Dadaepo Beach are affected. Therefore, we expect that shoreline changes happen due to the influence of barren land, wetlands, built-up areas and deposition. The causes are due to natural factors, such as weather, waves, tide currents, longshore currents, and also artificial factors such as coastal structures, construction, and dredging.

  17. Pleistocene Lake Bonneville and Eberswalde Crater of Mars: Quantitative Methods for Recognizing Poorly Developed Lacustrine Shorelines

    Science.gov (United States)

    Jewell, P. W.

    2014-12-01

    The ability to quantify shoreline features on Earth has been aided by advances in acquisition of high-resolution topography through laser imaging and photogrammetry. Well-defined and well-documented features such as the Bonneville, Provo, and Stansbury shorelines of Late Pleistocene Lake Bonneville are recognizable to the untrained eye and easily mappable on aerial photos. The continuity and correlation of lesser shorelines must rely quantitative algorithms for processing high-resolution data in order to gain widespread scientific acceptance. Using Savitsky-Golay filters and the geomorphic methods and criteria described by Hare et al. [2001], minor, transgressive, erosional shorelines of Lake Bonneville have been identified and correlated across the basin with varying degrees of statistical confidence. Results solve one of the key paradoxes of Lake Bonneville first described by G. K. Gilbert in the late 19th century and point the way for understanding climatically driven oscillations of the Last Glacial Maximum in the Great Basin of the United States. Similar techniques have been applied to the Eberswalde Crater area of Mars using HRiSE DEMs (1 m horizontal resolution) where a paleolake is hypothesized to have existed. Results illustrate the challenges of identifying shorelines where long term aeolian processes have degraded the shorelines and field validation is not possible. The work illustrates the promises and challenges of indentifying remnants of a global ocean elsewhere on the red planet.

  18. Spatiotemporal shoreline dynamics of Namibian coastal lagoons derived by a dense remote sensing time series approach

    Science.gov (United States)

    Behling, Robert; Milewski, Robert; Chabrillat, Sabine

    2018-06-01

    This paper proposes the remote sensing time series approach WLMO (Water-Land MOnitor) to monitor spatiotemporal shoreline changes. The approach uses a hierarchical classification system based on temporal MNDWI-trajectories with the goal to accommodate typical uncertainties in remote sensing shoreline extraction techniques such as existence of clouds and geometric mismatches between images. Applied to a dense Landsat time series between 1984 and 2014 for the two Namibian coastal lagoons at Walvis Bay and Sandwich Harbour the WLMO was able to identify detailed accretion and erosion progressions at the sand spits forming these lagoons. For both lagoons a northward expansion of the sand spits of up to 1000 m was identified, which corresponds well with the prevailing northwards directed ocean current and wind processes that are responsible for the material transport along the shore. At Walvis Bay we could also show that in the 30 years of analysis the sand spit's width has decreased by more than a half from 750 m in 1984-360 m in 2014. This ongoing cross-shore erosion process is a severe risk for future sand spit breaching, which would expose parts of the lagoon and the city to the open ocean. One of the major advantages of WLMO is the opportunity to analyze detailed spatiotemporal shoreline changes. Thus, it could be shown that the observed long-term accretion and erosion processes underwent great variations over time and cannot a priori be assumed as linear processes. Such detailed spatiotemporal process patterns are a prerequisite to improve the understanding of the processes forming the Namibian shorelines. Moreover, the approach has also the potential to be used in other coastal areas, because the focus on MNDWI-trajectories allows the transfer to many multispectral satellite sensors (e.g. Sentinel-2, ASTER) available worldwide.

  19. Erosive gastritis

    International Nuclear Information System (INIS)

    Mohammed, S.H.; Conrad, C.; Kjoergaad, J.

    1982-01-01

    Erosive gastritis is a well-defined radiologic and endoscopic entity. It is one of the common causes of upper gastrointestinal bleeding, yet it is seldom diagnosed and often confused with a number of other diseases. This communication re-emphasizes the characteristic endoscopic and radiologic features of erosive gastritis and its differential diagnosis. Two representative cases are reported. (orig.)

  20. Erosive gastritis

    Energy Technology Data Exchange (ETDEWEB)

    Mohammed, S.H.; Conrad, C.; Kjoergaad, J.

    1982-08-01

    Erosive gastritis is a well-defined radiologic and endoscopic entity. It is one of the common causes of upper gastrointestinal bleeding, yet it is seldom diagnosed and often confused with a number of other diseases. This communication re-emphasizes the characteristic endoscopic and radiologic features of erosive gastritis and its differential diagnosis. Two representative cases are reported.

  1. Utilizing topobathy LIDAR datasets to identify shoreline variations and to direct charting updates in the northern Gulf of Mexico

    Science.gov (United States)

    Gremillion, S. L.; Wright, S. L.

    2017-12-01

    Topographic and bathymetric light detection and ranging (LIDAR), remote sensing tools used to measure vertical elevations, are commonly employed to monitor shoreline fluctuations. Many of these publicly available datasets provide wide-swath, nearshore topobathy which can be used to extract shoreline positions and analyze coastlines experiencing the greatest temporal and spatial variability. This study focused on the shorelines of Mississippi's Jackson County to determine the minimum time for significant positional changes to occur, relative to currently published NOAA navigational charts. Many of these dynamic shorelines are vulnerable to relative sea level rise, storm surge, and coastal erosion. Utilizing LIDAR datasets from 1998-2015, shoreline positions were derived and analyzed against NOAA's Continually Updated Shoreline Product (CUSP) to recommend the frequency at which future surveys should be conducted. Advisement of charting updates were based upon the resolution of published charts, and the magnitude of observed variances. Jackson County shorelines were divided into four areas for analysis; the mainland, Horn Island, Petit Bois Island (PBI), and a dredge spoil area west of PBI. The mainland shoreline experienced an average change rate of +0.57 m/yr during the study period. This stability was due to engineering structures implemented in the early 1920's to protect against tropical storms. Horn Island, the most stable barrier island, changed an average of -1.34 m/yr, while PBI had an average change of -2.70 m/yr throughout. Lastly, the dredge spoil area changed by +9.06 m/yr. Based on these results, it is recommended that LIDAR surveys for Jackson County's mainland be conducted at least every two years, while surveys of the offshore barrier islands be conducted annually. Furthermore, insufficient LIDAR data for Round Island and the Round Island Marsh Restoration Project highlight these two areas as priority targets for future surveys.

  2. Preliminary study of soil liquefaction hazard at Terengganu shoreline, Peninsular Malaysia

    Science.gov (United States)

    Hashim, H.; Suhatril, M.; Hashim, R.

    2017-06-01

    Terengganu is a shoreline state located in Peninsular Malaysia which is a growing hub for port industries and tourism centre. The northern part offers pristine settings of a relax beach areas whereas the southern part are observed to be a growing centre for development. The serious erosion on soil deposit along the beach line presents vulnerable soil condition to soil liquefaction consists of sandy with low plasticity and shallow ground water. Moreover, local earthquake from nearby fault have present significant tremors over the past few years which need to be considered in the land usage or future development in catering the seismic loading. Liquefaction analysis based on field standard penetration of soil is applied on 546 boreholes scattered along the shoreline areas ranging 244 km of shoreline stretch. Based on simplified approach, it is found that more than 70% of the studied areas pose high liquefaction potential since there are saturated loose sand and silt deposits layer ranges at depth 3 m and up to 20 m. The presence of clay deposits and hard stratum at the remaining 30% of the studied areas shows good resistance to soil liquefaction hence making the area less significant to liquefaction hazard. Result indicates that liquefaction improving technique is advisable in future development of shoreline areas of Terengganu state.

  3. Shoreline clean-up methods : biological treatments

    Energy Technology Data Exchange (ETDEWEB)

    Massoura, S.T. [Oil Spill Response Limited, Southampton (United Kingdom)

    2009-07-01

    The cleanup of oil spills in shoreline environments is a challenging issue worldwide. Oil spills receive public and media attention, particularly in the event of a coastal impact. It is important to evaluate the efficiency and effectiveness of cleanup methods when defining the level of effort and consequences that are appropriate to remove or treat different types of oil on different shoreline substrates. Of the many studies that have compared different mechanical, chemical and biological treatments for their effectiveness on various types of oil, biological techniques have received the most attention. For that reason, this paper evaluated the effectiveness and effects of shoreline cleanup methods using biological techniques. It summarized data from field experiments and oil spill incidents, including the Exxon Valdez, Sea Empress, Prestige, Grand Eagle, Nakhodka, Guanabara Bay and various Gulf war oil spills. Five major shoreline types were examined, notably rocky intertidal, cobble/pebble/gravel, sand/mud, saltmarsh, and mangrove/sea-grass. The biological techniques that were addressed were nutrient enrichment, hydrocarbon-utilizing bacteria, vegetable oil biosolvents, plants, surf washing, oil-particle interactions and natural attenuation. The study considered the oil type, volume and fate of stranded oil, location of coastal materials, extent of pollution and the impact of biological techniques. The main factors that affect biodegradation of hydrocarbons are the volume, chemical composition and weathering state of the petroleum product as well as the temperature, oxygen availability of nutrients, water salinity, pH level, water content, and microorganisms in the shoreline environment. The interaction of these factors also affect the biodegradation of oil. It was concluded that understanding the fate of stranded oil can help in the development of techniques that improve the weathering and degradation of oil on complex shoreline substrates. 39 refs.

  4. National assessment of shoreline change—Summary statistics for updated vector shorelines and associated shoreline change data for the Gulf of Mexico and Southeast Atlantic coasts

    Science.gov (United States)

    Himmelstoss, Emily A.; Kratzmann, Meredith G.; Thieler, E. Robert

    2017-07-18

    Long-term rates of shoreline change for the Gulf of Mexico and Southeast Atlantic regions of the United States have been updated as part of the U.S. Geological Survey’s National Assessment of Shoreline Change project. Additional shoreline position data were used to compute rates where the previous rate-of-change assessment only included four shoreline positions at a given location. The long-term shoreline change rates also incorporate the proxy-datum bias correction to account for the unidirectional onshore bias of the proxy-based high water line shorelines relative to the datum-based mean high water shorelines. The calculation of uncertainty associated with the long-term average rates has also been updated to match refined methods used in other study regions of the National Assessment project. The average rates reported here have a reduced amount of uncertainty relative to those presented in the previous assessments for these two regions.

  5. Eureka Littoral Cell CRSMP Humboldt Bay Shoreline Types 2011

    Data.gov (United States)

    California Natural Resource Agency — In 2011 Aldaron Laird walked and kayaked the entire shoreline of Humboldt Bay mapping the shoreline conditions onto 11x17 laminated fieldmaps at a scale of 1' = 200'...

  6. Changes in the shoreline at Paradip Port, India in response to climate change

    Science.gov (United States)

    Gopikrishna, B.; Deo, M. C.

    2018-02-01

    One of the popular methods to predict shoreline shifts into the future involves use of a shoreline evolution model driven by the historical wave climate. It is however understood by now that historical wave conditions might substantially change in future in response to climate change induced by the global warming. The future shoreline changes as well as sediment transport therefore need to be determined with the help of future projections of wave climate. In this work this is done at the port of Paradip situated along the east coast of India. The high resolution wind resulting from a climate modelling experiment called: CORDEX, South Asia, was used to simulate waves over two time-slices of 25 years each in past and future. The wave simulations were carried out with the help of a numerical wave model. Thereafter, rates of longshore sediment transport as well as shoreline shifts were determined over past and future using a numerical shoreline model. It was found that at Paradip Port the net littoral drift per metre width of cross-shore might go up by 37% and so also the net accumulated drift over the entire cross-shore width by 71%. This could be caused by an increase in the mean significant wave height of around 32% and also by changes in the frequency and direction of waves. The intensification of waves in turn might result from an increase in the mean wind speed of around 19%. Similarly, the horizontal extent of the beach accretion and erosion at the port's southern breakwater might go up by 4 m and 8 m, respectively, from the current level in another 25 years. This study should be useful in framing future port management strategies.

  7. Optimal index related to the shoreline dynamics during a storm: the case of Jesolo beach

    Science.gov (United States)

    Archetti, Renata; Paci, Agnese; Carniel, Sandro; Bonaldo, Davide

    2016-05-01

    The paper presents an application of shoreline monitoring aimed at understanding the response of a beach to single storms and at identifying its typical behaviour, in order to be able to predict shoreline changes and to properly plan the defence of the shore zone. On the study area, in Jesolo beach (northern Adriatic Sea, Italy), a video monitoring station and an acoustic wave and current profiler were installed in spring 2013, recording, respectively, images and hydrodynamic data. The site lacks previous detailed hydrodynamic and morphodynamic data. Variations in the shoreline were quantified in combination with available near-shore wave conditions, making it possible to analyse the relationship between the shoreline displacement and the wave features. Results denote characteristic patterns of beach response to storm events, and highlight the importance of improving beach protection in this zone, notwithstanding the many interventions experimented in the last decades. A total of 31 independent storm events were selected during the period October 2013-October 2014, and for each of them synthetic indexes based on storm duration, energy and maximum wave height were developed and estimated. It was found that the net shoreline displacements during a storm are well correlated with the total wave energy associated to the considered storm by an empirical power law equation. A sub-selection of storms in the presence of an artificial dune protecting the beach (in the winter season) was examined in detail, allowing to conclude that the adoption of this coastal defence strategy in the study area can reduce shoreline retreat during a storm. This type of intervention can sometimes contribute to prolonging overall stability not only in the replenished zone but also in downdrift areas. The implemented methodology, which confirms to be economically attractive if compared to more traditional monitoring systems, proves to be a valuable system to monitor beach erosive processes and

  8. Monitoring Shoreline Change using Remote Sensing and GIS: A ...

    African Journals Online (AJOL)

    Key words: remote sensing, geographic information system (GIS), aerial photographs, shoreline change. Data from aerial photographs taken in 1981, 1992 and 2002 of the Kunduchi shoreline off the Dar es Salaam coast were integrated in a geographic information system (GIS) to determine shoreline change in that locality.

  9. Response of Living Shorelines to Wave Energy and Sea Level rise: Short-term Resilience and Long-term Vulnerability in North Carolina

    Science.gov (United States)

    Currin, C.; Davis, J.

    2017-12-01

    A decade of research and monitoring of Living Shoreline sites in North Carolina identifies both resilient and vulnerable features of this approach to estuarine shoreline stabilization. We used a wave energy model to calculate representative wave energy along 1500 miles of estuarine shoreline, and observed a linear, negative relationship between wind-wave energy and the width of fringing salt marshes. Proximity to navigation channels (boat wakes) further reduced fringing marsh width. These results provide guidance for Living Shoreline design alternatives. Surface elevation tables (SETs) deployed at the lower edge of both natural fringing marshes and `Living Shoreline' marsh-sill sites demonstrated that while natural marshes were losing surface elevation at an average rate of 6 mm y-1, marsh surface elevation at Living Shoreline sites increased at an average of 3 mm y-1. Marsh vegetation at the lower edge of natural sites exhibited a decline in biomass, while Living Shoreline sites exhibited an increase in upper marsh species and an extension of lower marsh into previous mudflat habitat. These changes provide Living Shoreline (marsh-sill) sites with added resilience to sea level rise, though decreased inundation alters the delivery of other ecosystem services (fish habitat, nutrient cycling). North Carolina lagoonal estuaries have low suspended sediment supply and low topography, and modeling predicts that landward transgression is the primary means by which salt marsh acreage can be maintained under moderate to high sea level rise scenarios. In this region, bank erosion can be important source of sediment to wetland habitats. Further, the association of built infrastructure with Living Shoreline sites portends a future scenario of coastal squeeze, as marsh migration landward will be inhibited.

  10. Bank erosion of navigation canals in the western and central Gulf of Mexico

    Science.gov (United States)

    Thatcher, Cindy A.; Hartley, Stephen B.; Wilson, Scott A.

    2011-01-01

    Erosion of navigation canal banks is a direct cause of land loss, but there has been little quantitative analysis to determine why certain major canals exhibit faster widening rates (indicative of erosion) than others in the coastal zones of Texas, Louisiana, Mississippi, and Alabama. We hypothesize that navigation canals exhibit varying rates of erosion based on soil properties of the embankment substrate, vegetation type, geologic region (derived from digital versions of state geologic maps), and the presence or absence of canal bank armaments (that is, rock rip-rap, concrete bulkheads, or other shoreline protection structures). The first objective of this project was to map the shoreline position and substrate along both banks of the navigation canals, which were digitized from 3 different time periods of aerial photography spanning the years of 1978/79 to 2005/06. The second objective was to quantify the erosion rates of the navigation canals in the study area and to determine whether differences in erosion rates are related to embankment substrate, vegetation type, geologic region, or soil type. To measure changes in shoreline position over time, transects spaced at 50-m (164-ft) intervals were intersected with shorelines from all three time periods, and an annual rate of change was calculated for each transect. Mean annual rates of shoreline change ranged from 1.75 m/year (5.74 ft/year) on the west side of the Atchafalaya River, La., where there was shoreline advancement or canal narrowing, to -3.29 m/year (-10.79 ft/year) on the south side of the Theodore Ship Channel, Ala., where there was shoreline retreat or erosion. Statistical analysis indicated that there were significant differences in shoreline retreat rates according to geologic region and marsh vegetation type, and a weak relationship with soil organic content. This information can be used to better estimate future land loss rates associated with navigation canals and to prioritize the location of

  11. Coastal erosion and accretion in Pak Phanang, Thailand by GIS analysis of maps and satellite imagery

    Directory of Open Access Journals (Sweden)

    Sayedur Rahman Chowdhury

    2013-12-01

    Full Text Available Coastal erosion and accretion in Pak Phanang of southern Thailand between 1973 and 2003 was measured using multi-temporal topographic maps and Landsat satellite imageries. Within a GIS environment landward and seaward movements of shoreline was estimated by a transect-based analysis, and amounts of land accretion and erosion were estimated by a parcel-based geoprocessing. The whole longitudinal extent of the 58 kilometer coast was classified based on the erosion and accretion trends during this period using agglomerative hierarchical clustering approach. Erosion and accretion were found variable over time and space, and periodic reversal of status was also noticed in many places. Estimates of erosion were evaluated against field-survey based data, and found reasonably accurate where the rates were relatively great. Smoothing of shoreline datasets was found desirable as its impacts on the estimates remained within tolerable limits.

  12. Oblique Aerial Photography of the Arctic Coast of Alaska, Cape Sabine to Milne Point, July 16-19, 2009

    Science.gov (United States)

    Gibbs, Ann E.; Richmond, Bruce M.

    2010-01-01

    The Arctic Coastal Plain of northern Alaska, an area of strategic economic importance to the United States, is home to remote Native American communities and encompasses unique habitats of global significance. Coastal erosion along the Arctic coast is chronic and widespread; recent evidence suggests that erosion rates are among the highest in the world (as high as ~16 m/yr) and may be accelerating. Coastal erosion adversely impacts energy-related infrastructure, natural shoreline habitats, and Native American communities. Climate change is thought to be a key component of recent environmental changes in the Arctic. Reduced sea-ice cover in the Arctic Ocean is one of the probable mechanisms responsible for increasing coastal exposure to wave attack and the resulting increase in erosion. Extended periods of permafrost melting and associated decreases in bluff cohesion and stability are another possible source of the increase in erosion. Several studies of selected areas on the Alaska coast document past shoreline positions and coastal change, but none have examined the entire North coast systematically. Results from these studies indicate high rates of coastal retreat that vary spatially along the coast. To address the need for a comprehensive and regionally consistent evaluation of shoreline change along the North coast of Alaska, the U.S. Geological Survey (USGS), as part of their Coastal and Marine Geology Program's (CMGP) National Assessment of Shoreline Change Study, is evaluating shoreline change from Peard Bay to the United States/Canadian border, using historical maps and photography and a standardized methodology that is consistent with other shoreline-change studies along the Nation's coastlines (see, for example, http://coastal.er.usgs.gov/shoreline-change/, last accessed February 12, 2010). This is the second in a series of publications containing photographs collected during reconnaissance surveys conducted in support of the National Assessment of

  13. Anthropogenic influences on shoreline and nearshore evolution in the San Francisco Bay coastal system

    Science.gov (United States)

    Dallas, K.L.; Barnard, P.L.

    2011-01-01

    Analysis of four historical bathymetric surveys over a 132-year period has revealed significant changes to the morphology of the San Francisco Bar, an ebb-tidal delta at the mouth of San Francisco Bay estuary. From 1873 to 2005 the San Francisco Bar vertically-eroded an average of 80 cm over a 125 km2 area, which equates to a total volume loss of 100 ± 52 million m3 of fine- to coarse-grained sand. Comparison of the surveys indicates the entire ebb-tidal delta contracted radially, with the crest moving landward an average of 1 km. Long-term erosion of the ebb-tidal delta is hypothesized to be due to a reduction in the tidal prism of San Francisco Bay and a decrease in coastal sediment supply, both as a result of anthropogenic activities. Prior research indicates that the tidal prism of the estuary was reduced by 9% from filling, diking, and sedimentation. Compilation of historical records dating back to 1900 reveals that a minimum of 200 million m3 of sediment has been permanently removed from the San Francisco Bay coastal system through dredging, aggregate mining, and borrow pit mining. Of this total, ~54 million m3 of sand-sized or coarser sediment was removed from central San Francisco Bay. With grain sizes comparable to the ebb-tidal delta, and its direct connection to the bay mouth, removal of sediments from central San Francisco Bay may limit the sand supply to the delta and open coast beaches. SWAN wave modeling illustrates that changes to the morphology of the San Francisco Bar have altered the alongshore wave energy distribution at adjacent Ocean Beach, and thus may be a significant factor in a persistent beach erosion ‘hot spot’ occurring in the area. Shoreline change analyses show that the sandy shoreline in the shadow of the ebb-tidal delta experienced long-term (1850s/1890s to 2002) and short-term (1960s/1980s to 2002) accretion while the adjacent sandy shoreline exposed to open-ocean waves experienced long-term and short-term erosion. Therefore

  14. Erhversbetinget erosion?

    DEFF Research Database (Denmark)

    Dige, Irene; Gjørup, Hans; Nyvad, Bente

    2012-01-01

    Baggrund – I forbindelse med dental erosion er en grundig udredning af patienten vigtig, således at årsagen til erosionernes opståen findes, og der kan iværksættes adækvat forebyggende indsats. En sådan udredning er ikke mindst vigtig, når arbejdsmiljøet mistænkes. Patienttilfælde – En 30-årig...... arbejdsskade, men ikke anerkendt, da erosioner ikke er optaget på Arbejdsskadestyrelsens liste over erhvervssygdomme. En systematisk registrering af lignende tilfælde kunne imidlertid på sigt ændre retspraksis for fremtidige patienter med arbejdsbetinget erosion....... patient, der arbejder som pladesmed, blev henvist til Landsdels- og Videnscenter, Århus Sygehus, med henblik på udredning af patientens kraftige slid. Patienten udviste ikke-alderssvarende tandslid af emalje og dentin svarende til erosion forårsaget af syredampe i arbejdsmiljøet, muligvis forstærket af...

  15. Early Cambrian wave-formed shoreline deposits

    DEFF Research Database (Denmark)

    Clemmensen, Lars B; Glad, Aslaug Clemmensen; Pedersen, Gunver Krarup

    2017-01-01

    -preserved subaqueous dunes and wave ripples indicates deposition in a wave-dominated upper shoreface (littoral zone) environment, and the presence of interference ripples indicates that the littoral zone environment experienced water level fluctuations due to tides and/or changing meteorological conditions. Discoidal....... During this period, wave-formed shoreline sediments (the Vik Member, Hardeberga Formation) were deposited on Bornholm and are presently exposed at Strøby quarry. The sediments consist of fine- and medium-grained quartz-cemented arenites in association with a few silt-rich mudstones. The presence of well...

  16. Extended Kalman Filter framework for forecasting shoreline evolution

    Science.gov (United States)

    Long, Joseph; Plant, Nathaniel G.

    2012-01-01

    A shoreline change model incorporating both long- and short-term evolution is integrated into a data assimilation framework that uses sparse observations to generate an updated forecast of shoreline position and to estimate unobserved geophysical variables and model parameters. Application of the assimilation algorithm provides quantitative statistical estimates of combined model-data forecast uncertainty which is crucial for developing hazard vulnerability assessments, evaluation of prediction skill, and identifying future data collection needs. Significant attention is given to the estimation of four non-observable parameter values and separating two scales of shoreline evolution using only one observable morphological quantity (i.e. shoreline position).

  17. The Arctic Coastal Erosion Problem

    Energy Technology Data Exchange (ETDEWEB)

    Frederick, Jennifer M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Thomas, Matthew Anthony [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bull, Diana L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Craig A. [Integral Consulting Inc., San Francisco, CA (United States); Roberts, Jesse D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-09-01

    Permafrost-dominated coastlines in the Arctic are rapidly disappearing. Arctic coastal erosion rates in the United States have doubled since the middle of the twentieth century and appear to be accelerating. Positive erosion trends have been observed for highly-variable geomorphic conditions across the entire Arctic, suggesting a major (human-timescale) shift in coastal landscape evolution. Unfortunately, irreversible coastal land loss in this region poses a threat to native, industrial, scientific, and military communities. The Arctic coastline is vast, spanning more than 100,000 km across eight nations, ten percent of which is overseen by the United States. Much of area is inaccessible by all-season roads. People and infrastructure, therefore, are commonly located near the coast. The impact of the Arctic coastal erosion problem is widespread. Homes are being lost. Residents are being dispersed and their villages relocated. Shoreline fuel storage and delivery systems are at greater risk. The U.S. Department of Energy (DOE) and Sandia National Laboratories (SNL) operate research facilities along some of the most rapidly eroding sections of coast in the world. The U.S. Department of Defense (DOD) is struggling to fortify coastal radar sites, operated to ensure national sovereignty in the air, against the erosion problem. Rapid alterations to the Arctic coastline are facilitated by oceanographic and geomorphic perturbations associated with climate change. Sea ice extent is declining, sea level is rising, sea water temperature is increasing, and permafrost state is changing. The polar orientation of the Arctic exacerbates the magnitude and rate of the environmental forcings that facilitate coastal land area loss. The fundamental mechanics of these processes are understood; their non-linear combination poses an extreme hazard. Tools to accurately predict Arctic coastal erosion do not exist. To obtain an accurate predictive model, a coupling of the influences of

  18. Combining pre-spill shoreline segmentation data and shoreline assessment tools to support early response management and planning

    International Nuclear Information System (INIS)

    Lamarche, A.; Owens, E.H.; Martin, V.; Laforest, S.

    2003-01-01

    Several organizations, such as Environment Canada and the Alyeska Pipeline Service Company, are developing or refining pre-spill databases containing information about physical shoreline characteristics. Automated links between these pre-spill shoreline characteristic databases and computerized shoreline assessment tools were recently created by Environment Canada (Quebec and Ontario regions). The tools, which use Geographical Information System (GIS) technology, can be used for planning and documenting support needed for shoreline cleanup operations. A training exercise, designed to evaluate a spill management system integrating the Quebec region pre-spill shoreline database and the ShoreAssess R shoreline assessment system, was conducted at Vercheres, Quebec in October 2002 by Eastern Canada Response Corporation. The testing took place during the planning stage of the early phases of a spill, namely after the first over-flight. The computerized shoreline assessment tools made it possible to evaluate the length and type of shoreline that would potentially be impacted by oil. The tools also made it possible to assess the shoreline treatment methods most likely to be used, and evaluate the probable duration of the cleanup operation. The information would have to be available in time to be considered during the planning activities. The training exercise demonstrated that the integration of the databases is a valuable tool during the early phases of an oil spill response. 9 refs., 2 tabs., 6 figs

  19. Αutomated 2D shoreline detection from coastal video imagery: an example from the island of Crete

    Science.gov (United States)

    Velegrakis, A. F.; Trygonis, V.; Vousdoukas, M. I.; Ghionis, G.; Chatzipavlis, A.; Andreadis, O.; Psarros, F.; Hasiotis, Th.

    2015-06-01

    Beaches are both sensitive and critical coastal system components as they: (i) are vulnerable to coastal erosion (due to e.g. wave regime changes and the short- and long-term sea level rise) and (ii) form valuable ecosystems and economic resources. In order to identify/understand the current and future beach morphodynamics, effective monitoring of the beach spatial characteristics (e.g. the shoreline position) at adequate spatio-temporal resolutions is required. In this contribution we present the results of a new, fully-automated detection method of the (2-D) shoreline positions using high resolution video imaging from a Greek island beach (Ammoudara, Crete). A fully-automated feature detection method was developed/used to monitor the shoreline position in geo-rectified coastal imagery obtained through a video system set to collect 10 min videos every daylight hour with a sampling rate of 5 Hz, from which snapshot, time-averaged (TIMEX) and variance images (SIGMA) were generated. The developed coastal feature detector is based on a very fast algorithm using a localised kernel that progressively grows along the SIGMA or TIMEX digital image, following the maximum backscatter intensity along the feature of interest; the detector results were found to compare very well with those obtained from a semi-automated `manual' shoreline detection procedure. The automated procedure was tested on video imagery obtained from the eastern part of Ammoudara beach in two 5-day periods, a low wave energy period (6-10 April 2014) and a high wave energy period (1 -5 November 2014). The results showed that, during the high wave energy event, there have been much higher levels of shoreline variance which, however, appeared to be similarly unevenly distributed along the shoreline as that related to the low wave energy event, Shoreline variance `hot spots' were found to be related to the presence/architecture of an offshore submerged shallow beachrock reef, found at a distance of 50-80 m

  20. Numerical modeling of shoreline undulations part 1: Constant wave climate

    DEFF Research Database (Denmark)

    Kærgaard, Kasper Hauberg; Fredsøe, Jørgen

    2013-01-01

    integrated flow model, a wave-phase resolving sediment transport description and a one-line shoreline model.First the length of the shoreline undulations is determined in the linear regime using a stability analysis. Next the further evolution from the linear to the fully non-linear regime is described...

  1. Preliminary assessment of bioengineered fringing shoreline reefs in Grand Isle and Breton Sound, Louisiana

    Science.gov (United States)

    La Peyre, Megan K.; Schwarting, Lindsay; Miller, Shea

    2013-01-01

    Restoration of three-dimensional shell habitats in coastal Louisiana presents a valuable and potentially self-sustaining approach to providing shoreline protection and critical nekton habitat and may contribute to water quality maintenance. The use of what has been called “living shorelines” is particularly promising because in addition to the hypothesized shoreline protection services, it is predicted that, if built and located in viable sites, these living shorelines may ultimately contribute to water quality maintenance through filtration of bivalves and may enhance nekton habitat. This approach, however, has not been tested extensively in different shallow water estuarine settings; understanding under what conditions a living shoreline must have to support a sustainable oyster population, and where these reefs may provide valuable shoreline protection, is key to ensuring that this approach provides an effective tool for coastal restoration. This project gathered preliminary data on the sustainability and shoreline stabilization of three large bioengineered fringing reefs located in Grand Isle, Lake Eloi, and Lake Fortuna, Louisiana. We collected preconstruction and postconstruction physiochemical and biological data by using a before-after-control-impact approach to evaluate the effectiveness of these living shoreline structures on reducing marsh erosion, enabling reef sustainability, and providing other ecosystem benefits. Although this project was originally designed to compare reef performance and impacts across three different locations over 2 years, delays in construction because of the Deepwater Horizon oil spill resulted in reefs being built from 12 to 18 months later than anticipated. As a result, monitoring postconstruction was severely limited. One reef, Grand Isle, was completed in March 2011 and monitored up to 18 months postcreation, whereas Lake Eloi and Lake Fortuna reefs were not completed until January 2012, and only 8 months of

  2. NOAA's Shoreline Survey Maps - Raster NOAA-NOS Shoreline Survey Manuscripts that define the shoreline and alongshore natural and man-made features

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOS coastal survey maps (often called t-sheet or tp-sheet maps) are special use planimetric or topographic maps that precisely define the shoreline and alongshore...

  3. Shoreline dynamics of the Lakshadweep Islands

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Anand, N.M.; Nayak, B.U.

    . The main reason for erosion at these islands seems to be the removal of coral reef for construction and other purposes, and to some extent the dredging of navigational channel in the lagoons. While the wave induced currents govern the sediment processes...

  4. The comparison of various approach to evaluation erosion risks and design control erosion measures

    Science.gov (United States)

    Kapicka, Jiri

    2015-04-01

    In the present is in the Czech Republic one methodology how to compute and compare erosion risks. This methodology contain also method to design erosion control measures. The base of this methodology is Universal Soil Loss Equation (USLE) and their result long-term average annual rate of erosion (G). This methodology is used for landscape planners. Data and statistics from database of erosion events in the Czech Republic shows that many troubles and damages are from local episodes of erosion events. An extent of these events and theirs impact are conditional to local precipitation events, current plant phase and soil conditions. These erosion events can do troubles and damages on agriculture land, municipally property and hydro components and even in a location is from point of view long-term average annual rate of erosion in good conditions. Other way how to compute and compare erosion risks is episodes approach. In this paper is presented the compare of various approach to compute erosion risks. The comparison was computed to locality from database of erosion events on agricultural land in the Czech Republic where have been records two erosion events. The study area is a simple agriculture land without any barriers that can have high influence to water flow and soil sediment transport. The computation of erosion risks (for all methodology) was based on laboratory analysis of soil samples which was sampled on study area. Results of the methodology USLE, MUSLE and results from mathematical model Erosion 3D have been compared. Variances of the results in space distribution of the places with highest soil erosion where compared and discussed. Other part presents variances of design control erosion measures where their design was done on based different methodology. The results shows variance of computed erosion risks which was done by different methodology. These variances can start discussion about different approach how compute and evaluate erosion risks in areas

  5. Land-cover types, shoreline positions, and sand extents derived From Landsat satellite imagery, Assateague Island to Metompkin Island, Maryland and Virginia, 1984 to 2014

    Science.gov (United States)

    Bernier, Julie C.; Douglas, Steven H.; Terrano, Joseph F.; Barras, John A.; Plant, Nathaniel G.; Smith, Christopher G.

    2015-12-17

    The U.S. Geological Survey has a long history of responding to and documenting the impacts of storms along the Nation’s coasts and incorporating these data into storm impact and coastal change vulnerability assessments. These studies, however, have traditionally focused on sandy shorelines and sandy barrier-island systems, without consideration of impacts to coastal wetlands. The goal of the Barrier Island and Estuarine Wetland Physical Change Assessment project is to integrate a wetland-change assessment with existing coastal-change assessments for the adjacent sandy dunes and beaches, initially focusing on Assateague Island along the Maryland and Virginia coastline. Assateague Island was impacted by waves and storm surge associated with the passage of Hurricane Sandy in October 2012, including erosion and overwash along the ocean-facing sandy shoreline as well as erosion and overwash deposition in the back-barrier and estuarine bay environments.

  6. Monitoring and modeling shoreline response due to shoreface nourishment on a high-energy coast

    Science.gov (United States)

    Barnard, P. L.; Erikson, Li H.; Hansen, J. E.

    2009-01-01

    Shoreface nourishment can be an efficient technique to feed sediment into the littoral zone without the order of magnitude cost increase incurred by directly nourishing the beach. An erosion hot spot at Ocean Beach in San Francisco, California, USA, threatens valuable public infrastructure as well as safe recreational use of the beach. In an effort to reduce the erosion at this location, a new beneficial reuse plan was implemented in May 2005 for the sediment dredged annually from the main shipping channel at the mouth of San Francisco Bay. From 2005 to 2007, approximately 230,000 m of sand was placed annually at depths between 9 and 14 m, in a location where strong tidal currents and open-ocean waves could potentially feed sediment onto the section of beach experiencing critical erosion. The evolution of the disposal mound and adjacent beach were monitored with 12 multibeam bathymetric surveys, and over 40 high-resolution beach topographic surveys. In addition, sediment transport processes were investigated using sediment grab samples, acoustic Doppler profilers, and two separate models: a cross-shore profile model (UNIBEST-TC) and a coastal area model (Delft3D). The results of the monitoring and modeling demonstrate that the disposal mound may be effective in dissipating wave energy striking this vulnerable stretch of coast with negligible shadowing effects, but a positive shoreline response can only be achieved by placing the sediment in water depths less than 5 m. 

  7. Observations of Interannual Dune Morphological Evolution With Comparisons to Shoreline Change Along the Columbia River Littoral Cell

    Science.gov (United States)

    Doermann, L.; Kaminsky, G. M.; Ruggiero, P.

    2006-12-01

    Beach topographic data have been collected along the 160 km-long Columbia River Littoral Cell in southwest Washington and northwest Oregon, USA as part of the Southwest Washington Coastal Erosion Study and a NANOOS pilot project. The monitoring program includes the collection of cross-shore beach profiles at 49 sites for each of the 34 seasons since 1997 (with few exceptions), enabling the investigation of the seasonal to interannual morphological variability of this high-energy coast. We focus here on the dunes backing the beaches, aiming to quantitatively describe the wide variety of characteristics they exhibit, as well as to relate dune evolution to shoreline change. To analyze the large volume of high-quality data, we use automated algorithms and systematic processes to identify the location of the dune toe, crest, and face, and calculate a volume (where enough data are available) and beach width for each survey. We define the position of the dune face as the elevation half-way between the average dune toe and average dune crest elevations at each profile location, and beach width as the horizontal distance between the 2-m contour (~MSL) and the dune toe. Much like shoreline proxies lower on the beach profile, (e.g., the 3-m contour), the location of the dune toe shows large seasonal variability with onshore deposition of sand in summer months and offshore sand transport in the winter. However, the location of the dune face and the elevation of the dune crest are much less variable and are useful in describing the evolution of the dune/beach system in the horizontal and vertical directions, respectively, over interannual time scales. On beaches with the highest shoreline change rates in the study area, the dune face follows the progradational trend of the shoreline with the dune face prograding at approximately 25-50% of the rate of the shoreline. Along many of these beaches that experienced severe erosion during the El Niño of 1997/98, the dune face

  8. The Digital Shoreline Analysis System (DSAS) Version 4.0 - An ArcGIS extension for calculating shoreline change

    Science.gov (United States)

    Thieler, E. Robert; Himmelstoss, Emily A.; Zichichi, Jessica L.; Ergul, Ayhan

    2009-01-01

    The Digital Shoreline Analysis System (DSAS) version 4.0 is a software extension to ESRI ArcGIS v.9.2 and above that enables a user to calculate shoreline rate-of-change statistics from multiple historic shoreline positions. A user-friendly interface of simple buttons and menus guides the user through the major steps of shoreline change analysis. Components of the extension and user guide include (1) instruction on the proper way to define a reference baseline for measurements, (2) automated and manual generation of measurement transects and metadata based on user-specified parameters, and (3) output of calculated rates of shoreline change and other statistical information. DSAS computes shoreline rates of change using four different methods: (1) endpoint rate, (2) simple linear regression, (3) weighted linear regression, and (4) least median of squares. The standard error, correlation coefficient, and confidence interval are also computed for the simple and weighted linear-regression methods. The results of all rate calculations are output to a table that can be linked to the transect file by a common attribute field. DSAS is intended to facilitate the shoreline change-calculation process and to provide rate-of-change information and the statistical data necessary to establish the reliability of the calculated results. The software is also suitable for any generic application that calculates positional change over time, such as assessing rates of change of glacier limits in sequential aerial photos, river edge boundaries, land-cover changes, and so on.

  9. Multidecadal (1960–2011 shoreline changes in Isbjørnhamna (Hornsund, Svalbard

    Directory of Open Access Journals (Sweden)

    Zagórski Piotr

    2015-12-01

    Full Text Available A section of a gravel-dominated coast in Isbjørnhamna (Hornsund, Svalbard was analysed to calculate the rate of shoreline changes and explain processes controlling coastal zone development over last 50 years. Between 1960 and 2011, coastal landscape of Isbjørnhamna experienced a significant shift from dominated by influence of tide-water glacier and protected by prolonged sea-ice conditions towards storm-affected and rapidly changing coast. Information derived from analyses of aerial images and geomorphological mapping shows that the Isbjørnhamna coastal zone is dominated by coastal erosion resulting in a shore area reduction of more than 31,600 m2. With ~3,500 m2 of local aggradation, the general balance of changes in the study area of the shore is negative, and amounts to a loss of more than 28,000 m2. Mean shoreline change is −13.1 m (−0.26 m a−1. Erosional processes threaten the Polish Polar Station infrastructure and may damage of one of the storage buildings in nearby future.

  10. Modelling shoreline evolution in the vicinity of a groyne and a river

    Science.gov (United States)

    Valsamidis, Antonios; Reeve, Dominic E.

    2017-01-01

    Analytical solutions to the equations governing shoreline evolution are well-known and have value both as pedagogical tools and for conceptual design. Nevertheless, solutions have been restricted to a fairly narrow class of conditions with limited applicability to real-life situations. We present a new analytical solution for a widely encountered situation where a groyne is constructed close to a river to control sediment movement. The solution, which employs Laplace transforms, has the advantage that a solution for time-varying conditions may be constructed from the solution for constant conditions by means of the Heaviside procedure. Solutions are presented for various combinations of wave conditions and sediment supply/removal by the river. An innovation introduced in this work is the capability to provide an analytical assessment of the accretion or erosion caused near the groyne due to its proximity to the river which may act either as a source or a sink of sediment material.

  11. St. Croix: Shore-based Fishing Access Points (2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Two local experts delineated access points for shore-based fishing along the shoreline of St. Croix, USVI. The points were documented at different times, and then...

  12. SPATIO-TEMPORAL ANALYSIS OF SHORELINE CHANGES IN ...

    African Journals Online (AJOL)

    Osondu

    2011-12-05

    Dec 5, 2011 ... The study recommended periodic monitoring of the coastal area on monthly and yearly bases. Keywords: Shoreline, GIS, Remote sensing, Bonny Island, Water transport, .... imported to Arcview GIS 3.3 for enhancement.

  13. Research on bioremediation of oil polluted shorelines in Norway

    International Nuclear Information System (INIS)

    Sveum, P.

    1995-01-01

    Marine bioremediation research in Norway has been directed towards the use of fertilizers on arctic shorelines and ice infested waters. In addition from the focus on fertilizers, the research has paid considerable attention to nutrient dynamics, and the influence of microfauna such as bacterial and fungal grazers on the dynamics of macronutrients. The interactions between microbial and physical processes on the shorelines, between photochemical processes and nutrient dynamics, have also been addressed. 29 refs., 5 figs., 2 tabs

  14. Observations and 3D hydrodynamics-based modeling of decadal-scale shoreline change along the Outer Banks, North Carolina

    Science.gov (United States)

    Safak, Ilgar; List, Jeffrey; Warner, John C.; Kumar, Nirnimesh

    2017-01-01

    erosion (∼−1 m/yr) averaged over the northern half of the section as compared to the southern half where the observed and modeled averaged net shoreline changes are smaller (analysis identifies that the magnitude of net alongshore sediment transport is strongly dominated by events associated with high wave energy. However, both big- and small- wave events cause shoreline change of the same order of magnitude because it is the gradients in transport, not the magnitude, that are controlling shoreline change. Results also indicate that alongshore momentum is not a simple balance between wave breaking and bottom stress, but also includes processes of horizontal vortex force, horizontal advection and pressure gradient that contribute to long-term alongshore sediment transport. As a comparison to a more simple approach, an empirical formulation for alongshore sediment transport is used. The empirical estimates capture the effect of the breaking term in the hydrodynamics-based model, however, other processes that are accounted for in the hydrodynamics-based model improve the agreement with the observed alongshore sediment transport.

  15. A post-Calumet shoreline along southern Lake Michigan

    Science.gov (United States)

    Capps, D.K.; Thompson, T.A.; Booth, R.K.

    2007-01-01

    The southern shore of Lake Michigan is the type area for many of ancestral Lake Michigan's late Pleistocene lake phases, but coastal deposits and features of the Algonquin phase of northern Lake Michigan, Lake Huron, and Lake Superior are not recognized in the area. Isostatic rebound models suggest that Algonquin phase deposits should be 100 m or more below modern lake level. A relict shoreline, however, exists along the lakeward margin of the Calumet Beach that was erosional west of Deep River and depositional east of the river. For this post-Calumet shoreline, the elevation of basal foreshore deposits east of Deep River and the base of the scarp west of Deep River indicate a slightly westward dipping water plane that is centered at ???184 m above mean sea level. Basal foreshore elevations also indicate that lake level fell ???2 m during the development of the shoreline. The pooled mean of radiocarbon dates from the surface of the peat below post-Calumet shoreline foreshore deposits indicate that the lake transgressed over the peat at 10,560 ?? 70 years B.P. Pollen assemblages from the peat are consistent with this age. The elevation and age of the post-Calumet shoreline are similar to the Main Algonquin phase of Lake Huron. Recent isostatic rebound models do not adequately address a high-elevation Algonquin-age shoreline along the southern shore of Lake Michigan, but the Goldthwait (1908) hinge-line model does. ?? 2006 Springer Science+Business Media B.V.

  16. Uncertainties in shoreline position analysis: the role of run-up and tide in a gentle slope beach

    Directory of Open Access Journals (Sweden)

    G. Manno

    2017-09-01

    Full Text Available In recent decades in the Mediterranean Sea, high anthropic pressure from increasing economic and touristic development has affected several coastal areas. Today the erosion phenomena threaten human activities and existing structures, and interdisciplinary studies are needed to better understand actual coastal dynamics. Beach evolution analysis can be conducted using GIS methodologies, such as the well-known Digital Shoreline Analysis System (DSAS, in which error assessment based on shoreline positioning plays a significant role. In this study, a new approach is proposed to estimate the positioning errors due to tide and wave run-up influence. To improve the assessment of the wave run-up uncertainty, a spectral numerical model was used to propagate waves from deep to intermediate water and a Boussinesq-type model for intermediate water up to the swash zone. Tide effects on the uncertainty of shoreline position were evaluated using data collected by a nearby tide gauge. The proposed methodology was applied to an unprotected, dissipative Sicilian beach far from harbors and subjected to intense human activities over the last 20 years. The results show wave run-up and tide errors ranging from 0.12 to 4.5 m and from 1.20 to 1.39 m, respectively.

  17. Geographic information system for the study of coastal erosion in the Department of Cordoba, Colombia: design tools, and use

    International Nuclear Information System (INIS)

    Hoyos, Natalia; Acosta, Susana; Correa, Ivan D

    2006-01-01

    The study and monitoring of factors that cause shoreline erosion processes require the use of geographic information systems (GIS) to integrate and analyze data on different topics and with various formats. The scope of this project was to design and build a GIS for the study of erosion processes along the coastline of Cordoba Department, Colombia. In this article, we present some of the tools used for the SIG design and implementation, as well as a specific application for shoreline erosion analysis. The Geo database diagrammed tool (ArcGISa) was used to document the geo database structure. The process is semiautomatic and delivers a comprehensive and friendly format for the end users. Linear referencing and dynamic segmentation tools (ArcGISa) were used to characterize the coastline according to several criteria, without subdividing or duplicating it. Shoreline retreat between 1938 and 2004 was analyzed with OSAS (Digital shoreline analysis system, USGS). Maximum distance between both shorelines was recorded by a Punta Arboletes transect (972 m). Real (on the ground) maximum distance however, was larger (around 1.5 km). Nevertheless it was not recorded by any of the OSAS generated transect

  18. Waves Generated by Asteroid Impacts and Their Hazard Consequences on The Shorelines

    Science.gov (United States)

    Ezzedine, S. M.; Miller, P. L.; Dearborn, D. S.

    2014-12-01

    We have performed numerical simulations of a hypothetical asteroid impact onto the ocean in support of an emergency preparedness, planning, and management exercise. We addressed the scenario from asteroid entry; to ocean impact (splash rim); to wave generation, propagation, and interaction with the shoreline. For the analysis we used GEODYN, a hydrocode, to simulate the impact and generate the source wave for the large-scale shallow water wave program, SWWP. Using state-of-the-art, high-performance computing codes we simulated three impact areas — two are located on the West Coast near Los Angeles's shoreline and the San Francisco Bay, respectively, and the third is located in the Gulf of Mexico, with a possible impact location between Texas and Florida. On account of uncertainty in the exact impact location within the asteroid risk corridor, we examined multiple possibilities for impact points within each area. Uncertainty in the asteroid impact location was then convolved and represented as uncertainty in the shoreline flooding zones. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, and partially funded by the Laboratory Directed Research and Development Program at LLNL under tracking code 12-ERD-005.

  19. Rainfall Erosivity in Europe

    DEFF Research Database (Denmark)

    Panagos, Panos; Ballabio, Cristiano; Borrelli, Pasquale

    2015-01-01

    Rainfall is one the main drivers of soil erosion. The erosive force of rainfall is expressed as rainfall erosivity. Rainfall erosivity considers the rainfall amount and intensity, and is most commonly expressed as the Rfactor in the USLE model and its revised version, RUSLE. At national...... and continental levels, the scarce availability of data obliges soil erosion modellers to estimate this factor based on rainfall data with only low temporal resolution (daily, monthly, annual averages). The purpose of this study is to assess rainfall erosivity in Europe in the form of the RUSLE R-factor, based...

  20. Shoreline dynamics of the active Yellow River delta since the implementation of Water-Sediment Regulation Scheme: A remote-sensing and statistics-based approach

    Science.gov (United States)

    Fan, Yaoshen; Chen, Shenliang; Zhao, Bo; Pan, Shunqi; Jiang, Chao; Ji, Hongyu

    2018-01-01

    The Active Yellow River (Huanghe) Delta (AYRD) is a complex landform in which rapid deposition takes place due to its geologic formation and evolution. Continuous monitoring of shoreline dynamics at high-temporal frequency is crucial for understanding the processes and the driving factors behind this rapidly changing coast. Great efforts have been devoted to map the changing shoreline of the Yellow River delta and explain such changes through remote sensing data. However, the temporal frequency of shoreline in the obtained datasets are generally not fine enough to reflect the detailed or subtly variable processes of shoreline retreat and advance. To overcome these limitations, we continuously monitored the dynamics of this shoreline using time series of Landsat data based on tidal-level calibration model and orthogonal-transect method. The Abrupt Change Value (ACV) results indicated that the retreat-advance patterns had a significant impact regardless of season or year. The Water-Sediment Regulation Scheme (WSRS) plays a dominant role in delivering river sediment discharge to the sea and has an impact on the annual average maximum ACV, especially at the mouth of the river. The positive relationship among the average ACV, runoff and sediment load are relatively obvious; however, we found that the Relative Exposure Index (REI) that measures wave energy was able to explain only approximately 20% of the variation in the data. Based on the abrupt change at the shoreline of the AYRD, river flow and time, we developed a binary regression model to calculate the critical sediment load and water discharge for maintaining the equilibrium of the active delta from 2002 to 2015. These values were approximately 0.48 × 108 t/yr and 144.37 × 108 m3/yr. If the current water and sediment proportions released from the Xiaolangdi Reservoir during the WSRS remain stable, the erosion-accretion patterns of the active delta will shift from rapid accretion to a dynamic balance.

  1. Erosion in the Beaches of Crete

    Science.gov (United States)

    Synolakis, C. E.; Foteinis, S.; Voukouvalas, V.; Kalligeris, N.

    2009-04-01

    In the past decade, erosion rates for the coastlines of Greece are rapidly increasing. Many beaches on the northern coast of the island have substantially retreated, while others have disappeared or will disappear within the present or the following decade if no action is taken. For the better understanding and visualization of the current situation, specific examples of rapid erosion are described and afterwards we speculate as to the causes. We infer that, as in other parts of the Mediterranean, the causes are anthropogenic and include removal of sand dunes to build roads, sand mining from beaches and rivers, permanent building construction within the active coastal zone, on or too close to shoreline, and poor design of coastal structures. The reason behind the rapid erosion of Greece coastlines is the complete lack of any semblance of coastal zone management and antiquated legislation. We conclude that unless urgent measures for the protection and even salvation of the beaches are taken and if the sand mining and dune removal does not stop, then several beaches will disappear within the present and the following decade.

  2. Spatial and temporal patterns of shoreline change of a 280-km high-energy disrupted sandy coast from 1950 to 2014: SW France

    Science.gov (United States)

    Castelle, Bruno; Guillot, Benoit; Marieu, Vincent; Chaumillon, Eric; Hanquiez, Vincent; Bujan, Stéphane; Poppeschi, Coline

    2018-01-01

    A dataset of 15 geo-referenced orthomosaics photos was generated to address long-term shoreline change along approximately 270 km of high-energy sandy coast in SW France between 1950 and 2014. The coast consists of sandy beaches backed by coastal dunes, which are only disrupted by two wide tidal inlets (Arcachon and Maumusson), a wide estuary mouth (Gironde) and a few small wave-dominated inlets and coastal towns. A time and spatially averaged erosion trend of 1.12 m/year is found over 1950-2014, with a local maximum of approximately 11 m/year and a maximum local accretion of approximately 6 m/year, respectively. Maximum shoreline evolutions are observed along coasts adjacent to the inlets and to the estuary mouth, with erosion and accretion alternating over time on the timescale of decades. The two inlet-sandspit systems of Arcachon and Maumusson show a quasi-synchronous behaviour with the two updrift coasts accreting until the 1970s and subsequently eroding since then, which suggests that shoreline change at these locations is controlled by allocyclic mechanisms. Despite sea level rise and the well-established increase in winter wave height over the last decades, there is no capture of significant increase in mean erosion rate. This is hypothesized to be partly the result of relevant coastal dune management works from the 1960s to the 1980s after a long period of coastal dune disrepair during and after the Second World War. This study suggests that long-term shoreline change of high-energy sandy coasts disrupted by inlets and/or estuaries is complex and needs to consider a wide range of parameters including, non-extensively, waves, tides, inlet dynamics, sea level rise, coastal dune management and coastal defences, which challenges the development of reliable long-term coastal evolution numerical models.

  3. Low - Cost Shore Protection. Final Report on the Shoreline Erosion Control Demonstration Program (Section 54) 1981

    Science.gov (United States)

    1981-08-01

    Office of Naval Research, Arlington, Va.) Dr. Robert A. Sweeney: Director, Great Lakes Laboratory, Professor of Biology , New York State University College...4.0 0-1 1 --3-- = Kotaebue, Alaeka 0-1 6.5 0-1 - 3 - tnil•hik, Alaska 0-1 6.5 0-1 6 9 235,314 a 307,146 1 71,831(k) HANAII Koalas . Hawaii 0-1 1.7...by interaction between waves and water currents across which the waves are moving. CORAL - (1) ( Biology ) Marine coelenterates (Madreporaria), solitary

  4. Biological conditions of shorelines following the Exxon Valdez spill

    International Nuclear Information System (INIS)

    Stoker, S.W.; Neff, J.M.; Schroeder, T.R.; McCormick, D.M.

    1993-01-01

    This report is based primarily on survey results from Prince William Sound, where most of the heavy shoreline oiling occurred. Although not strictly quantitative, the shoreline surveys provide an unprecedented, broad base of professional observations covering the entire spill-affected area from 1989 through 1992 by which to evaluate spill impacts and recovery. Shoreline surveys documented that the extent of shoreline oiling declined substantially from 1989 to 1992. In 1989, oil was found on about 16 percent of the 3,000 miles of shoreline in Prince William Sound; by the spring of 1991, oil was found on only about 2 percent of the shoreline; and by May of 1992, on only 0.2 percent. In all years, most of this oil was located in the biologically least productive upper intertidal and supratidal zones. In both 1991 and 1992, small, isolated pockets of subsurface oil were found on some boulder/cobble beaches. Most of these deposits were also located in the upper intertidal and were usually buried beneath clean sediments. In almost all cases, the condition of intertidal biological communities improved correspondingly from 1989 to 1992. By the spring of 1991, recovery appeared to be well under way on virtually all previously oiled shores, with species composition, abundance, and diversity levels usually comparable to those of nearby shores that were not oiled in 1989. Recruitment of intertidal plants and animals was observed as early as the summer of 1989, and increasingly through 1991 and 1992. Recruitment was evident even in areas with remnant deposits of surface and subsurface oil, indicating that toxicity levels of the oil had declined substantially and that, in most cases, the residual oil no longer interfered with biological recovery. Observations of birds and marine mammals on or near shorelines surveyed during 1991 and 1992 confirmed that species present before the spill were still present and were feeding and reproducing in areas affected by oil in 1989

  5. Mapping erosion from space

    NARCIS (Netherlands)

    Vrieling, A.

    2007-01-01

    Soil erosion by water is the most important land degradation problem worldwide. Spatial information on erosion is required for defining effective soil and water conservation strategies. Satellite remote sensing can provide relevant input to regional erosion assessment. This thesis comprises a review

  6. Erosion-corrosion

    International Nuclear Information System (INIS)

    Aghili, B.

    1999-05-01

    A literature study on erosion-corrosion of pipings in the nuclear industry was performed. Occurred incidents are reviewed, and the mechanism driving the erosion-corrosion is described. Factors that influence the effect in negative or positive direction are treated, as well as programs for control and inspection. Finally, examples of failures from databases on erosion-corrosion are given in an attachment

  7. Assessing storm erosion hazards

    NARCIS (Netherlands)

    Ranasinghe, Ranasinghe W M R J B; Callaghan, D.; Ciavola, Paolo; Coco, Giovanni

    2017-01-01

    The storm erosion hazard on coasts is usually expressed as an erosion volume and/or associated episodic coastline retreat. The accurate assessment of present-day and future storm erosion volumes is a key task for coastal zone managers, planners and engineers. There are four main approaches that can

  8. Linking rapid erosion of the Mekong River delta to human activities.

    Science.gov (United States)

    Anthony, Edward J; Brunier, Guillaume; Besset, Manon; Goichot, Marc; Dussouillez, Philippe; Nguyen, Van Lap

    2015-10-08

    As international concern for the survival of deltas grows, the Mekong River delta, the world's third largest delta, densely populated, considered as Southeast Asia's most important food basket, and rich in biodiversity at the world scale, is also increasingly affected by human activities and exposed to subsidence and coastal erosion. Several dams have been constructed upstream of the delta and many more are now planned. We quantify from high-resolution SPOT 5 satellite images large-scale shoreline erosion and land loss between 2003 and 2012 that now affect over 50% of the once strongly advancing >600 km-long delta shoreline. Erosion, with no identified change in the river's discharge and in wave and wind conditions over this recent period, is consistent with: (1) a reported significant decrease in coastal surface suspended sediment from the Mekong that may be linked to dam retention of its sediment, (2) large-scale commercial sand mining in the river and delta channels, and (3) subsidence due to groundwater extraction. Shoreline erosion is already responsible for displacement of coastal populations. It is an additional hazard to the integrity of this Asian mega delta now considered particularly vulnerable to accelerated subsidence and sea-level rise, and will be exacerbated by future hydropower dams.

  9. Linking Backbarrier Lacustrine Stratigraphy with Spatial Dynamics of Shoreline Retreat in a Rapidly Subsiding Region of the Mississippi River Delta

    Science.gov (United States)

    Dietz, M.; Liu, K. B.; Bianchette, T. A.; Yao, Q.

    2017-12-01

    The shoreline along the northern Gulf of Mexico is rapidly retreating as coastal features of abandoned Mississippi River delta complexes erode and subside. Bay Champagne is located in the Caminada-Moreau headland, a region of shoreline west of the currently active delta that has one of the highest rates of retreat and land loss. As a result, this site has transitioned from a stable, circular inland lake several kilometers from the shore to a frequently perturbed, semi-circular backbarrier lagoon, making it ideal to study the environmental effects of progressive land loss. Analyses of clastic layers in a series of sediment cores collected at this site over the past decade indicate the lake was less perturbed in the past and has become increasingly more sensitive to marine incursion events caused by tropical cyclones. Geochemical and pollen analyses of these cores also reveal profound changes in environmental and chemical conditions in Bay Champagne over the past century as the shoreline has retreated. Through relating stratigraphy to spatial changes observed from satellite imagery, this study attempts to identify the tipping point at which Bay Champagne began the transition from an inland lake to a backbarrier environment, and to determine the rate at which this transition occurred. Results will be used to develop a model of the environmental transition experienced by a rapidly retreating coastline and to predict how other regions of the Mississippi River deltaic system could respond to future shoreline retreat.

  10. Ancient shoreline reconstruction at a Maritime Maya Port in Yucatan, Mexico

    Science.gov (United States)

    Jaijel, Roy; Goodman, Beverly; Glover, Jeffrey; Rissolo, Dominique; Beddows, Patricia; Carter, Alice; Smith, Derek; Ben Avraham, Zvi

    2017-04-01

    Throughout history, worldwide, a major part of the human experience has been to adapt to changing landscapes, and environments. These adaptations can take many forms, sometimes as innovation, manipulation of the conditions, behavioral or technological changes; and in some cases the decision to abandon the area. The northeastern Yucatan peninsula, home of the Maritime maya port site Vista-Alegre, shows signs of such human changes, though little is known about the corresponding landscape and environment. Vista Alegre is located on the meeting point of the Caribbean Sea and the Gulf of Mexico, at the north-eastern tip of the Yucatan peninsula, in the back of the Holbox lagoon. The site was inhabited from the 9th century B.C until the mid 16th century A.D., with an apparent two century abandonment phase from the mid 7th to 9th century A.D. A multidisciplinary effort ("Costa Escondida project") has been investigating the life of past Mayan inhabitants and the broader connections of the site to the Maritime Maya trade network. One of the questions that has arisen is what were the mutual influences between the inhabitants to their surrounding environment. In order to answer that question the site's shoreline geomorphology and climate history is being reconstructed for the past 2-3000 years. The reconstruction is based on multiproxy analysis of marine sediment cores and surface samples, combined with archaeological data. The study presented focuses on the shoreline shifts at the site, revealing the complexity, and significant affect of sea level rise on the marine environment of Vista Alegre. This study contributes to our understanding of the site's possible functions, the environmental challenges the local inhabits contended with, and the identification of ancient harboring locations. The results show five depositional phases over the past 2-3000 years. The ancient shoreline maps show a general trend of sea level rise, though with varying rates over time that relates well

  11. Using Shoreline Video Assessment for coastal planning and restoration in the context of climate change in Kien Giang, Vietnam

    Science.gov (United States)

    Van Cuong, Chu; Russell, Michael; Brown, Sharon; Dart, Peter

    2015-06-01

    Kien Giang, bordering Cambodia in the Mekong River Delta, is one of the two most vulnerable provinces in the region to coastal erosion and flooding. Coastal protection can conflict with current land use and economic development activities. The conditions of the mangrove forest and mainland coastline of the Kien Giang province were assessed using the Shoreline Video Assessment Method (SVAM) backed up with information from satellite images. Half of the 206 km Kien Giang coastline has been eroded or is being eroded. Protective mangrove forests naturally occurred in 74% of the coastline but have been under threat from illegal cutting, erosion and coastal retreat. Accurate information on the state of the coastline and mangrove forest health provided invaluable data for developing a new coastal rehabilitation plan to guard against future sea level rise. In contrast to the current boundary management of land and natural resources, this plan divided the provincial coastline into 19 sections based on the landscape condition and exposure to erosion. Priority strategic actions for erosion management, mangrove restoration and sustainable livelihood development for local communities for each section of coast were developed based on an integrated cross sectoral approach and practical experience in the Conservation and Development of the Kien Giang Biosphere Reserve Project.

  12. Molybdenum erosion measurements in Alcator C-Mod

    Energy Technology Data Exchange (ETDEWEB)

    Wampler, W.R. [Sandia National Labs., Albuquerque, NM (United States); LaBombard, B.; Lipshultz, B.; Pappas, D.; Pitcher, C.S. [Massachusetts Inst. of Tech., Cambridge, MA (United States); McCracken, G.M. [JET Joint Undertaking, Abingdon (United Kingdom)

    1998-05-01

    Erosion of molybdenum was measured on a set of 21 tiles after a run campaign of 1,090 shots in the Alcator C-Mod tokamak. The net erosion of molybdenum, was determined from changes in the depth of a thin chromium marker layer measured by Rutherford backscattering. Net Mo erosion was found to be approximately 150 nm near the outer divertor strike point, and much less everywhere else. Gross erosion rates by sputtering were estimated using ion energies and fluxes obtained from Langmuir probe measurements of edge-plasma conditions. Predicted net erosion using calculated gross erosion with prompt redeposition and measured net erosion agree within a factor of 3. Sputtering by boron and molybdenum impurities dominates erosion.

  13. Managing dental erosion.

    Science.gov (United States)

    Curtis, Donald A; Jayanetti, Jay; Chu, Raymond; Staninec, Michal

    2012-01-01

    The clinical signs of dental erosion are initially subtle, yet often progress because the patient remains asymptomatic, unaware and uninformed. Erosion typically works synergistically with abrasion and attrition to cause loss of tooth structure, making diagnosis and management complex. The purpose of this article is to outline clinical examples of patients with dental erosion that highlight the strategy of early identification, patient education and conservative restorative management. Dental erosion is defined as the pathologic chronic loss of dental hard tissues as a result of the chemical influence of exogenous or endogenous acids without bacterial involvement. Like caries or periodontal disease, erosion has a multifactorial etiology and requires a thorough history and examination for diagnosis. It also requires patient understanding and compliance for improved outcomes. Erosion can affect the loss of tooth structure in isolation of other cofactors, but most often works in synergy with abrasion and attrition in the loss of tooth structure (Table 1). Although erosion is thought to be an underlying etiology of dentin sensitivity, erosion and loss of tooth structure often occurs with few symptoms. The purpose of this article is threefold: first, to outline existing barriers that may limit early management of dental erosion. Second, to review the clinical assessment required to establish a diagnosis of erosion. And third, to outline clinical examples that review options to restore lost tooth structure. The authors have included illustrations they hope will be used to improve patient understanding and motivation in the early management of dental erosion.

  14. An integrated approach to shoreline mapping for spill response planning

    International Nuclear Information System (INIS)

    Owens, E.H.; LeBlanc, S.R.; Percy, R.J.

    1996-01-01

    A desktop mapping package was introduced which has the capability to provide consistent and standardized application of mapping and data collection/generation techniques. Its application in oil spill cleanup was discussed. The data base can be updated easily as new information becomes available. This provides a response team with access to a wide range of information that would otherwise be difficult to obtain. Standard terms and definitions and shoreline segmentation procedures are part of the system to describe the shore-zone character and shore-zone oiling conditions. The program that is in place for Atlantic Canada involves the integration of (1) Environment Canada's SCAT methodology in pre-spill data generation, (2) shoreline segmentation, (3) response management by objectives, (4) Environment Canada's national sensitivity mapping program, and (5) Environment Canada's field guide for the protection and treatment of oiled shorelines. 7 refs., 6 figs

  15. Shoreline changes and its impact on archaeological sites in West Greenland

    Science.gov (United States)

    Fenger-Nielsen, R.; Kroon, A.; Elberling, B.; Hollesen, J.

    2017-12-01

    Coastal erosion is regarded as a major threat to archaeological sites in the Arctic region. The problem arises because the predominantly marine-focused lifeways of Arctic people means that the majority of archaeological sites are found near the coast. On a Pan-Arctic scale, coastal erosion is often explained by long-term processes such as sea level rise, lengthening of open water periods due to a decline in sea ice, and a predicted increase in the frequency of major storms. However, on a local scale other short-term processes may be important parameters determining the coastal development. In this study, we focus on the Nuuk fjord system in West Greenland, which has been inhabited over the past 4000 years by different cultures and holds around 260 registered archaeological settlements. The fjord is characterized by its large branching of narrow deep-water and well-shaded water bodies, where tidal processes and local sources of sediment supply by rivers are observed to be the dominant factors determining the coastal development. We present a regional model showing the vulnerability of the shoreline and archeological sites due to coastal processes. The model is based on a) levelling surveys and historical aerial photographs of nine specific sites distributed in the region, b) water level measurements at three sites representing the inner-, middle- and outer fjord system, c) aerial photographs, satellite images and meteorological data of the entire region used to up-scale our local information at a specific settlement scale towards a regional scale. This deals with spatial and temporal variability in erosion and accumulation patterns along the shores in fjords and open seas.

  16. Elastic source model of the North Mono eruption (1325-1368 A.D.) based on shoreline deformation

    Science.gov (United States)

    Shaffer, Wil; Bursik, Marcus; Renshaw, Carl

    2010-12-01

    Topographic data from the Shuttle Radar Topography Mission (SRTM) captures the permanent deformation of a prominent highstand of Mono Lake, California USA. Deformation of the Dechambeau Ranch highstand shoreline was measured using the elevation of the beach berm—shoreline bluff break-in-slope. Point source models and a boundary element dike model were used to approximate the source of deformation underneath the northern end of the Mono Craters. The point source model could not adequately explain the observed deformation. The dike model yielded the best results for a NW trending dike dipping 60° NE and inflated to widths greater than 60 m. The results suggest that the geometry of the source is more complex than a simple vertical dike and that the deformation is better explained with a dipping dike following a normal fault, or an elongated cryptodome.

  17. National assessment of shoreline change—Summary statistics for updated vector shorelines and associated shoreline change data for the north coast of Alaska, U.S.-Canadian Border to Icy Cape

    Science.gov (United States)

    Gibbs, Ann E.; Richmond, Bruce M.

    2017-09-25

    Long-term rates of shoreline change for the north coast of Alaska, from the U.S.-Canadian border to the Icy Cape region of northern Alaska, have been updated as part of the U.S. Geological Survey’s National Assessment of Shoreline Change Project. Short-term shoreline change rates are reported for the first time. Additional shoreline position data were used to compute rates where the previous rate-of-change assessment only included two shoreline positions at a given location. The calculation of uncertainty associated with the long-term average rates has also been updated to match refined methods used in other study regions of the National Assessment of Shoreline Change Project. The average rates of this report have a reduced amount of uncertainty compared to those presented in the first assessment for this region.

  18. Archaeological sites along the Gujarat coast: Proxies to decipher the past shoreline

    Digital Repository Service at National Institute of Oceanography (India)

    Vora, K.H.; Gaur, A; Sundaresh

    on northwestern Saurashtra coast presents a classical case of shoreline shift in recent past. The paper discusses the archaeological evidences to decipher the past shoreline of the Saurashtra region...

  19. 78 FR 33051 - Non-Rock Alternatives to Shoreline Protection Demonstration Project (LA-16) Iberia, Jefferson...

    Science.gov (United States)

    2013-06-03

    ... DEPARTMENT OF AGRICULTURE Natural Resources Conservation Service Non-Rock Alternatives to...-Rock Alternatives to Shoreline Protection Demonstration Project (LA-16), Iberia, Jefferson, and... and environmental limitations preclude the use of rock structures. The shoreline protection systems...

  20. Shoreline changes in and around the Thubon River mouth, Central Vietnam

    Digital Repository Service at National Institute of Oceanography (India)

    Mau, L.D.; Nayak, G.N.; SanilKumar, V.

    Application of GENESIS model (GENEralized model for Simulating Shoreline change) for studying the shoreline change in and around the Thubon River Mouth, Central Vietnam is presented in this paper The input parameters used are the near shore wave...

  1. Pre-spill shoreline mapping in Prince William Sound, Alaska

    International Nuclear Information System (INIS)

    Owens, E.H.; Lamarche, A.; Reimer, P.D.; Marchant, S.O.; O'Brien, D.K.

    2003-01-01

    A long-term shoreline mapping program has been initiated in Prince William Sound, Alaska, to generate pre-spill data to assist in the planning activities for oil spill response in the area. Low-altitude aerial videotape surveys and video images form the basis for the mapping effort. The coast was initially divided into alongshore segments. The physical shore-zone is relatively homogeneous within each segment. A pre-spill Shoreline Cleanup Assessment Team (SCAT) database, using the ShoreData software, was created based on this initial detailed mapping. The SCAT field teams are therefore equipped with a detailed analysis of the shore-zone character. The same information was also used to develop a separate database for use by planning and response operations groups. The data is entered into the Graphical Resource Database (GRD), and a Geographic Information System (GIS). A simplified characterization of the primary features of each segment is then made available through interpretation of the data. In the event of an oil spill, the SCAT data in the ShoreData files can be combined with field data on shoreline oiling conditions using a second software package called ShoreAccess R which provides summaries of the main parameters required by the planning group. It can also be used as a data storage and management tool. As part of this program, more than 1700 kilometres of shoreline in Prince William Sound have already been mapped. 24 refs., 4 tabs., 5 figs

  2. Shoreline stability in the vicinity of Cochin Harbour

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Vethamony, P.

    , showing stability over a period of one year. The growth of shoreline north of Cochin harbour channel takes place at the cost of sediment that should have otherwise by-passed the estuarine mouth. During the southwest monsoon the development of opposing...

  3. Subtidal Bathymetric Changes by Shoreline Armoring Removal and Restoration Projects

    Science.gov (United States)

    Wallace, J.

    2016-12-01

    The Salish Sea, a region with a diverse coastline, is altered by anthropogenic shoreline modifications such as seawalls. In recent years, local organizations have moved to restore these shorelines. Current research monitors the changes restoration projects have on the upper beach, lower beach, and intertidal, however little research exists to record possible negative effects on the subtidal. The purpose of this research is to utilize multibeam sonar bathymetric data to analyze possible changes to the seafloor structure of the subtidal in response to shoreline modification and to investigate potential ecosystem consequences of shoreline alteration. The subtidal is home to several species including eelgrass (Zostera marina). Eelgrass is an important species in Puget Sound as it provides many key ecosystem functions including providing habitat for a wide variety of organisms, affecting the physics of waves, and sediment transport in the subtidal. Thus bathymetric changes could impact eelgrass growth and reduce its ability to provide crucial ecosystem services. Three Washington state study sites of completed shoreline restoration projects were used to generate data from areas of varied topographic classification, Seahurst Park in Burien, the Snohomish County Nearshore Restoration Project in Everett, and Cornet Bay State Park on Whidbey Island. Multibeam sonar data was acquired using a Konsberg EM 2040 system and post-processed in Caris HIPS to generate a base surface of one-meter resolution. It was then imported into the ArcGIS software suite for the generation of spatial metrics. Measurements of change were calculated through a comparison of historical and generated data. Descriptive metrics generated included, total elevation change, percent area changed, and a transition matrix of positive and negative change. Additionally, pattern metrics such as, surface roughness, and Bathymetric Position Index (BPI), were calculated. The comparison of historical data to new data

  4. 36 CFR 327.30 - Shoreline Management on Civil Works Projects.

    Science.gov (United States)

    2010-07-01

    ... ADMINISTERED BY THE CHIEF OF ENGINEERS § 327.30 Shoreline Management on Civil Works Projects. (a) Purpose. The... this regulation, shoreline management plans are not required for those projects where construction was... approval, one copy of each project Shoreline Management Plan will be forwarded to HQUSACE (CECW-ON) WASH DC...

  5. Quantification of shoreline change along Hatteras Island, North Carolina: Oregon Inlet to Cape Hatteras, 1978-2002, and associated vector shoreline data

    Science.gov (United States)

    Hapke, Cheryl J.; Henderson, Rachel E.

    2015-01-01

    Shoreline change spanning twenty-four years was assessed along the coastline of Cape Hatteras National Seashore, at Hatteras Island, North Carolina. The shorelines used in the analysis were generated from georeferenced historical aerial imagery and are used to develop shoreline change rates for Hatteras Island, from Oregon Inlet to Cape Hatteras. A total of 14 dates of aerial photographs ranging from 1978 through 2002 were obtained from the U.S. Army Corp of Engineers Field Research Facility in Duck, North Carolina, and scanned to generate digital imagery. The digital imagery was georeferenced and high water line shorelines (interpreted from the wet/dry line) were digitized from each date to produce a time series of shorelines for the study area. Rates of shoreline change were calculated for three periods: the full span of the time series, 1978 through 2002, and two approximately decadal subsets, 1978–89 and 1989–2002.

  6. Protection from erosion following wildfire

    Science.gov (United States)

    Peter R. Robichaud; William J. Elliot

    2006-01-01

    Erosion in the first year after a wildfire can be up to three orders of magnitude greater than the erosion from undisturbed forests. To mitigate potential postfire erosion, various erosion control treatments are applied on highly erodible areas with downstream resources in need of protection. Because postfire erosion rates generally decline by an order of magnitude for...

  7. National evaluation of Chinese coastal erosion to sea level rise using a Bayesian approach

    International Nuclear Information System (INIS)

    Zhan, Q; Fan, X; Du, X; Zhu, J

    2014-01-01

    In this paper a Causal Bayesian network is developed to predict decadal-scale shoreline evolution of China to sea-level rise. The Bayesian model defines relationships between 6 factors of Chinese coastal system such as coastal geomorphology, mean tide range, mean wave height, coastal slope, relative sea-level rise rate and shoreline erosion rate. Using the Bayesian probabilistic model, we make quantitative assessment of china's shoreline evolution in response to different future sea level rise rates. Results indicate that the probability of coastal erosion with high and very high rates increases from 28% to 32.3% when relative sea-level rise rates is 4∼6mm/a, and to 44.9% when relative sea-level rise rates is more than 6mm/a. A hindcast evaluation of the Bayesian model shows that the model correctly predicts 79.3% of the cases. Model test indicates that the Bayesian model shows higher predictive capabilities for stable coasts and very highly eroding coasts than moderately and highly eroding coasts. This study demonstrates that the Bayesian model is adapted to predicting decadal-scale Chinese coastal erosion associated with sea-level rise

  8. Saliva and dental erosion

    Directory of Open Access Journals (Sweden)

    Marília Afonso Rabelo Buzalaf

    2012-10-01

    Full Text Available Dental erosion is a multifactorial condition. The consideration of chemical, biological and behavioral factors is fundamental for its prevention and therapy. Among the biological factors, saliva is one of the most important parameters in the protection against erosive wear. Objective: This review discusses the role of salivary factors on the development of dental erosion. Material and Methods: A search was undertaken on MeDLINe website for papers from 1969 to 2010. The keywords used in the research were "saliva", "acquired pellicle", "salivary flow", "salivary buffering capacity" and "dental erosion". Inclusion of studies, data extraction and quality assessment were undertaken independently and in duplicate by two members of the review team. Disagreements were solved by discussion and consensus or by a third party. Results: Several characteristics and properties of saliva play an important role in dental erosion. Salivary clearance gradually eliminates the acids through swallowing and saliva presents buffering capacity causing neutralization and buffering of dietary acids. Salivary flow allows dilution of the acids. In addition, saliva is supersaturated with respect to tooth mineral, providing calcium, phosphate and fluoride necessary for remineralization after an erosive challenge. Furthermore, many proteins present in saliva and acquired pellicle play an important role in dental erosion. Conclusions: Saliva is the most important biological factor affecting the progression of dental erosion. Knowledge of its components and properties involved in this protective role can drive the development of preventive measures targeting to enhance its known beneficial effects.

  9. Scales and erosion

    Science.gov (United States)

    There is a need to develop scale explicit understanding of erosion to overcome existing conceptual and methodological flaws in our modelling methods currently applied to understand the process of erosion, transport and deposition at the catchment scale. These models need to be based on a sound under...

  10. Saliva and dental erosion.

    Science.gov (United States)

    Buzalaf, Marília Afonso Rabelo; Hannas, Angélicas Reis; Kato, Melissa Thiemi

    2012-01-01

    Dental erosion is a multifactorial condition. The consideration of chemical, biological and behavioral factors is fundamental for its prevention and therapy. Among the biological factors, saliva is one of the most important parameters in the protection against erosive wear. This review discusses the role of salivary factors on the development of dental erosion. A search was undertaken on MeDLINe website for papers from 1969 to 2010. The keywords used in the research were "saliva", "acquired pellicle", "salivary flow", "salivary buffering capacity" and "dental erosion". Inclusion of studies, data extraction and quality assessment were undertaken independently and in duplicate by two members of the review team. Disagreements were solved by discussion and consensus or by a third party. Several characteristics and properties of saliva play an important role in dental erosion. Salivary clearance gradually eliminates the acids through swallowing and saliva presents buffering capacity causing neutralization and buffering of dietary acids. Salivary flow allows dilution of the acids. In addition, saliva is supersaturated with respect to tooth mineral, providing calcium, phosphate and fluoride necessary for remineralization after an erosive challenge. Furthermore, many proteins present in saliva and acquired pellicle play an important role in dental erosion. Saliva is the most important biological factor affecting the progression of dental erosion. Knowledge of its components and properties involved in this protective role can drive the development of preventive measures targeting to enhance its known beneficial effects.

  11. Nile Delta exhibited a spatial reversal in the rates of shoreline retreat on the Rosetta promontory comparing pre- and post-beach protection

    Science.gov (United States)

    Ghoneim, Eman; Mashaly, Jehan; Gamble, Douglas; Halls, Joanne; AbuBakr, Mostafa

    2015-01-01

    The coastline of the Nile Delta experienced accelerated erosion since the construction of the Aswan High Dam in 1964 and, consequently, the entrapment of a large amount of river sediments behind it. The coastline of the Rosetta promontory showed the highest erosion in the Delta with an average retreat rate of 137.4 m year- 1. In 1991, in an effort to mitigate sediment loss, a 4.85 km long seawall was built on the outer margin of the promontory. For additional beach protection, 15 groins were constructed along the eastern and western sides of the seawall in 2003 and 2005. To quantify erosion and accretion patterns along the Rosetta promontory, 11 Landsat images acquired at unequal intervals during a 40 year time span (1972 and 2012) were analyzed. The positions of shorelines were automatically extracted from satellite imagery and compared with three very high resolution QuickBird and WorldView2 images for data validation. Analysis of the rates of shoreline change revealed that the construction of the seawall was largely successful in halting the recession along the tip of the promontory, which lost 10.8 km2 prior to coastal protection. Conversely, the construction of the 15 groins has negatively affected the coastal morphology of the promontory and caused a reversal from accretion to fast erosion along the promontory leeside, where some segments of the shoreline have undergone as much as 30.8 m year- 1 of erosion. Without hard structures, the tip of the Rosetta promontory would have retreated 2.3 km by 2013 and lost 7.2 km2 of land. About 10% of this land is deltaic fertile cultivated farms. Moreover, without additional protection the sides of the promontory will lose about 1.3 km2 of land and the coastline would recede at an average rate of 200 m by 2020. Unless action is taken, coastal erosion, enhanced by rising sea level, will steadily eat away the Nile Delta at an alarming rate. The successful demonstration of the advocated procedures in this study could be

  12. Divertor erosion in DIII-D

    International Nuclear Information System (INIS)

    Whyte, D.G.; Bastasz, R.; Wampler, W.R.; Brooks, J.N.; West, W.P.; Wong, C.P.C.; Buzhinskij, O.I.; Opimach, I.V.

    1998-08-01

    Net erosion rates of carbon target plates have been measured in situ for the DIII-D lower divertor. The principal method of obtaining this data is the DiMES sample probe. Recent experiments have focused on erosion at the outer strike-point (OSP) of two divertor plasma conditions: attached (T e > 40 eV) ELMing plasmas, and detached (T e 2 . In this case, measurements and modeling agree for both gross and net carbon erosion, showing the near-surface transport and redeposition of the carbon is well understood. In the attached cases, physical sputtering (with enhancement from self-sputtering and oblique incidence) is dominant, and the effective sputtering yield, Y, is greater than 10%. In ELM-free discharges, the total OSP net erosion rate is equal to the rate of carbon accumulation in the core plasma. For the detached divertor cases, the cold incident plasma eliminates physical sputtering. Attempts to measure chemically eroded hydrocarbon molecules spectroscopically indicate an upper limit of Y ≤ 0.1% for the chemical sputtering yield. Net erosion is suppressed at the outer strike-point, which becomes a region of net redeposition (∼ 4 cm/exposure-year). The private flux wall is measured to be a region of net redeposition with dense, high neutral pressure, attached divertor plasmas. Leading edges intercepting parallel heat flux (∼ 50 MW/m 2 ) have very high net erosion rates at the OSP of an attached plasma (∼ 10 microm/s > 1,000x erosion rate of aligned surfaces). Leading edge erosion, and subsequent carbon redeposition, caused by tile gaps can account for half of the deuterium codeposition in the DIII-D divertor

  13. Divertor erosion in DIII-D

    International Nuclear Information System (INIS)

    Whyte, D.G.; Bastasz, R.; Wampler, W.R.; Brooks, J.N.; West, W.P.; Wong, C.P.C.

    1998-05-01

    Net erosion rates of carbon target plates have been measured in situ for the DIII-D lower divertor. The principal method of obtaining this data is the DiMES sample probe. Recent experiments have focused on erosion at the outer strike-point of two divertor plasma conditions: (1) attached (Te > 40 eV) ELMing plasmas and (2) detached (Te 10 cm/year, even with incident heat flux 2 . In this case, measurements and modeling agree for both gross and net carbon erosion, showing the near-surface transport and redeposition of the carbon is well understood and that effective sputtering yields are > 10%. In ELM-free discharges, this erosion rate can account for the rate of carbon accumulation in the core plasma. Divertor plasma detachment eliminates physical sputtering, while spectroscopically measured chemical erosion yields are also found to be low (Y(C/D + ) ≤ 2.0 x 10 -3 ). This leads to suppression of net erosion at the outer strike-point, which becomes a region of net redeposition (∼ 4 cm/year). The private flux wall is measured to be a region of net redeposition with dense, high neutral pressure, attached divertor plasmas. Leading edges intercepting parallel heat flux (∼ 50 MW/m 2 ) have very high net erosion rates (∼ 10 microm/s) at the OSP of an attached plasma. Leading edge erosion, and subsequent carbon redeposition, caused by tile gaps can account for half of the deuterium codeposition in the DIII-D divertor

  14. The impact of Cyclone Nargis on the Ayeyarwady (Irrawaddy) River delta shoreline and nearshore zone (Myanmar): Towards degraded delta resilience?

    Science.gov (United States)

    Besset, Manon; Anthony, Edward J.; Dussouillez, Philippe; Goichot, Marc

    2017-10-01

    The Ayeyarwady River delta (Myanmar) is exposed to tropical cyclones, of which the most devastating has been cyclone Nargis (2-4 May 2008). We analysed waves, flooded area, nearshore suspended sediments, and shoreline change from satellite images. Suspended sediment concentrations up to 40% above average during the cyclone may reflect fluvial mud supply following heavy rainfall and wave reworking of shoreface mud. Massive recession of the high-water line resulted from backshore flooding by cyclone surge. The shoreline showed a mean retreat of 47 m following Nargis. Erosion was stronger afterwards (-148 m between August 2008 and April 2010), largely exceeding rates prior to Nargis (2000-2005: -2.14 m/year) and over 41 years (1974-2015: -0.62 m/year). This implies that resilience was weak following cyclone impact. Consequently, the increasingly more populous Ayeyarwady delta, rendered more and more vulnerable by decreasing fluvial sediment supply, could, potentially, become more severely impacted by future high-energy events.

  15. Pacemaker lead erosion simulating "Loch Ness Monster": conservative management.

    Science.gov (United States)

    Garg, Naveen; Moorthy, Nagaraja

    2012-12-01

    The majority of pacemaker pocket or lead erosions are due to either mechanical erosion by the bulky pulse generator or secondary to pacemaker pocket infection. We describe an unusual case of delayed pacemaker lead erosion causing extrusion of a portion of the pacing lead, with separate entry and exit points, with the gap filled with new skin formation, simulating the "Loch Ness Monster", which was successfully managed conservatively by surgical reinsertion.

  16. Wave energy fluxes and multi-decadal shoreline changes

    DEFF Research Database (Denmark)

    Kabuth, Alina Kristin; Kroon, Aart

    2014-01-01

    Spatial patterns of multidecadal shoreline changes in two microtidal, low-energetic embayments of southern Zealand, Denmark, were investigated by using the directional distribution of wave energy fluxes. The sites include a barrier island system attached to moraine bluffs, and a recurved spit...... variability of directional distributions of wave energy fluxes furthermore outlined potential sediment sources and sinks for the evolution of the barrier island system and for the evolution of the recurved spit....... adjacent to a cliff coast. The barrier island system is characterized by cross-shore translation and by an alignment of the barrier alongshore alternating directions of barrier-spit progradation in a bidirectional wave field. The recurved spit adjacent to the cliff coast experienced shoreline rotation...

  17. Decision analysis of shoreline protection under climate change uncertainty

    Science.gov (United States)

    Chao, Philip T.; Hobbs, Benjamin F.

    1997-04-01

    If global warming occurs, it could significantly affect water resource distribution and availability. Yet it is unclear whether the prospect of such change is relevant to water resources management decisions being made today. We model a shoreline protection decision problem with a stochastic dynamic program (SDP) to determine whether consideration of the possibility of climate change would alter the decision. Three questions are addressed with the SDP: (l) How important is climate change compared to other uncertainties?, (2) What is the economic loss if climate change uncertainty is ignored?, and (3) How does belief in climate change affect the timing of the decision? In the case study, sensitivity analysis shows that uncertainty in real discount rates has a stronger effect upon the decision than belief in climate change. Nevertheless, a strong belief in climate change makes the shoreline protection project less attractive and often alters the decision to build it.

  18. Canadian coastal environments, shoreline processes, and oil spill cleanup

    International Nuclear Information System (INIS)

    Owens, E.H.

    1994-03-01

    The coastal zone is a dynamic environment, so that in developing practical and effective oil spill response strategies it is necessary to understand the forces that contribute to shore-zone processs. The coasts of Canada encompass a wide range of environments and are characterized by a variety of shoreline types that include the exposed, resistant cliffs of eastern Newfoundland and the sheltered marshes of the Beaufort Sea. A report is presented to provide an understanding of the dynamics and physical processes as they vary on the different coasts of Canada, including the Great Lakes. An outline of the general character and processes on a regional basis describes the coastal environments and introduces the literature that can be consulted for more specific information. The likely fate and persistence of oil that reaches the shoreline is discussed to provide the framework for development of spill response strategies and for the selection of appropriate shoreline cleanup or treatment countermeasures. Lessons learned from recent experience with major oil spills and field experiments are integrated into the discussion. Separate abstracts have been prepared for each of the four sections of this report. 502 refs., 5 figs

  19. Pan-European Coastal Erosion and Accretion: translating incomplete data and information for coastal reslience assessments

    Science.gov (United States)

    van Heteren, Sytze; Moses, Cherith; van der Ven, Tamara

    2017-04-01

    EMODnet has changed the face of the European marine data landscape and is developing tools to connect national data and information resources to make them easily available for multiple users, for multiple purposes. Building on the results of EUROSION, an EU-project completed some ten years ago, EMODnet-Geology has been compiling coastal erosion and sedimentation data and information for all European shorelines. Coverage is being expanded, and data and information are being updated. Challenges faced during this compilation phase are posed by a) differences between parameters used as indicators of shoreline migration, b) restricted access to third-party data, and c) data gaps. There are many indicators of coastal behaviour, with inherent incompatibilities and variations between low-lying sediment and cliffed rock shorelines. Regionally, low data availability and limited access result in poor coverage. With Sentinel data expected to become increasingly available, it is time to invest in automated methods to derive coastal-erosion data from satellite monitoring. Even so, consistency of data and derived information on coastal erosion and accretion does not necessarily translate into usability in pan-European coastal-zone management. Indicators of shoreline change need to be assessed and weighted regionally in light of other parameters in order to be of value in assessing coastal resilience or vulnerability. There is no single way to portray coastal vulnerability for all of Europe in a meaningful way. A common legend, however attractive intuitively, results in data products that work well for one region but show insufficient or excessive detail elsewhere. For decision making, uniform products are often not very helpful. The ability to zoom in on different spatial levels is not a solution either. It is better to compile and visualize vulnerability studies with different legends, and to provide each map with a confidence assessment and other relevant metadata.

  20. Sand mining impacts on long-term dune erosion in southern Monterey Bay

    Science.gov (United States)

    Thornton, E.B.; Sallenger, Abby; Sesto, Juan Conforto; Egley, L.; McGee, Timothy; Parsons, Rost

    2006-01-01

    Southern Monterey Bay was the most intensively mined shoreline (with sand removed directly from the surf zone) in the U.S. during the period from 1906 until 1990, when the mines were closed following hypotheses that the mining caused coastal erosion. It is estimated that the yearly averaged amount of mined sand between 1940 and 1984 was 128,000 m3/yr, which is approximately 50% of the yearly average dune volume loss during this period. To assess the impact of sand mining, erosion rates along an 18 km range of shoreline during the times of intensive sand mining (1940–1990) are compared with the rates after sand mining ceased (1990–2004). Most of the shoreline is composed of unconsolidated sand with extensive sand dunes rising up to a height of 46 m, vulnerable to the erosive forces of storm waves. Erosion is defined here as a recession of the top edge of the dune. Recession was determined using stereo-photogrammetry, and LIDAR and GPS surveys. Long-term erosion rates vary from about 0.5 m/yr at Monterey to 1.5 m/yr in the middle of the range, and then decrease northward. Erosion events are episodic and occur when storm waves and high tides coincide, allowing swash to undercut the dune and resulting in permanent recession. Erosion appears to be correlated with the occurrence of El Niños. The calculated volume loss of the dune in southern Monterey Bay during the 1997–98 El Niño winter was 1,820,000 m3, which is almost seven times the historical annual mean dune erosion of 270,000 m3/yr. The alongshore variation in recession rates appears to be a function of the alongshore gradient in mean wave energy and depletions by sand mining. After cessation of sand mining in 1990, the erosion rates decreased at locations in the southern end of the bay but have not significantly changed at other locations.

  1. Quebec region's shoreline segmentation in the St. Lawrence River : response tool for oil spills

    International Nuclear Information System (INIS)

    Laforest, S.; Martin, V.

    2004-01-01

    Environment Canada, the Canadian Coast Guard, and the Eastern Canada Response Corporation are developing and refining pre-spill databases containing information about physical shoreline characteristics. Automated links between these pre-spill shoreline characteristic databases and computerized shoreline assessment tools have also been created using Geographical Information System (GIS) technology. The pre-spill databases can be used for planning shoreline cleanup operations. A training exercise, designed to evaluate a spill management system integrating the Quebec region pre-spill shoreline database and the ShoreAssess R shoreline assessment system was performed by Eastern Canada Response Corporation during an aerial survey where shoreline was segmented into digitized information. The cartography of segmentation covers the fluvial part of the St. Lawrence River. The oil spill-oriented database includes geomorphologic information from the supratidal to the lower intertidal zones. It also includes some statistical information and other requirements for cleanup operations. The computerized shoreline assessment tools made it possible to evaluate the length and type of shoreline that would potentially be impacted by oil. The tools also made it possible to assess the shoreline treatment methods most likely to be used, and evaluate the probable duration of the cleanup operation. The training exercise demonstrated that the integration of the databases is a valuable tool during the early phases of an oil spill response. 9 refs., 3 figs

  2. Monitoring oiled shorelines in Prince William Sound Alaska, following the Exxon Valdez oil spill

    International Nuclear Information System (INIS)

    Gilfillan, E.S.; Page, D.S.; Harner, E.J.; Boehm, P.D.; Stoker, S.W.

    1993-01-01

    Three types of shoreline monitoring programs were employed to evaluate the recovery of the ecological communities of Prince William Sound (PWS) shorelines after the oil spill: (a) Extensive shoreline surveys conducted (1989--1992) over much of the oiled shoreline to define extent of shoreline oiling and to assess biological conditions; (b) Detailed sampling in 1989 at nonrandomly chosen locations representing a range of oiling conditions (c) Comprehensive shoreline ecology program initiated in 1990 to assess shoreline recovery in Prince William Sound using (1) a rigorous stratified random sampling study design with 64 sites representing 4 shoreline habitats and 4 oiling levels (unoiled, light, moderate, heavy); (2) periodic sampling at 12 nonrandomly chosen sites of particular concern. Biological communities were analyzed to detect differences due to oiling in each of 16 habitat/tide zone combinations. Following the spill, populations of all major species survived as sources for recolonization. Recruitment to oiled shores began in summer 1989. By 1990, shoreline biota in PWS had largely recovered. Estimates of shoreline recovery (biological community indistinguishable from reference) ranged from 91% based on univariate analysis of standard community parameters to 73% based on multivariate correspondence analysis

  3. Measurement of erosion: Is it possible?

    NARCIS (Netherlands)

    Stroosnijder, L.

    2005-01-01

    Reasons for erosion measurements are: (1) to determine the environmental impact of erosion and conservation practices, (2) scientific erosion research; (3) development and evaluation of erosion control technology; (4) development of erosion prediction technology and (5) allocation of conservation

  4. Numerical modelling of concentrated leak erosion during Hole Erosion Tests

    OpenAIRE

    Mercier, F.; Bonelli, S.; Golay, F.; Anselmet, F.; Philippe, P.; Borghi, R.

    2015-01-01

    This study focuses on the numerical modelling of concentrated leak erosion of a cohesive soil by a turbulent flow in axisymmetrical geometry, with application to the Hole Erosion Test (HET). The numerical model is based on adaptive remeshing of the water/soil interface to ensure accurate description of the mechanical phenomena occurring near the soil/water interface. The erosion law governing the interface motion is based on two erosion parameters: the critical shear stress and the erosion co...

  5. IN SITU MEASUREMENT OF BEDROCK EROSION

    Directory of Open Access Journals (Sweden)

    D. H. Rieke-Zapp

    2012-07-01

    Full Text Available While long term erosion rates of bedrock material may be estimated by dating methods, current day erosion rates are – if at all available – based on rough estimates or on point measurements. Precise quantification of short term erosion rates are required to improve our understanding of short term processes, for input in landscape evolution models, as well as for studying the mechanics and efficiency of different erosion processes in varying geomorphological settings. Typical current day erosion rates in the European Alps range from sub-millimetre to several millimetres per year depending on the dominant erosion processes. The level of surveying accuracy required for recurring sub-millimetre to millimetre measurements in the field is demanding. A novel surveying setup for in-situ measurement of bedrock erosion was tested recently in three different locations in Switzerland. Natural bedrock was investigated in the Gornera gorge close to Zermatt. Further on, bedrock samples were installed in exposed locations in the Erlenbach research watershed close to Einsiedeln, and in the Illgraben debris flow channel, located in the Canton Schwyz and Valais, respectively. A twofold measurement approach was chosen for all locations. For the first setup control points providing an absolute reference frame for recurrent measurements were embedded close to the area of interest. Close range photogrammetry was applied to measure surface changes on the bedrock samples. The precision for surface measurements in the field was 0.1 mm (1 σ and thus suitable for the application. The equipment needed for the surveys can easily be carried to the field. At one field site a structured light scanner was used along with the photogrammetric setup. Although the current generation of structured light scanners appeared less suitable for field application, data acquisition was much faster and checking the data for completeness in the field was straight forward. The latest

  6. In Situ Measurement of Bedrock Erosion

    Science.gov (United States)

    Rieke-Zapp, D. H.; Beer, A.; Turowski, J. M.; Campana, L.

    2012-07-01

    While long term erosion rates of bedrock material may be estimated by dating methods, current day erosion rates are - if at all available - based on rough estimates or on point measurements. Precise quantification of short term erosion rates are required to improve our understanding of short term processes, for input in landscape evolution models, as well as for studying the mechanics and efficiency of different erosion processes in varying geomorphological settings. Typical current day erosion rates in the European Alps range from sub-millimetre to several millimetres per year depending on the dominant erosion processes. The level of surveying accuracy required for recurring sub-millimetre to millimetre measurements in the field is demanding. A novel surveying setup for in-situ measurement of bedrock erosion was tested recently in three different locations in Switzerland. Natural bedrock was investigated in the Gornera gorge close to Zermatt. Further on, bedrock samples were installed in exposed locations in the Erlenbach research watershed close to Einsiedeln, and in the Illgraben debris flow channel, located in the Canton Schwyz and Valais, respectively. A twofold measurement approach was chosen for all locations. For the first setup control points providing an absolute reference frame for recurrent measurements were embedded close to the area of interest. Close range photogrammetry was applied to measure surface changes on the bedrock samples. The precision for surface measurements in the field was 0.1 mm (1 σ) and thus suitable for the application. The equipment needed for the surveys can easily be carried to the field. At one field site a structured light scanner was used along with the photogrammetric setup. Although the current generation of structured light scanners appeared less suitable for field application, data acquisition was much faster and checking the data for completeness in the field was straight forward. The latest generation of compact

  7. Validation of a short-term shoreline evolution model and coastal risk management implications. The case of the NW Portuguese coast (Ovar-Marinha Grande)

    Science.gov (United States)

    Cenci, Luca; Giuseppina Persichillo, Maria; Disperati, Leonardo; Oliveira, Eduardo R.; de Fátima Lopes Alves, Maria; Boni, Giorgio; Pulvirenti, Luca; Phillips, Mike

    2015-04-01

    Coastal zones are fragile and dynamic environments where environmental, economic and social aspects are interconnected. While these areas are often highly urbanised, they are especially vulnerable to natural hazards (e.g. storms, floods, erosion, storm surges). Hence, high risk affects people and goods in several coastal zones throughout the world. The recent storms that hit the European coasts (Hercules, Christian and Stephanie, among others) showed the high vulnerability of these territories. Integrated Coastal Management (ICM) deals with the sustainable development of coastal zones by taking into account the different aspects that affect them, including risks adaptation and mitigation. Accurate mapping of shoreline position through time and models to predict shoreline evolution play a fundamental role for coastal zone risk management. In this context, spaceborne remote sensing is fundamental because it provides synoptic and multitemporal information that allow the extraction of shorelines' proxies. These are stable coastal features (e.g. the vegetation lines, the foredune toe, etc.) that can be mapped instead of the proper shoreline, which is an extremely dynamic boundary. The use of different proxies may provide different evolutionary patterns for the same study area; therefore it is important to assess which is the most suitable, given the environmental characteristics of a specific area. In Portugal, the coastal stretch between Ovar and Marinha Grande is one of the greatest national challenges in terms of integrated management of resources and risks. This area is characterised by intense erosive processes that largely exceed the shoreline's retreat predictions made in the first Coastal Zone Management Plan, developed in 2000. The aim of this work was to assess the accuracy of a new model of shoreline evolution implemented in 2013 in order to check its robustness for short-term predictions. The method exploited the potentialities of the Landsat archive

  8. Spatial bedrock erosion distribution in a natural gorge

    Science.gov (United States)

    Beer, A. R.; Turowski, J. M.; Kirchner, J. W.

    2015-12-01

    Quantitative analysis of morphological evolution both in terrestrial and planetary landscapes is of increasing interest in the geosciences. In mountainous regions, bedrock channel formation as a consequence of the interaction of uplift and erosion processes is fundamental for the entire surface evolution. Hence, the accurate description of bedrock channel development is important for landscape modelling. To verify existing concepts developed in the lab and to analyse how in situ channel erosion rates depend on the interrelations of discharge, sediment transport and topography, there is a need of highly resolved topographic field data. We analyse bedrock erosion over two years in a bedrock gorge downstream of the Gorner glacier above the town of Zermatt, Switzerland. At the study site, the Gornera stream cuts through a roche moutonnée in serpentine rock of 25m length, 5m width and 8m depth. We surveyed bedrock erosion rates using repeat terrestrial laser scanning (TLS) with an average point spacing of 5mm. Bedrock erosion rates in direction of the individual surface normals were studied directly on the scanned point clouds applying the M3C2 algorithm (Lague et al., 2013, ISPRS). The surveyed erosion patterns were compared to a simple stream erosivity visualisation obtained from painted bedrock sections at the study location. Spatially distributed erosion rates on bedrock surfaces based on millions of scan points allow deduction of millimeter-scale mean annual values of lateral erosion, incision and downstream erosion on protruding streambed surfaces. The erosion rate on a specific surface point is shown to depend on the position of this surface point in the channel's cross section, its height above the streambed and its spatial orientation to the streamflow. Abrasion by impacting bedload was likely the spatially dominant erosion process, as confirmed by the observed patterns along the painted bedrock sections. However, a single plucking event accounted for the half

  9. Rainfall erosivity in Europe.

    Science.gov (United States)

    Panagos, Panos; Ballabio, Cristiano; Borrelli, Pasquale; Meusburger, Katrin; Klik, Andreas; Rousseva, Svetla; Tadić, Melita Perčec; Michaelides, Silas; Hrabalíková, Michaela; Olsen, Preben; Aalto, Juha; Lakatos, Mónika; Rymszewicz, Anna; Dumitrescu, Alexandru; Beguería, Santiago; Alewell, Christine

    2015-04-01

    Rainfall is one the main drivers of soil erosion. The erosive force of rainfall is expressed as rainfall erosivity. Rainfall erosivity considers the rainfall amount and intensity, and is most commonly expressed as the R-factor in the USLE model and its revised version, RUSLE. At national and continental levels, the scarce availability of data obliges soil erosion modellers to estimate this factor based on rainfall data with only low temporal resolution (daily, monthly, annual averages). The purpose of this study is to assess rainfall erosivity in Europe in the form of the RUSLE R-factor, based on the best available datasets. Data have been collected from 1541 precipitation stations in all European Union (EU) Member States and Switzerland, with temporal resolutions of 5 to 60 min. The R-factor values calculated from precipitation data of different temporal resolutions were normalised to R-factor values with temporal resolutions of 30 min using linear regression functions. Precipitation time series ranged from a minimum of 5 years to a maximum of 40 years. The average time series per precipitation station is around 17.1 years, the most datasets including the first decade of the 21st century. Gaussian Process Regression (GPR) has been used to interpolate the R-factor station values to a European rainfall erosivity map at 1 km resolution. The covariates used for the R-factor interpolation were climatic data (total precipitation, seasonal precipitation, precipitation of driest/wettest months, average temperature), elevation and latitude/longitude. The mean R-factor for the EU plus Switzerland is 722 MJ mm ha(-1) h(-1) yr(-1), with the highest values (>1000 MJ mm ha(-1) h(-1) yr(-1)) in the Mediterranean and alpine regions and the lowest (<500 MJ mm ha(-1) h(-1) yr(-1)) in the Nordic countries. The erosivity density (erosivity normalised to annual precipitation amounts) was also the highest in Mediterranean regions which implies high risk for erosive events and floods

  10. Evolving Landscapes: the Effect of Genetic Variation on Salt Marsh Erosion

    Science.gov (United States)

    Bernik, B. M.; Blum, M. J.

    2014-12-01

    Ecogeomorphic studies have demonstrated that biota can exert influence over geomorphic processes, such as sediment transport, which in turn have biotic consequences and generate complex feedbacks. However, little attention has been paid to the potential for feedback to arise from evolutionary processes as population genetic composition changes in response to changing physical landscapes. In coastal ecosystems experiencing land loss, for example, shoreline erosion entails reduced plant survival and reproduction, and thereby represents a geomorphic response with inherent consequences for evolutionary fitness. To get at this topic, we examined the effect of genetic variation in the saltmarsh grass Spartina alterniflora, a renowned ecosystem engineer, on rates of shoreline erosion. Field transplantation studies and controlled greenhouse experiments were conducted to compare different genotypes from both wild and cultivated populations. Plant traits, soil properties, accretion/subsidence, and rates of land loss were measured. We found significant differences in rates of erosion between field plots occupied by different genotypes. Differences in erosion corresponded to variation in soil properties including critical shear stress and subsidence. Plant traits that differed across genotypes included belowground biomass, root tensile strength, and C:N ratios. Our results demonstrate the importance of genetic variation to salt marsh functioning, elucidating the relationship between evolutionary processes and ecogeomorphic dynamics in these systems. Because evolutionary processes can occur on ecological timescales, the direction and strength of ecogeomorphic feedbacks may be more dynamic than previously accounted for.

  11. Coastal Hazard Vulnerability Assessment: A Case Study of Erosion and Flooding on Herschel Island, Yukon Territory, Canada

    Science.gov (United States)

    Radosavljevic, B.; Lantuit, H.; Overduin, P. P.; Fritz, M.

    2015-12-01

    Coastal infrastructure, cultural, and archeological sites are increasingly vulnerable to erosion and flooding along permafrost coasts. Amplified warming of the Arctic, sea level rise, lengthening of the open water period, and a predicted increase in frequency of major storms compound these threats. Mitigation necessitates decision-making tools at an appropriate scale. We present a study of coastal erosion combining it with a flooding risk assessment for the culturally important historic settlement on Herschel Island, a UNESCO World Heritage candidate site. The resulting map may help local stakeholders devise management strategies to cope with rapidly changing environmental conditions. We analyzed shoreline movement using the Digital Shoreline Analysis System (DSAS) after digitizing shorelines from 1952, 1970, and 2011. Using these data, forecasts of shoreline positions were made for 20 and 50 years into the future. Flooding risk was assessed using a cost-distance map based on a high-resolution Light Detection and Ranging (LiDAR) dataset and current Intergovernmental Panel on Climate Change sea level estimates. Widespread erosion characterizes the study area. The rate of shoreline movement for different periods of the study ranges from -5.5 to 2.7 m·a-1 (mean -0.6 m·a-1). Mean coastal retreat decreased from -0.6 m·a-1 to -0.5 m·a-1, for 1952-1970 and 1970-2000, respectively, and increased to -1.3 m·a-1 in the period 2000-2011. Ice-rich coastal sections, and coastal sections most exposed to wave attack exhibited the highest rates of coastal retreat. The geohazard map resulting from shoreline projections and flood risk analysis indicates that most of the area occupied by the historic settlement is at extreme or very high risk of flooding, and some buildings are vulnerable to coastal erosion. The results of this study indicate a greater threat by coastal flooding than erosion. Our assessment may be applied in other locations where limited data are available.

  12. COREXIT 9580 shoreline cleaner: Development, application, and status

    International Nuclear Information System (INIS)

    Canevari, G.P.; Fiocco, R.J.; Lessard, R.R.; Fingas, M.

    1995-01-01

    This paper will describe research on chemical beach cleaners for treatment of oiled shorelines that was initiated in support of the cleaning activities in Prince William Sound (PWS) following the Valdez oil spill in March 1989. The concept for using beach cleaners for shoreline cleanup is to apply a pre-soak to the weathered crude oil on shore and then flush with sea water to wash the oil into a boomed area for subsequent recovery. Criteria imposed on the use of chemical beach cleaners for the cleanup of the Valdez spill were: (1) effective rock cleaning agents should have very little or no toxicity to marine and terrestrial life, (2) there should be no dispersion of the oil washed from the shoreline into the water column; oil was to be recovered by techniques such as skimming or sorbents, and (3) the agents should be on the EPA National Contingency Plan (NCP) list. A laboratory-scale rock washing test was developed to measure cleaner effectiveness and dispersion. A large number of commercially available formulated products were evaluated, as well as development formulations. The commercial products included all of the available NCP-listed products which could function as cleaners. None of the commercial products completely satisfied all the requirements established by the agencies for beach cleaning. However, a new formula, called COREXIT 9580, consisting of two surfactants and a solvent was developed. It exhibited low fish toxicity, low dispersancy and effective rock cleaning capability. The paper reviews the laboratory and field testing to explore the potential use of the COREXIT 9580 to save and restore oiled vegetation

  13. Living Shoreline Designs in Urban Systems: Examples from New York and Baltimore Harbors

    Science.gov (United States)

    Doss, T.

    2017-12-01

    In the aftermath of Hurricanes Irene and Sandy, there was a renewed interest in protecting our shorelines and restoring community resiliency by using natural and nature based features. We observed in the wake of these storms that those shorelines that had been protected by natural features sustained less damage. But how well can we mimic these natural features? And how do we determine which strategy is best along a given shoreline? A series of living shoreline pilot projects are presented, highlighting the design and construction for the different strategies and how they are being monitored and adapted to sea level rise.

  14. Variability and correlations of shoreline and dunes on the southern Baltic coast (CRS Lubiatowo, Poland)

    OpenAIRE

    Zbigniew Pruszak; Rafal Ostrowski; Jan Schönhofer

    2011-01-01

    The paper analyses the results of field investigations into the evolution of the shoreline and dune toe positions in a multi-bar,dissipative coastal zone. The correlations between the changes in the shoreline and the dune toe range from -0.4 to 0.8. It is most often the case that the dune toe is stable while the shoreline moves. Consistent cross-shore migration is slightly more likelyto happen than the divergent or convergent movements of both lines. Shoreline retreat and advance attain resp...

  15. Development of a practical methodology for integrating shoreline oil-holding capacity into modeling

    International Nuclear Information System (INIS)

    Schmidt Etkin, D.; French-McCay, D.; Rowe, J.; Michel, J.; Boufadel, M.; Li, H.

    2008-01-01

    The factors that influence the behaviour of oil in the aftermath of an oil spill on water include oil type and characteristics; oil thickness on the shoreline; time until shoreline impact; timing with regards to tides; weathering during and after the spill; and nearshore wave energy. The oil behaviour also depends on the shoreline characteristics, particularly porosity and permeability. The interactions of spilled oil with sediments on beaches must be well understood in order to model the oil spill trajectory, fate and risk. The movement of oil can be most accurately simulated if the algorithm incorporates an estimate of shoreline oil retention. This paper presented a literature review of relevant shoreline oiling studies and considered the relevance of study findings for inclusion in modelling. Survey data from a detailed shoreline cleanup assessment team (SCAT) were analyzed for patterns in oil penetration and oil-holding capacity by shoreline sediment type and oil type for potential use in modelling algorithms. A theoretical beach hydraulics model was then developed for use in a stochastic spill model. Gaps in information were identified, including the manner in which wave action and other environmental variables have an impact on the dynamic processes involved in shoreline oiling. The methodology presented in this paper can be used to estimate the amount of oil held by a shoreline upon impact to allow a trajectory model to more accurately project the total spread of oil. 27 refs., 13 tabs., 3 figs

  16. Erosive Lichen Planus.

    Science.gov (United States)

    Mauskar, Melissa

    2017-09-01

    Lichen planus is an inflammatory mucocutaneous condition with a myriad of clinical manifestations. There are 3 forms of lichen planus that effect the vulva: papulosquamous, hypertrophic, and erosive. Erosive lichen planus can progress to vulvar scaring, vaginal stenosis, and squamous cell carcinoma; these long-term sequelae cause sexual distress, depression, and decreased quality of life for patients. Diagnosis is often delayed because of patient embarrassment or clinician misdiagnosis. Early recognition and treatment is essential to decreasing the morbidity of this condition. Multimodal treatment, along with a multidisciplinary approach, will improve outcomes and further clinical advances in studying this condition. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Radiation dates of holocene shorelines in Peninsula Malaysia

    International Nuclear Information System (INIS)

    Tjia, H.D.; Kigoshi, K.

    1977-01-01

    Fifteen newly determined radiocarbon dates indicate the presence of former shorelines up to 3 meters above present high tide level in the tectonically stable Peninsula of Malaysia. The sea level indicators consist of oysters in growth position (9 samples), molluscs in beach deposits (2), corals in growth position (3), and beachrock (1). In the Peninsula living oysters occur up to or slightly above high tide, modern beach deposits may occur as high as 1.5 meters above high tide, and corals live up to low tide level. The literature shows that high tide, and corals live up to low tide level. The literature shows that beachrock marks intertidal zones. Combined with seven previously published ages of raised shorelines in the region, strong evidence is presented for one or more high Holocene, eustatic sea level stands in the continental part of Southeast Asia. Periods of high sea levels occur between 2500 and 2900 yr BP, and between 4200 and 5700 yr BP. There is also some indication of high sea level between 8300 and 9500 yr BP. (author)

  18. Uplift of quaternary shorelines in eastern Patagonia: Darwin revisited

    Science.gov (United States)

    Pedoja, Kevin; Regard, Vincent; Husson, Laurent; Martinod, Joseph; Guillaume, Benjamin; Fucks, Enrique; Iglesias, Maximiliano; Weill, Pierre

    2011-04-01

    During his journey on the Beagle, Darwin observed the uniformity in the elevation of coastal Eastern Patagonia along more than 2000 km. More than one century later, the sequences of Quaternary shorelines of eastern Patagonia have been described and their deposits dated but not yet interpreted in terms of geodynamics. Consequently, we i) mapped the repartition of the Quaternary coastal sequences in Argentinean Patagonia, ii) secured accurate altitudes of shoreline angles associated with erosional morphologies (i.e. marine terraces and notches), iii) took into account previous chrono-stratigraphical interpretations in order to calculate mean uplift rates since ~ 440 ka (MIS 11) and proposed age ranges for the higher and older features (up to ~ 180 m), and iv) focused on the Last Interglacial Maximum terrace (MIS 5e) as the best constrained marine terrace (in terms of age and altitude) in order to use it as a tectonic benchmark to quantify uplift rates along the entire passive margin of Eastern South America. Our results show that the eastern Patagonia uplift is constant through time and twice the uplift of the rest of the South American margin. We suggest that the enhanced uplift along the eastern Patagonian coast that interested Darwin during his journey around South America on the Beagle could originate from the subduction of the Chile ridge and the associated dynamic uplift.

  19. Investigation of Erosion of Cement-Bentonite via Piping

    Directory of Open Access Journals (Sweden)

    Zijun Wang

    2017-01-01

    Full Text Available Cement-bentonite is one of the main materials used in the seepage barriers to protect earth dams and levees from water erosion. However, the current understanding of the erodibility of the cementitious materials and the interactions between cracked seepage barriers and the water flow is inadequate. Based on the laboratory pinhole erosion test, we first investigated the impacts of cement-bentonite treatments by using the ground granulated blast-furnace slag (GGBS as replacement on the erosion characteristics, compared with the original mixtures; the inclusion of GGBS highlighted a potential advantage against water erosion. In addition, we proposed to calculate the erosion percentage and establish the mathematical relationships between the erosion percentage and different regimes, that is, different curing period, erosion time, and sizes of initial holes. Results showed that enough curing period was critical to avoid the increases of hydraulic conductivity in the macrofabric of the barrier; meanwhile, the materials were eroded quickly at the beginning and slowed down with the erosion time, where the enlargement of the initial creaks would be stabilised at some point in time. Moreover, the sizes of initial holes may affect the erosion situation varying from the sample curing periods.

  20. Illuminating wildfire erosion and deposition patterns with repeat terrestrial lidar

    Science.gov (United States)

    Rengers, Francis K.; Tucker, G.E.; Moody, J.A.; Ebel, Brian

    2016-01-01

    Erosion following a wildfire is much greater than background erosion in forests because of wildfire-induced changes to soil erodibility and water infiltration. While many previous studies have documented post-wildfire erosion with point and small plot-scale measurements, the spatial distribution of post-fire erosion patterns at the watershed scale remains largely unexplored. In this study lidar surveys were collected periodically in a small, first-order drainage basin over a period of 2 years following a wildfire. The study site was relatively steep with slopes ranging from 17° to > 30°. During the study period, several different types of rain storms occurred on the site including low-intensity frontal storms (2.4 mm h−1) and high-intensity convective thunderstorms (79 mm h−1). These storms were the dominant drivers of erosion. Erosion resulting from dry ravel and debris flows was notably absent at the site. Successive lidar surveys were subtracted from one another to obtain digital maps of topographic change between surveys. The results show an evolution in geomorphic response, such that the erosional response after rain storms was strongly influenced by the previous erosional events and pre-fire site morphology. Hillslope and channel roughness increased over time, and the watershed armored as coarse cobbles and boulders were exposed. The erosional response was spatially nonuniform; shallow erosion from hillslopes (87% of the study area) contributed 3 times more sediment volume than erosion from convergent areas (13% of the study area). However, the total normalized erosion depth (volume/area) was highest in convergent areas. From a detailed understanding of the spatial locations of erosion, we made inferences regarding the processes driving erosion. It appears that hillslope erosion is controlled by rain splash (for detachment) and overland flow (for transport and quasi-channelized erosion), with the sites of highest erosion corresponding to locations

  1. Mesh erosion after abdominal sacrocolpopexy.

    Science.gov (United States)

    Kohli, N; Walsh, P M; Roat, T W; Karram, M M

    1998-12-01

    To report our experience with erosion of permanent suture or mesh material after abdominal sacrocolpopexy. A retrospective chart review was performed to identify patients who underwent sacrocolpopexy by the same surgeon over 8 years. Demographic data, operative notes, hospital records, and office charts were reviewed after sacrocolpopexy. Patients with erosion of either suture or mesh were treated initially with conservative therapy followed by surgical intervention as required. Fifty-seven patients underwent sacrocolpopexy using synthetic mesh during the study period. The mean (range) postoperative follow-up was 19.9 (1.3-50) months. Seven patients (12%) had erosions after abdominal sacrocolpopexy with two suture erosions and five mesh erosions. Patients with suture erosion were asymptomatic compared with patients with mesh erosion, who presented with vaginal bleeding or discharge. The mean (+/-standard deviation) time to erosion was 14.0+/-7.7 (range 4-24) months. Both patients with suture erosion were treated conservatively with estrogen cream. All five patients with mesh erosion required transvaginal removal of the mesh. Mesh erosion can follow abdominal sacrocolpopexy over a long time, and usually presents as vaginal bleeding or discharge. Although patients with suture erosion can be managed successfully with conservative treatment, patients with mesh erosion require surgical intervention. Transvaginal removal of the mesh with vaginal advancement appears to be an effective treatment in patients failing conservative management.

  2. Decadal shoreline changes in the muddy coastline of Ondo State, Nigeria

    Directory of Open Access Journals (Sweden)

    TEMITOPE D. TIMOTHY OYEDOTUN

    2015-12-01

    Full Text Available Modifications du littoral décennales dans le l ittoral boueux de l'Etat d'Ondo , Nigeria . Les changements dans les positions du rivage à proximité du littoral boueux de l'Etat d'Ondo (sud - ouest du Nigeria sont étudiés, entre 1972 et 2014. Les mouvements de l'eau (HW rivage haut ont été étudiés en utilisant le système n umérique Shoreline Analyse (DSAS, une extension ArcGIS développé par l'USGS. Les ensembles de données comprend plusieurs éditions de photographie de Landsat et le Nigeria Imageries satellite. le Shoreline délimitées les unes des images année inclus les po sitions de HW, qui ont été calculées à partir du rivage Mouvement net (NSM et End Point Noter (EPR, le taux annuel de mouvement. Les résultats préliminaires montrent que les rivages de Ondo côte État ont connu un mouvement vers la terre constante au cour s des quatre décennies. Ces changements sont attribués à des attaques d'onde, l'augmentation des niveaux des marées dans le golfe de l'Atlantique du Bénin, la récente hausse du niveau de la mer, canalisation de la rivière qui réduisent le transport de sédi ments dans la zone côtière, l'extraction historique probable de sable et d'autres activités anthropiques dans la zone côtière.

  3. Erosion of dust aggregates

    NARCIS (Netherlands)

    Seizinger, A.; Krijt, S.; Kley, W.

    2013-01-01

    Aims: The aim of this work is to gain a deeper insight into how much different aggregate types are affected by erosion. Especially, it is important to study the influence of the velocity of the impacting projectiles. We also want to provide models for dust growth in protoplanetary disks with simple

  4. Hydrology and soil erosion

    Science.gov (United States)

    Leonard J. Lane; Mary R. Kidwell

    2003-01-01

    We review research on surface water hydrology and soil erosion at the Santa Rita Experimental Range (SRER). Almost all of the research was associated with eight small experimental watersheds established from 1974 to 1975 and operated until the present. Analysis of climatic features of the SRER supports extending research findings from the SRER to broad areas of the...

  5. Bentonite erosion. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Birgersson, Martin; Boergesson, Lennart; Hedstroem, Magnus; Karnland, Ola; Nilsson, Ulf (Clay Technology AB, Lund (Sweden))

    2009-12-15

    Low saline water may reach KBS-3 repository depth, e.g. during periods of glaciation. Under such aqueous conditions, the montmorillonite part of the bentonite buffer might transform into a sol and thereby be transported away with flowing water in fractures. The primary aim with this report is to improve the understanding of the basic principles for this possible montmorillonite particle release. The report includes experimental and theoretical work performed at Clay Technology. Natural bentonite and ion-exchanged purified montmorillonite from three different geographical origins, Wyoming (U.S.), Milos (Greece) and Kutch (India) have been studied. Experimental and/or theoretical investigations have been performed with respect to: - Free swelling ability; - Rheological properties; - Rate of bentonite loss into fractures; - Filtering; - Ion exchange; - Sol formation ability; - Ion diffusion; - Mass loss due to erosion. The performed erosion experiments show that erosion does not occur in a mixed calcium/sodium montmorillonite with at least 20% calcium in exchange positions, when the external solution contains above 4 mM charge equivalents. This result is in agreement with the presented conceptual view of sol formation and measured equilibrium properties in mixed calcium/sodium montmorillonite. The findings imply that the buffer will be stable for non-glacial conditions. However, erosion due to sol formation cannot be ruled out for glacial conditions.

  6. Erosion scenarios for Wellenberg

    International Nuclear Information System (INIS)

    Klemenz, W.

    1993-09-01

    The proposed Wellenberg site for a radioactive waste repository is located between Altzellen in the Engelberger valley and the Oberrickenbach valley, in a thick Valanginian marl series. The marl is generally overlaid with unconsolidated rocks but reaches to the surface in some places. In contrast to the situation in the Oberbauenstock region this marl complex is not protected by an overlying erosion resistant series and exhibits a marked relief. The question therefore arises with respect to the Wellenberg site, to what extent will the marl (i.e. the repository host rock formation) be removed by erosion processes during the 100,000 years interval under consideration and what overburden will remain at the end of this period. This report presents the results of an investigation of the longterm behaviour of the proposed site in respect of those processes of erosion and deposition which can lead to changes in the terrain surface and its location relative to the repository. A wide range of possible scenarios encompassing different developments of climatic conditions during the 100,000 year period of interest, was investigated. In addition to the continuation of the present climate and the occurrence of a new ice age on the scale of the Wuerm glaciation the consequences of altered climatic conditions on erosion removal of the repository overburden were considered. Within the 100,000 year period of interest none of the scenarios considered leads to the exposure of the repository. (author) figs., tabs, refs

  7. Dune erosion above revetments

    NARCIS (Netherlands)

    Van Thiel de Vries, J.S.M.

    2012-01-01

    In a situation with a narrow dune, the dune base can be protected with a revetment to reduce dune erosion during extreme events. To quantify the effects of a revetment on storm impact, the functionality of the numerical storm impact model XBeach (Roelvink et al., 2009) is extended to account for the

  8. Bentonite erosion. Final report

    International Nuclear Information System (INIS)

    Birgersson, Martin; Boergesson, Lennart; Hedstroem, Magnus; Karnland, Ola; Nilsson, Ulf

    2009-12-01

    Low saline water may reach KBS-3 repository depth, e.g. during periods of glaciation. Under such aqueous conditions, the montmorillonite part of the bentonite buffer might transform into a sol and thereby be transported away with flowing water in fractures. The primary aim with this report is to improve the understanding of the basic principles for this possible montmorillonite particle release. The report includes experimental and theoretical work performed at Clay Technology. Natural bentonite and ion-exchanged purified montmorillonite from three different geographical origins, Wyoming (U.S.), Milos (Greece) and Kutch (India) have been studied. Experimental and/or theoretical investigations have been performed with respect to: - Free swelling ability; - Rheological properties; - Rate of bentonite loss into fractures; - Filtering; - Ion exchange; - Sol formation ability; - Ion diffusion; - Mass loss due to erosion. The performed erosion experiments show that erosion does not occur in a mixed calcium/sodium montmorillonite with at least 20% calcium in exchange positions, when the external solution contains above 4 mM charge equivalents. This result is in agreement with the presented conceptual view of sol formation and measured equilibrium properties in mixed calcium/sodium montmorillonite. The findings imply that the buffer will be stable for non-glacial conditions. However, erosion due to sol formation cannot be ruled out for glacial conditions.

  9. Categorization of erosion control matting.

    Science.gov (United States)

    2012-05-29

    Erosion control is a critical aspect of any Georgia Department of Transportation (GDOT) : construction project, with the extreme negative impacts of high sediment loads in natural : waterways having been well documented. A variety of erosion control ...

  10. Comparing Fuzzy Sets and Random Sets to Model the Uncertainty of Fuzzy Shorelines

    NARCIS (Netherlands)

    Dewi, Ratna Sari; Bijker, Wietske; Stein, Alfred

    2017-01-01

    This paper addresses uncertainty modelling of shorelines by comparing fuzzy sets and random sets. Both methods quantify extensional uncertainty of shorelines extracted from remote sensing images. Two datasets were tested: pan-sharpened Pleiades with four bands (Pleiades) and pan-sharpened Pleiades

  11. TOXICITY TRENDS DURING AN OIL SPILL BIOREMEDIATION EXPERIMENT ON A SANDY SHORELINE IN DELAWARE, USA

    Science.gov (United States)

    A 13-week, refereed, inter-agency toxicity testing program involving five bioassay methods was used to document the effectiveness of shoreline bioremediation to accelerate toxicity reduction of an oiled sandy shoreline at Fowler Beach, Delaware, USA. The study was part of an inte...

  12. Impact of an offshore wind farm on wave conditions and shoreline development

    DEFF Research Database (Denmark)

    Christensen, Erik Damgaard; Kristensen, Sten Esbjørn; Deigaard, Rolf

    2014-01-01

    the shoreline’s sensitivity to the distance from the OWF to the shoreline was studied. The effect of the reduced wind speed inside and on the lee side of the offshore wind farm was incorporated in a parameterized way in a spectral wind wave model. The shoreline impact was studied with a one-line model....

  13. Development of an Integrated Water and Wind Erosion Model

    Science.gov (United States)

    Flanagan, D. C.; Ascough, J. C.; Wagner, L. E.; Geter, W. F.

    2006-12-01

    Prediction technologies for soil erosion by the forces of wind or water have largely been developed independently from one another, especially within the United States. Much of this has been due to the initial creation of equations and models which were empirical in nature (i.e., Universal Soil Loss Equation, Wind Erosion Equation) and based upon separate water erosion or wind erosion plot and field measurements. Additionally, institutional organizations in place typically divided research efforts and funding to unique wind or water erosion research and modeling projects. However, during the past 20 years computer technologies and erosion modeling have progressed to the point where it is now possible to merge physical process-based computer simulation models into an integrated water and wind erosion prediction system. In a physically- based model, many of the processes which must be simulated for wind and water erosion computations are the same, e.g., climate, water balance, runoff, plant growth, etc. Model components which specifically deal with the wind or water detachment, transport and deposition processes are those that must differ, as well as any necessary parameterization of input variables (e.g., adjusted soil erodibilities, critical shear stresses, etc.) for those components. This presentation describes current efforts towards development of a combined wind and water erosion model, based in part upon technologies present in the Water Erosion Prediction Project (WEPP) and the Wind Erosion Prediction System (WEPS) models. Initial efforts during the past two years have resulted in modular modeling components that allow for prediction of infiltration, surface runoff, and water erosion at a hillslope scale within an Object Modeling System. Additional components currently in development include wind detachment at a single field point, continuous water balance, and unified plant growth. Challenges in this project are many, and include adequate field

  14. Field guide for the protection and cleanup of oiled Arctic shorelines

    International Nuclear Information System (INIS)

    Owens, E.H.

    1996-01-01

    Practical suggestions for the protection, treatment and cleanup of oiled shorelines during summer and open-water conditions are described. This manual was developed as a field guide to be used during spill response operations for the rapid identification of shoreline response options. Special attention is given to techniques that are normally available and appropriate for shoreline types and coastal environmental setting that are typical of Arctic regions. The guide is divided into four main sections: (1) shoreline protection, (2) treatment strategy by shoreline type, (3) treatment or cleanup methods, and (4) response strategies for specific environments. The importance of the type and volume of oil spilled, and the environmental factors that should be taken into account in the event of a spill (time of year, weather, ice and wave conditions) are stressed. The presence of sensitive resources such as wildlife, fish stocks, plant communities and human-use activities are also considered. tabs., figs

  15. The management of shoreline protection and treatment operations

    International Nuclear Information System (INIS)

    Owens, E.H.

    1996-01-01

    The management of shoreline cleaning operations in the event of an oil spill, was discussed. An eight-step approach was introduced which was based on the definition of objectives and strategies. The discussion included evaluation of the feasibility of each of these strategies, as well as the effects of the proposed actions. It was emphasized that apart from natural recovery, any response action will have an effect either directly, by the protection or treatment actions, or indirectly, by the support actions, on the shore zone or the adjacent backshore. The main purpose of a response is to accelerate natural recovery. This new response approach can be an effective management tool, since the use of standard terms and strategy statements give operations personnel a well defined set of instruction which reduce the potential for misinterpretation. 4 refs., 9 figs

  16. Shoreline oil cleanup, recovery and treatment evaluation system (SOCRATES)

    International Nuclear Information System (INIS)

    Rusin, J.; Lunel, T.; Sommerville, M.; Tyler, A.; Marshall, I.

    1996-01-01

    A beach cleanup computer system was developed to mitigate the impact of shoreline oiling. The program, entitled SOCRATES, was meant to determine the most suitable cleanup methodologies for a range of different spill scenarios. The development, operation and capabilities of SOCRATES was described, with recent examples of successful use during the Sea Empress spill. The factors which influenced decision making and which were central to the numerical solution were: (1) the volumetric removal rate of oil, (2) area removal rate of oil, (3) length of oil slick removed per hour, (4) volumetric removal rate of oily waste, (5) area of the oil slick, (6) length of the oil slick, (7) volume of liquid emulsion, and (8) length of beach. 14 figs

  17. Multiscale analysis of restoration priorities for marine shoreline planning.

    Science.gov (United States)

    Diefenderfer, Heida L; Sobocinski, Kathryn L; Thom, Ronald M; May, Christopher W; Borde, Amy B; Southard, Susan L; Vavrinec, John; Sather, Nichole K

    2009-10-01

    Planners are being called on to prioritize marine shorelines for conservation status and restoration action. This study documents an approach to determining the management strategy most likely to succeed based on current conditions at local and landscape scales. The conceptual framework based in restoration ecology pairs appropriate restoration strategies with sites based on the likelihood of producing long-term resilience given the condition of ecosystem structures and processes at three scales: the shorezone unit (site), the drift cell reach (nearshore marine landscape), and the watershed (terrestrial landscape). The analysis is structured by a conceptual ecosystem model that identifies anthropogenic impacts on targeted ecosystem functions. A scoring system, weighted by geomorphic class, is applied to available spatial data for indicators of stress and function using geographic information systems. This planning tool augments other approaches to prioritizing restoration, including historical conditions and change analysis and ecosystem valuation.

  18. Megascale rhythmic shoreline forms on a beach with multiple bars

    Directory of Open Access Journals (Sweden)

    Zbigniew Pruszak

    2008-06-01

    Full Text Available The study, carried out in 2003 and 2006 at the Lubiatowo Coastal ResearchStation (Poland, located on the non-tidal southern Baltic coast(tidal range < 0.06 m, focused on larger rhythmic forms (mega-cusps withwavelengths in the interval 500 m > Lc > 20 m. Statistical analyses of detailed shoreline configurations were performed mostly with the Discrete Wavelet Transformmethod (DWT. The beach is composed of fine sand with grain diameter D50 ≈ 0.22 mm, which produces 4 longshore sandbars and a gently sloping seabed with β = 0.015. The analysis confirms the key role of bars in hydro- and morphodynamic surf zone processes.The hypothesis was therefore set up that, in a surf zone with multiple bars, the bars and mega-scale shoreline rhythmic forms form one integrated physical system; experimental evidence to substantiate this hypothesis was also sought.In such a system not only do self-regulation processes include swash zone phenomena, they also incorporate processes in offshore surf zone locations.The longshore dimensions of large cusps are thus related to the distances between periodically active large bed forms (bars. The spatial dimension of bar system activity (number of active bars depends, at a given time scale, on the associated hydrodynamic conditions. It was assumed that such a time scale could include either the development and duration of a storm, or a period of stable, yet distinct waves, capable of remodelling the beach configuration.The indentation to wavelength ratio of mega-cusps for the studied non-tidal dissipative environment may be one order of magnitude greater than for mesotidal, reflective beaches.

  19. Hydrodynamic Modeling for Channel and Shoreline Stabilization at Rhodes Point, Smith Island, MD

    Science.gov (United States)

    2016-11-01

    γβ), and 1,−sξ is the Iribarren parameter based on the first negative moment wave period: , , tan s s m φξ H L   1 1 0 (3-17) with ,, m m...capabilities of CMS-Wave: A coastal wave model for inlets and navigation projects. In Proceedings, Symposium to Honor Dr. Nicholas Kraus. Journal of Coastal

  20. Assessment of coastal erosion and quantification of land loss on Western Pacific atolls during the last 50 years

    Science.gov (United States)

    Taborosi, Danko; Zega, Mojca; Jenson, John W.

    2010-05-01

    others, and that land is not always eroding but in some cases accreting. We are currently engaged in a systematic survey of islands across the region in order to differentiate local problems from wide-ranging phenomena and gain insight into the temporal and geospatial "big picture." The direct aim is to comprehensively and more precisely assess coastal erosion and quantify changes in land area of different islands over the past 50 years. The project consists of fieldwork and GIS analyses, and it is the first to employ such methods to evaluate shoreline transformation in the western Pacific. We visit each island, interview local people regarding recent land changes and events, and carry out site investigations and mapping. Each inhabited island is circumambulated on foot, and beach slopes and scarps are measured, sediments examined, human activities and vegetation damage noted, etc. More importantly, the entire coast of each island is mapped using MobileMapper PRO portable units capable of generating GIS shapefiles in the field. Created coverages include the actual shoreline, sandy banks, vegetated areas, coastal engineering, control points, etc. Data collected on the ground is imported into ArcGIS and rectified using remote sensing imagery. It is then compared to all available historical maps, notably US Army Corps of Engineers 1960s topographic charts, which were previously assembled, digitized, and georeferenced for the purposes of this project. Any discrepancies in island outline and land area would have occurred over the past half a century. Due to the vastness of western Pacific region and logistical obstacles to working on remote islands, data are accumulated gradually. Ultimately, this island-by-island approach will allow documentation of historical and regional erosion patterns, contribute to understanding of local and global components of recent coastal changes, and deliver recommendations for environmental management and emergency avoidance on atolls and other

  1. Rainfall erosivity map for Ghana

    International Nuclear Information System (INIS)

    Oduro Afriyie, K.

    1995-10-01

    Monthly rainfall data, spanning over a period of more than thirty years, were used to compute rainfall erosivity indices for various stations in Ghana, using the Fournier index, c, defined as p 2 /P, where p is the rainfall amount in the wettest month and P is the annual rainfall amount. Values of the rainfall erosivity indices ranged from 24.5 mm at Sunyani in the mid-portion of Ghana to 180.9 mm at Axim in the south western coastal portion. The indices were used to construct a rainfall erosivity map for the country. The map revealed that Ghana may be broadly divided into five major erosion risk zones. The middle sector of Ghana is generally in the low erosion risk zone; the northern sector is in the moderate to severe erosion risk zone, while the coastal sector is in the severe to extreme severe erosion risk zone. (author). 11 refs, 1 fig., 1 tab

  2. A Mechanistic Model of Waterfall Plunge Pool Erosion into Bedrock

    Science.gov (United States)

    Scheingross, Joel S.; Lamb, Michael P.

    2017-11-01

    Landscapes often respond to changes in climate and tectonics through the formation and upstream propagation of knickzones composed of waterfalls. Little work has been done on the mechanics of waterfall erosion, and instead most landscape-scale models neglect waterfalls or use rules for river erosion, such as stream power, that may not be applicable to waterfalls. Here we develop a physically based model to predict waterfall plunge pool erosion into rock by abrasion from particle impacts and test the model against flume experiments. Both the model and experiments show that evolving plunge pools have initially high vertical erosion rates due to energetic particle impacts, and erosion slows and eventually ceases as pools deepen and deposition protects the pool floor from further erosion. Lateral erosion can continue after deposition on the pool floor, but it occurs at slow rates that become negligible as pools widen. Our work points to the importance of vertical drilling of successive plunge pools to drive upstream knickzone propagation in homogenous rock, rather than the classic mechanism of headwall undercutting. For a series of vertically drilling waterfalls, we find that upstream knickzone propagation is faster under higher combined water and sediment fluxes and for knickzones composed of many waterfalls that are closely spaced. Our model differs significantly from stream-power-based erosion rules in that steeper knickzones can retreat faster or more slowly depending on the number and spacing of waterfalls within a knickzone, which has implications for interpreting climatic and tectonic history through analysis of river longitudinal profiles.

  3. Fundamental study on cavitation erosion in liquid metal. Effect of liquid parameter on cavitation erosion in liquid metals (Joint research)

    International Nuclear Information System (INIS)

    Hattori, Shuji; Kurachi, Hiroaki; Inoue, Fumitaka; Watashi, Katsumi; Tsukimori, Kazuyuki; Yada, Hiroki; Hashimoto, Takashi

    2009-02-01

    Cavitation erosion, which possibly occurs on the surfaces of fluid machineries and components contacting flowing liquid and causes sponge-like damage on the material surface, is important problem, since it may become the cause of performance deduction, life shortening, noise, vibration of mechanical components and moreover failure of machine. Research on cavitation erosion in liquid metal is very important to confirm the safety of fast breeder reactor using sodium coolant and to avoid serious damage of the target vessel of spallation neutron source containing liquid-mercury. But the research on cavitation erosion in liquid metal has been hardly performed because of its specially in comparison with that in water. In this study, a cavitation erosion test apparatus was developed to carry out the erosion tests in low-temperature liquid metals. Cavitation erosion tests were carried out in liquid lead-bismuth alloy and in deionized water. We discuss the effect of liquid parameters and temperature effects on the erosion rate. We reach to the following conclusions. The erosion rate was evaluated in terms of a relative temperature which was defind as the percentage between freezing and boiling points. At 14degC relative temperature, the erosion rate is 10 times in lead-bismuth alloy, and 2 to 5 times in sodium, compared with that in deionized water. At 14degC relative temperature, the erosion rate can be evaluated in terms of the following parameter. 1 / (1/ρ L /C L +1/ρ S C S )√ρ L . Where ρ is the material density and c is the velocity of sound, L and S denote liquid and solid. In the relative temperature between 14 and 30degC, the temperature dependence on the erosion rate is due to the increase in vapor pressure. (author)

  4. Synthesis study of an erosion hot spot, Ocean Beach, California

    Science.gov (United States)

    Barnard, Patrick L.; Hansen, Jeff E.; Erikson, Li H.

    2012-01-01

    A synthesis of multiple coastal morphodynamic research efforts is presented to identify the processes responsible for persistent erosion along a 1-km segment of 7-km-long Ocean Beach in San Francisco, California. The beach is situated adjacent to a major tidal inlet and in the shadow of the ebb-tidal delta at the mouth of San Francisco Bay. Ocean Beach is exposed to a high-energy wave climate and significant alongshore variability in forcing introduced by varying nearshore bathymetry, tidal forcing, and beach morphology (e.g., beach variably backed by seawall, dunes, and bluffs). In addition, significant regional anthropogenic factors have influenced sediment supply and tidal current strength. A variety of techniques were employed to investigate the erosion at Ocean Beach, including historical shoreline and bathymetric analysis, monthly beach topographic surveys, nearshore and regional bathymetric surveys, beach and nearshore grain size analysis, two surf-zone hydrodynamic experiments, four sets of nearshore wave and current experiments, and several numerical modeling approaches. Here, we synthesize the results of 7 years of data collection to lay out the causes of persistent erosion, demonstrating the effectiveness of integrating an array of data sets covering a huge range of spatial scales. The key findings are as follows: anthropogenic influences have reduced sediment supply from San Francisco Bay, leading to pervasive contraction (i.e., both volume and area loss) of the ebb-tidal delta, which in turn reduced the regional grain size and modified wave focusing patterns along Ocean Beach, altering nearshore circulation and sediment transport patterns. In addition, scour associated with an exposed sewage outfall pipe causes a local depression in wave heights, significantly modifying nearshore circulation patterns that have been shown through modeling to be key drivers of persistent erosion in that area.

  5. Characterizing rainfall parameters which influence erosivity in southeastern Nigeria

    International Nuclear Information System (INIS)

    Obi, M.E.; Salako, F.K.

    1993-12-01

    An investigation was carried out to characterize some selected parameters which influence rainfall erosivity in southeastern Nigeria. Rainfall amount, distribution, duration, intensity, storm types, energy loads and frequency of rain events in the region were studied using data from stations located in three major agroecological zones. Raindrop size and detaching capacity were evaluated in one of the stations for two months. The mean annual rainfall erosivity values for southeastern Nigeria point to the fact that rainfall tend to be highly erosive. 25 refs, 6 figs, 8 tabs

  6. Monitoring of shoreline changes using remote sensing (case study: coastal city of Bandar Abbas)

    International Nuclear Information System (INIS)

    Tamassoki, E; Amiri, H; Soleymani, Z

    2014-01-01

    Shoreline change is one of the most common natural processes that prevail upon coastal areas. The most important aspect of managing coastal areas is identifying the location and change over time of shoreline. This requires frequent monitoring of the shoreline using satellite imagery over time. We have used imagery from the Landsat TM-5 sensor from 1984,1998 and 2009 in order to monitor shoreline changes using the Max Likelihood Classification method (MLC) in Bandar Abbas city. Monitoring showed that during the period from 1984 to 1998 the area of coastline of Bandar Abbas increased 804.09 hectares. The increase over the next 11-year period was as less, at only 140.81 hectares. In 2009 there was a drastic decrease in shoreline, with the total length of shoreline decreasing from 330 km to 271 km during the period from 1984 to 2009.Results showed that in each period in which the area of coastline advanced, changes in length of shoreline had been less prominent

  7. Erosion prediction for alpine slopes: a symbiosis of remote sensing and a physical based erosion model

    Science.gov (United States)

    Kaiser, Andreas; Neugirg, Fabian; Haas, Florian; Schindewolf, Marcus; Schmidt, Jürgen

    2014-05-01

    As rainfall simulations represent an established tool for quantifying soil detachment on cultivated area in lowlands and low mountain ranges, they are rarely used on steep slopes high mountain ranges. Still this terrain represents productive sediment sources of high morphodynamic. A quantitative differentiation between gravitationally and fluvially relocated material reveals a major challenge in understanding erosion on steep slopes: does solifluction as a result of melting in spring or heavy convective rainstorms during summer cause the essential erosion processes? This paper aims to answer this question by separating gravitational mass movement (solifluction, landslides, mudflow and needle ice) and runoff-induced detachment. First simulated rainstorm experiments are used to assess the sediment production on bare soil on a strongly inclined plot (1 m², 42°) in the northern limestone Alps. Throughout precipitation experiments runoff and related suspended sediments were quantified. In order to enlarge slope length virtually to around 20 m a runoff feeding device is additionally implemented. Soil physical parameters were derived from on-site sampling. The generated data is introduced to the physically based and catchment-scaled erosion model EROSION 3D to upscale plot size to small watershed conditions. Thus infiltration, runoff, detachment, transport and finally deposition can be predicted for single rainstorm events and storm sequences. Secondly, in order to separate gravitational mass movements and water erosion, a LiDAR and structure-from-motion based monitoring approach is carried out to produce high-resolution digital elevation models. A time series analysis of detachment and deposition from different points in time is implemented. Absolute volume losses are then compared to sediment losses calculated by the erosion model as the latter only generates data that is connected to water induced hillside erosion. This methodology will be applied in other watersheds

  8. Spatial and temporal assessment of back-barrier erosion on Cumberland Island National Seashore, Georgia, 2011–2013

    Science.gov (United States)

    Calhoun, Daniel L.; Riley, Jeffrey W.

    2016-07-15

    Much research has been conducted to better understand erosion and accretion processes for the seaward zones of coastal barrier islands; however, at Cumberland Island National Seashore, Georgia, the greater management concern is the effect that erosion is having on the resources of the island’s western shoreline, or the back barrier. Catastrophic slumping and regular rates of erosion greater than 1 meter per year threaten important habitat, historical and pre-historical resources, and modern infrastructure on the island. Prior research has helped National Park Service (NPS) staff identify the most severe and vulnerable areas, but in order to develop effective management actions, information is needed on what forces and conditions cause erosion. To this end, the U.S. Geological Survey, in cooperation with the NPS, conducted two longitudinal surveys, one each at the beginning and end of the approximately year-long monitoring period from late 2011 to early 2013, along five selected segments of the back barrier of the Cumberland Island National Seashore. Monitoring stations were constructed at four of these locations that had previously been identified as erosional hotspots. The magnitude of erosion at each location was quantified to determine the relative influence of causative agents. Results indicate that erosion is, in general, highly variable within and among these segments of the Cumberland Island National Seashore’s back barrier. Observed erosion ranged from a maximum of 2.5 meters of bluff-line retreat to some areas that exhibited no net erosion over the 1-year study period. In terms of timing of erosion, three of the four sites were primarily affected by punctuated erosional events that were coincident with above-average high tides and elevated wind speeds. The fourth site exhibited steady, low-magnitude retreat throughout the study period. While it is difficult to precisely subscribe certain amounts of erosion to specific agents, this study provides

  9. Erosion-corrosion synergistics in the low erosion regime

    International Nuclear Information System (INIS)

    Corey, R.G.; Sethi, V.K.

    1986-01-01

    Many engineering alloys display good high temperature corrosion resistance. However, when they are used in corrosive environments where they are subjected to erosion also, the corrosion resistance has been adversely affected. The phenomenon known as erosion-corrosion is complex and requires detailed investigation of how the erosion and corrosion kinetics interact and compete. At the Kentucky Center for Energy Research Laboratory, an erosion-corrosion tester was used to perform erosion-oxidation tests on 2 1/4 Cr-1 Mo steel at 500-600 0 C using alumina abrasive at low velocities. The erosion-oxidation rate data and morphology of exposed surfaces are consistent with oxide chipping and fracturing being the mode of material loss

  10. Detection of Oil near Shorelines during the Deepwater Horizon Oil Spill Using Synthetic Aperture Radar (SAR

    Directory of Open Access Journals (Sweden)

    Oscar Garcia-Pineda

    2017-06-01

    Full Text Available During any marine oil spill, floating oil slicks that reach shorelines threaten a wide array of coastal habitats. To assess the presence of oil near shorelines during the Deepwater Horizon (DWH oil spill, we scanned the library of Synthetic Aperture Radar (SAR imagery collected during the event to determine which images intersected shorelines and appeared to contain oil. In total, 715 SAR images taken during the DWH spill were analyzed and processed, with 188 of the images clearly showing oil. Of these, 156 SAR images showed oil within 10 km of the shoreline with appropriate weather conditions for the detection of oil on SAR data. We found detectable oil in SAR images within 10 km of the shoreline from west Louisiana to west Florida, including near beaches, marshes, and islands. The high number of SAR images collected in Barataria Bay, Louisiana in 2010 allowed for the creation of a nearshore oiling persistence map. This analysis shows that, in some areas inside Barataria Bay, floating oil was detected on as many as 29 different days in 2010. The nearshore areas with persistent floating oil corresponded well with areas where ground survey crews discovered heavy shoreline oiling. We conclude that satellite-based SAR imagery can detect oil slicks near shorelines, even in sheltered areas. These data can help assess potential shoreline oil exposure without requiring boats or aircraft. This method can be particularly helpful when shoreline assessment crews are hampered by difficult access or, in the case of DWH, a particularly large spatial and temporal spill extent.

  11. A method to detect soil carbon degradation during soil erosion

    OpenAIRE

    F. Conen; M. Schaub; C. Alewell

    2009-01-01

    Soil erosion has been discussed intensively but controversial both as a significant source or a significant sink of atmospheric carbon possibly explaining the gap in the global carbon budget. One of the major points of discussion has been whether or not carbon is degraded and mineralized to CO2 during detachment, transport and deposition of soil material. By combining the caesium-137 (137Cs) approach (quantification of erosion rates) with stable c...

  12. Western Lake Erie Shore Study, Ohio. Reconnaissance Report (Stage 1) on Flood Protection and Shoreline Erosion Control,

    Science.gov (United States)

    1981-06-01

    The indoor games and sports activities are not inclusive. The affected area for the recreation and open space may be defined as the distance which...kAFN- 7tA F cGFV,&7- T\\ANGtP t -7-%cz.n, 𔃻oA 1 ka EAFoo.E. ovCT\\), AR~E FFKOwM TE, ,s vjiTR 1--o 5WS)"-E, T-"E Ak-T\\)Ad.. 1EEAC,\\ S\\- OPV IS LE 7S JV

  13. An empirical orthogonal function analysis of ocean shoreline location on the Virginia barrier islands

    Science.gov (United States)

    Haluska, J. D.

    2017-12-01

    Shoreline change along the Eastern Atlantic shore of Virginia has been studied for the individual barrier islands but not as an integrated system. This study combines the Atlantic shoreline locations for eleven barrier islands obtained from LANDSAT 5, 7, and 8 images. Approximately 250 shoreline locations over a 24-year period from Jan 1990 to Dec 2014 were extracted from the digitized shoreline data at 338 transects. The resulting 338 by 250 matrix was analyzed by the empirical orthogonal function (EOF) technique. The first four principal components (PC) explained 86 percent of the sample variance. Since the data was not detrended, the first PC was the overall trend of the data with a discontinuity in 2004-2005. The 2004-2005 interval included storm events and large shoreline changes. PCs 2 to 4 reflect the effects of El Nino events and tropical and non-tropical storms. Eigenvectors 1 to 4 all show the effects of the nine inlets in the island group. Eigenvector (EV) 1 explains 59 percent of the shoreline spatial variance and shows the largest changes at the northern and southern island ends. EVs 2 to 4 reflect the pattern of EV1 but at sequentially smaller percentages of the spatial variance. As a group, the eleven islands are losing ocean side shoreline. The lone exception is Hog Island. Sea level had the strongest correlation with the shoreline loss trend of PC1. The coefficient of determination was 0.41. The NAO and MEI also correlated with PC1 with correlations of determination of 0.05 and 0.12 respectively. These confidence level for the three factors was better than 99 percent. Sea level also correlated with PC3 and PC4. The PCs as a group show that the year intervals 2004-2005 and 2009-2010 had large effects on the shoreline change pattern for the island group. EVs 1 to 4 had the highest range of shoreline change at the island ends indicating the effect the changes of the inlets have on the adjacent islands. The smaller islands as a group had a higher level

  14. Multi-decadal shoreline changes on Takú Atoll, Papua New Guinea: Observational evidence of early reef island recovery after the impact of storm waves

    Science.gov (United States)

    Mann, Thomas; Westphal, Hildegard

    2016-03-01

    Hurricanes, tropical cyclones and other high-magnitude events are important steering mechanisms in the geomorphic development of coral reef islands. Sandy reef islands located outside the storm belts are strongly sensitive to the impact of occasional high-magnitude events and show abrupt, commonly erosive geomorphic change in response to such events. Based on the interpretation of remote sensing data, it is well known that the process of landform recovery might take several decades or even longer. However, despite the increasing amount of scientific attention towards short- and long-term island dynamics, the lack of data and models often prevent a robust analysis of the timing and nature of recovery initiation. Here we show how natural island recovery starts immediately after the impact of a high-magnitude event. We analyze multi-temporal shoreline changes on Takú Atoll, Papua New Guinea and combine our findings with a unique set of published field observations (Smithers and Hoeke, 2014). Trends of shoreline change since 1943 and changes in planform island area indicate a long-term accretionary mode for most islands. Apparent shoreline instability is detected for the last decade of analysis, however this can be explained by the impact of storm waves in December 2008 that (temporarily?) masked the long-term trend. The transition from negative to positive rates of change in the aftermath of this storm event is indicative of inherent negative feedback processes that counteract short-term changes in energy input and represent the initiation of island recovery. Collectively, our results support the concept of dynamic rather than static reef islands and clearly demonstrate how short-term processes can influence interpretations of medium-term change.

  15. A terminological matter: paragenesis, antigravitative erosion or antigravitational erosion ?

    Directory of Open Access Journals (Sweden)

    Pasini G.

    2009-07-01

    Full Text Available In the speleological literature three terms are utilized to designate the “ascending erosion”: paragenesis (= paragénésis, coined in1968, antigravitative erosion (= erosione antigravitativa, coined in 1966 and antigravitational erosion (wrong English translation ofthe Italian term erosione antigravitativa, utilized later on. The term paragenesis should be abandoned because of the priority of theterm erosione antigravitativa - on the ground of the “law of priority” – and because of its ambiguous etimology. On the other hand,the term antigravitational erosion should be forsaken in favour of the term antigravitative erosion, given the meaning that the termsgravitation and gravity have in Physics. Therefore, to designate the phenomenon of the “ascending erosion” there would be nothingleft but the term antigravitative erosion.The antigravitative erosion process and its recognizability are illustrated.Examples of caves with evident antigravitative erosion phenomena, developed in different karstifiable rocks and in several partsof the world, are given.It is recalled that the antigravitative erosion is a phenomenon well-known since 1942 and widely proven and supported, and that it isrelatively easy – in many cases - to recognize the antigravitative origin of karstic passages.It is stressed that the antigravitative erosion is an important phenomenon, exclusive of the karstic caves and unique in nature.

  16. Evaluating the new soil erosion map of Hungary

    Science.gov (United States)

    Waltner, István; Centeri, Csaba; Takács, Katalin; Pirkó, Béla; Koós, Sándor; László, Péter; Pásztor, László

    2017-04-01

    With growing concerns on the effects of climate change and land use practices on our soil resources, soil erosion by water is becoming a significant issue internationally. Since the 1964 publication of the first soil erosion map of Hungary, there have been several attempts to provide a countrywide assessment of erosion susceptibility. However, there has been no up-to-date map produced in the last decade. In 2016, a new, 1:100 000 scale soil erosion map was published, based on available soil, elevation, land use and meteorological data for the extremely wet year of 2010. The map utilized combined outputs for two spatially explicit methods: the widely used empirical Universal Soil Loss Equation (USLE) and the process-based Pan-European Soil Erosion Risk Assessment (PESERA) models. The present study aims to provide a detailed analysis of the model results. In lieu of available national monitoring data, information from other sources were used. The Soil Degradation Subsystem (TDR) of the National Environmental Information System (OKIR) is a digital database based on a soil survey and farm dairy data collected from representative farms in Hungary. During the survey all kind of degradation forms - including soil erosion - were considered. Agricultural and demographic data was obtained from the Hungarian Central Statistical Office (KSH). Data from an interview-based survey was also used in an attempt to assess public awareness of soil erosion risks. Point-based evaluation of the model results was complemented with cross-regional assessment of soil erosion estimates. This, combined with available demographic information provides us with an opportunity to address soil erosion on a community level, with the identification of regions with the highest risk of being affected by soil erosion.

  17. 50 Years of coastal erosion analysis: A new methodological approach.

    Science.gov (United States)

    Prieto Campos, Antonio; Diaz Cuevas, Pilar; Ojeda zujar, Jose; Guisado-Pintado, Emilia

    2017-04-01

    Coasts over the world have been subjected to increased anthropogenic pressures which combined with natural hazards impacts (storm events, rising sea-levels) have led to strong erosion problems with negative impacts on the economy and the safety of coastal communities. The Andalusian coast (South Spain) is a renowned global tourist destination. In the past decades a deep transformation in the economic model led to significant land use changes: strong regulation of rivers, urbanisation and occupation of dunes, among others. As a result irreversible transformations on the coastline, from the aggressive urbanisation undertaken, are now to be faced by local authorities and suffered by locals and visitors. Moreover, the expected impacts derived from the climate change aggravated by anthropic activities emphasises the need for tools that facilitates decision making for a sustainable coastal management. In this contribution a homogeneous (only a proxy and one photointerpreter) methodology is proposed for the calculation of coastal erosion rates of exposed beaches in Andalusia (640 km) through the use of detailed series (1:2500) of open source orthophotographies for the period (1956-1977-2001-2011). The outstanding combination of the traditional software DSAS (Digital Shoreline Analysis System) with a spatial database (PostgreSQL) which integrates the resulting erosion rates with related coastal thematic information (geomorphology, presence of engineering infrastructures, dunes and ecosystems) enhances the capacity of analysis and exploitation. Further, the homogeneity of the method used allows the comparison of the results among years in a highly diverse coast, with both Mediterranean and Atlantic façades. The novelty development and integration of a PostgreSQL/Postgis database facilitates the exploitation of the results by the user (for instance by relating calculated rates with other thematic information as geomorphology of the coast or the presence of a dune field on

  18. Shoreline change assessment using multi-temporal satellite images: a case study of Lake Sapanca, NW Turkey.

    Science.gov (United States)

    Duru, Umit

    2017-08-01

    The research summarized here determines historical shoreline changes along Lake Sapanca by using Remote Sensing (RS) and Geographical Information Systems (GIS). Six multi-temporal satellite images of Landsat Multispectral Scanner (L1-5 MMS), Enhanced Thematic Mapper Plus (L7 ETM+), and Operational Land Imager Sensors (L8 OLI), covering the period between 17 June 1975 and 15 July 2016, were used to monitor shoreline positions and estimate change rates along the coastal zone. After pre-possessing routines, the Normalized Difference Water Index (NDWI), Modified Normalized Difference Water Index (MNDWI), and supervised classification techniques were utilized to extract six different shorelines. Digital Shoreline Analysis System (DSAS), a toolbox that enables transect-based computations of shoreline displacement, was used to compute historical shoreline change rates. The average rate of shoreline change for the entire cost was 2.7 m/year of progradation with an uncertainty of 0.2 m/year. While the great part of the lake shoreline remained stable, the study concluded that the easterly and westerly coasts and deltaic coasts are more vulnerable to shoreline displacements over the last four decades. The study also reveals that anthropogenic activities, more specifically over extraction of freshwater from the lake, cyclic variation in rainfall, and deposition of sediment transported by the surrounding creeks dominantly control spatiotemporal shoreline changes in the region. Monitoring shoreline changes using multi-temporal satellite images is a significant component for the coastal decision-making and management.

  19. Management of Coastal Erosion Using Remote Sensing and GIS Techniques (SE India

    Directory of Open Access Journals (Sweden)

    S. Saravanan

    2014-12-01

    Full Text Available World wide, coastal erosion is recognized as a great threat for beach environment. Total control of coastal erosion is not feasible but it should not be ignored and needs timely management. Erosional activities have been significantly noticed along the coastal tract of Vembar and Kallar (Kallurani, South India. An attempt has been made here to delineate different zones based on their sand budget and erosion rate. Linear Imaging Self Scanning Sensor (LISS III 2001 and Linear Imaging Self Scanning Sensor III and PAN merged data of the year 2001 have been utilized to identify the coastal geomorphological features, shoreline changes and river course changes. A Geographic Information System (GIS software namely ArcGIS (9.1 has been used as a tool to delineate the coastal erosion hazard for proper planning and management of coastal developments. Beach profile studies have shown significant variation in the beach morphology. The study area has been categorized into five different zones in the GIS analysis based on the degree of coastal erosion and sediment dynamics namely (i very high - Kalaignanapuram, (ii high - Sippikulam (iii medium - Periyasamypuram (iv low - Vembar and Kallar (Kallurani (v very low - Pachayapuram.

  20. Raised Holocene paleo-shorelines along the Capo Vaticano coast (western Calabria, Italy): Evidence of co-seismic and steady-state deformation

    Science.gov (United States)

    Spampinato, Cecilia Rita; Ferranti, Luigi; Monaco, Carmelo; Scicchitano, Giovanni; Antonioli, Fabrizio

    2014-12-01

    Detailed mapping of geomorphological and biological sea-level markers around the Capo Vaticano promontory (western Calabria, Italy), has documented the occurrence of four Holocene paleo-shorelines raised at different altitudes. The uppermost shoreline (PS1) is represented by a deeply eroded fossiliferous beach deposit, reaching an elevation of ∼2.2 m above the present sea-level, and by a notch whose roof is at ∼2.3 m. The subjacent shoreline PS2 is found at an elevation of ∼1.8 m and is represented by a Dendropoma rim, a barnacle band and by a wave-cut platform. Shoreline PS3 includes remnants of vermetid concretions, a barnacle band, a notch and a marine deposit, and reaches an elevation of ∼1.4 m. The lowermost paleo-shoreline (PS4) includes a wave-cut platform and a notch and reaches an elevation of ∼0.8 m. Radiocarbon dating of material from individual paleo-shorelines points to an average uplift rate of 1.2-1.4 mm/yr in the last ∼6 ka at Capo Vaticano. Our data suggest that Holocene uplift was asymmetric, with a greater magnitude in the south-west sector of the promontory, in a manner similar to the long-term deformation attested by Pleistocene terraces. The larger uplift in the south-western sector is possibly related to the additional contribution, onto a large-wavelength regional signal, of co-seismic deformation events, which are not registered to the north-east. We have recognized four co-seismic uplift events at 5.7-5.4 ka, 3.9-3.5 ka, ∼1.9 ka and <1.8 ka ago, superposed on a regional uplift that in the area, is occurring at a rate of ∼1 mm/yr. Our findings places new constrains on the recent activity of border faults south of the peninsula and on the location of the seismogenic source the 1905 destructive earthquake.

  1. Erosion in extruder flow

    Science.gov (United States)

    Kaufman, Miron; Fodor, Petru S.

    A detailed analysis of the fluid flow in Tadmor's unwound channel model of the single screw extruder is performed by combining numerical and analytical methods. Using the analytical solution for the longitudinal velocity field (in the limit of zero Reynolds number) allows us to devote all the computational resources solely for a detailed numerical solution of the transversal velocity field. This high resolution 3D model of the fluid flow in a single-screw extruder allows us to identify the position and extent of Moffatt eddies that impede mixing. We further consider the erosion of particles (e.g. carbon-black agglomerates) advected by the polymeric flow. We assume a particle to be made of primary fragments bound together. In the erosion process a primary fragment breaks out of a given particle. Particles are advected by the laminar flow and they disperse because of the shear stresses imparted by the fluid. The time evolution of the numbers of particles of different sizes is described by the Bateman coupled differential equations used to model radioactivity. Using the particle size distribution we compute an entropic fragmentation index which varies from 0 for a monodisperse system to 1 for an extreme poly-disperse system.

  2. Habitat structure and zonation patterns of northwestern Mediterranean shoreline strands

    Directory of Open Access Journals (Sweden)

    Simone Mariani

    2017-06-01

    Full Text Available We studied the habitat structure (macrofaunal assemblages and bottom types and zonation patterns of 29 unvegetated shoreline strands along the 900-km coast of Catalonia (NW Mediterranean Sea. Organisms were sampled with grabs, pitfall traps, sticky traps, clam nets and spades to ensure capture of the different proportions of macrofaunal assemblages from the supra-, medio- and infralittoral levels. We collected 211 taxa: 194 animals and 17 algae. The most abundant and dominant organisms collected with van Veen grabs were Nematoda, Oligochaeta and Collembola at the supralittoral level; the polychaetes Saccocirrus spp. and Pisione remota, the amphipod Corophium orientale, Nematoda, and Turbellaria at the mediolittoral level; and Nematoda at the upper infralittoral level. SIMPER analysis revealed great dissimilarity between the organisms inhabiting the supralittoral and the other littoral levels. Regarding the epifauna, the sticky traps used at the supralittoral level mainly collected Collembola, which were nearly absent in pitfall traps. The qualitative study performed with a clam net and a small spade revealed that Nematoda, Saccocirrus spp., Turbellaria, Nemertea and the polychaete P. remota were the most abundant animals at both the medio- and the infralittoral levels and no differences were found between these levels. Different qualitative sampling methodologies showed that in fine sediments the bivalves Donax trunculus and D. semistriatus determined more than 97% of dissimilarity from coarse-sand sites. Richness increased in protected sandy and cobble shores. Littoral level and bottom-type features were only to a certain extent valid indicators of specific biotic components for a specific habitat.

  3. Nutrient-enhanced bioremediation of oil-contaminated shoreline

    International Nuclear Information System (INIS)

    Glaser, J.A.

    1991-01-01

    On March 24, 1989, the collision of the supertanker Exxon Valdez with a submerged reef in Prince William Sound AK, released 41.6 million L (11 million gal) of Prudhoe Bay crude oil. The oil spread with time to contaminate an estimated 565 km (350 miles) of shoreline. The degradation of oil components by biological mechanisms has been intensively studied during the last 20 years. The general outline of biodegradation pathways for aliphatic and aromatic hydrocarbons has been formulated and continues to be developed in greater detail. Consequently, the microbial decomposition of oil in aquatic environments is well understood to include descriptions of biodegradation kinetics; temperature effects for biodegradation can be described by an Arrhenius relationship. Even cold-water environments have been shown to support the biodegradation of oil components. This paper reports that a panel of experts was assembled to assist the U.S. Environmental Protection Agency (EPA) in determining the best treatment strategy to accelerate the natural biodegradation process in Prince William Sound

  4. Bioremediation of oil on shorelines with organic and inorganic nutrients

    International Nuclear Information System (INIS)

    Sveum, P.; Ramstad, S.

    1995-01-01

    Two experiments to study the mechanisms associated with nutrient-enhanced biodegradation of oil (Statfjord crude oil)-contaminated shorelines were done in continuous-flow seawater exchange basins with simulated tides. The fertilizers included fish and meal pellets, stick water pellets, and two concentrations of Max Bac: standard and five times higher. Both one-time and repeated additions of fish meal were studied. The number of oil-degrading bacteria in the sediment increased by three to four orders of magnitude after adding oil and fertilizer, and repeated fertilization had little effect. Oil degradation was found to be extensive with all treatments in both experiments, which lasted 35 or 98 days. Polycyclic aromatic hydrocarbon degradation seems to be most extensive in the sediments with repeated application of fish meal. The relation between accumulated total soluble nitrogen in interstitial water and nC 17 /pristane differs between the sediments treated with Max Bac and the organic additives, and indicates that this concentration cannot be used as a sole indication of the oil degradation rate if organic nutrients are used. The relation between accumulated CO 2 production and nC 17 /pristane ratio indicates a diauxic use of the two different sources of carbon present, without being absolute. Repeated fertilization with organic additives is neither beneficial nor detrimental to the oil degradation activity

  5. Biological effects of three different shoreline cleanup methods

    Energy Technology Data Exchange (ETDEWEB)

    Mattsson, J.; Lethinen, C.; Linden, O.

    1981-06-01

    In order to simulate a real oil spill the shore of a small island in the Baltic proper was treated with a weathered crude oil. The aim of the study was to investigate and compare environmental impact of some shoreline cleanup techniques as well as the effectiveness of these methods. Hot water was the quickest cleanup method, whereas cleaning with a solvent took twice as much time and mechanical recovery three and a half time as much. The hot water treatment resulted in the smallest amounts of oil left in the soil compared to the two other methods, where two to three times as much was left. The oil content in sedimenting material and in mussels was highest outside the area cleaned with hot water. The oil content in mussel tissues increased 75 times after cleaning and the sediment contained about twice as much oil as outside the other areas. The vegetation on all four oiled areas was considerably reduced and the soil fauna was completely eliminated. Since no animals were found on the four oiled areas, not even on the untreated area, it appeared to be the oil itself that caused this effect. The number of animals caught with pitfall traps decreased after oiling and cleanup to between 10-40 % of the original amount. The results from the investigation of the fauna in the Cladophora-belt do not indicate any effects so far.

  6. Guam and the Northern Mariana Islands ESI: ESI (Environmental Sensitivity Index Shoreline Types - Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector lines representing the shoreline and coastal habitats for Guam and the Northern Mariana Islands, classified according to the...

  7. National Coastal Condition Assessment (NCCA) Sampling Areas Polygons, Hawaiian Islands Shoreline, 2015, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — This is a polygon feature dataset with areas along the shoreline of the Hawaiian islands. The National Coastal Condition Assessment (NCCA) is a national coastal...

  8. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: South Florida: ESIL (ESI Shoreline Types - Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The ESIL data set contains vector lines representing the shoreline and coastal habitats of South Florida classified according to the Environmental Sensitivity Index...

  9. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: South Florida: ESIP (ESI Shoreline Types - Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The ESIP data set contains vector polygons representing the shoreline and coastal habitats of South Florida classified according to the Environmental Sensitivity...

  10. Impact of port structures on the shoreline of Karnataka, west coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Deepa, N.; Kunte, P.D.

    (GIS) as the location of the shoreline and its historical rate of change can provide important information for the design of coastal protection, plans for coastal development, coastal and social vulnerability study, and the calibration...

  11. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Florida Panhandle: ESIL (ESI Shoreline Types - Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The ESIL data set contains vector lines representing the shoreline and coastal habitats of the Florida Panhandle, classified according to the Environmental...

  12. Virginia ESI: ESI (Environmental Sensitivity Index Shoreline Types - Lines and Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector lines and polygons representing the shoreline and coastal habitats for Virginia, classified according to the Environmental Sensitivity...

  13. Maryland ESI: ESI (Environmental Sensitivity Index Shoreline Types - Lines and Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector lines and polygons representing the shoreline and coastal habitats for Maryland, classified according to the Environmental Sensitivity...

  14. Aquifer Sampling Tube Completion Report: 100 Area and Hanford Townsite Shorelines

    International Nuclear Information System (INIS)

    Peterson, R.E.; Borghese, J.V.; Erb, D.B.

    1998-02-01

    Groundwater contamination is known or suspected along the Hanford Site shoreline of the Columbia River adjacent to the retired reactor areas. Along the shoreline away from the reactor areas, where contamination is presumed to be absent, monitoring sites are frequently widely spaced or unavailable to confirm the presumption. Previous characterizations of contamination near the river have relied on data from a limited number of near-river wells, contaminant plume migration predictions, and river bank seepage sampling to anticipate shoreline conditions. In recent years, new methods have been developed to obtain groundwater samples from the aquifer near the groundwater/river water interface. These methods include using (1) divers to obtain samples of pore water from riverbed sediment and (2) sampling tubes that are driven into the aquifer at the shoreline. The latter method also permits sampling the aquifer at multiple depths, which helps to determine the thickness of the potentially contaminated groundwater layer that discharges into the river

  15. Cook Inlet and Kenai Peninsula, Alaska ESI: ESI (Environmental Sensitivity Index Shoreline Types - Polygons and Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector lines and polygons representing the shoreline and coastal habitats of Cook Inlet and Kenai Peninsula, Alaska, classified according to...

  16. Methodology update for determination of the erosion coefficient(Z

    Directory of Open Access Journals (Sweden)

    Tošić Radislav

    2012-01-01

    Full Text Available The research and mapping the intensity of mechanical water erosion that have begun with the empirical methodology of S. Gavrilović during the mid-twentieth century last, by various intensity, until the present time. A many decades work on the research of these issues pointed to some shortcomings of the existing methodology, and thus the need for its innovation. In this sense, R. Lazarević made certain adjustments of the empirical methodology of S. Gavrilović by changing the tables for determination of the coefficients Φ, X and Y, that is, the tables for determining the mean erosion coefficient (Z. The main objective of this paper is to update the existing methodology for determining the erosion coefficient (Z with the empirical methodology of S. Gavrilović and amendments made by R. Lazarević (1985, but also with better adjustments to the information technologies and the needs of modern society. The proposed procedure, that is, the model to determine the erosion coefficient (Z in this paper is the result of ten years of scientific research and project work in mapping the intensity of mechanical water erosion and its modeling using various models of erosion in the Republic of Srpska and Serbia. By analyzing the correlation of results obtained by regression models and results obtained during the mapping of erosion on the territory of the Republic of Srpska, a high degree of correlation (R² = 0.9963 was established, which is essentially a good assessment of the proposed models.

  17. Net erosion measurements on plasma facing components of Tore Supra

    International Nuclear Information System (INIS)

    Tsitrone, E.; Chappuis, P.; Corre, Y.; Gauthier, E.; Grosman, A.; Pascal, J.Y.

    2001-01-01

    Erosion of the plasma facing components is a crucial point of investigation in long pulse operation of future fusion devices. Therefore erosion measurements have been undertaken in the Tore Supra tokamak. After each experimental campaign, different plasma facing components have been monitored in situ by non-destructive means, in order to evaluate their net erosion following a long plasma exposure. This paper presents the results obtained over three experimental campaigns on the Tore Supra ergodic divertor B 4 C-coated neutralisers and CFC Langmuir probes. The erosion on the Langmuir probes after one year of plasma exposure can reach 100 μm, leading to an effective erosion coefficient of around 5x10 -3 to 10 -2 , in reasonable agreement with values found on other tokamaks. The erosion of the ergodic divertor neutraliser plates is lower (10 μm). This is coherent with the attenuated particle flux due to a lower incidence angle, and might also be due to some surface temperature effect, since the neutralisers are actively cooled while the Langmuir probes are not. Moreover, the profile along the neutraliser shows net erosion in zones wetted by the plasma and net redeposition in shadowed zones

  18. Emerging and Submerging Shorelines: Impacts of Physical Change on Bioband Length

    Science.gov (United States)

    Kruger, L. E.; Johnson, A. C.; Gregovich, D.; Buma, B.; Noel, J.

    2017-12-01

    We approximated shifts in coastal benthic species for shoreline length units undergoing both sea level rise and relative sea level lowering (often post-glacial, termed isostatic rebound) where subsistence-based, southeast Alaska Natives reside. From six community centers, we examined 30 km radii shoreline reaches by merging relevant portions of the NOAA ShoreZone database with near shore bathymetry and measures of mean global sea level rise with local global positioning system information (GIS) of tectonic shift and isostatic rebound. For our analysis, we estimated change for 9,868 assessed shoreline length units having uniform substrate and biologic type over a 100-yr time span (2008-2108) using geometric analysis of shoreline attributes. For each shoreline length unit we assessed relationships among substrate, slope, exposure, and presence of five benthic species including eel grass (Zostera marina), blue mussel (Mytilus edulis), butter clams (Saxidomus gigantean), bull kelp (Nereocytis leutkeana), and foliose red algae including ribbon kelp (Palmaria sp.). Our research indicates that both emergence, up to 1.8 m, and submergence, up 0.2 m, of the land will result in disportionately larger shoreline length segment alterations for habitats in protected low-slope gradient bays and estuaries (dominated by eelgrass and butter clam habitats) with less change for rocky steep-gradient exposed penninsulas (red algae and canopy kelp). This trend, holding true regardless of isostatic rebound, tectonic shift or sea level rise rate, highlights the importance of initial geomorphology-based assessments serving to improve bio-physical, chemical, and socially-related coastal research. Where shorelines are emerging 30% decreases in estuary lengths are predicted, but where shorelines are submerging up to 3% increases in estuaries are expected. Our research results are consistent with anthropology studies assessing past coastal change. Coastal change, influencing subsistance foods

  19. EPro Non-contact erosion profiling

    DEFF Research Database (Denmark)

    Meinert, Palle

    Pro is a profiling program build to measure the same surface or work piece multiple times and track changes due to erosion. It was developed during 2001 - 2002 at Aalborg University and was part of a Master of Science project dealing with stability of rubble mound breakwaters. The goal was to aut......Pro is a profiling program build to measure the same surface or work piece multiple times and track changes due to erosion. It was developed during 2001 - 2002 at Aalborg University and was part of a Master of Science project dealing with stability of rubble mound breakwaters. The goal...... was to automate the measuring of profiles in order to save manpower and to increase the number of possible measure points. Additional requirement was that measurements should be done in a non-contact way and that the measuring should not be hindered by the presence of water....

  20. Rill erosion rates in burned forests

    Science.gov (United States)

    Joseph W. Wagenbrenner; Peter R. Robichaud

    2011-01-01

    Introduction Wildfires often produce large increases in runoff and erosion rates (e.g., Moody and Martin, 2009), and land managers need to predict the frequency and magnitude of postfire erosion to determine the needs for hazard response and possible erosion mitigation to reduce the impacts of increased erosion on public safety and valued resources. The Water Erosion...

  1. Quantification Of Erosion Rates Of Agriculturally Used Soils By Artificial

    Science.gov (United States)

    Jha, Abhinand

    2010-05-01

    for 137Cs and 53 days for 7Be), delivery rates, delivery histories, and land use (Fig. 2). An Physical processes, such as water and wind, are the dominant factors moving 137Cs, 7Be tagged soil particles within and between landscape compartments. PIC Figure 2: Generalized sketch illustrating the distributions of 137Cs and 7Be in tilled and undisturbed soils 2 Erosion study at Young Moraine regions of Germany Recently, a study had been performed to evaluate erosion rates in a typical pattern of landscapes in the Young Moraine regions of North-East Germany [5]. The 137Cs concentrations were measured at selected sampling points of various study sites. Among the areas selected for sampling was Basedow, which is a cultivated area, situated north of Berlin. During a master thesis study at university of Bremen in the academic year 2008-2009 [6] a second sampling campaign was performed at the same study site and 137Cs and 7Be concentrations were measured. Two mathematical models (a proportional model and a mass balance model) were applied to estimate erosion or deposition rates giving a distinction between uncultivated or essentially undisturbed soils and cultivated or soils under permanent pasture (Fig.3A). An improved depositional model was developed during this study. The simulation results from this model are presented in Fig.4. Due to the half-life (53.2 days) of 7Be, a mass balance model was developed and used to calculate erosion rates from 7Be (Fig.3B). PIC Figure 3: A: Erosion rates for 137Cs calculated by mass balance model. B: Erosion rates calculated with mass balance model using the 7Be data at Basedow (2008). The results verify that there is long term erosion as a result of wind, water and agricultural practices. The annual erosion rates at Basedow calculated using a mass balance and a proportional model were in the range between 30-50 t ha-1yr-1. These values were comparable to the erosion rates calculated in the previous study [5] by the models mentioned above

  2. Seismic surface-wave prospecting methods for sinkhole hazard assessment along the Dead Sea shoreline

    Science.gov (United States)

    Ezersky, M.; Bodet, L.; Al-Zoubi, A.; Camerlynck, C.; Dhemaied, A.; Galibert, P.-Y.; Keydar, S.

    2012-04-01

    The Dead Sea's coastal areas have been dramatically hit by sinkholes occurrences since around 1990 and there is an obvious potential for further collapse beneath main highways, agricultural lands and other populated places. The sinkhole hazard in this area threatens human lives and compromise future economic developments. The understanding of such phenomenon is consequently of great importance in the development of protective solutions. Several geological and geophysical studies tend to show that evaporite karsts, caused by slow salt dissolution, are linked to the mechanism of sinkhole formation along both Israel and Jordan shorelines. The continuous drop of the Dead Sea level, at a rate of 1m/yr during the past decade, is generally proposed as the main triggering factor. The water table lowering induces the desaturation of shallow sediments overlying buried cavities in 10 to 30 meters thick salt layers, at depths from 25 to 50 meters. Both the timing and location of sinkholes suggest that: (1) the salt weakens as result of increasing fresh water circulation, thus enhancing the karstification process; (2) sinkholes appear to be related to the decompaction of the sediments above karstified zones. The location, depth, thickness and weakening of salt layers along the Dead Sea shorelines, as well as the thickness and mechanical properties of the upper sedimentary deposits, are thus considered as controlling factors of this ongoing process. Pressure-wave seismic methods are typically used to study sinkhole developments in this area. P-wave refraction and reflection methods are very useful to delineate the salt layers and to determine the thickness of overlying sediments. But the knowledge of shear-wave velocities (Vs) should add valuable insights on their mechanical properties, more particularly when the groundwater level plays an important role in the process. However, from a practical point of view, the measurement of Vs remains delicate because of well-known shear

  3. Vegetation of natural and artificial shorelines in Upper Klamath Basin’s fringe wetlands

    Science.gov (United States)

    Ray, Andrew M.; Irvine, Kathryn M.; Hamilton, Andy S.

    2013-01-01

    The Upper Klamath Basin (UKB) in northern California and southern Oregon supports large hypereutrophic lakes surrounded by natural and artificial shorelines. Lake shorelines contain fringe wetlands that provide key ecological services to the people of this region. These wetlands also provide a context for drawing inferences about how differing wetland types and wave exposure contribute to the vegetative assemblages in lake-fringe wetlands. Here, we summarize how elevation profiles and vegetation richness vary as a function of wave exposure and wetland type. Our results show that levee wetland shorelines are 4X steeper and support fewer species than other wetland types. We also summarize the occurrence probability of the five common wetland plant species that represent the overwhelming majority of the diversity of these wetlands. In brief, the occurrence probability of the culturally significant Nuphar lutea spp. polysepala and the invasive Phalaris arundinacea in wave exposed and sheltered sites varies based on wetland type. The occurrence probability for P. arundinacea was greatest in exposed portions of deltaic shorelines, but these trends were reversed on levees where the occurrence probability was greater in sheltered sites. The widespread Schoenoplectus acutus var. acutus occurred throughout all wetland and exposure type combinations but had a higher probability of occurrence in wave exposed sites. Results from this work will add to our current understanding of how wetland shoreline profiles interact with wave exposure to influence the occurrence probability of the dominant vegetative species in UKB’s shoreline wetlands.

  4. The erosive potential of lollipops

    NARCIS (Netherlands)

    Brand, H.S.; Gambon, D.L.; Paap, A.; Bulthuis, M.S.; Veerman, E.C.I.; Nieuw Amerongen, A.V.

    2009-01-01

    Aim: To determine the erosive potential of several commercially available lollipops and the protective effect of saliva. Methods: The erosive potential of lollipops was determined in vitro by measuring the pH and neutralisable acidity. Subsequently, 10 healthy volunteers tested different types of

  5. Wind erosion processes and control

    Science.gov (United States)

    Wind erosion continues to threaten the sustainability of our nations' soil, air, and water resources. To effectively apply conservation systems to prevent wind driven soil loss, an understanding of the fundamental processes of wind erosion is necessary so that land managers can better recognize the ...

  6. Erosion--corrosion

    International Nuclear Information System (INIS)

    Vyas, B.

    1978-01-01

    The deterioration of materials by corrosion or erosion by itself presents a formidable problem and for this reason investigators have studied these two phenomena independently. In fact, there are very few systematic studies on E-C and the majority of references mention it only in passing. In most real systems, however, the two destructive processes take place simultaneously, hence the purpose of this review is to present the various interactions between the chemical and mechanical agents leading to accelerated degradation of the material. The papers cited in the review are those that lead to a better understanding of the process involved in the accelerated rate of material loss under E-C conditions

  7. Assessing the multidimensionality of coastal erosion risks: public participation and multicriteria analysis in a Mediterranean coastal system.

    Science.gov (United States)

    Roca, Elisabet; Gamboa, Gonzalo; Tàbara, J David

    2008-04-01

    The complex and multidimensional nature of coastal erosion risks makes it necessary to move away from single-perspective assessment and management methods that have conventionally predominated in coastal management. This article explores the suitability of participatory multicriteria analysis (MCA) for improving the integration of diverse expertises and values and enhancing the social-ecological robustness of the processes that lead to the definition of relevant policy options to deal with those risks. We test this approach in the Mediterranean coastal locality of Lido de Sète in France. Results show that the more adaptive alternatives such as "retreating the shoreline" were preferred by our selected stakeholders to those corresponding to "protecting the shoreline" and the business as usual proposals traditionally put forward by experts and policymakers on these matters. Participative MCA contributed to represent coastal multidimensionality, elicit and integrate different views and preferences, facilitated knowledge exchange, and allowed highlighting existing uncertainties.

  8. Oblique Aerial Photography of the Arctic Coast of Alaska, Nulavik to Demarcation Point, August 7-10, 2006

    Science.gov (United States)

    Gibbs, Ann E.; Richmond, Bruce M.

    2009-01-01

    The Arctic Coastal Plain of northern Alaska, an area of strategic economic importance to the United States, is home to remote Native American communities and encompasses unique habitats of global significance. Coastal erosion along the Arctic coast is chronic and widespread; recent evidence suggests that erosion rates are among the highest in the world (up to ~16 m/yr) and may be accelerating. Coastal erosion adversely impacts energy-related infrastructure, natural shoreline habitats, and Native American communities. Climate change is thought to be a key component of recent environmental changes in the Arctic. Reduced sea-ice cover in the Arctic Ocean is one of the probable mechanisms responsible for increasing coastal exposure to wave attack and the resulting increase in erosion. Extended periods of permafrost melting and associated decrease in bluff cohesion and stability are another possible source of the increase in erosion. Several studies of selected areas on the Alaska coast document past shoreline positions and coastal change, but none have examined the entire North coast systematically. Results from these studies indicate high rates of coastal retreat that vary spatially along the coast. To address the need for a comprehensive and regionally consistent evaluation of shoreline change along the North coast of Alaska, the U.S. Geological Survey (USGS), as part of their Coastal and Marine Geology Program's (CMGP) National Assessment of Shoreline Change Study, is evaluating shoreline change from Peard Bay to the United States/Canadian border, using historical maps and photography and a standardized methodology that is consistent with other shoreline-change studies along the Nation's coastlines (for example, URL http://coastal.er.usgs.gov/shoreline-change/ (last accessed March 2, 2009). This report contains photographs collected during an aerial-reconnaissance survey conducted in support of this study. An accompanying ESRI ArcGIS shape file (and plain-text copy

  9. In situ bioremediation strategies for oiled shoreline environments

    International Nuclear Information System (INIS)

    Lee, K.; Mora, S. de

    1999-01-01

    Despite advances in preventative measures, recent events have demonstrated that accidental oil spills at sea will still occur. While physical (e.g. booms and skimmers) and chemical (e.g. chemical dispersants) methods have been developed to recover and/or disperse oil spilled at sea, they are not 100% effective and are frequently limited by operational constraints attributed to sea state and/or nature of the contamination. As a result, oil spills frequently impact shoreline environments. In situ bioremediation, the addition of substances or modification of habitat at contaminated sites to accelerate natural biodegradation processes, is now recognised as an alternative spill response technology of the remediation of these sites. Recommended for use following the physical removal of bulk oil, this treatment strategy has an operational advantage in that it breaks down and/or removes the residual contamination in place. Laboratory experiments and field trials have demonstrated the feasibility and success of bioremediation strategies such as nutrient enrichment to enhance bacterial degradation of oil on cobble, sand beach and salt marsh environments. With improved knowledge of the factors that limit natural oil degradation rates, the feasibility of other strategies such as phytoremediation, enhanced oil-mineral fines interaction and the addition of oxygen or alternative electron acceptors are now being evaluated. Laboratory and field test protocols are being refined for the selection of effective bioremediation agents and methods of application. It is recommended that future operational guidelines include real time product efficacy test and environmental effects monitoring programs. Termination of treatment should be implemented when: 1) it is no longer effective; 2) the oil has degraded to acceptable biologically benign concentrations; or 3) toxicity due to the treatment is increasing. (Author)

  10. Coastal Vulnerability to Erosion Processes: Study Cases from Different Countries

    Science.gov (United States)

    Anfuso, Giorgio; Martinez Del Pozo, Jose Angel; Rangel-Buitrago, Nelson

    2010-05-01

    When natural processes affect or threaten human activities or infrastructures they become a natural hazard. In order to prevent the natural hazards impact and the associated economic and human losses, coastal managers need to know the intrinsic vulnerability of the littoral, using information on the physical and ecological coastal features, human occupation and present and future shoreline trends. The prediction of future coastline positions can be based on the study of coastal changes which have occurred over recent decades. Vertical aerial photographs, satellite imagery and maps are very useful data sources for the reconstruction of coast line changes at long (>60 years) and medium (between 60 and 10 years) temporal and spatial scales. Vulnerability maps have been obtained for several coastal sectors around the world through the use of Geographical Information Systems (GIS), computer-assisted multivariate analysis and numerical models. In the USA, "Flood Insurance Rate Maps" have been created by the government and "Coastal Zone Hazard Maps" have been prepared for coastal stretches affected by hurricane Hugo. In Spain, the vulnerability of the Ebro and an Andalusia coastal sector were investigated over different time scales. McLaughlin et al., (2002) developed a GIS based coastal vulnerability index for the Northern Ireland littoral that took into account socio-economic activities and coastal resistance to erosion and energetic characteristics. Lizárraga et al., (2001) combined beach reduction at Rosario (Mexico) with the probability of damage to landward structures, obtaining a vulnerability matrix. In this work several coastal vulnerability maps have also been created by comparing data on coastal erosion/accretion and land use along different coastal sectors in Italy, Morocco and Colombia. Keywords: Hazard, Vulnerability, Coastal Erosion, Italy, Morocco, Colombia.

  11. Using REE tracers to measure sheet erosion changing to rill erosion

    International Nuclear Information System (INIS)

    Liu Puling; Xue Yazhou; Song Wei; Wang Mingyi; Ju Tongjun

    2004-01-01

    Rare Earth Elements (REE) tracer method was used to study sheet erosion changing to rill erosion on slope land. By placing different rare earth elements of different soil depth across a slope in an indoor plot, two simulated rainfalls were applied to study the change of erosion type and the rill erosion process. The results indicate that the main erosion type is sheet erosion at the beginning of the rainfalls, and serious erosion happens after rill erosion appears. Accumulated sheet and rill erosion amounts increase with the rainfalls time. The percentage of sheet erosion amount decreases and rill erosion percentage increases with time. At the end of the rainfalls, the total rill erosion amounts are 4-5 times more than sheet erosion. In this paper, a new REE tracer method was used to quantitatively distinguish sheet and rill erosion amounts. The new REE tracer method should be useful to future studying of erosion processes on slope lands. (authors)

  12. Modeling soil erosion in a watershed

    OpenAIRE

    Lanuza, R.

    1999-01-01

    Most erosion models have been developed based on a plot scale and have limited application to a watershed due to the differences in aerial scale. In order to address this limitation, a GIS-assisted methodology for modeling soil erosion was developed using PCRaster to predict the rate of soil erosion at watershed level; identify the location of erosion prone areas; and analyze the impact of landuse changes on soil erosion. The general methodology of desktop modeling or soil erosion at watershe...

  13. 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

  14. The similarity of river evolution at the initial stage of channel erosion

    Science.gov (United States)

    Lin, Jiun-Chuan

    2014-05-01

    The study deals with a comparison study of two types of rocks at the initial stage of channel erosion in Taiwan. It is interesting that channel erosion at different types of rocks shows some similarity. There are two types of rocks: sandstone at Ta-an River, central Taiwan where river channel erosion from the nick point because of earthquake uplifting and mud rock at Tainan, southern Taiwan where rill erosion on a flat surface after artificial engineering. These two situations are both at the beginning stage of channel erosion, there are some similar landform appeared on channels. However the rate of erosion and magnitude of erosion are different. According to the using of photogrammetry method to reconstruct archive imageries and field surveying by total station and 3D scanner at different stages. The incision rate is high both at the Ta-an River and the bank erosion and it is even more obvious at mud rock area because of erodibility of mud rock. The results show that bank erosion and incision both are obvious processes. Bank erosion made channel into meander. The bank erosion cause slope in a asymmetric channel profile. The incision process will start at the site where land is relatively uplifted. This paper demonstrates such similarity and landform characters.

  15. Erosion problems in Alexandroupolis coastline, North-Eastern Greece

    Science.gov (United States)

    Xeidakis, G. S.; Delimani, P.; Skias, S.

    2007-12-01

    This paper deals with the coastal erosion processes and the related problems around the city of Alexandroupolis, NE Aegean Sea, N. Greece. The area is very fast developing, as the city is an important port and a summer resort center in SE Balkans, and will become soon a transportation and energy center, as well. The coastline under study exhibits an east west orientation and has a length of more than 50 km. The spatial distribution and the characteristics of the changes in the shoreline were studied by comparing old and new air photographs and topographic maps, as well as through repeated series of field observations and local measurements regarding the erosion process. From these studies it was concluded that the greater stretch of the western part of the coast, under consideration, is of moderate to high relief, with a considerable participation of coastal cliffs. It consists of conglomerates of varying granulometry and consistency and is under moderate to severe erosion process. The erosion phenomena in the western part of the coast may be attributed, primarily, to strong S, SW winds, blowing in the area and to trapping of sediments by Alexandroupolis’ port breakwaters; the port stops or/and diverts the sediments to the open sea; and to the east to west longshore sea current, prevailing in the area. The eastern stretch of the coast is a plain area, formed by sandy silty sediments; being a part of the river Evros’ Delta, it is under deposition and accretes seawards. The majority of the coasts under consideration are classified as coasts of high wave energy potential. Hard structures, as shore protection measures, have been constructed in some places, but they were proved, in rather short time-period, ineffective and suffered extensive failures. Thus, it is argued that for a long-term cost-effective tackling of the various erosion problems on any stretch, priority must be given to soft engineering measures; although, certain hard measures, carefully selected

  16. Gastric Mucosal Erosions - Radiologic evaluation -

    International Nuclear Information System (INIS)

    Kim, Seung Hyup

    1985-01-01

    70 cases of gastric mucosal erosions were diagnosed by double contrast upper gastrointestinal examinations and endoscopic findings. Analyzing the radiologic findings of these 70 cases of gastric mucosal erosions, the following results were obtained. 1. Among the total 70 cases, 65 cases were typical varioliform erosions showing central depressions and surrounding mucosal elevations. Remaining 5 cases were erosions of acute phase having multiple irregular depressions without surrounding elevations. 2. The gastric antrum was involved alone or in part in all cases. Duodenal bulb was involved with gastric antrum in 4 cases. 3. The majority of the cases had multiple erosions. There were only 2 cases of single erosion. 4. In 65 cases of varioliform erosions; 1) The diameter of the surrounding elevations varied from 3 to 20 mm with the majority (47 cases) between 6 and 10 mm. 2) In general, the surrounding elevations with sharp margin on double contrast films were also clearly demonstrated on compression films but those with faint margin were not. 3) The size of the central barium collections varied from pinpoint to 10 mm with the majority under 5 mm. The shape of the central barium collections in majority of the cases were round with a few cases of linear, triangular or star-shape. 5. In 5 cases of acute phase erosions; 1) All the 5 cases were females. 2) On double contrast radiography, all the cases showed multiple irregular depressed lesions without surrounding elevations. 3) 1 case had the history of hematemesis. 4) In 1 case, there was marked radiological improvement on follow-up study of 2 months interval. 6. In 23 cases, there were coexistent diseases with gastric mucosal erosions. These were 13 cases of duodenal bulb ulcers,7 cases of benign gastric ulcers and 3 others

  17. Shoreline deposits and diagenesis resulting from two Late Pleistocene highstands near +5 and +6 metres, Durban, South Africa

    Science.gov (United States)

    Cooper, J.A.G.; Flores, R.M.

    1991-01-01

    In exposures of Pleistocene rocks on the east coast of South Africa, eight sedimentary facies were distinguished on the basis of petrology, grain size, internal structures and field relationships. These are interpreted as deposits of surf zone, breaker zone, swash zone, backbeach, boulder beach and dune environments. Three phases of deposition and diagenesis are recognized. As a result of the stabilising effect of pre-existing coastal facies, the deposits from successive sea level stands are stacked vertically in a narrow coast-normal strip. Early cementation prevented erosion of the deposits during subsequent transgressions. Deposition of subsequent facies took place on an existing coastal dune (Facies 1). A terrace was cut into this dune at a sea level 4.5 to 5 m above present. At this sea level, clastic shoreline sediments were deposited which make up the main sedimentary sequence exposed (Facies 2-7). The steep swash zone, coarse grain size, and comparison with modern conditions in the study area indicate clastic deposition on a high-energy, wave-dominated, microtidal coastline. Vertical stacking of progressively shallower water facies indicates progradation associated with slightly regressive conditions, prior to stranding of the succession above sea level. During a subsequent transgression to 5.5 or 6 m above present sea level, a second terrace was cut across the existing facies, which by then were partly lithified. A boulder beach (Facies 8) deposited on this terrace is indicative of high wave energy and a rocky coastline, formed by existing cemented coastal facies. Comparison with dated deposits from other parts of the South African coast suggest a Late Pleistocene age for Facies 2-8. Deposition was terminated by subsequent regression and continuing low sea levels during the remainder of the Pleistocene. Cementation of the facies took place almost entirely by carbonate precipitation. The presence of isopachous fibrous cements suggests early cementation of

  18. Buffer erosion in dilute groundwater

    International Nuclear Information System (INIS)

    Schatz, T.; Kanerva, N.; Martikainen, J.; Sane, P.; Olin, M.; Seppaelae, A.; Koskinen, K.

    2013-08-01

    One scenario of interest for repository safety assessment involves the loss of bentonite buffer material in contact with dilute groundwater flowing through a transmissive fracture interface. In order to examine the extrusion/erosion behavior of bentonite buffer material under such circumstances, a series of experiments were performed in a flow-through, 1 mm aperture, artificial fracture system. These experiments covered a range of solution chemistry (salt concentration and composition), material composition (sodium montmorillonite and admixtures with calcium montmorillonite), and flow velocity conditions. No erosion was observed for sodium montmorillonite against solution compositions from 0.5 g/L to 10 g/L NaCl. No erosion was observed for 50/50 calcium/sodium montmorillonite against 0.5 g/L NaCl. Erosion was observed for both sodium montmorillonite and 50/50 calcium/sodium montmorillonite against solution compositions ≤ 0.25 g/L NaCl. The calculated erosion rates for the tests with the highest levels of measured erosion, i.e., the tests run under the most dilute conditions (ionic strength (IS) < ∼1 mM), were well-correlated to flow velocity, whereas the calculated erosion rates for the tests with lower levels of measured erosion, i.e., the tests run under somewhat less dilute conditions (∼1 mM < IS < ∼4 mM), were not similarly correlated indicating that material and solution composition can significantly affect erosion rates. In every experiment, both erosive and non-erosive, emplaced buffer material extruded into the fracture and was observed to be impermeable to water flowing in the fracture effectively forming an extended diffusive barrier around the intersecting fracture/buffer interface. Additionally, a model which was developed previously to predict the rate of erosion of bentonite buffer material in low ionic strength water in rock fracture environments was applied to three different cases: sodium montmorillonite expansion in a vertical tube, a

  19. Erosion of the Mekong delta: the role of human activities

    Science.gov (United States)

    Anthony, E.; Dussouillez, P.; Goichot, M.; Brunier, G.; Dolique, F.; Nguyen, V.; Loisel, H.; Mangin, A.; Vantrepotte, V.

    2013-12-01

    River deltas are threatened by dams, dykes, flow channelling, and aggregate extraction. These activities outweigh climate change and sea-level rise in causing delta vulnerability1, and will aggravate the impacts to be expected from these effects2. We show here from analysis of: (1) delta channel morphology and sediment budgets, and (2) satellite imagery, that the Mekong delta, considered as the world's third largest, and hitherto strongly prograding, is now in a phase of large-scale erosion. We discuss the mechanistic links involved in erosion and the way these are related to human activities. High-resolution (2.5 m) SPOT 5 images for the years 2003, 2007, 2011/12 covering 405 km of the delta shoreline show an overall retreat rate of over 8 m a year. 75% of the analysed shoreline, i.e., the muddy western sector, is now retreating at rates exceeding 50 m a year in places. The sandy river-mouth sector maintains a semblance of stability, but with strong variations. We attribute erosion to a cascade of morphosedimentary changes linked to sediment mining from the deltaic channels and upstream dam interception. We estimated from Meris satellite imagery an annual 5% decrease in surface suspended concentrations exiting at the mouths of the Mekong over the period 2003-2011 that may reflect increased trapping of mud behind dams in China. We also infer modification of river-mouth and coastal mud storage patterns resulting from a loss of ca. 200 million m3 of delta channel sediments between 1998 and 2008 from aggregate extraction. Dykes have been shown to result in increased channel flow velocities during the high-discharge monsoon season, favouring further channel deepening3. Stronger river-mouth outflow velocities during this season may be leading to export of a greater proportion of mud far offshore of the coastal longshore transport corridor that ensured mud supply to, and past progradation of, the muddy western coast. In contrast, greater seawater penetration in the

  20. Numerical simulation of hydrodynamic and water quality effects of shoreline changes in Bohai Bay

    Science.gov (United States)

    Jia, Han; Shen, Yongming; Su, Meirong; Yu, Chunxue

    2018-02-01

    This study uses the HD and Ecolab modules of MIKE to simulate the hydrodynamic and water quality and predict the influence of shoreline changes in Bohai Bay, China. The study shows that shoreline changes weaken the residual current and generate a counter-clockwise circulation south of Huanghua Port, thereby resulting in weak water exchange capacity and low pollutant-diffusing capacity. Shoreline changes reduce the area of Bohai Bay, resulting in a smaller tidal prism and further weakening the water exchange capacity. This situation is not conducive to the diffusion of pollutants, and therefore may lead to increased water pollution in the bay. Shoreline changes hinder the spread of runoff, weaken the dilution effect of the river on seawater, and block the spread of coastal residual current, thereby resulting in increased salinity near the reclamation area. Shoreline changes lead to an increase in PO4-P concentration and decrease in DIN concentration. The value of N/P near the project decreases, thereby weakening the phosphorus-limited effect.

  1. Erosive tooth wear in children

    NARCIS (Netherlands)

    Carvalho, T.S.; Lussi, A.; Jaeggi, T.; Gambon, D.L.; Lussi, A.; Ganss, C.

    2014-01-01

    Erosive tooth wear in children is a common condition. Besides the anatomical differences between deciduous and permanent teeth, additional histological differences may influence their susceptibility to dissolution. Considering laboratory studies alone, it is not clear whether deciduous teeth are

  2. Erosion-resistant composite material

    Science.gov (United States)

    Finch, C.B.; Tennery, V.J.; Curlee, R.M.

    A highly erosion-resistant composite material is formed of chemical vapor-deposited titanium diboride on a sintered titanium diboride-nickel substrate. This material may be suitable for use in cutting tools, coal liquefaction systems, etc.

  3. Soil Erosion and Agricultural Sustainability

    Science.gov (United States)

    Montgomery, D. R.

    2009-04-01

    Data drawn from a global compilation of studies support the long articulated contention that erosion rates from conventionally plowed agricultural fields greatly exceed rates of soil production, erosion under native vegetation, and long-term geological erosion. Whereas data compiled from around the world show that soil erosion under conventional agriculture exceeds both rates of soil production and geological erosion rates by up to several orders of magnitude, similar global distributions of soil production and geological erosion rates suggest an approximate balance. Net soil erosion rates in conventionally plowed fields on the order of 1 mm/yr can erode typical hillslope soil profiles over centuries to millennia, time-scales comparable to the longevity of major civilizations. Well-documented episodes of soil loss associated with agricultural activities date back to the introduction of erosive agricultural methods in regions around the world, and stratigraphic records of accelerated anthropogenic soil erosion have been recovered from lake, fluvial, and colluvial stratigraphy, as well as truncation of soil stratigraphy (such as truncated A horizons). A broad convergence in the results from studies based on various approaches employed to study ancient soil loss and rates of downstream sedimentation implies that widespread soil loss has accompanied human agricultural intensification in examples drawn from around the world. While a broad range of factors, including climate variability and society-specific social and economic contexts — such as wars or colonial relationships — all naturally influence the longevity of human societies, the ongoing loss of topsoil inferred from studies of soil erosion rates in conventional agricultural systems has obvious long-term implications for agricultural sustainability. Consequently, modern agriculture — and therefore global society — faces a fundamental question over the upcoming centuries. Can an agricultural system

  4. Erosion properties of unipolar arcs

    International Nuclear Information System (INIS)

    Chekalin, Eh.K.

    1982-01-01

    Processes modelling the formation of unipolar arcs on the elements of the first wall in limiters of the vacuum chamber and on active elements of tokamak divertor, are experimentally investigated. Erosion, processes that take place at two types of non-stationary cathode spots are considered. Experimental data prove the possibility of reducing erosion intensity by coating the surface of electrodes by oxide films, reduction of the temperature of electrode and discharge current

  5. Introduction to littoral erosion problem in Uraba (Arboletes-Turbo area) Colombian Caribbean Coast

    International Nuclear Information System (INIS)

    Correa; Ivan D; Vernette, Georges

    2004-01-01

    Shoreline retreat has been the net dominant historical trend along the 145 km-length littoral between Arboletes and Turbo (southern Caribbean of Colombia). For the last four decades, there were identified in this littoral shoreline retreat of about 50-100 m in several places (Uveros, Damaquiel, Zapata, Turbo) and a maximum of 1.6 km in the Punta Rey-Arboletes area, where land losses were of 4.5 km 2 , at exceptional rates of 40 rn/year. The synthesis of the available information suggest that the general susceptibility to erosion between Arboletes and turbo could be related primarily to relative sea level rise, associated to tectonic movements as well as to the effects of mud diapirism and hydroisostacy. In the more critical areas (Arboletes, Turbo), the natural erosive trends were accelerated by anthropic actions, including river diversion (Turbo), beach mining and inadequate (or total absence) practices for controlling residual and natural waters. Up to august 2000, there were invested about $ Col 10.000 billions in 155 engineering defenses (groins, sea walls and rip-rap which totalize 6.2 km of total length and a volume of materials of 37.000 m 3 ). With few exceptions, groins have not been successful and are now part of the problem, accelerating shore erosion along the adjacent sectors. In the short term, the littoral erosion between Arboletes and turbo is caused both by marine and by sub aerial factors. it is facilitated by the poor lithological strengths of cliffs and marine terraces, mainly composed of highly fractured and weathered claystones and mudstones (with stratification and weakness planes dipping toward sea) and non-consolidated, easily liquefacted, fine sediments; both conditions facilitate the occurrence of rocks falls, slides and mud flows that result in high figures of cliff retreat (3 to 4 m), specially during the first 15 days of the summer-winter transition (April) and in high waves periods. The case of the littoral erosion between Arboletes

  6. Soil Erosion as a stochastic process

    Science.gov (United States)

    Casper, Markus C.

    2015-04-01

    The main tools to provide estimations concerning risk and amount of erosion are different types of soil erosion models: on the one hand, there are empirically based model concepts on the other hand there are more physically based or process based models. However, both types of models have substantial weak points. All empirical model concepts are only capable of providing rough estimates over larger temporal and spatial scales, they do not account for many driving factors that are in the scope of scenario related analysis. In addition, the physically based models contain important empirical parts and hence, the demand for universality and transferability is not given. As a common feature, we find, that all models rely on parameters and input variables, which are to certain, extend spatially and temporally averaged. A central question is whether the apparent heterogeneity of soil properties or the random nature of driving forces needs to be better considered in our modelling concepts. Traditionally, researchers have attempted to remove spatial and temporal variability through homogenization. However, homogenization has been achieved through physical manipulation of the system, or by statistical averaging procedures. The price for obtaining this homogenized (average) model concepts of soils and soil related processes has often been a failure to recognize the profound importance of heterogeneity in many of the properties and processes that we study. Especially soil infiltrability and the resistance (also called "critical shear stress" or "critical stream power") are the most important empirical factors of physically based erosion models. The erosion resistance is theoretically a substrate specific parameter, but in reality, the threshold where soil erosion begins is determined experimentally. The soil infiltrability is often calculated with empirical relationships (e.g. based on grain size distribution). Consequently, to better fit reality, this value needs to be

  7. Wind erosion of soils burned by wildfire

    Science.gov (United States)

    N. S. Wagenbrenner; M. J. Germino; B. K. Lamb; R. B. Foltz; P. R. Robichaud

    2011-01-01

    Wind erosion and aeolian transport processes are largely unstudied in the post-wildfire environment, but recent studies have shown that wind erosion can play a major role in burned landscapes. A wind erosion monitoring system was installed immediately following a wildfire in southeastern Idaho, USA to measure wind erosion from the burned area (Figure 1). This paper...

  8. Comparison of two shoreline assessment programs conducted for the Exxon Valdez oil spill

    International Nuclear Information System (INIS)

    Harner, E.J.; Gilfillan, E.S.

    1995-01-01

    Two large shoreline assessment studies conducted in 1990 in Prince William Sound, Alaska, after the Exxon Valdez oil spill used different design strategies to determine the impact of oiling on shoreline biota. One of the studies, the Coastal Habitat Injury Assessment (CHIA) conducted for the Exxon Valdez Oil Spill Council, used matched pairs of sites, normal population distributions for biota, and meta-analysis. The power of the CHIA study to detect oiling impacts depends on being able to identify and select appropriate pairs of sites for comparison. The CHIA study also increased the oiling signal by focusing on moderate to heavily oiled sites. The Shoreline Ecology Program (SEP), conducted for Exxon, used a stratified-random-sampling study design, normal and non-normal population distributions and covariates. The SEP study was able to detect oiling impacts by using a sufficient number of sites and widely spaced transects

  9. Measuring Sea Level Rise-Induced Shoreline Changes and Inundation in Real Time

    Science.gov (United States)

    Shilling, F.; Waetjen, D.; Grijalva, E.

    2016-12-01

    We describe a method to monitor shoreline inundation and changes in response to sea level rise (SLR) using a network of time-lapse cameras. We found for coastal tidal marshes that this method was sensitive to vertical changes in sea level of 20 cm has occurred in the San Francisco Bay and other US coastal areas and is likely to rise by another 30-45 cm by mid-century, which will flood and erode many coastal ecosystems, highways, and urban areas. This rapid degree of rise means that it is imperative to co-plan for natural and built systems. Many public facilities are adjacent to shoreline ecosystems, which both protect infrastructure from wave and tide energy and are home to regulated species and habitats. Accurate and timely information about the actual extent of SLR impacts to shorelines will be critical during built-system adaptation. Currently, satellite-sourced imagery cannot provide the spatial or temporal resolution necessary to investigate fine-scale shoreline changes, leaving a gap between predictive models and knowing how, where and when these changes are occurring. The method described is feasible for near-term (1 to 10 years) to long-term application and can be used for measuring fine-resolution shoreline changes (organize photographs that could be combined with related external data (e.g., gauged water levels) to create an information mashup. This information could be used to validate models predicting shoreline inundation and loss, inform SLR-adaptation planning, and to visualize SLR impacts to the public.

  10. Further ecological and shoreline stability reconnaissance surveys of Back Island, Behm Canal, Southeast Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Young, J.S.; Strand, J.A.; Ecker, R.M.

    1987-09-01

    A diver reconnaissance of the intertidal and subtidal zones of Back Island was performed to catalog potentially vulnerable shellfish, other invertebrates, and marine plant resources occurring at three proposed alternate pier sites on the west side of Back Island. Additionally, a limited survey of terrestrial vegetation was conducted in the vicinity of one of the proposed alternate pier sites to describe the littoral community and to list the dominant plant species found there. Finally, a reconnaissance survey of the shoreline of Back Island was conducted to evaluate potential changes in shoreline stability resulting from construction of onshore portions of the Southeast Alaska Acoustic Measurement Facility (SEAFAC).

  11. Simulation of shoreline development in a groyne system, with a case study Sanur Bali beach

    Science.gov (United States)

    Gunawan, P. H.; Pudjaprasetya, S. R.

    2018-03-01

    The process of shoreline changes due to transport of sediment by littoral drift is studied in this paper. Pelnard-Considère is the commonly adopted model. This model is based on the principle of sediment conservation, without diffraction. In this research, we adopt the Pelnard-Considère equation with diffraction, and a numerical scheme based on the finite volume method is implemented. Shoreline development in a groyne system is then simulated. For a case study, the Sanur Bali Beach, Indonesia is considered, in which from Google Earth photos, the beach experiences changes of coastline caused by sediment trapped in a groyne system.

  12. A field guide for the protection and treatment of shorelines following an Orimulsion spill

    International Nuclear Information System (INIS)

    Owens, E. O.; Sergy, G.

    1997-01-01

    A field guide for use in marine shoreline protection and treatment for Orimulsion was prepared. Orimulsion is a bitumen-based fuel consisting of 70 per cent bitumen and 30 per cent water, stabilized by a surfactant. The guide addresses a wide range of issues related to the protection and cleanup of Orimulsion contamination. Topics covered include the fate, behaviour, persistence and natural removal rates, recommended techniques for shoreline protection, terminology for assessment documentation, and response decision guidelines. The manual covers both forms of Orimulsion, i.e. the non-sticky dispersed bitumen, as well as the tarry residue that results from weathering. 13 refs., 8 figs

  13. Auto consolidated cohesive sediments erosion

    International Nuclear Information System (INIS)

    Ternat, F.

    2007-02-01

    Pollutants and suspended matters of a river can accumulate into the sedimentary column. Once deposited, they are submitted to self-weight consolidation processes, ageing and burying, leading to an increase of their erosion resistance. Pollutant fluxes can be related to sedimentary fluxes, determined by threshold laws. In this work, an erosion threshold model is suggested by introducing a cohesion force into the usual force balance. A model of cohesion is developed on the basis of interactions between argillaceous cohesive particles (clays), particularly the Van der Waals force, whose parameterization is ensured by means of granulometry and porosity. Artificial erosion experiments were performed in a recirculating erosion flume with natural cored sediments where critical shear stress measurements were performed. Other analyses provided granulometry and porosity. The results obtained constitute a good database for the literature. The model is then applied to the experimental conditions and gives good agreement with measurements. An example of the accounting for self-weight consolidation processes is finally suggested, before finishing on a Mohr like diagram dedicated to soft cohesive sediment erosion. (author)

  14. Rainfall erosivity and sediment load over the Poyang Lake Basin under variable climate and human activities since the 1960s

    Science.gov (United States)

    Gu, Chaojun; Mu, Xingmin; Gao, Peng; Zhao, Guangju; Sun, Wenyi; Yu, Qiang

    2018-03-01

    Accelerated soil erosion exerts adverse effects on water and soil resources. Rainfall erosivity reflects soil erosion potential driven by rainfall, which is essential for soil erosive risk assessment. This study investigated the spatiotemporal variation of rainfall erosivity and its impacts on sediment load over the largest freshwater lake basin of China (the Poyang Lake Basin, abbreviate to PYLB). The spatiotemporal variations of rainfall erosivity from 1961 to 2014 based on 57 meteorological stations were detected using the Mann-Kendall test, linear regression, and kriging interpolation method. The sequential t test analysis of regime shift (STARS) was employed to identify the abrupt changes of sediment load, and the modified double mass curve was used to assess the impacts of rainfall erosivity variability on sediment load. It was found that there was significant increase (P change-points were identified in both 1985 and 2003. It was found that take annual rainfall erosivity as the explanatory variables of the double mass curves is more reasonable than annual rainfall and erosive rainfall. The estimation via the modified double mass curve demonstrated that compared with the period before change-point (1961-1984), the changes of rainfall erosivity increased 8.0 and 2.1% of sediment load during 1985-2002 and 2003-2014, respectively. Human activities decreased 50.2 and 69.7% of sediment load during the last two periods, which indicated effects of human activities on sediment load change was much larger than that of rainfall erosivity variability in the PYLB.

  15. A model for landscape development in terms of shoreline displacement, sediment dynamics, lake formation, and lake choke-up processes

    International Nuclear Information System (INIS)

    Brydsten, Lars

    2006-12-01

    This project expands on the study 'A mathematical model for lake ontogeny in terms of filling with sediments and macrophyte vegetation' published in SKB TR-04-09. As the title suggests, this older model focuses on lakes (existing and future lakes). This newer study extends the model to examine progress of terrestrial objects such as mires or arable land. Furthermore, this newer model could simulate progress of the areas close to the objects. These areas are divided according to their watershed boundaries. If two or more objects are situated along the same brook, the lower situated area is defined as its catchments minus the catchments of the closest higher situated object. The model encourages the study of an object situated in the sea from the time of deglaciation (c. 10,000 BP) to the time for the object due to positive shore displacement is situated on land or that a lake object has progressed to a wetland, however not longer than 18,000 AP. The model focuses on the object and its location in 100-year steps. The model is written in VisualBasic and is divided into two modules, a marine module and a lake module. The marine module deals with shoreline displacement, erosion and accumulation of postglacial fine-grained sediments and erosion of glacial clay. Inputs to the marine module are a digital elevation model (DEM), a digital map showing the extension of the objects and a marine quaternary map. The two maps are in raster formats with exactly the same formats (extension and cell sizes) as the DEM. For each time step the water depths at each pixel are calculated using a shore displacement equation. Next, the water depth changes due to sediment dynamics are calculated using the following rules; accumulation of fine-grained sediments are allowed if the pixel is situated within a future lake object; erosion of fine-grained sediment is allowed if the pixel is not within a future lake object and the marine quaternary map shows occurrence of postglacial sediments and

  16. A model for landscape development in terms of shoreline displacement, sediment dynamics, lake formation, and lake choke-up processes

    Energy Technology Data Exchange (ETDEWEB)

    Brydsten, Lars [Umeaa University, Dept. of Ecology and Environmental Science (Sweden)

    2006-12-15

    This project expands on the study 'A mathematical model for lake ontogeny in terms of filling with sediments and macrophyte vegetation' published in SKB TR-04-09. As the title suggests, this older model focuses on lakes (existing and future lakes). This newer study extends the model to examine progress of terrestrial objects such as mires or arable land. Furthermore, this newer model could simulate progress of the areas close to the objects. These areas are divided according to their watershed boundaries. If two or more objects are situated along the same brook, the lower situated area is defined as its catchments minus the catchments of the closest higher situated object. The model encourages the study of an object situated in the sea from the time of deglaciation (c. 10,000 BP) to the time for the object due to positive shore displacement is situated on land or that a lake object has progressed to a wetland, however not longer than 18,000 AP. The model focuses on the object and its location in 100-year steps. The model is written in VisualBasic and is divided into two modules, a marine module and a lake module. The marine module deals with shoreline displacement, erosion and accumulation of postglacial fine-grained sediments and erosion of glacial clay. Inputs to the marine module are a digital elevation model (DEM), a digital map showing the extension of the objects and a marine quaternary map. The two maps are in raster formats with exactly the same formats (extension and cell sizes) as the DEM. For each time step the water depths at each pixel are calculated using a shore displacement equation. Next, the water depth changes due to sediment dynamics are calculated using the following rules; accumulation of fine-grained sediments are allowed if the pixel is situated within a future lake object; erosion of fine-grained sediment is allowed if the pixel is not within a future lake object and the marine quaternary map shows occurrence of postglacial

  17. Bentonite erosion. Laboratory studies

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Mats (Div. of Nuclear Chemistry, Royal Inst. of Technology, Stockholm (Sweden), School of Chemical Science and Engineering)

    2009-11-15

    This report covers the laboratory studies that have been performed at Nuclear Chemistry, KTH in the project 'Bentonite Erosion'. Many of the experiments in this report were performed to support the work of the modelling group and were often relatively simple. One of the experiment series was performed to see the impact of gravity and concentration of mono- and di-valent cations. A clay suspension was prepared in a test tube. A net was placed in contact with the suspension, the test tube was filled with solutions of different concentrations and the system was left overnight to settle. The tube was then turned upside down and the behaviour was visually observed. Either the clay suspension fell through the net or stayed on top. By using this method surprisingly sharp determinations of the Critical Coagulation (Flocculation) Concentration (CCC/CFC) could be made. The CCC/CFC of Ca2+ was for sodium montmorillonite determined to be between 1 and 2 mM. An artificial fracture was manufactured in order to simulate the real case scenario. The set-up was two Plexiglas slabs separated by 1 mm thick spacers with a bentonite container at one side of the fracture. Water was pumped with a very low flow rate perpendicular to bentonite container and the water exiting the fracture was sampled and analyzed for colloid content. The bentonite used was treated in different ways. In the first experiment a relatively montmorillonite rich clay was used while in the second bentonite where only the readily soluble minerals had been removed was used. Since Plexiglas was used it was possible to visually observe the bentonite dispersing into the fracture. After the compacted bentonite (1,000 kg/m3) had been water saturated the clay had expanded some 12 mm out into the fracture. As the experiment progressed the clay expanded more out into the fracture and seemed to fractionate in two different phases with less material in the outmost phase. A dark rim which was later analyzed to contain

  18. Bentonite erosion - Laboratory studies

    International Nuclear Information System (INIS)

    Jansson, Mats

    2010-01-01

    Document available in extended abstract form only. Bentonite clay is proposed as buffer material in the KBS-3 concept of storing spent nuclear fuel. Since the clay is plastic it will protect the canisters containing the spent fuel from movements in the rock. Furthermore, the clay will expand when taking up water, become very compact and hence limit the transport of solutes to and from the canister to only diffusion. The chemical stability of the bentonite barrier is of vital importance. If much material would be lost the barrier will lose its functions. As a side effect, lots of colloids will be released which may facilitate radionuclide transport in case of a breach in the canister. There are scenarios where during an ice age fresh melt water may penetrate down to repository depths with relatively high flow rates and not mix with older waters of high salinity. Under such conditions bentonite colloids will be more stable and there is a possibility that the bentonite buffer would start to disperse and bentonite colloids be carried away by the passing water. This work is a part of a larger project called Bentonite Erosion, initiated and supported by SKB. In this work several minor experiments have been performed in order to investigate the influence of for instance di-valent cations, gravity, etc. on the dispersion behaviour of bentonite and/or montmorillonite. A bigger experiment where the real situation was simulated using an artificial fracture was conducted. Two Plexiglas slabs were placed on top of each other, separated by plastic spacers. Bentonite was placed in a container in contact with a fracture. The bentonite was water saturated before deionized water was pumped through the fracture. The evolution of the bentonite profile in the fracture was followed visually. The eluate was collected in five different slots at the outlet side and analyzed for colloid concentration employing Photon Correlation Spectroscopy (PCS) and a Single Particle Counter (SPC). Some

  19. Using GPS-surveyed intertidal zones to determine the validity of shorelines automatically mapped by Landsat water indices

    Science.gov (United States)

    Kelly, Joshua T.; Gontz, Allen M.

    2018-03-01

    Satellite remote sensing has been used extensively in a variety of shoreline studies and validated using aerial photography. This ground truth method only represents an instantaneous depiction of the shoreline at the time of acquisition and does not take into account the spatial and temporal variability of the dynamic shoreline boundary. Landsat 8‧s Operational Land Imager sensor's capability to accurately delineate a shoreline is assessed by comparing all known Landsat water index-derived shorelines with two GPS-surveyed intertidal zones that coincide with the satellite flyover date, one of which had near-neap tide conditions. Seven indices developed for automatically classifying water pixels were evaluated for their ability to delineate shorelines. The shoreline is described here as the area above and below maximum low and high tide, otherwise known as the intertidal zone. The high-water line, or wet/dry sediment line, was chosen as the shoreline indicator to be mapped using a handheld GPS. The proportion of the Landsat-derived shorelines that fell within this zone and their alongshore profile lengths were calculated. The most frequently used water index and the predecessor to Modified Normalized Difference Water Index (MNDWI), Normalized Difference Water Index (NDWI), was found to be the least accurate by a significant margin. Other indices required calibration of their threshold value to achieve accurate results, thus diminishing their replicability success for other regions. MNDWI was determined to be the best index for automated shoreline mapping, based on its superior accuracy and repeatable, stable threshold value.

  20. Shoreline type and subsurface oil persistence in the Exon Valdez spill zone of Prince William Sound, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Page, D.S. [Bowdoin College, Brunswick, ME (United States). Dept. of Chemistry; Boehm, P.D. [Exponent Inc., Maynard, MA (United States); Neff, J.M. [Neff and Associates, Duxbury, MA (United States)

    2008-07-01

    The grounding of the Exxon Valdez in Prince William Sound (PWS), Alaska in the spring of 1989 resulted in the release of 258,000 barrels of Alaska North Slope crude oil into the marine environment. Nearly 800 km of shoreline were oiled to some degree. There was an unprecedented oil spill cleanup effort following the spill. The shoreline surveys of the spill zone were synthesized in this paper in an effort to demonstrate the relationship between shoreline type and persistence of subsurface oil (SSO) residues. Shoreline surveys of surface and SSO indicate rapid initial oil loss with a decline from about 800 linear km of PWS shoreline in 1989 to about 10 km of oiled shoreline in 1992. The period of rapid loss was attributed to natural physical process, biodegradation and cleanup activities that removed accessible spill remnants from shorelines. This was followed by a slower natural average loss rate for less accessible surface and SSO deposits of about 22 per cent per year for the period 1992-2001. This paper emphasized that shoreline type plays a key role in determining SSO persistence. The geology of PWS is complex. Many of the shorelines where SSO persists have armouring layers composed of hard, dense clasts, such as the quartzite boulders and cobblestones that can protect SSO deposits. Eighteen years after the spill, persistent SSO deposits in PWS shorelines remain protected from tidal water-washing and biodegradation by a surface boulder/cobble armour and low sediment porosity. The SSO deposits are in a physical/chemical form and location where they do not pose a health risk to intertidal biological communities and animals. The surveys continue to substantiate that remaining SSO deposits in PWS continue to degrade and go away slowly. 37 refs., 5 tabs., 7 figs.

  1. Seasonal variation and climate change impact in Rainfall Erosivity across Europe

    Science.gov (United States)

    Panagos, Panos; Borrelli, Pasquale; Meusburger, Katrin; Alewell, Christine; Ballabio, Cristiano

    2017-04-01

    Rainfall erosivity quantifies the climatic effect on water erosion and is of high importance for soil scientists, land use planners, agronomists, hydrologists and environmental scientists in general. The rainfall erosivity combines the influence of rainfall duration, magnitude, frequency and intensity. Rainfall erosivity is calculated from a series of single storm events by multiplying the total storm kinetic energy with the measured maximum 30-minute rainfall intensity. This estimation requests high temporal resolution (e.g. 30 minutes) rainfall data for sufficiently long time periods (i.e. 20 years). The European Commission's Joint Research Centr(JRC) in collaboration with national/regional meteorological services and Environmental Institutions made an extensive data collection of high resolution rainfall data in the 28 Member States of the European Union plus Switzerland to estimate rainfall erosivity in Europe. This resulted in the Rainfall Erosivity Database on the European Scale (REDES) which included 1,675 stations. The interpolation of those point erosivity values with a Gaussian Process Regression (GPR) model has resulted in the first Rainfall Erosivity map of Europe (Science of the Total Environment, 511: 801-815). In 2016, REDES extended with a monthly component, which allowed developing monthly and seasonal erosivity maps and assessing rainfall erosivity both spatially and temporally for European Union and Switzerland. The monthly erosivity maps have been used to develop composite indicators that map both intra-annual variability and concentration of erosive events (Science of the Total Environment, 579: 1298-1315). Consequently, spatio-temporal mapping of rainfall erosivity permits to identify the months and the areas with highest risk of soil loss where conservation measures should be applied in different seasons of the year. Finally, the identification of the most erosive month allows recommending certain agricultural management practices (crop

  2. Soil erosion in Slovene Istria

    Directory of Open Access Journals (Sweden)

    Matjaž Mikoš

    2009-12-01

    Full Text Available From the end of nineties of the 20th century, intense hydrologic and geomorphologic research is taking place in the Slovene Istria. As a part of this research also studies on soil erosion were undertaken in the period from 2005 to 2008. The field measurements were under taken onclosed 1m2 large erosion plots under three different land uses (on bare soils in an olive grove, on an overgrown meadow, in a forest, placed south of the Marezige village in the Rokava River basin.We show weekly measurements of surface erosion (interrill erosion for the period of 13 months (the end of March 2005 – the end of April 2006, as well as monthly and seasonal averages together with selected linear statistical correlations between soil erosion and weather parameters.From May 2005 to April 2006 the interrill erosion on bare soils in an olive grove with an inclination of 5.5° amounted to 9013 g/m2 (90 t/ha that corresponds to surface lowering rate of 8.5 mm/yr; on an overgrown meadow with an inclination of 9.4° it amounted to 168 g/m2 (1,68 t/ha that corresponds to surface lowering rate of 0.16 mm//yr; and in a forest with an inclination of 7.8° it amounted to 391 g/m2 (3,91 t/ha and in a forest with an inclination of 21.4° it amounted to 415 g/m2 (4,15 t/ha, respectively, that corresponds to surface lowering rate of 0.4 mm/yr.

  3. 18 CFR 1304.208 - Shoreline stabilization on TVA-owned residential access shoreland.

    Science.gov (United States)

    2010-04-01

    ... of gabions and riprap to stabilize eroded shorelines. (1) The riprap material must be quarry-run stone, natural stone, or other material approved by TVA. (2) Rubber tires, concrete rubble, or other... concrete, gabions, or other materials acceptable to TVA. Railroad ties, rubber tires, broken concrete...

  4. Shoreline oiling conditions in Prince William Sound following the Exxon Valdez oil spill

    International Nuclear Information System (INIS)

    Neff, J.M.; Owens, E.H.; Stoker, S.W.; McCormick, D.M.

    1995-01-01

    Following the Exxon Valdez oil spill of March 24, 1989, in Prince William Sound, Alaska, Exxon conducted comprehensive, systematic shoreline surveys in cooperation with federal and state authorities to obtain information on the distribution and magnitude of shoreline oiling and to identify natural and cultural resources requiring special protection. Similar joint surveys were performed during the springs of 1990, 1991, and 1992 on all Prince william Sound and Gulf of Alaska shorelines that were suspected of having remnants of weathered oil and that would benefit from further cleanup. In the springs of 1990, 1991, and 1992, isolated pockets of subsurface oil were found, chiefly in small scattered zones in coarse cobble/boulder sediments in the upper intertidal or supratidal zones. In 1991, about one-third of the subdivisions in Prince William Sound with surface oil also contained some subsurface oil. The areal extent of this subsurface oil declined by nearly 70% between 1991 and 1992, from about 37,000 m 2 to about 12,000 m 2 . Moreover, where subsurface oil remained in 1992, it was present in lesser amounts. Rates of oil removal were greatest on coastal sections treated early in the spring and summer of 1989. Where shoreline treatment was delayed, the subsequent rate of removal of oil from the shore by natural processes was slower. 27 refs., 10 figs., 3 tabs

  5. A chronology for glacial Lake Agassiz shorelines along Upham's namesake transect

    Science.gov (United States)

    Lepper, Kenneth; Buell, Alex W.; Fisher, Timothy G.; Lowell, Thomas V.

    2013-07-01

    Four traditionally recognized strandline complexes in the southern basin of glacial Lake Agassiz are the Herman, Norcross, Tintah and Campbell, whose names correspond to towns in west-central Minnesota that lie on a linear transect defined by the Great Northern railroad grade; the active corridor for commerce at the time when Warren Upham was mapping and naming the shorelines of Lake Agassiz (ca.1880-1895). Because shorelines represent static water planes, their extension around the lake margin establishes time-synchronous lake levels. Transitions between shoreline positions represent significant water-level fluctuations. However, geologic ages have never been obtained from sites near the namesake towns in the vicinity of the southern outlet. Here we report the first geologic ages for Lake Agassiz shorelines obtained at field sites along the namesake transect, and evaluate the emerging chronology in light of other paleoclimate records. Our current work from 11 sampling sites has yielded 16 independent ages. These results combined with a growing OSL age data set for Lake Agassiz's southern basin provide robust age constraints for the Herman, Norcross and Campbell strandlines with averages and standard deviations of 14.1 ± 0.3 ka, 13.6 ± 0.2 ka, and 10.5 ± 0.3 ka, respectively.

  6. Microbial diversity in oiled and un-oiled shoreline sediments in the Norwegian Arctic

    International Nuclear Information System (INIS)

    Grossman, M.J.; Prince, R.C.; Garrett, R.M.; Garrett, K.K.; Bare, R.E.; O'Neil, K.R.; Sowlay, M.R.; Hinton, S.M.; Lee, K.; Sergy, G.A.; Guenette, C.C.

    2000-01-01

    Field trials were conducted at an oiled shoreline on the island of Spitsbergen to examine the effect of nutrient addition on the metabolic status, potential for aromatic hydrocarbon degradation, and the phylogenetic diversity of the microbial community in oiled Arctic shoreline sediments. IF-30 intermediate fuel grade oil was applied to the shoreline which was then divided into four plots. One was left untreated and two were tilled. Four applications of fertilizer were applied over a two-month period. Phospholipid fatty acid (PLFA), gene probe and 16S microbial community analysis suggested that bioremediation stimulated the metabolic activity, increased microbial biomass and genetic potential for aromatic hydrocarbon degradation, and increased the population of hydrocarbon degradation of an oiled Arctic shoreline microbial community. The results of this study are in agreement with the results from stimulation of oil biodegradation in temperate marine environments. It was concluded that biodegradation and fertilizer addition are feasible treatment methods for oil spills in Arctic regions. 31 refs., 3 tabs., 3 figs

  7. SCAT 2000 : a new generation of forms for the description and documentation of oiled shorelines

    International Nuclear Information System (INIS)

    Owens, E.H.; Sergy, G.A.; Martin, R.D.; Tarpley, J.A.; Michel, J.; Yender, R.

    2000-01-01

    Over ten years ago, the Exxon Valdez and the Nestucca both generated major oil spills which highlighted the need to develop appropriate response procedures and documentation protocols. The Shoreline Cleanup Assessment Team approach was born. In recent years, the forms were used to describe the conditions resulting from oil spills and shoreline oiling conditions and recommendations were made for improvements and modifications. The call was heard and the staff at Environment Canada worked closely with the staff at the National Oceanic and Atmospheric Administration (NOAA) to review the forms and provide a suitable upgrade for the third generation set of forms. The authors described the improvements which included: (1) a revised standard shoreline oiling form, (2) a revised short form, (3) a tar ball form, and (4) a revised marsh/wetlands oiling form. Environment Canada also introduced (5) a tidal flat form, and (6) a revised sketch map base. It also made provisions for the use of those forms for large freshwater lakes, arctic coasts, mangroves, coral reefs, rivers, and stream environments and for winter ice or snow conditions with a few minor adjustments suggested. Only a few minor differences remained, specifically in the standard shoreline types, between the systems used by NOAA and Environment Canada since both agencies cooperated for their development. 24 refs., 3 tabs., 2 figs

  8. Palaeoenvironment and shoreline displacement on Suursaari Island, the Gulf of Finland

    Directory of Open Access Journals (Sweden)

    Atko Heinsalu

    2000-01-01

    Full Text Available The island of Suursaari in the middle of the Gulf of Finland is exceptionally high (175 m a.s.l.. Sediment profiles from one mire and three lakes were investigated using diatom and pollen analysis, radiocarbon dating and levelling of the elevations of ancient shorelines. The pollen stratigraphy of the Lounatkorkiasuo Mire sediment suggests a sedimentary record dating from the late Allerød.The development of late-glacial vegetation went through the same phases as in southern Finland, however these are probably somewhat earlier on the island of Suursaari. There are differences in the Holocene vegetation history of the higher and lower areas of the island. Lake Ruokalahenjärvi was isolated around 10 000 BP during the initial phase of the Yoldia Sea and the diatom assemblage indicates that at that time brackish-water flow had not penetrated into the Gulfof Finland. Diatoms from the isolation sediments of Lake Liivalahenjärvi and Lake Veteljärvi indicate a freshwater environment for the Yoldia Sea final phase at 9500–9600 BP. Levelling of coastal formations on Suursaari Island reveals that the Late Weichselian and early Holocene ancient shorelines are 5–15 m higher than expected from the isobase data for similar land uplift areas on the mainland.The anomalous shoreline levels on Suursaari Island may be explained byirregular land uplift. By the time of the Litorina Sea differences in shoreline altitudes had disappeared.

  9. Hurricane impact and recovery shoreline change analysis of the Chandeleur Islands, Louisiana, USA: 1855 to 2005

    Science.gov (United States)

    Fearnley, Sarah Mary; Miner, Michael D.; Kulp, Mark; Bohling, Carl; Penland, Shea

    2009-12-01

    Results from historical (1855-2005) shoreline change analysis conducted along the Chandeleur Islands, Louisiana demonstrate that tropical cyclone frequency dominates the long-term evolution of this barrier island chain. Island area decreased at a rate of -0.16 km2/year for the relatively quiescent time period up until 1996, when an increase in tropical cyclone frequency accelerated this island area reduction to a rate of -1.01 km2/year. More frequent hurricanes also affected shoreline retreat rates, which increased from -11.4 m/year between 1922 and 1996 to -41.9 m/year between 1982 and 2005. The erosional impact caused by the passage of Hurricane Katrina in 2005 was unprecedented. Between 2004 and 2005, the shoreline of the northern islands retreated -201.5 m/year, compared with an average retreat rate of -38.4 m/year between 1922 and 2004. A linear regression analysis of shoreline change predicts that, as early as 2013, the backbarrier marsh that serves to stabilize the barrier island chain will be completely destroyed if storm frequency observed during the past decade persists. If storm frequency decreases to pre-1996 recurrence intervals, the backbarrier marsh is predicted to remain until 2037. Southern portions of the barrier island chain where backbarrier marsh is now absent behave as ephemeral islands that are destroyed after storm impacts and reemerge during extended periods of calm weather, a coastal behavior that will eventually characterize the entire island chain.

  10. Shoreline resilience to individual storms and storm clusters on a meso-macrotidal barred beach

    NARCIS (Netherlands)

    Angnuureng, Donatus Bapentire; Almar, Rafael; Senechal, Nadia; Castelle, Bruno; Addo, Kwasi Appeaning; Marieu, Vincent; Ranasinghe, Roshanka

    2017-01-01

    This study investigates the impact of individual storms and storm clusters on shoreline recovery for the meso-to macrotidal, barred Biscarrosse beach in SW France, using 6 years of daily video observations. While the study area experienced 60 storms during the 6-year study period, only 36 storms

  11. Growth and decline of shoreline industry in Sydney estuary (Australia) and influence on adjacent estuarine sediments.

    Science.gov (United States)

    Birch, G F; Lean, J; Gunns, T

    2015-06-01

    Sydney estuary (Australia), like many urbanised waterways, is degraded due to an extended history of anthropogenic activity. Two major sources of contamination to this estuary are discharge by former shoreline industries and historic and contemporary catchment stormwater. The objectives of the present study were to document changes in shoreline land use from European settlement to the present day and determine the influence of this trend on the metal content of adjacent estuarine sediments. Temporal analysis of land use for seven time horizons between 1788 and 2010 showed rapid expansion of industry along much of the Sydney estuary foreshore soon after European settlement due to the benefits of easy and inexpensive access and readily available water for cooling and power. Shoreline industry attained maximum development in 1978 (32-km length) and declined rapidly to the present-day (9-km length) through redevelopment of industrial sites into medium- to high-density, high-value residential housing. Cores taken adjacent to 11 long-term industrial sites showed that past industrial practices contributed significantly to contamination of estuarine sediment. Subsurface metal concentrations were up to 35 times that of present-day surface sediment and over 100 times greater than natural background concentrations. Sedimentation rates for areas adjacent to shoreline industry were between 0.6 and 2.5 cm/year, and relaxation times were estimated at 50 to 100 years. Natural relaxation and non-disturbance of sediments may be the best management practice in most locations.

  12. Guidance For The Bioremediation Of Oil-Contaminated Wetlands, Marshes, And Marine Shorelines

    Science.gov (United States)

    Marine shorelines are important public and ecological resources that serve as a home to a variety of wildlife and provide public recreation. Marine oil spills, particularly large scale spill accidents, have posed great threats and cause extensive damage to the marine coastal env...

  13. EFFECTS OF SLOPE SHAPES ON SOIL EROSION

    Directory of Open Access Journals (Sweden)

    Hüseyin ŞENSOY, Şahin PALTA

    2009-01-01

    Full Text Available Water is one of the most important erosive forces. A great number of factors also play a role in erosion process and slope characteristic is also one of them. The steepness and length of the slope are important factors for runoff and soil erosion. Another slope factor that has an effect on erosion is the shape of the slope. Generally, different erosion and runoff characteristics exist in different slopes which can be classified as uniform, concave, convex and complex shape. In this study, the effects of slope shape on erosion are stated and emphasized by taking similar researches into consideration.

  14. Estimates of soil erosion using cesium-137 tracer models.

    Science.gov (United States)

    Saç, M M; Uğur, A; Yener, G; Ozden, B

    2008-01-01

    The soil erosion was studied by 137Cs technique in Yatagan basin in Western Turkey, where there exist intensive agricultural activities. This region is subject to serious soil loss problems and yet there is not any erosion data towards soil management and control guidelines. During the soil survey studies, the soil profiles were examined carefully to select the reference points. The soil samples were collected from the slope facets in three different study areas (Kirtas, Peynirli and Kayisalan Hills). Three different models were applied for erosion rate calculations in undisturbed and cultivated sites. The profile distribution model (PDM) was used for undisturbed soils, while proportional model (PM) and simplified mass balance model (SMBM) were used for cultivated soils. The mean annual erosion rates found using PDM in undisturbed soils were 15 t ha(-1) year(-1) at the Peynirli Hill and 27 t ha(-1) year(-1) at the Kirtas Hill. With the PM and SMBM in cultivated soils at Kayişalan, the mean annual erosion rates were obtained to be 65 and 116 t ha(-1) year(-1), respectively. The results of 137Cs technique were compared with the results of the Universal Soil Loss Equation (USLE).

  15. Increase in the rate and uniformity of coastline erosion in Arctic Alaska

    Science.gov (United States)

    Jones, Benjamin M.; Arp, C.D.; Jorgenson, M.T.; Hinkel, Kenneth M.; Schmutz, J.A.; Flint, P.L.

    2009-01-01

    Analysis of a 60 km segment of the Alaskan Beaufort Sea coast using a time-series of aerial photography revealed that mean annual erosion rates increased from 6.8 m a-1 (1955 to 1979), to 8.7 m a-1 (1979 to 2002), to 13.6 m a-1 (2002 to 2007). We also observed that spatial patterns of erosion have become more uniform across shoreline types with different degrees of ice-richness. Further, during the remainder of the 2007 ice-free season 25 m of erosion occurred locally, in the absence of a westerly storm event. Concurrent arctic changes potentially responsible for this shift in the rate and pattern of land loss include declining sea ice extent, increasing summertime sea surface temperature, rising sea-level, and increases in storm power and corresponding wave action. Taken together, these factors may be leading to a new regime of ocean-land interactions that are repositioning and reshaping the Arctic coastline. Copyright 2009 by the American Geophysical Union.

  16. Elevated temperature erosive wear of metallic materials

    International Nuclear Information System (INIS)

    Roy, Manish

    2006-01-01

    Solid particle erosion of metals and alloys at elevated temperature is governed by the nature of the interaction between erosion and oxidation, which, in turn, is determined by the thickness, pliability, morphology, adhesion characteristics and toughness of the oxide scale. The main objective of this paper is to critically review the present state of understanding of the elevated temperature erosion behaviour of metals and alloys. First of all, the erosion testing at elevated temperature is reviewed. This is followed by discussion of the essential features of elevated temperature erosion with special emphasis on microscopic observation, giving details of the erosion-oxidation (E-O) interaction mechanisms. The E-O interaction has been elaborated in the subsequent section. The E-O interaction includes E-O maps, analysis of transition criteria from one erosion mechanism to another mechanism and quantification of enhanced oxidation kinetics during erosion. Finally, the relevant areas for future studies are indicated. (topical review)

  17. Understanding Soil Erosion in Irrigated Agriculture

    OpenAIRE

    O' Schwankl, Lawrence J

    2006-01-01

    A soil's physical and chemical properties determine whether it is vulnerable to erosion, which can reduce soil quality and cause other problems besides. Learn the basics of identifying what type of erosion is affecting your land and what's causing it.

  18. 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.

  19. Large-scale assessment of soil erosion in Africa: satellites help to jointly account for dynamic rainfall and vegetation cover

    Science.gov (United States)

    Vrieling, Anton; Hoedjes, Joost C. B.; van der Velde, Marijn

    2015-04-01

    Efforts to map and monitor soil erosion need to account for the erratic nature of the soil erosion process. Soil erosion by water occurs on sloped terrain when erosive rainfall and consequent surface runoff impact soils that are not well-protected by vegetation or other soil protective measures. Both rainfall erosivity and vegetation cover are highly variable through space and time. Due to data paucity and the relative ease of spatially overlaying geographical data layers into existing models like USLE (Universal Soil Loss Equation), many studies and mapping efforts merely use average annual values for erosivity and vegetation cover as input. We first show that rainfall erosivity can be estimated from satellite precipitation data. We obtained average annual erosivity estimates from 15 yr of 3-hourly TRMM Multi-satellite Precipitation Analysis (TMPA) data (1998-2012) using intensity-erosivity relationships. Our estimates showed a positive correlation (r = 0.84) with long-term annual erosivity values of 37 stations obtained from literature. Using these TMPA erosivity retrievals, we demonstrate the large interannual variability, with maximum annual erosivity often exceeding two to three times the mean value, especially in semi-arid areas. We then calculate erosivity at a 10-daily time-step and combine this with vegetation cover development for selected locations in Africa using NDVI - normalized difference vegetation index - time series from SPOT VEGETATION. Although we do not integrate the data at this point, the joint analysis of both variables stresses the need for joint accounting for erosivity and vegetation cover for large-scale erosion assessment and monitoring.

  20. Erosion of the first wall of Tokamaks

    International Nuclear Information System (INIS)

    Guseva, M.I.; Ionova, E.S.; Martynenko, Yu.V.

    1980-01-01

    An estimate of the rate of erosion of the wall due to sputtering and blistering requires knowledge of the fluxes and energies of the particles which go from the plasma to the wall, of the sputtering coefficients S, and of the erosion coefficients S* for blistering. The overall erosion coefficient is equal to the sum of the sputtering coefficient and the erosion coefficient for blistering. Here the T-20 Tokamak is examined as an example of a large-scale Tokamak. 18 refs

  1. Mobile Laser Scanning along Dieppe coastal cliffs: reliability of the acquired point clouds applied to rockfall assessments

    Science.gov (United States)

    Michoud, Clément; Carrea, Dario; Augereau, Emmanuel; Cancouët, Romain; Costa, Stéphane; Davidson, Robert; Delacourt, Chirstophe; Derron, Marc-Henri; Jaboyedoff, Michel; Letortu, Pauline; Maquaire, Olivier

    2013-04-01

    Dieppe coastal cliffs, in Normandy, France, are mainly formed by sub-horizontal deposits of chalk and flintstone. Largely destabilized by an intense weathering and the Channel sea erosion, small and large rockfalls are regularly observed and contribute to retrogressive cliff processes. During autumn 2012, cliff and intertidal topographies have been acquired with a Terrestrial Laser Scanner (TLS) and a Mobile Laser Scanner (MLS), coupled with seafloor bathymetries realized with a multibeam echosounder (MBES). MLS is a recent development of laser scanning based on the same theoretical principles of aerial LiDAR, but using smaller, cheaper and portable devices. The MLS system, which is composed by an accurate dynamic positioning and orientation (INS) devices and a long range LiDAR, is mounted on a marine vessel; it is then possible to quickly acquire in motion georeferenced LiDAR point clouds with a resolution of about 15 cm. For example, it takes about 1 h to scan of shoreline of 2 km long. MLS is becoming a promising technique supporting erosion and rockfall assessments along the shores of lakes, fjords or seas. In this study, the MLS system used to acquire cliffs and intertidal areas of the Cap d'Ailly was composed by the INS Applanix POS-MV 320 V4 and the LiDAR Optech Ilirs LR. On the same day, three MLS scans with large overlaps (J1, J21 and J3) have been performed at ranges from 600 m at 4 knots (low tide) up to 200 m at 2.2 knots (up tide) with a calm sea at 2.5 Beaufort (small wavelets). Mean scan resolutions go from 26 cm for far scan (J1) to about 8.1 cm for close scan (J3). Moreover, one TLS point cloud on this test site has been acquired with a mean resolution of about 2.3 cm, using a Riegl LMS Z390i. In order to quantify the reliability of the methodology, comparisons between scans have been realized with the software Polyworks™, calculating shortest distances between points of one cloud and the interpolated surface of the reference point cloud. A Mat

  2. LiDAR Mapping of Earthquake Uplifted Paleo-shorelines, Southern Wairarapa Coast, North Island, New Zealand

    Science.gov (United States)

    Valenciano, J.; Angenent, J.; Marshall, J. S.; Clark, K.; Litchfield, N. J.

    2017-12-01

    The Hikurangi subduction margin along the east coast of the North Island, New Zealand accommodates oblique convergence of the Pacific Plate westward beneath the Australian plate at 45 mm/yr. Pronounced forearc uplift occurs at the southern end of the margin along the Wairarapa coast, onshore of the subducting Hikurangi plateau. Along a narrow coastal lowland, a series of uplifted Holocene marine terraces and beach ridges preserve a geologic record of prehistoric coseismic uplift events. In January 2017, we participated in the Research Experience for Undergraduates (REU) program of the NSF SHIRE Project (Subduction at Hikurangi Integrated Research Experiment). We visited multiple coastal sites for reconnaissance fieldwork to select locations for future in-depth study. For the coastline between Flat Point and Te Kaukau Point, we used airborne LiDAR data provided by Land Information New Zealand (LINZ) to create ArcGIS digital terrain models for mapping and correlating uplifted paleo-shorelines. Terrace elevations derived from the LiDAR data were calibrated through the use of Real Time Kinematic (RTK) GPS surveying at one field site (Glenburn Station). Prior field mapping and radiocarbon dating results (Berryman et al., 2001; Litchfield and Clark, 2015) were used to guide our LiDAR mapping efforts. The resultant maps show between four and seven uplifted terraces and associated beach ridges along this coastal segment. At some sites, terrace mapping and lateral correlation are impeded by discontinuous exposures and the presence of landslide debris, alluvial fan deposits, and sand dunes. Tectonic uplift along the southern Hikurangi margin is generated by a complex interaction between deep megathrust slip and shallow upper-plate faulting. Each uplifted Holocene paleo-shoreline is interpreted to represent a single coseismic uplift event. Continued mapping, surveying, and age dating may help differentiate between very large margin-wide megathrust earthquakes (M8.0-9.0+) and

  3. Soil Erosion. LC Science Tracer Bullet.

    Science.gov (United States)

    Buydos, John F., Comp.

    Soil erosion is the detachment and movement of topsoil or soil material from the upper part of the soil profile. It may occur in the form of rill, gully, sheet, or wind erosion. Agents of erosion may be water, wind, glacial ice, agricultural implements, machinery, and animals. Soil conservation measures require a thorough understanding of the…

  4. Natural and anthropogenic rates of soil erosion

    Science.gov (United States)

    Regions of land that are brought into crop production from native vegetation typically undergo a period of soil erosion instability, and long term erosion rates are greater than for natural lands as long as the land continues being used for crop production. Average rates of soil erosion under natur...

  5. Soil erosion in humid regions: a review

    Science.gov (United States)

    Daniel J. Holz; Karl W.J. Williard; Pamela J. Edwards; Jon E. Schoonover

    2015-01-01

    Soil erosion has significant implications for land productivity and surface water quality, as sediment is the leading water pollutant worldwide. Here, erosion processes are defined. The dominant factors influencing soil erosion in humid areas are reviewed, with an emphasis on the roles of precipitation, soil moisture, soil porosity, slope steepness and length,...

  6. The ecology, status, and conservation of marine and shoreline birds on the west coast of Vancouver Island

    International Nuclear Information System (INIS)

    Vermeer, K.; Butler, R.W.; Morgan, K.H.

    1992-01-01

    A symposium was held to combine various disciplines to provide a review of current knowledge about the marine biology of the west coast of Vancouver Island, with a particular emphasis on birds. Papers were presented on the physical and biological environment of the study region, the population and breeding ecology of marine and shoreline birds, the distribution of marine and shoreline birds at sea, the effects of oil pollution on the bird population, and the conservation of marine and shoreline birds. Separate abstracts have been prepared for two papers from this symposium

  7. Ancient shorelines of Gujarat, India, during the Indus civilization (Late Mid-Holocene): A study based on archaeological evidences

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.; Vora, K.H.

    or production of salt, etc. as indicators of palaeo-shorelines. As of today, these sites are located away from the present shoreline. Lothal, believed to be the oldest dockyard in the world, is located at the head of the Gulf of Khambhat, now situated about... shorelines of Gujarat, India, during the Indus civilization (Late Mid-Holocene): A study ... 16-Nov-06http://www.ias.ac.in/currsci/jul10/articles29.htm centre for acquiring and processing raw materials for manufacturing articles for export. Discovery of two...

  8. Are mangroves as tough as a seawall? Flow-vegetation interaction in a living shoreline restoration

    Science.gov (United States)

    Kibler, K. M.; Kitsikoudis, V.; Spiering, D. W.

    2017-12-01

    This study aims to assess the impact of an established living shoreline restoration on near-shore hydraulics, shoreline slope, and sediment texture and organic matter content. We collected data from three 100 m shoreline sites within an estuarine lagoon in Canaveral National Seashore: one restored; one that had been stabilized by a seawall; and one in a reference condition stabilized by mature mangrove vegetation. The living shoreline site was restored five years prior with a breakwater of oyster shell bags, emergent marsh grasses (Spartina alterniflora), and mangroves (Rhizophora mangle and Avicennia germinans). We sampled water depth and incoming velocity profiles of the full water column at 2 Hz using a 2 MHz Acoustic Doppler Current Profiler (ADCP, Nortek), stationed down-looking, approximately 10 m offshore. A 2 - 3 cm velocity profile above the bed was sampled on the shoreline at 100 Hz, using a Nortek Vectrino profiler. In restored and reference sites, the onshore probe was placed within vegetation. We surveyed vegetation upstream of the probe for species and diameter at water level. Windspeed and direction were collected 2 m above the water surface. Shorelines were surveyed in transects using GPS survey equipment. Five sediment cores were collected to 20 cm depth from both onshore and offshore of each site. Individual cores were processed for loss on ignition before being pooled by site for analysis of grain size distribution. While incoming velocity profiles were similar between sites, hydraulic conditions onshore within the vegetated sites deviated from the seawall site, which was devoid of vegetation. Offshore to onshore gradients in shear stress, mean velocity, and turbulent kinetic energy differed widely between sites, despite similar wind and tidal conditions. Sediment grain sizes were finer and contained more organic matter in the restored and reference sites than in the seawall site. Profiles of the restored and seawall sites were similar, though

  9. Sea-level rise and shoreline retreat: time to abandon the Bruun Rule

    Science.gov (United States)

    Cooper, J. Andrew G.; Pilkey, Orrin H.

    2004-11-01

    In the face of a global rise in sea level, understanding the response of the shoreline to changes in sea level is a critical scientific goal to inform policy makers and managers. A body of scientific information exists that illustrates both the complexity of the linkages between sea-level rise and shoreline response, and the comparative lack of understanding of these linkages. In spite of the lack of understanding, many appraisals have been undertaken that employ a concept known as the "Bruun Rule". This is a simple two-dimensional model of shoreline response to rising sea level. The model has seen near global application since its original formulation in 1954. The concept provided an advance in understanding of the coastal system at the time of its first publication. It has, however, been superseded by numerous subsequent findings and is now invalid. Several assumptions behind the Bruun Rule are known to be false and nowhere has the Bruun Rule been adequately proven; on the contrary several studies disprove it in the field. No universally applicable model of shoreline retreat under sea-level rise has yet been developed. Despite this, the Bruun Rule is in widespread contemporary use at a global scale both as a management tool and as a scientific concept. The persistence of this concept beyond its original assumption base is attributed to the following factors: Appeal of a simple, easy to use analytical model that is in widespread use. Difficulty of determining the relative validity of 'proofs' and 'disproofs'. Ease of application. Positive advocacy by some scientists. Application by other scientists without critical appraisal. The simple numerical expression of the model. Lack of easy alternatives. The Bruun Rule has no power for predicting shoreline behaviour under rising sea level and should be abandoned. It is a concept whose time has passed. The belief by policy makers that it offers a prediction of future shoreline position may well have stifled much

  10. [Assessment of the impacts of soil erosion on water environment based on the integration of soil erosion process and landscape pattern].

    Science.gov (United States)

    Liu, Yu; Wu, Bing-Fang; Zeng, Yuan; Zhang, Lei

    2013-09-01

    The integration of the effects of landscape pattern to the assessment of the impacts of soil erosion on eco-environmental is of practical significance in methodological prospect, being able to provide an approach for identifying water body's sediment source area, assessing the potential risks of sediment export of on-site soil erosion to the target water body, and evaluating the capacity of regional landscape pattern in preventing soil loss. In this paper, the RUSLE model was applied to simulate the on-site soil erosion rate. With the consideration of the soil retention potential of vegetation cover and topography, a quantitative assessment was conducted on the impacts of soil erosion in the water source region of the middle route for South-to-North Water Transfer Project on rivers and reservoirs by delineating landscape pattern at point (or cell) scale and sub-watershed level. At point (or grid cell) scale, the index of soil erosion impact intensity (I) was developed as an indicator of the potential risk of sediment export to the water bodies. At sub-watershed level, the landscape leakiness index (LI) was employed to indicate the sediment retention capacity of a given landscape pattern. The results revealed that integrating the information of landscape pattern and the indices of soil erosion process could spatially effectively reflect the impact intensity of in situ soil erosion on water bodies. The LI was significantly exponentially correlated to the mean sediment retention capacity of landscape and the mean vegetation coverage of watershed, and the sediment yield at sub-watershed scale was significantly correlated to the LI in an exponential regression. It could be concluded that the approach of delineating landscape pattern based on soil erosion process and the integration of the information of landscape pattern with its soil retention potential could provide a new approach for the risk evaluation of soil erosion.

  11. Modeling the fluid/soil interface erosion in the Hole Erosion Test

    Directory of Open Access Journals (Sweden)

    Kissi B.

    2012-07-01

    Full Text Available Soil erosion is a complex phenomenon which yields at its final stage to insidious fluid leakages under the hydraulic infrastructures known as piping and which are the main cause of their rupture. The Hole Erosion Test is commonly used to quantify the rate of piping erosion. In this work, The Hole Erosion Test is modelled by using Fluent software package. The aim is to predict the erosion rate of soil during the hole erosion test. The renormalization group theory – based k–ε turbulence model equations are used. This modelling makes it possible describing the effect of the clay concentration in flowing water on erosion. Unlike the usual one dimensional models, the proposed modelling shows that erosion is not uniform erosion along the hole length. In particular, the concentration of clay is found to increase noticeably the erosion rate.

  12. Erosion resistance and adhesion of composite metal/ceramic coatings produced by plasma spraying

    International Nuclear Information System (INIS)

    Ramm, D.A.J.; Hutchings, I.M.; Clyne, T.W.

    1993-01-01

    Ceramic coatings can exhibit greater erosion resistance than most metallic coatings. Such coatings are conveniently produced by thermal spraying. Unfortunately, thermally sprayed ceramic coatings often exhibit poor adhesion, partly as a consequence of the development of residual stresses during spraying and subsequent cooling. Composite coatings have been studied using aluminium/alumina deposits on steel substrates. The incorporation of ceramics within a ductile matrix has potential for sharply reducing the erosive wear at high erodent impact angles, whilst retaining the good erosion resistance of ceramics at low angles. It is shown that the proportion of metal and ceramic at the free surface can be specified so as to optimise the erosion resistance. Experiments have also been carried out on the resistance of the coatings to debonding during four-point bending of the coated substrate. Progress is being made towards the tailoring of composition profiles in graded coatings so as to optimise the combination of erosion resistance and adhesion. (orig.)

  13. Investigation of Soil Erosion and Phosphorus Transport within an Agricultural Watershed

    Science.gov (United States)

    Klik, A.; Jester, W.; Muhar, A.; Peinsitt, A.; Rampazzo, N.; Mentler, A.; Staudinger, B.; Eder, M.

    2003-04-01

    In a 40 ha agricultural used watershed in Austria, surface runoff, soil erosion and nutrient losses are measured spatially distributed with 12 small erosion plots. Crops during growing season 2002 are canola, corn, sunflower, winter wheat, winter barley, rye, sugar beets, and pasture. Canopy height and canopy cover are observed in 14-day intervals. Four times per year soil water content, shear stress and random roughness of the surface are measured in a 25 x 25 m grid (140 points). The same raster is sampled for soil texture analyses and content of different phosphorus fractions in the 0-10 cm soil depth. Spatially distributed data are used for geostatistical analysis. Along three transects hydrologic conditions of the hillslope position (top, middle, foot) are investigated by measuring soil water content and soil matrix potential. After erosive events erosion features (rills, deposition, ...) are mapped using GPS. All measured data will be used as input parameters for the Limburg Soil Erosion Model (LISEM).

  14. Use of synthetic aperture radar for recognition of Coastal Geomorphological Features, land-use assessment and shoreline changes in Bragança coast, Pará, Northern Brazil

    Directory of Open Access Journals (Sweden)

    Souza-Filho Pedro W. M.

    2003-01-01

    Full Text Available Synthetic Aperture Radar (SAR images are being used more extensively than ever before for geoscience applications in the moist tropics. In this investigation, a RADARSAT1-1 C-HH SAR image acquired in 1998 was used for coastal mapping and land-cover assessment in the Bragança area, in the northern Brazil. The airborne GEMS 1000 X-HH radar image acquired in 1972 during the RADAM Project was also used for evaluating coastal changes occurring over the last three decades. The research has confirmed the usefulness of RADARSAT-1 image for geomorphological mapping and land-cover assessment, particularly in macrotidal mangrove coasts. It was possible to map mangroves, salt marshes, chenier sand ridges, dunes, barrier-beach ridges, shallow water morphologies and different forms of land-use. Furthermore, a new method to estimate shoreline changes based on the superimposition of vectors extracted from both sources of SAR data has indicated that the shoreline has been subjected to severe coastal erosion responsible for retreat of 32 km² and accretion of 20 km², resulting in a mangrove land loss of almost 12 km². In an application perspective, orbital and airborne SAR data proved to be a fundamental source of information for both geomorphological mapping and monitoring coastal changes in moist tropical environments.

  15. Preventing erosion at pipeline crossings of watercourses

    International Nuclear Information System (INIS)

    Sawatsky, L.; Arnold, G.

    1997-01-01

    Watercourses are naturally vulnerable to erosion but the risk is particularly acute after sub-soil and armour materials have been disturbed by trenching and backfilling during construction. Various types of erosion (river scour, river bed, river channel bed and river bank ) and the progressive removal of pipeline cover resulting from erosion were discussed. Methods of estimating the risk of progressive erosion, river avulsions and beaver dam scour, and methods of mitigating erosion at pipeline crossings such as deep burial, proper siting, conventional armouring, and a combination of bank toe protection, and upper bank vegetation cover, were described

  16. The Impact of Climate Change in Rainfall Erosivity Index on Humid Mudstone Area

    Science.gov (United States)

    Yang, Ci-Jian; Lin, Jiun-Chuan

    2017-04-01

    It has been quite often pointed out in many relevant studies that climate change may result in negative impacts on soil erosion. Then, humid mudstone area is highly susceptible to climate change. Taiwan has extreme erosion in badland area, with annual precipitation over 2000 mm/y which is a considerably 3 times higher than other badland areas around the world, and with around 9-13 cm/y in denudation rate. This is the reason why the Erren River, a badland dominated basin has the highest mean sediment yield in the world, over 105 t km2 y. This study aims to know how the climate change would affect soil erosion from the source in the Erren River catchment. Firstly, the data of hourly precipitation from 1992 to 2016 are used to establish the regression between rainfall erosivity index (R, one of component for USLE) and precipitation. Secondly, using the 10 climate change models (provide form IPCC AR5) simulates the changes of monthly precipitation in different scenario from 2017 to 2216, and then over 200 years prediction R values can be use to describe the tendency of soil erosion in the future. The results show that (1) the relationship between rainfall erosion index and precipitation has high correction (>0.85) during 1992-2016. (2) From 2017 to 2216, 7 scenarios show that annual rainfall erosion index will increase over 2-18%. In contrast, the others will decrease over 7-14%. Overall, the variations of annual rainfall erosion index fall in the range of -14 to 18%, but it is important to pay attention to the variation of annual rainfall erosion index in extreme years. These fall in the range of -34 to 239%. This explains the extremity of soil erosion will occur easily in the future. Keywords: Climate Change, Mudstone, Rainfall Erosivity Index, IPCC AR5

  17. Soil Erosion Threatens Food Production

    Directory of Open Access Journals (Sweden)

    Michael Burgess

    2013-08-01

    Full Text Available Since humans worldwide obtain more than 99.7% of their food (calories from the land and less than 0.3% from the oceans and aquatic ecosystems, preserving cropland and maintaining soil fertility should be of the highest importance to human welfare. Soil erosion is one of the most serious threats facing world food production. Each year about 10 million ha of cropland are lost due to soil erosion, thus reducing the cropland available for world food production. The loss of cropland is a serious problem because the World Health Organization and the Food and Agricultural Organization report that two-thirds of the world population is malnourished. Overall, soil is being lost from agricultural areas 10 to 40 times faster than the rate of soil formation imperiling humanity’s food security.

  18. Environmental disturbance and conservation of marine and shoreline birds on the west coast of Vancouver Island

    International Nuclear Information System (INIS)

    Morgan, K.H.; Butler, R.W.; Vermeer, R.W.

    1992-01-01

    Loss of habitat and oiling of birds represent two major threats to marine and shoreline bird populations on Vancouver Island's west coast, since their effects are widespread and cumulative. Offshore tanker traffic and local inshore shipments of petroleum products expose the coast to high risks of oiling. Large numbers of birds are most at risk when concentrated in relatively small areas, such as highly productive feeding areas, at communal roosting sites, and around nesting colonies. Logging of mature and old-growth forests has led to destruction of the nesting habitat of marbled murrelets (Brachyramphus marmoratus), while industrial development of estuaries, mudflats, and spawning grounds of Pacific herring (Clupea harengus pallasi) has diminished feeding habitats for other marine and shoreline birds. Fisheries operations, human disturbance of colonies, and introduced predators, notably the raccoon (Procyon lotor) and mink (Mustela vison), have impacted upon local populations. Management actions and research needs to mitigate these threats are addressed. 40 refs

  19. On inhibition of dental erosion.

    Science.gov (United States)

    Rölla, Gunnar; Jonski, Grazyna; Saxegaard, Erik

    2013-11-01

    To examine the erosion-inhibiting effect of different concentrations of hydrofluoric acid. Thirty-six human molars were individually treated with 10 ml of 0.1 M citric acid for 30 min (Etch 1), acid was collected and stored until analysis. The teeth were randomly divided into six groups and then individually treated with 10 ml of one of six dilutions (from 0.1-1%) of hydrofluoric acid. The teeth were then again treated with citric acid (Etch 2). The individual acid samples from Etch 1 and 2 were analyzed for calcium by flame atomic absorption spectroscopy and difference in calcium loss was calculated. The highest erosion inhibiting effect was obtained in groups with the highest concentrations of hydrofluoric acid, where the pH was lowest, below pKa of 3.17, thus the hydrofluoric acids being mainly in an undissociated state. Diluted hydrofluoric acid is present in aqueous solution of SnF2 and TiF4 (which are known to inhibit dental erosion): SnF2 + 3H2O = Sn(OH)2 + 2HF + H2O and TiF4 + 5H2O = Ti(OH)4 + 4HF + H2O. It is also known that pure, diluted hydrofluoric acid can inhibit dental erosion. Teeth treated with hydrofluoric acid are covered by a layer of CaF2-like mineral. This mineral is acid resistant at pH acid resistant mineral, initiated by tooth enamel treatment with hydrofluoric acid. Hydrofluoric acid is different in having fluoride as a conjugated base, which provides this acid with unique properties.

  20. Erosive forms in rivers systems

    International Nuclear Information System (INIS)

    Una Alvarez, E. de; Vidal Romani, J. R.; Rodriguez Martinez-Conde, R.

    2009-01-01

    The purpose of this work is to analyze the geomorphological meaning of the concepts of stability/change and to study its influence on a fluvial erosion system. Different cases of fluvial potholes in Galicia (NW of the Iberian Peninsula) are considered. The work conclusions refer to the nature of the process and its morphological evolution in order to advance towards later contributions with respect of this type of systems. (Author) 14 refs.

  1. Shoreline change detection from Karwar to Gokarna - South West coast of India using remotely Sensed data

    Digital Repository Service at National Institute of Oceanography (India)

    Choudhary, R.; Gowthaman, R.; SanilKumar, V.

    -494 #02060313 Copyright ©2013 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved. Shoreline change detection from Karwar to Gokarna - South West coast of India using remotely Sensed data RICHA CHOUDHARY 1 , R. GOWTHAMAN 2 AND V. SANIL KUMAR 2 1... years period. Gangavali river mouth has narrowed due to siltation. Significant changes in the geomorphic features like spit growth, braided island, creeks, tidal flat are observed near Kali and Gangavali river mouth. Keywords: Remote sensing...

  2. Research into the further development of the LIMPET shoreline wave energy plant

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This report summarises the findings of a project focussing on technical issues associated with the design of the LIMPET shoreline oscillating water column (OWC) wave energy plant. Fifteen tasks are listed as the objectives of the project which was carried out to broaden the knowledge of the wave environment and the construction and operation of a wave energy plant. The experience gained in LIMPET instrumentation, control systems, and grid integration issues are discussed.

  3. The ichthyofauna of the shoreline zone in the longitudinal profile of the Danube River, Bulgaria

    Czech Academy of Sciences Publication Activity Database

    Polačik, Matej; Trichkova, T.; Janáč, Michal; Vassilev, M.; Jurajda, Pavel

    2008-01-01

    Roč. 60, č. 1 (2008), s. 77-88 ISSN 0324-0770 R&D Projects: GA MŠk LC522 Grant - others:National Science Fund(BG) B-1510/05 Institutional research plan: CEZ:AV0Z60930519 Keywords : Lower Danube * shoreline zone * fish community * distribution * abundance * endangered species Subject RIV: EH - Ecology, Behaviour http://www.acta-zoologica-bulgarica.eu/downloads/acta-zoologica-bulgarica/2008/60-1-077-088.pdf

  4. Morphodynamic implications for shoreline management of the western-Mediterranean sector of Egypt

    Science.gov (United States)

    Frihy, Omran E.

    2009-09-01

    Although the western-Mediterranean coast of Egypt between Sallum and Alexandria, ~550 km long, has maintained a considerable equilibrium throughout history, developers have built traditional protective structures in an effort to form sheltered recreational beaches without taking into consideration its geomorphologic characteristics, coastal processes and their harmful impact on the coastal environment and human safety. The improper practices in this environmentally valuable region have induced us to undertake an initiative to carry out a morphodynamic analysis to provide a framework for understanding the relationship between coastal morphology and the prevailing dynamic forces. Based on the degree of natural protection or wave sheltering, the study shoreline can be categorized into four distinct morphotypical stretches: (1) high-energy wave-exposed shores and the outer margins of the rocky headlands, (2) moderate to high wave-energy beaches along semi-exposed embayments and bays mostly downdrift of the rocky headlands, (3) low-wave energy at semi-exposed headland lee-sided and pocket beaches, and (4) calm wave-sheltered enclosing water basins for safe anchorages, moorings and recreation beaches. The results deducted will have practical applications for shoreline management initiatives regarding sustained sites suitable for future beachfront development such as safe swimming conditions, sport facilities, water intakes and sheltered areas for vessels. In addition, benefits realized by the understanding of the morphodynamic processes would enhance our awareness of the significance of the role of western coast morphodynamics in supporting sustainable development via shoreline management. As far as sustainability is concerned, the selection of appropriate sites would help avoiding or minimizing the formation of the hard structures needed for creating safe recreation beaches. On a national scale, results reached could provide reliable database for information that can be

  5. Hurricane impact and recovery shoreline change analysis of the Chandeleur Islands, Louisiana, USA: 1855 to 2005

    Science.gov (United States)

    Fearnley, Sarah M.; Miner, Michael; Brock, John C.

    2011-01-01

    Results from historical (1855-2005) shoreline change analysis of the Chandeleur Islands, Louisiana, demonstrate that tropical cyclone frequency dominates the long-term evolution of this barrier-island arc. The detailed results of this study were published in December 2009 as part of a special issue of Geo-Marine Letters that documents early results from the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazard Susceptibility Project.

  6. Erosion corrosion in wet steam

    International Nuclear Information System (INIS)

    Tavast, J.

    1988-03-01

    The effect of different remedies against erosion corrosion in wet steam has been studied in Barsebaeck 1. Accessible steam systems were inspected in 1984, 1985 and 1986. The effect of hydrogen peroxide injection of the transport of corrosion products in the condensate and feed water systems has also been followed through chemical analyses. The most important results of the project are: - Low alloy chromium steels with a chromium content of 1-2% have shown excellent resistance to erosion corrosion in wet steam. - A thermally sprayed coating has shown good resistance to erosion corrosion in wet steam. In a few areas with restricted accessibility minor attacks have been found. A thermally sprayed aluminium oxide coating has given poor results. - Large areas in the moisture separator/reheater and in steam extraction no. 3 have been passivated by injection of 20 ppb hydrogen peroxide to the high pressure steam. In other inspected systems no significant effect was found. Measurements of the wall thickness in steam extraction no. 3 showed a reduced rate of attack. - The injection of 20 ppb hydrogen peroxide has not resulted in any significant reduction of the iron level result is contrary to that of earlier tests. An increase to 40 ppb resulted in a slight decrease of the iron level. - None of the feared disadvantages with hydrogen peroxide injection has been observed. The chromium and cobalt levels did not increase during the injection. Neither did the lifetime of the precoat condensate filters decrease. (author)

  7. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Upper Coast of Texas: ESIL (ESI Shoreline Types - Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The ESIL data set contains lines representing the shoreline and coastal habitats of the Upper Coast of Texas, classified according to the Environmental Sensitivity...

  8. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Upper Coast of Texas: ESIP (ESI Shoreline Types - Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The ESIP data set contains polygons representing the shoreline and coastal habitats of the Upper Coast of Texas, classified according to the Environmental...

  9. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Hudson River: ESI (Environmental Sensitivity Index Shoreline Types - Lines and Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector lines and polygons representing the shoreline and coastal habitats for the Hudson River, classified according to the Environmental...

  10. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Northern California: ESI (Environmental Sensitivity Index Shoreline Types - Lines and Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector lines and polygons representing the shoreline and coastal habitats of Northern California, classified according to the Environmental...

  11. Review of erosion dynamics along the major N-S climatic gradient in Chile and perspectives

    Science.gov (United States)

    Carretier, S.; Tolorza, V.; Regard, V.; Aguilar, G.; Bermúdez, M. A.; Martinod, J.; Guyot, J.-L.; Hérail, G.; Riquelme, R.

    2018-01-01

    Chile is an elongated country, running in a north-south direction for more than 30° along a subduction zone. Its climate is progressively wetter and colder from north to south. This particular geography has been used positively by a growing number of studies to better understand the relationships between erosion processes and climate, land use, slope, tectonics, volcanism, etc. Here we review the erosion rates, factors, and dynamics over millennial to daily periods reported in the literature. In addition, 21 new catchment mean erosion rates (suspended sediment and 10Be) are provided, and previous suspended sediment-derived erosion rates are updated. A total of 485 local and catchment mean erosion rates are reported. Erosion rates vary between some of the smallest values on earth (10-5 mm/a) to moderate values ≤0.5 mm/a compared to other active ranges. This review highlights strong limitations concerning the quantification of local erosion factors because of uncertainties in sampling point location, slope and rainfall data. For the mean erosion rates E for the millennial and decennial catchments, a model of the form E ∝ S/ [1 - (S/0.6)2] Rα with α = [0.3,0.8] accounts for 40 to 70% of the erosion variance, confirming a primary role of slope S compared to precipitation rate R over this time scale. Over the long-term, this review points to the long (5 to >10 Ma) response time of rivers to surface uplift in north-central arid Chile. Over millennia, data provide evidence for the progressive contribution of extreme erosion events to millennial averages for drier climates, as well as the link between glacier erosion and glacier sliding velocity. In this period of time, a discrepancy exists between the long-term offshore sedimentological record and continental decennial or millennial erosion data, for which no single explanation appears. Still, little information is available concerning the magnitude of variation of millennial erosion rates. Over centuries, data

  12. Soil Erosion Estimation Using Remote Sensing Techniques in Wadi Yalamlam Basin, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Jarbou A. Bahrawi

    2016-01-01

    Full Text Available Soil erosion is one of the major environmental problems in terms of soil degradation in Saudi Arabia. Soil erosion leads to significant on- and off-site impacts such as significant decrease in the productive capacity of the land and sedimentation. The key aspects influencing the quantity of soil erosion mainly rely on the vegetation cover, topography, soil type, and climate. This research studies the quantification of soil erosion under different levels of data availability in Wadi Yalamlam. Remote Sensing (RS and Geographic Information Systems (GIS techniques have been implemented for the assessment of the data, applying the Revised Universal Soil Loss Equation (RUSLE for the calculation of the risk of erosion. Thirty-four soil samples were randomly selected for the calculation of the erodibility factor, based on calculating the K-factor values derived from soil property surfaces after interpolating soil sampling points. Soil erosion risk map was reclassified into five erosion risk classes and 19.3% of the Wadi Yalamlam is under very severe risk (37,740 ha. GIS and RS proved to be powerful instruments for mapping soil erosion risk, providing sufficient tools for the analytical part of this research. The mapping results certified the role of RUSLE as a decision support tool.

  13. Application of Low-Cost Fixed-Wing UAV for Inland Lakes Shoreline Investigation

    Science.gov (United States)

    Templin, Tomasz; Popielarczyk, Dariusz; Kosecki, Rafał

    2017-10-01

    One of the most important factors that influences the performance of geomorphologic parameters on urban lakes is the water level. It fluctuates periodically, causing shoreline changes. It is especially significant for typical environmental studies like bathymetric surveys, morphometric parameters calculation, sediment depth changes, thermal structure, water quality monitoring, etc. In most reservoirs, it can be obtained from digitized historical maps or plans or directly measured using the instruments such as: geodetic total station, GNSS receivers, UAV with different sensors, satellite and aerial photos, terrestrial and airborne light detection and ranging, or others. Today one of the most popular measuring platforms, increasingly applied in many applications is UAV. Unmanned aerial system can be a cheap, easy to use, on-demand technology for gathering remote sensing data. Our study presents a reliable methodology for shallow lake shoreline investigation with the use of a low-cost fixed-wing UAV system. The research was implemented on a small, eutrophic urban inland reservoir located in the northern part of Poland—Lake Suskie. The geodetic TS, and RTK/GNSS measurements, hydroacoustic soundings and experimental aerial mapping were conducted by the authors in 2012-2015. The article specifically describes the UAV system used for experimental measurements, the obtained results and the accuracy analysis. Final conclusions demonstrate that even a low-cost fixed-wing UAV can provide an excellent tool for accurately surveying a shallow lake shoreline and generate valuable geoinformation data collected definitely faster than when traditional geodetic methods are employed.

  14. A multi-indicator approach for identifying shoreline sewage pollution hotspots adjacent to coral reefs.

    Science.gov (United States)

    Abaya, Leilani M; Wiegner, Tracy N; Colbert, Steven L; Beets, James P; Carlson, Kaile'a M; Kramer, K Lindsey; Most, Rebecca; Couch, Courtney S

    2018-04-01

    Sewage pollution is contributing to the global decline of coral reefs. Identifying locations where it is entering waters near reefs is therefore a management priority. Our study documented shoreline sewage pollution hotspots in a coastal community with a fringing coral reef (Puakō, Hawai'i) using dye tracer studies, sewage indicator measurements, and a pollution scoring tool. Sewage reached shoreline waters within 9 h to 3 d. Fecal indicator bacteria concentrations were high and variable, and δ 15 N macroalgal values were indicative of sewage at many stations. Shoreline nutrient concentrations were two times higher than those in upland groundwater. Pollution hotspots were identified with a scoring tool using three sewage indicators. It confirmed known locations of sewage pollution from dye tracer studies. Our study highlights the need for a multi-indicator approach and scoring tool to identify sewage pollution hotspots. This approach will be useful for other coastal communities grappling with sewage pollution. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Radiological survey of shoreline vegetation from the Hanford Reach of the Columbia River, 1990--1992

    International Nuclear Information System (INIS)

    Antonio, E.J.; Poston, T.M.; Rickard, W.H. Jr.

    1993-09-01

    A great deal of interest exists concerning the seepage of radiologically contaminated groundwater into the Columbia River where it borders the US Department of Energy's Hanford Site (Hanford Reach). Areas of particular interest include the 100-N Area, the Old Hanford Townsite, and the 300 Area springs. While the radiological character of the seeps and springs along the Hanford Site shoreline has been studied, less attention has been given to characterizing the radionuclides that may be present in shoreline vegetation. The objective of this study was to characterize radionuclide concentrations in shoreline plants along the Hanford Reach of the Columbia River that were usable by humans for food or other purposes. Vegetation in two areas was found to have elevated levels of radionuclides. Those areas were the 100-N Area and the Old Hanford Townsite. There was also some indication of uranium accumulation in milfoil and onions collected from the 300 Area. Tritium was elevated above background in all areas; 60 Co and 9O Sr were found in highest concentrations in vegetation from the 100-N Area. Technetium-99 was found in 2 of 12 plants collected from the Old Hanford Townsite and 1 of 10 samples collected upstream from the Vernita Bridge. The concentrations of 137 Cs, 238 Pu, 239,240 Pu, and isotopes of uranium were just above background in all three areas (100-N Area, Old Hanford Townsite, and 300 Area)

  16. Lake Izabal (Guatemala) shoreline detection and inundated area estimation from ENVISAT ASAR images

    Science.gov (United States)

    Medina, C.; Gomez-Enri, J.; Alonso, J. J.; Villares, P.

    2008-10-01

    The surface extent of a lake reflects its water storage variations. This information has important hydrological and operational applications. However, there is a lack of information regarding this subject because the traditional methodologies for this purposes (ground surveys, aerial photos) requires high resources investments. Remote sensing techniques (optical/radar sensors) permit a low cost, constant and accurate monitoring of this parameter. The objective of this study was to determine the surface variations of Lake Izabal, the largest one in Guatemala. The lake is located close to the Caribbean Sea coastline. The climate in the region is predominantly cloudy and rainy, being the Synthetic Aperture Radar (SAR) the best suited sensor for this purpose. Although several studies have successfully used SAR products in detecting land-water boundaries, all of them highlighted some sensor limitations. These limitations are mainly caused by roughened water surfaces caused by strong winds which are frequent in Lake Izabal. The ESA's ASAR data products were used. From the set of 9 ASAR images used, all of them have wind-roughened ashore waters in several levels. Here, a chain of image processing steps were applied in order to extract a reliable shoreline. The shoreline detection is the key task for the surface estimation. After the shoreline extraction, the inundated area of the lake was estimated. In-situ lake level measurements were used for validation. The results showed good agreement between the inundated areas estimations and the lake level gauges.

  17. Shoreline changes in reef islands of the Central Pacific: Takapoto Atoll, Northern Tuamotu, French Polynesia

    Science.gov (United States)

    Duvat, Virginie K. E.; Pillet, Valentin

    2017-04-01

    Atoll reef islands are considered highly vulnerable to the impacts of climate change. While accelerated sea-level rise is expected to destabilize reef islands, ocean warming and acidification are considered as major threats to coral reef growth, which is of primary importance for the persistence of islands and of food supply to islanders. Using multi-date aerial imagery, shoreline and island changes between 1969 and 2013 were assessed on Takapoto Atoll, Northern Tuamotu region, in French Polynesia. Results show that over the 44-year study period, 41% of islands were stable in area while 33% expanded and 26% contracted. Island expansion was the dominant mode of change on the leeward side of the atoll. Tropical Cyclone Orama (category 3, 1983) contributed to shoreline and island change on the windward side of the atoll through the reworking of previous storm deposits and the injection of fresh sediments in the island system (with up to 62% of an island's land area being covered with fresh sediments). Human activities contributed significantly to shoreline and island change throughout the atoll through infrastructure construction, the removal of the indigenous vegetation from a number of islets and sediment mining.

  18. Coral reefs as the first line of defense: Shoreline protection in face of climate change.

    Science.gov (United States)

    Elliff, Carla I; Silva, Iracema R

    2017-06-01

    Coral reefs are responsible for a wide array of ecosystem services including shoreline protection. However, the processes involved in delivering this particular service have not been fully understood. The objective of the present review was to compile the main results in the literature regarding the study of shoreline protection delivered by coral reefs, identifying the main threats climate change imposes to the service, and discuss mitigation and recovery strategies that can and have been applied to these ecosystems. While different zones of a reef have been associated with different levels of wave energy and wave height attenuation, more information is still needed regarding the capacity of different reef morphologies to deliver shoreline protection. Moreover, the synergy between the main threats imposed by climate change to coral reefs has also not been thoroughly investigated. Recovery strategies are being tested and while there are numerous mitigation options, the challenge remains as to how to implement them and monitor their efficacy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. A Personal Digital Assistant (PDA) system for data acquisition during shoreline assessment field surveys

    International Nuclear Information System (INIS)

    Lamarche, A.; Owens, E.H.; Laflamme, A.; Laforest, S.; Clement, S.

    2004-01-01

    The Shoreline Cleanup Assessment Technique (SCAT) is a recognized method in North America to collect shoreline information and report observations on an oil spill. The long processing time required to analyze SCAT observations sometimes causes delays in oil spill response. Computerized systems have been developed to address this problem, but data entry of SCAT within such system involves much effort and is subject to potential errors. This paper described the development of a tool dedicated to the field capture of SCAT data on a Windows CE based Personal Digital Assistant (PDA). The system is compatible with both the SCAT methodology and Global Positioning System technology. A prototype of the system was tested during oil spills in Ontario and Nova Scotia. This paper described how the field data collection system was designed, developed and tested. Details of some user interfaces were provided to demonstrate how the large paper Shoreline Oiling Summary forms were made to fit on the small display screen of pocket-size devices. 8 refs., 1 tab., 12 figs

  20. Radiological survey of shoreline vegetation from the Hanford Reach of the Columbia River, 1990--1992

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, E.J.; Poston, T.M.; Rickard, W.H. Jr.

    1993-09-01

    A great deal of interest exists concerning the seepage of radiologically contaminated groundwater into the Columbia River where it borders the US Department of Energy`s Hanford Site (Hanford Reach). Areas of particular interest include the 100-N Area, the Old Hanford Townsite, and the 300 Area springs. While the radiological character of the seeps and springs along the Hanford Site shoreline has been studied, less attention has been given to characterizing the radionuclides that may be present in shoreline vegetation. The objective of this study was to characterize radionuclide concentrations in shoreline plants along the Hanford Reach of the Columbia River that were usable by humans for food or other purposes. Vegetation in two areas was found to have elevated levels of radionuclides. Those areas were the 100-N Area and the Old Hanford Townsite. There was also some indication of uranium accumulation in milfoil and onions collected from the 300 Area. Tritium was elevated above background in all areas; {sup 60}Co and {sup 9O}Sr were found in highest concentrations in vegetation from the 100-N Area. Technetium-99 was found in 2 of 12 plants collected from the Old Hanford Townsite and 1 of 10 samples collected upstream from the Vernita Bridge. The concentrations of {sup 137}Cs, {sup 238}Pu, {sup 239,240}Pu, and isotopes of uranium were just above background in all three areas (100-N Area, Old Hanford Townsite, and 300 Area).

  1. Interaction of oil and mineral fines on shorelines: review and assessment

    International Nuclear Information System (INIS)

    Owens, Edward H.; Lee, Kenneth

    2003-01-01

    The interaction of fine mineral particles with stranded oil in an aqueous medium reduces the adhesion of the oil to solid surfaces, such as sediments or bedrock. The net result is the formation of stable, micron-sized, oil droplets that disperse into the water column. In turn, the increase in surface area makes the oil more available for biodegradation. This interaction, referred to as oil-mineral aggregate (OMA) formation, can explain how oiled shorelines are cleaned naturally in the absence of wave action in very sheltered coastal environments. OMA formation also plays an important role in the efficacy of shoreline treatment techniques, such as physical mixing and sediment relocation that move oiled sediments into the zone of wave action to promote the interaction between oil and mineral fines. Successful application of these shoreline treatment options has been demonstrated at two spill events (the Tampa Bay response in Florida and the Sea Empress operation in Wales) and at a controlled oil spill experiment in the field (the 1997 Svalbard ITOSS program). Sediment relocation harnesses the hydraulic action of waves so that the processes of fine-particle interaction and physical abrasion usually occur in tandem on open coasts. There has been no evidence of significant detrimental side-effects of residual oil in pelagic or benthic environments associated with the use of these treatment options to enhance rates of dispersion and oil biodegradation

  2. Interaction of oil and mineral fines on shorelines: review and assessment

    Energy Technology Data Exchange (ETDEWEB)

    Owens, Edward H.; Lee, Kenneth

    2003-12-01

    The interaction of fine mineral particles with stranded oil in an aqueous medium reduces the adhesion of the oil to solid surfaces, such as sediments or bedrock. The net result is the formation of stable, micron-sized, oil droplets that disperse into the water column. In turn, the increase in surface area makes the oil more available for biodegradation. This interaction, referred to as oil-mineral aggregate (OMA) formation, can explain how oiled shorelines are cleaned naturally in the absence of wave action in very sheltered coastal environments. OMA formation also plays an important role in the efficacy of shoreline treatment techniques, such as physical mixing and sediment relocation that move oiled sediments into the zone of wave action to promote the interaction between oil and mineral fines. Successful application of these shoreline treatment options has been demonstrated at two spill events (the Tampa Bay response in Florida and the Sea Empress operation in Wales) and at a controlled oil spill experiment in the field (the 1997 Svalbard ITOSS program). Sediment relocation harnesses the hydraulic action of waves so that the processes of fine-particle interaction and physical abrasion usually occur in tandem on open coasts. There has been no evidence of significant detrimental side-effects of residual oil in pelagic or benthic environments associated with the use of these treatment options to enhance rates of dispersion and oil biodegradation.

  3. Tracking of the LAZIO region shoreline from orthophotos AGEA 2014 and implementation of the database layer

    Science.gov (United States)

    Biscotti, Erik; Pizzeghello, Nicola; Murri, Chiara; Colistra, Graziano; Batzu, Ilenia

    2018-05-01

    The integrated coastal zone management (ICZM) is the modern approach used in the study, management and exploitation of the coastal area in various applications whereas in this area are concentrated interests concerning the most different fields, economic, environmental, legal, scientific and social. The coast is in fact inherently unstable by nature and consequently its characterization should take into account a continuous monitoring and updating of its variations and trends. The coastal area is that portion of land emerged and submerged containing the shoreline and is subject to both continental and marine geomorphic processes. The shoreline is the clearest expression of how this sector is particularly dynamic. Proper analysis and representation of the shape and nature of the coastal area are a first step to provide reliable and comparable tools to those who study and manage it. This paper presents the results of a study aimed to the realization of an integrated approach in the extraction of the shoreline using a case study of Lazio coast as a part of the European Project "Intercoast". This work is based on national and international directives on the coastal zone, whether linked to a more terrestrial or maritime area, still within the broad definition of Hydrography provided by the International Hydrographic Organization (IHO). The spatial information extracted by direct or indirect measurements of the most dynamic coastal sector emerged and submerged (emerged coast and sea bottom) have been provided by associating with a budget of measurement uncertainties, and assessing the quality.

  4. Geographic information systems-based expert system modelling for shoreline sensitivity to oil spill disaster in Rivers State, Nigeria

    Directory of Open Access Journals (Sweden)

    Olanrewaju Lawal

    2017-07-01

    Full Text Available In the absence of adequate and appropriate actions, hazards often result in disaster. Oil spills across any environment are very hazardous; thus, oil spill contingency planning is pertinent, supported by Environmental Sensitivity Index (ESI mapping. However, a significant data gap exists across many low- and middle-income countries in aspect of environmental monitoring. This study developed a geographic information system (GIS-based expert system (ES for shoreline sensitivity to oiling. It focused on the biophysical attributes of the shoreline with Rivers State as a case study. Data on elevation, soil, relative wave exposure and satellite imageries were collated and used for the development of ES decision rules within GIS. Results show that about 70% of the shoreline are lined with swamp forest/mangroves/nympa palm, and 97% have silt and clay as dominant sediment type. From the ES, six ranks were identified; 61% of the shoreline has a rank of 9 and 19% has a rank of 3 for shoreline sensitivity. A total of 568 km out of the 728 km shoreline is highly sensitive (ranks 7–10. There is a clear indication that the study area is a complex mixture of sensitive environments to oil spill. GIS-based ES with classification rules for shoreline sensitivity represents a rapid and flexible framework for automatic ranking of shoreline sensitivity to oiling. It is expected that this approach would kick-start sensitivity index mapping which is comprehensive and openly available to support disaster risk management around the oil producing regions of the country.

  5. In-Situ Measurement of Hall Thruster Erosion Using a Fiber Optic Regression Probe

    Science.gov (United States)

    Polzin, Kurt; Korman, Valentin

    2009-01-01

    One potential life-limiting mechanism in a Hall thruster is the erosion of the ceramic material comprising the discharge channel. This is especially true for missions that require long thrusting periods and can be problematic for lifetime qualification, especially when attempting to qualify a thruster by analysis rather than a test lasting the full duration of the mission. In addition to lifetime, several analytical and numerical models include electrode erosion as a mechanism contributing to enhanced transport properties. However, there is still a great deal of dispute over the importance of erosion to transport in Hall thrusters. The capability to perform an in-situ measurement of discharge channel erosion is useful in addressing both the lifetime and transport concerns. An in-situ measurement would allow for real-time data regarding the erosion rates at different operating points, providing a quick method for empirically anchoring any analysis geared towards lifetime qualification. Erosion rate data over a thruster s operating envelope would also be useful in the modeling of the detailed physics inside the discharge chamber. There are many different sensors and techniques that have been employed to quantify discharge channel erosion in Hall thrusters. Snapshots of the wear pattern can be obtained at regular shutdown intervals using laser profilometry. Many non-intrusive techniques of varying complexity and sensitivity have been employed to detect the time-varying presence of erosion products in the thruster plume. These include the use quartz crystal microbalances, emission spectroscopy, laser induced flourescence, and cavity ring-down spectroscopy. While these techniques can provide a very accurate picture of the level of eroded material in the thruster plume, it is more difficult to use them to determine the location from which the material was eroded. Furthermore, none of the methods cited provide a true in-situ measure of erosion at the channel surface while

  6. The use of color infrared photography for wetlands mapping with special reference to shoreline and waterfowl habitat assessment

    Science.gov (United States)

    1973-01-01

    Evaluation of low altitude oblique photography obtained by hand-held cameras was useful in determining specifications of operational mission requirements for conventional smaller-scaled vertical photography. Remote sensing techniques were used to assess the rapid destruction of marsh areas at Pointe Mouillee. In an estuarian environment where shoreline features change yearly, there is a need for revision in existing area maps. A land cover inventory, mapped from aerial photography, provided essential data necessary for determining adjacent lands suitable for marshland development. To quantitatively assess the wetlands environment, a detailed inventory of vegetative communities (19 categories) was made using color infrared photography and intensive ground truth. A carefully selected and well laid-out transect was found to be a key asset to photointerpretation and to the analysis of vegetative conditions. Transect data provided the interpreter with locally representative areas of various vegetative types. This facilitated development of a photointerpretation key. Additional information on vegetative conditions in the area was also obtained by evaluating the transect data.

  7. Comparison of erosion and erosion control works in Macedonia, Serbia and Bulgaria

    Directory of Open Access Journals (Sweden)

    Ivan Blinkov

    2013-12-01

    Natural conditions in the Balkan countries contribute to the appearance of various erosion forms and the intensity of the erosion processes. Over the history of these countries, people who settled this region used the available natural resources to fill their needs (tree cutting, incorrect plugging, overgrazing, which contributed to soil erosion. Organized erosion control works in the Balkans started in the beginning of the 20th century (1905 in Bulgaria. The highest intensity of erosion control works were carried out during the period 1945 – 1990. Various erosion control works were launched. Bulgaria had a large anti-erosion afforestation, almost 1 million ha. Bulgaria's ecological river restoration approach has been in use for almost 50 years. Serbia contributed significant erosion and torrent control works on hilly agricultural areas. Specific screen barrages and afforestation on extremely dry areas are characteristic in Macedonia. A common characteristic for all countries is a high decrease in erosion control works in the last 20 years.

  8. Deepwater Horizon MC252 shoreline data from the Environmental Response Management Application (ERMA) containing shoreline exposure and data related to the shoreline exposure model, coastal wetland vegetation sites and other datasets collected between 2010-01-01 to 2015-01-01 for the DWH response in the Northern Gulf of Mexico (NCEI Accession 0163814)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Archival Information Package (AIP) contains Environmental Resource Management Application (ERMA) GIS layers including shoreline exposure model for beach and...

  9. Evaluation of rate of swelling and erosion of verapamil (VRP) sustained-release matrix tablets.

    Science.gov (United States)

    Khamanga, Sandile M; Walker, Roderick B

    2006-01-01

    Tablets manufactured in-house were compared to a marketed sustained-release product of verapamil to investigate the rate of hydration, erosion, and drug-release mechanism by measuring the wet and subsequent dry weights of the products. Swelling and erosion rates depended on the polymer and granulating fluid used, which ultimately pointed to their permeability characteristics. Erosion rate of the marketed product was highest, which suggests that the gel layer that formed around these tablets was weak as opposed to the robust and resistant layers of test products. Anomalous and near zero-order transport mechanisms were dominant in tests and commercial product, respectively.

  10. An assessment for the erosion rate of DEMO first wall

    Science.gov (United States)

    Tokar, M. Z.

    2018-01-01

    In a fusion reactor a significant fraction of plasma particles lost from the confined volume will reach the vessel wall. The recombination of these charged species, electrons and ions of hydrogen isotopes, is a source of neutral molecules and atoms, recycling back into the plasma. Here they participate, in particular, in charge-exchange (c-x) collisions with the plasma ions and, as a result, atoms of high energies with chaotically oriented velocities are generated. A significant fraction of these hot neutrals will hit the wall, leading, as well as the outflowing fuel and impurity ions, to its erosion, limiting the reactor operation time. The rate of the wall erosion in DEMO is assessed by applying a one-dimensional model which takes into account the transport of charged and neutral species across the flux surfaces in the main part of the scrape-off layer, beyond the X-point vicinity and divertor, and by considering the shift of the centers of flux surfaces, their elongation and triangularity. Atoms generated by c-x of recycling neutrals are modeled kinetically to define firmly their energy spectrum, being of particular importance for the erosion assessment. It is demonstrated the erosion rate of the DEMO wall armor of tungsten will have a pronounced ballooning character with a significant maximum of 0.3 mm per full power year at the low field side, decreasing with an increase in the anomalous perpendicular transport in the ‘far’ SOL or the plasma density at the separatrix.

  11. New approaches to the estimation of erosion-corrosion

    International Nuclear Information System (INIS)

    Bakirov, Murat; Ereemin, Alexandr; Levchuck, Vasiliy; Chubarov, Sergey

    2006-09-01

    elements behavior from point of view of erosion-corrosion effects and determination of lifetime for the equipment, operating in the conditions of increased thermal-mechanical and hydro-dynamical loads, which cause intensive erosion-corrosion wear of the metal; - creation of system for monitoring of erosion-corrosion conditions of the secondary circuit's elements of WWER power units; - optimization and effectiveness increasing of diagnostic and preventive regulations, inspection methods of erosion-corrosion state and prevention of emergency situations and unplanned shutdowns occurrence as a result of damaging of NPPs' working elements; - creation of the normative base for data collection, diagnostic and monitoring of the secondary circuit's equipment and pipelines of WWER power unit; - making recommendations to the main designer for improving the design of NPP

  12. Estimates of soil erosion and deposition of cultivated soil of Nakhla watershed, Morocco, using 137Cs technique and calibration models

    International Nuclear Information System (INIS)

    Bouhlassa, S.; Moukhchane, M.; Aiachi, A.

    2000-01-01

    Despite the effective threat of erosion, for soil preservation and productivity in Morocco, there is still only limited information on rates of soil loss involved. This study is aimed to establish long-term erosion rates on cultivated land in the Nakhla watershed located in the north of the country, using 137 Cs technique. Two sampling strategies were adopted. The first is aimed at establishing areal estimates of erosion, whereas the second, based on a transect approach, intends to determine point erosion. Twenty-one cultivated sites and seven undisturbed sites apparently not affected by erosion or deposition were sampled to 35 cm depth. Nine cores were collected along the transect of 149 m length. The assessment of erosion rates with models varying in complexity from the simple Proportional Model to more complex Mass Balance Models which attempts to include the processes controlling the redistribution of 137 Cs in soil, enables us to demonstrate the significance of soil erosion problem on cultivated land. Erosion rates rises up to 50 t ha -1 yr -1 . The 137 Cs derived erosion rates provide a reliable representation of water erosion pattern in the area, and indicate the importance of tillage process on the redistribution of 137 Cs in soil. For aggrading sites a Constant Rate Supply (CRS) Model had been adapted and introduced to estimate easily the depositional rate. (author) [fr

  13. Development of Methodology to Classify Historical Panchromatic Aerial Photography. Analysis of Landscape Features on Point Au Fer Island, Louisiana - from 1956 to 2009: A Case Study

    Science.gov (United States)

    2011-12-01

    7,386 acres). Hurricanes and other extreme extratropical storms have been shown to contribute to extensive shoreline erosion and breaching, and the...that provide protection from storms ; serve as species habitat; act as a control for nutrient and pollution transfer; support fish, agriculture...quickly and accurately classify historical panchromatic photography in order to identify storm -induced land loss and impacts (Morton et al. 2005; Barras

  14. Multifractal Model of Soil Water Erosion

    Science.gov (United States)

    Oleshko, Klaudia

    2017-04-01

    Breaking of solid surface symmetry during the interaction between the rainfall of high erosivity index and internally unstable volcanic soil/vegetation systems, results in roughness increasing as well as fertile horizon loosing. In these areas, the sustainability of management practices depends on the ability to select and implement the precise indicators of soil erodibility and vegetation capacity to protect the system against the extreme damaging precipitation events. Notwithstanding, the complex, non-linear and scaling nature of the phenomena involved in the interaction among the soil, vegetation and precipitation is still not taken into account by the numerous commonly used empirical, mathematical and computer simulation models: for instance, by the universal soil loss equation (USLE). The soil erodibility factor (K-factor) is still measuring by a set of empirical, dimensionless parameters and indexes, without taking into account the scaling (frequently multifractal) origin of a broad range of heterogeneous, anisotropic and dynamical phenomena involved in hydric erosion. Their mapping is not representative of this complex system spatial variability. In our research, we propose to use the toolbox of fractals and multifractals techniques in vista of its ability to measure the scale invariance and type/degree of soil, vegetation and precipitation symmetry breaking. The hydraulic units are chosen as the precise measure of soil/vegetation stability. These units are measured and modeled for soils with contrasting architecture, based on their porosity/permeability (Poroperm) as well as retention capacity relations. The simple Catalog of the most common Poroperm relations is proposed and the main power law relations among the elements of studied system are established and compared for some representative agricultural and natural Biogeosystems of Mexico. All resulted are related with the Mandelbrot' Baby Theorem in order to construct the universal Phase Diagram which

  15. Response of roseate tern to a shoreline protection project on Falkner Island, Connecticut

    Science.gov (United States)

    Rogers, C.J.; Spendelow, J.A.; Guilfoyle, Michael P.; Fischer, Richard A.; Pashley, David N.; Lott, Casey A.

    2007-01-01

    Construction was initiated following the 2000 tern breeding season for Phase 1 of a planned two-phase ?Shoreline Protection and Erosion Control Project? at the Falkner Island Unit of the USFWS Stewart B. McKinney National Wildlife Refuge located in Long Island Sound off the coast of Guilford, CT. When the Common Tern (Sterna hirundo) and federally endangered Roseate Tern (S. dougallii) arrived in spring 2001, they encountered several major habitat changes from what had existed in previous years. These changes included: a rock revetment covering most of the former nesting habitat on the beach from the northwestern section around the northern tip and covering about 60% of the eastern side; an elevated 60- ? 4-m shelf covering the beach and lower bank of the southwestern section; and about 2,000 sq m of devegetated areas on top of the island on the northeast side above the revetment, and about one-third of the southern half of the island. The southwest shelf was created by bulldozing and compacting extra construction fill and in situ materials. This shelf differed in internal structure from the main revetment on the north and eastern sections of the island because it lacked the deep internal crevices of the revetment. The deep internal crevices were created from the large stones and boulders (up to 2 tons) used in the construction of the main revetment. Small rock and gravel was used to fill the crevices to within 3 feet (0.9 m) of the surface of the revetment. Because half-buried tires and nest boxes for the six Roseate Tern (Sterna dougallii) sub-colony areas were deployed in similar patterns on the remaining beach, and nest boxes were placed on the newly elevated shelf areas several meters above previous locations on the now-covered beach areas, the distribution of Roseate Tern nests did not change much from 2000 to 2001. However, the movements of Roseate Tern chicks ? in many cases led by their parents towards traditional hiding places ? into the labyrinth of

  16. Influence of Intrinsic Factors on Erosive Tooth Wear in a Large-Scale Epidemiological Study.

    Science.gov (United States)

    Alaraudanjoki, Viivi; Laitala, Marja-Liisa; Tjäderhane, Leo; Pesonen, Paula; Lussi, Adrian; Ronkainen, Jukka; Anttonen, Vuokko

    2016-01-01

    To assess the influence of self-reported intrinsic factors [gastroesophageal reflux disease (GERD), long-term alcoholism, long-term heavy use of alcohol and multiple pregnancies] on erosive tooth wear in a middle-aged cohort sample. Of the total Northern Finland Birth Cohort (NFBC 1966), a convenience sample (n = 3,181) was invited for an oral health examination in 2012-2013, of which 1,962 participated, comprising the final study group. Erosive tooth wear was assessed by sextants using the Basic Erosive Wear Examination Index (BEWE, 0-18). Clinical data were supplemented by questionnaires conducted in 1997/1998 and 2012/2013. The participants were divided into severe (BEWE sum ≥9) and no-to-moderate (BEWE sum 0-8) erosive wear groups, and the logistic regression model was applied. Selected intrinsic factors were quite rare in this cohort sample and explained only 5.9% of the difference in the prevalence and severity of erosive wear. Daily symptoms of GERD [odds ratio (OR) 3.8, confidence interval (CI) 1.2-12.0] and hyposalivation (OR 3.8, CI 1.2-11.8) were the strongest risk indicators for severe erosive wear. Additionally, variables associated with an elevated risk for severe erosive wear were diagnosed alcoholism at any point (OR 2.5, CI 0.7-9.7) and self-reported heavy use of alcohol in both questionnaires (OR 2.0, CI 0.6-6.2). Even low-dose long-term consumption of alcohol was associated with erosive wear. In this cohort sample, intrinsic factors such as GERD or alcoholism alone are relatively uncommon causes of erosive tooth wear. The role of long-term use of alcohol in the erosion process may be bigger than presumed. © 2016 S. Karger AG, Basel.

  17. The influence of basal-ice debris on patterns and rates of glacial erosion

    Science.gov (United States)

    Ugelvig, Sofie V.; Egholm, David L.

    2018-05-01

    Glaciers have played a key role for shaping much of Earth's high topography during the cold periods of the Late Cenozoic. However, despite of their distinct influence on landscapes, the mechanisms of glacial erosion, and the properties that determine their rate of operation, are still poorly understood. Theoretical models of subglacial erosion generally highlight the influence of basal sliding in setting the pace of erosion, but they also point to a strong influence of other subglacial properties, such as effective bed pressure and basal-ice debris concentration. The latter properties are, however, not easily measured in existing glaciers, and hence their influence cannot readily be confirmed by observations. In order to better connect theoretical models for erosion to measurable properties in glaciers, we used computational landscape evolution experiments to study the expected influence of basal-ice debris concentration for subglacial abrasion at the scale of glaciers. The computational experiments couple the two erosion processes of quarrying and abrasion, and furthermore integrate the flow of ice and transport of debris within the ice, thus allowing for the study of dynamic feedbacks between subglacial erosion and systematic glacier-scale variations in basal-ice debris concentration. The experiments explored several physics-based models for glacial erosion, in combination with different models for basal sliding to elucidate the relationship between sliding speed, erosion rate and basal-ice debris concentration. The results demonstrate how differences in debris concentration can explain large variations in measured rates. The experiments also provide a simple explanation for the observed dependence of glacier-averaged rate of erosion on glacier size: that large glacier uplands feed more debris into their lower-elevation parts, thereby strengthening their erosive power.

  18. Cavitation erosion - scale effect and model investigations

    Science.gov (United States)

    Geiger, F.; Rutschmann, P.

    2015-12-01

    The experimental works presented in here contribute to the clarification of erosive effects of hydrodynamic cavitation. Comprehensive cavitation erosion test series were conducted for transient cloud cavitation in the shear layer of prismatic bodies. The erosion pattern and erosion rates were determined with a mineral based volume loss technique and with a metal based pit count system competitively. The results clarified the underlying scale effects and revealed a strong non-linear material dependency, which indicated significantly different damage processes for both material types. Furthermore, the size and dynamics of the cavitation clouds have been assessed by optical detection. The fluctuations of the cloud sizes showed a maximum value for those cavitation numbers related to maximum erosive aggressiveness. The finding suggests the suitability of a model approach which relates the erosion process to cavitation cloud dynamics. An enhanced experimental setup is projected to further clarify these issues.

  19. Mapping monthly rainfall erosivity in Europe

    DEFF Research Database (Denmark)

    Ballabio, C; Meusburger, K; Klik, A

    2017-01-01

    to Eastern Europe. The maps also show a clear delineation of areas with different erosivity seasonal patterns, whose spatial outline was evidenced by cluster analysis. The monthly erosivity maps can be used to develop composite indicators that map both intra-annual variability and concentration of erosive...... and seasonal R-factor maps and assess rainfall erosivity both spatially and temporally. During winter months, significant rainfall erosivity is present only in part of the Mediterranean countries. A sudden increase of erosivity occurs in major part of European Union (except Mediterranean basin, western part...... selected among various statistical models to perform the spatial interpolation due to its excellent performance, ability to model non-linearity and interpretability. The monthly prediction is an order more difficult than the annual one as it is limited by the number of covariates and, for consistency...

  20. Erosion and sedimentation caused by watercourse regulation

    International Nuclear Information System (INIS)

    Dahl, T.E.; Godtland, K.

    1995-01-01

    This report describes the observations made by SINTEF NHL in 1993 - 1994 on the development of erosion in three regulated lakes in Norway: Devdesjavri, Store Maalvatn and Gjevilvatnet. Surveys, profile levelling, water sample analyses, aerial photography etc were all used. Erosion was dramatic in all three magazines the first year of regulation and then slowed down. It has since remained relatively stable. However, there is a risk of further strong erosion connected with flooding tributaries, notably at low water such as usually occurs in spring. This is true in particular of the main river discharging into Devdesjavri, which is subject to landslides, wave and river erosion. In addition, ground water erosion may occur if the magazine is drained too fast. The report is lavishly illustrated with colour pictures of the effects of erosion. 21 refs., 15 figs., 13 tabs

  1. Varioliform erosions in the stomach and duodenum

    Energy Technology Data Exchange (ETDEWEB)

    Lotz, W.; Schulz, D.; Munkel, G.

    1984-04-01

    One thousand five hundred and eighty-three patients who were x-rayed for dyspepsia showed varioliform erosions in 15.3%. Men had an incidence of 9.8%, almost twice as common as in women (5.5%). Mucosal polyps, usually of the hyperplastic type, occurred in 2.4%. 15% of patients with gastric ulcers and 16% of patients with duodenal ulcers had varioliform erosions. On the other hand, amongst patients with erosions, 11% had gastric ulcers and 8.3% duodenal ulcers. The definitions of erosion which have been given in the literature are partly contradictory, and are discussed. Varioliform erosions, also known as complete erosions, may be acute or chronic. They are the third most common cause of bleeding from the upper gastrointestinal tract. With modern radiological methods of examining the stomach, they are no longer a rare finding. 5 figs.

  2. Varioliform erosions in the stomach and duodenum

    International Nuclear Information System (INIS)

    Lotz, W.; Schulz, D.; Munkel, G.

    1984-01-01

    One thousand five hundred and eighty-three patients who were x-rayed for dyspepsia showed varioliform erosions in 15.3%. Men had an incidence of 9.8%, almost twice as common as in women (5.5%). Mucosal polyps, usually of the hyperplastic type, occurred in 2.4%. 15% of patients with gastric ulcers and 16% of patients with duodenal ulcers had varioliform erosions. On the other hand, amongst patients with erosions, 11% had gastric ulcers and 8.3% duodenal ulcers. The definitions of erosion which have been given in the literature are partly contradictory, and are discussed. Varioliform erosions, also known as complete erosions, may be acute or chronic. They are the third most common cause of bleeding from the upper gastrointestinal tract. With modern radiological methods of examining the stomach, they are no longer a rare finding. (orig.) [de

  3. Assessment and management of dental erosion.

    Science.gov (United States)

    Wang, Xiaojie; Lussi, Adrian

    2010-07-01

    Studies have shown a growing trend toward increasing prevalence of dental erosion, associated with the declining prevalence of caries disease in industrialized countries. Erosion is an irreversible chemical process that results in tooth substance loss and leaves teeth susceptible to damage as a result of wear over the course of an individual's lifetime. Therefore, early diagnosis and adequate prevention are essential to minimize the risk of tooth erosion. Clinical appearance is the most important sign to be used to diagnose erosion. The Basic Erosive Wear Examination (BEWE) is a simple method to fulfill this task. The determination of a variety of risk and protective factors (patient-dependent and nutrition-dependent factors) as well as their interplay are necessary to initiate preventive measures tailored to the individual. When tooth loss caused by erosive wear reaches a certain level, oral rehabilitation becomes necessary. Copyright 2010 Elsevier Inc. All rights reserved.

  4. DENTAL EROSION IN PRIMARY DENTITION- A REVIEW

    Directory of Open Access Journals (Sweden)

    Rafi Shaik

    2017-06-01

    Full Text Available BACKGROUND The pattern of oral diseases has been influenced by ever changing human lifestyle. Tooth wear especially dental erosion has drawn increasing attention as risk factor for tooth damage or loss in recent years. It is a common condition in primary dentition compared to permanent dentition due to thinner and less mineralised enamel. However, it is more worrying, when this condition is being found in an alarming proportion among children. The presence of dental erosion in children is likely to be associated with a number of general health and dietary factors, but it is also aggravated by the relatively more rapid progression of erosion in the deciduous teeth. An understanding of the aetiologies and risk factors for erosion is important for early recognition of dental erosion to prevent serious irreversible damage to the dentition. This paper discusses the erosion in children with regard to its epidemiology, prevalence, clinical features, measurement and prevention.

  5. PROBLEMS OF SOIL PROTECTION FROM EROSION

    OpenAIRE

    M. Voloshuk; Natalia Kiriak

    2007-01-01

    In this article the problems of soil protection from erosion in Moldova are considered. The history (evolution) of erosive processes is generalized, the first items of information on presence washed off soils are marked. Purposeful study of soil erosion, development of measures of struggle with it were begun in Moldova at the end of 40 years. In connection with transition to new economic methods of conducting economy (farmers, rent, privatization of land) before pedologist, the experts of des...

  6. Tipping Point

    Medline Plus

    Full Text Available ... en español Blog About OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by ... danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe ...

  7. Action Plan on Base Erosion and Profit Shifting: An Indian Perspective.

    OpenAIRE

    Rao, R. Kavita; Sengupta, D.P.

    2014-01-01

    The discussion in this paper highlights some evidence to support the notion that there is base erosion in India. On the specific action points listed in the OECD's Action Plan, a perspective from India's stand point has been presented along with a brief discussion on the steps needed to prepare for complying with likely proposed measures.

  8. Erosion products in disruption simulation experiments

    International Nuclear Information System (INIS)

    Safronov, V.; Arkhipov, N.; Bakhtin, V.; Barsuk, V.; Kurkin, S.; Mironova, E.; Toporkov, D.; Vasenin, S.; Zhitlukhin, A.; Arkhipov, I.; Werle, H.; Wuerz, H.

    1998-01-01

    Erosion of divertor materials under tokamak disruption event presents a serious problem of ITER technology. Erosion restricts the divertor lifetime and leads to production of redeposited layers of the material retaining large amount of tritium, which is a major safety issue for future fusion reactor. Since ITER disruptive heat loads are not achievable in existing tokamaks, material erosion is studied in special simulation experiments. Till now the simulation experiments have focused mainly on investigation of shielding effect and measurement of erosion rate. In the present work the properties of eroded and redeposited graphite are studied under condition typical for hard ITER disruption. (author)

  9. Reduction of surface erosion in fusion reactors

    International Nuclear Information System (INIS)

    Rossing, T.D.; Das, S.K.; Kaminsky, M.

    1976-01-01

    Some of the major processes leading to surface erosion in fusion reactors are reviewed briefly, including blistering by implanted gas, sputtering by ions, atoms, and neutrons, and vaporization by local heating. Surface erosion affects the structural integrity and limits the lifetime of reactor components exposed to plasma radiation. In addition, some of the processes leading to surface erosion also cause the release of plasma contaminants. Methods proposed to reduce surface erosion have included control of surface temperature, selection of materials with a favorable microstructure, chemical and mechanical treatment of surfaces, and employment of protective surface coatings, wall liners, and divertors. The advantages and disadvantages of some of these methods are discussed

  10. Erosive lichen planus: a therapeutic challenge.

    Science.gov (United States)

    Romero, Williams; Giesen, Laura; Navajas-Galimany, Lucas; Gonzalez, Sergio

    2016-01-01

    Erosive lichen planus is an uncommon variant of lichen planus. Chronic erosions of the soles, accompanied by intense and disabling pain, are some of its most characteristic manifestations. We present the case of a woman who developed oral and plantar erosive lichen planus associated with lichen planus pigmentosus and ungueal lichen planus that were diagnosed after several years. The patient failed to respond to multiple therapies requiring longstanding medication but remained refractory. Knowledge of the treatment options for erosive lichen planus is insufficient. Further research is required to clarify their effectiveness, ideally adopting an evidence-based methodology.

  11. Robotic weld overlay coatings for erosion control

    Science.gov (United States)

    The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterfalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in CFB's.

  12. Remontant erosion in desert soils of Tamaulipas, México.

    Science.gov (United States)

    Rivera-Ortiz, P.; Andrade-Limas, E.; De la Garza-Requena, F.; Castro-Meza, B.

    2012-04-01

    REMONTANT EROSION IN DESERT SOILS OF TAMAULIPAS MÉXICO Rivera-Ortiz, P.1; Andrade-Limas, E.1; De la Garza-Requena, F.1 and Castro-Meza, B.1 1Facultad de Ingeniería y Ciencias, Universidad Autónoma de Tamaulipas, México The degradation of soil reduces the capacity of soils to produce food and sustain life. Erosion is one of the main types of soil degradation. Hydric erosion of remontant type can occur in soils located close to the channel of a river through the expansion of a gully that begins as a fluvial incision over the ravine of one side of the river. The incision takes place at the point of greatest flow of runoff from areas adjacent to empty into the river. The depth of the incision causes the growth of the gully by collapse to move their heads back, upstream. The soil loss by remontant erosion on land use in agriculture and livestock was estimated in order to understand the evolution of gullies formed by this type of erosion. Through measurements on satellite images and GPS (Global Positioning System) two gullies, developed on alluvial soils which drain into the river Chihue, were studied. The investigation was conducted during 2003 to 2010 period in the municipality of Jaumave, Tamaulipas, in northeastern Mexico. Soil loss in gullies developed by remontant erosion was large and it was caused by soil collapse and drag of soil on the headers. The estimated loss of soil by remontant erosion was 3500 t in the deeper gully during 2010 and nearly 1200 t per year in the period 2003-2009. New sections of gully of about 20 m length, with more than 3 m deep and up to 13 m wide, were formed each year. This degradation has significantly reduced the productive surface of soil that for many years has been used to the cultivation of maize (Zea mays) and beans (Phaseolus vulgaris) as well as pasture production.

  13. The influence of rill density on soil erosion against USLE-soil erosion methode

    OpenAIRE

    Rizalihadi, A.M.; Faimah, B.E.; Nazia, C.L.

    2013-01-01

    Land and water is one of the major natural resource which has an important role for human life. Exploitation of land in catchment areas that not correspond to its carrying capacity will cause damage. One of the effect is increassing the soil erosion. Continuous erosion will also lead to increased sediment transport in rivers that disrupt the ship navigation on estuary due sediment accumulation. At present, soil erosion is estimated using USLE method, which is only limited to the erosion in th...

  14. Quantifying accelerated soil erosion through ecological site-based assessments of wind and water erosion

    Science.gov (United States)

    This work explores how organising soil erosion assessments using established groupings of similar soils (ecological sites) can inform systems for managing accelerated soil erosion. We evaluated aeolian sediment transport and fluvial erosion rates for five ecological sites in southern New Mexico, USA...

  15. Farmers' identification of erosion indicators and related erosion damage in the Central Highlands of Kenya

    NARCIS (Netherlands)

    Sterk, G.; Okoba, B.O.

    2006-01-01

    Most soil and water conservation planning approaches rely on empirical assessment methods and hardly consider farmers' knowledge of soil erosion processes. Farmers' knowledge of on-site erosion indicators could be useful in assessing the site-specific erosion risk before planning any conservation

  16. Numerical Investigation of Temperature Distribution in an Eroded Bend Pipe and Prediction of Erosion Reduced Thickness

    Science.gov (United States)

    Zhu, Hongjun; Feng, Guang; Wang, Qijun

    2014-01-01

    Accurate prediction of erosion thickness is essential for pipe engineering. The objective of the present paper is to study the temperature distribution in an eroded bend pipe and find a new method to predict the erosion reduced thickness. Computational fluid dynamic (CFD) simulations with FLUENT software are carried out to investigate the temperature field. And effects of oil inlet rate, oil inlet temperature, and erosion reduced thickness are examined. The presence of erosion pit brings about the obvious fluctuation of temperature drop along the extrados of bend. And the minimum temperature drop presents at the most severe erosion point. Small inlet temperature or large inlet velocity can lead to small temperature drop, while shallow erosion pit causes great temperature drop. The dimensionless minimum temperature drop is analyzed and the fitting formula is obtained. Using the formula we can calculate the erosion reduced thickness, which is only needed to monitor the outer surface temperature of bend pipe. This new method can provide useful guidance for pipeline monitoring and replacement. PMID:24719576

  17. The Monsoon Erosion Pump and the Indian Monsoon since Eocene

    Science.gov (United States)

    Giosan, L.

    2017-12-01

    Lack of consensus on the Neogene establishment and evolution of the Indian Monsoon is remarkable after half a century of research. Conflicting interpretations point toward the possibility of periodic decoupling between monsoon winds and monsoon precipitation. Here I introduce the concept of a monsoon erosion pump based on terrestrial and oceanic records reconstructed from recent NGHP and IODP drilling and spanning the last 34 million years in the Bay of Bengal, Arabian and Andaman Seas. From millennial to orbital to tectonic timescales, these records suggest that vegetation land cover interacts and modulates the regime of erosion and weathering under perennial but variable monsoonal rain conditions. Under this new proposed paradigm the Indian monsoon exhibits two distinct flavours during the Neogene that can be largely explained by its heartbeat, or astronomical forcing, mediated by the global glacial state and interacting with the paleogeography of South Asia.

  18. Sheen surveillance: An environmental monitoring program subsequent to the 1989 Exxon Valdez shoreline cleanup

    International Nuclear Information System (INIS)

    Taft, D.G.; Egging, D.E.; Kuhn, H.A.

    1995-01-01

    In the fall of 1989, an aerial surveillance program was implemented to locate oil sheens (or slicks) originating from shorelines affected by the Exxon Valdez spill. The objectives of the program were to identify any oil on the water that warranted response and to identify those sections of shoreline that would be priority candidates for further cleanup in 1990. The program initially surveyed the entire affected area, but, because proportionally fewer sheens were spotted in the Gulf of Alaska, the program was refocused on Prince Williams Sound in early 1990. The surveillance program consisted of frequent low-altitude flights with trained observers in a deHavilland Twin otter outfitted with observation ports and communication equipment. The primary surveillance technique used was direct visual observation. Other techniques, including photography, were tested but proved less effective. The flights targeted all shorelines of concern, particularly those near fishing, subsistence, and recreational areas.the observers attempted to locate all sheens, estimate their size and color, ad identify the source of the oil found in the sheen. Size and color were used to estimate the volume of oil in each sheen. Samples were collected whenever possible during the summer of 1990 using a floating Teflon trademark sampling device that was developed for easy deployment from a boat or the pontoon of a float plane. Forty four samples were analyzed by UV-fluorescence spectroscopy. Eleven of these samples were also analyzed by GC/MS. In general, the analyses confirmed the observers' judgment of source. 16 refs., 9 figs., 2 tabs

  19. Recent Niger Delta shoreline response to Niger River hydrology: Conflict between forces of Nature and Humans

    Science.gov (United States)

    Dada, Olusegun A.; Li, Guangxue; Qiao, Lulu; Asiwaju-Bello, Yinusa Ayodele; Anifowose, Adeleye Yekini Biodun

    2018-03-01

    The Niger River Delta is a prolific hydrocarbon province and a mega-delta of economic and environmental relevance. To understand patterns of its recent shoreline evolution (1923-2013) in response to the Niger River hydrology, and establish the role played by forces of Nature and Human, available topographic and satellite remote sensing data, combined with hydro-climatic (rainfall and runoff) data were analyzed. Results indicate that the entire delta coastline dramatically receded: 82% of the >400 km-long coast retreated, during the period 1950-1987; and 69% between 2007 and 2012. Prior to 1950, there was a continuation of seaward advancement along 53-74% of the delta coast. The 1950-1987 shoreline recession coincided with occurrences of two major events in the Niger River basin; these are downward trends in hydro-climatic conditions (the great droughts of the 1970s-1980s), and dam construction on the Lower Niger River at Kainji (1964-1968). The 2007-2012 event corresponded with the extensive channel dredging during 2009-2012 in the Lower Niger River from the coastal town of Warri in the south to Baro in the north. Remarkably, the largest net shoreline advancement recorded in 74% of the entire delta area occurred within a year (2012-2013), which we link to increased sediment supply to the coast caused by the '2012' floods, adjudged the worst floods in the entire Niger River Basin in the last few decades. With both anthropogenic and environmental factors inducing delta evolution, only innovative river and coastal management can determine the fortune of the future coastal development of the Niger Delta.

  20. Investigation of groundwater seepage from the Hanford shoreline of the Columbia River

    International Nuclear Information System (INIS)

    McCormack, W.D.; Carlile, J.M.V.

    1984-11-01

    Groundwater discharges to the Columbia River are evaluated by the Hanford Environmental Surveillance and Groundwater Surveillance Programs via monitoring of the Columbia River and Hanford groundwater. Both programs concluded that Hanford groundwater has not adversely affected Columbia River water quality. This report supplements the above programs by investigating the general characteristics of groundwater entering the Columbia River from the Hanford Site. Specific objectives of the investigation were to identify general shoreline areas where Hanford-related materials were entering the river, and to evaluate qualitatively the physical characteristics and relative magnitudes of those discharges. The study was conducted in two phases. Phase 1 involved visual inspection of Columbia River shoreline, within the Hanford Site, for indications of groundwater seepage. As a result of that inspection, 115 springs suspected of discharging groundwater were recorded. During Phase 2, water samples were collected from these springs and analyzed for Hanford-related materials known to be present in the groundwater. The specific materials used as indicators for the majority of samples were tritium or uranium and nitrate. The magnitude and distribution of concentrations measured in the spring samples were consistent with concentrations of these materials measured in groundwater near the sampled spring locations. Water samples were also collected from the Columbia River to investigate the localized effects of groundwater discharges occurring above and below river level. These samples were collected within 2 to 4 m of the Hanford shoreline and analyzed for tritium, nitrate, and uranium. Elevated concentrations were measured in river samples collected near areas where groundwater and spring concentrations were elevated. All concentrations were below applicable DOE Concentration Guides. 8 references, 6 figures, 7 tables

  1. Drivers of shoreline change in atoll reef islands of the Tuamotu Archipelago, French Polynesia

    Science.gov (United States)

    Duvat, Virginie K. E.; Salvat, Bernard; Salmon, Camille

    2017-11-01

    This paper increases by around 30% the sample of atoll reef islands studied from a shoreline change perspective, and covers an under-studied geographical area, i.e. the French Tuamotu Archipelago. It brings new irrefutable evidences on the persistence of reef islands over the last decades, as 77% of the 111 study islands exhibited areal stability while 15% and 8% showed expansion and contraction, respectively. This paper also addresses a key research gap by interpreting the major local drivers controlling recent shoreline and island change, i.e. tropical cyclones and seasonal swells, sediment supply by coral reefs and human activities. The 1983 tropical cyclones had contrasting impacts, depending on the shoreline indicator considered. While they generally caused a marked retreat of the stability line, the base of the beach advanced at some locations, as a result of either sediment reworking or fresh sediment inputs. The post-cyclone fair weather period was characterised by reversed trends indicating island morphological readjustment. Cyclonic waves contributed to island upwards growth, which reached up to 1 m in places, through the transfer of sediments up onto the island surface. However, the steep outer slopes of atolls limited sediment transfers to the reef flat and island system. We found that 57% of the study islands are disturbed by human activities, including 'rural' and uninhabited islands. Twenty-six percent of these islands have lost the capacity to respond to ocean-climate related pressures, including the 'capital' islands concentrating atolls' population, infrastructures and economic activities, which is preoccupying under climate change.

  2. Monthly Rainfall Erosivity Assessment for Switzerland

    Science.gov (United States)

    Schmidt, Simon; Meusburger, Katrin; Alewell, Christine

    2016-04-01

    Water erosion is crucially controlled by rainfall erosivity, which is quantified out of the kinetic energy of raindrop impact and associated surface runoff. Rainfall erosivity is often expressed as the R-factor in soil erosion risk models like the Universal Soil Loss Equation (USLE) and its revised version (RUSLE). Just like precipitation, the rainfall erosivity of Switzerland has a characteristic seasonal dynamic throughout the year. This inter-annual variability is to be assessed by a monthly and seasonal modelling approach. We used a network of 86 precipitation gauging stations with a 10-minute temporal resolution to calculate long-term average monthly R-factors. Stepwise regression and Monte Carlo Cross Validation (MCCV) was used to select spatial covariates to explain the spatial pattern of R-factor for each month across Switzerland. The regionalized monthly R-factor is mapped by its individual regression equation and the ordinary kriging interpolation of its residuals (Regression-Kriging). As covariates, a variety of precipitation indicator data has been included like snow height, a combination of hourly gauging measurements and radar observations (CombiPrecip), mean monthly alpine precipitation (EURO4M-APGD) and monthly precipitation sums (Rhires). Topographic parameters were also significant explanatory variables for single months. The comparison of all 12 monthly rainfall erosivity maps showed seasonality with highest rainfall erosivity in summer (June, July, and August) and lowest rainfall erosivity in winter months. Besides the inter-annual temporal regime, a seasonal spatial variability was detectable. Spatial maps of monthly rainfall erosivity are presented for the first time for Switzerland. The assessment of the spatial and temporal dynamic behaviour of the R-factor is valuable for the identification of more susceptible seasons and regions as well as for the application of selective erosion control measures. A combination with monthly vegetation

  3. Bioremediation of oil on shoreline environments: development of techniques and guidelines

    International Nuclear Information System (INIS)

    Lee, K.; Merlin, F.X.

    1999-01-01

    Over the last 20 years, the development of operational procedures to accelerate the natural biodegradation rates of oil spilled on shoreline environments has been the focus of numerous research programs. As a result, bioremediation has been demonstrated to be an effective oil spill countermeasure for use in cobble, sand beach, salt marsh, and mudflat environments. Today, studies are directed towards improving the efficacy and evaluating the ecological impacts of available bioremediation agents and/or procedures. This review describes the latest developments in bioremediation strategies and their key success factors. (author)

  4. Observations and modelling of shoreline and multiple sandbar behaviour on a high-energy meso-tidal beach

    Science.gov (United States)

    Splinter, Kristen D.; Gonzalez, Maria V. G.; Oltman-Shay, Joan; Rutten, Jantien; Holman, Robert

    2018-05-01

    This contribution describes 10 years of observed sandbar and shoreline cross-shore position variability at a meso-tidal, high energy, multiple sandbar beach. To examine relationships between the temporal variability in shoreline/sandbar position with offshore wave forcing, a simple equilibrium model is applied to these data. The analysis presented in this paper shows that the equilibrium model is skilled at predicting the alongshore-averaged, time-varying position of the shoreline (R = 0.82) and the outer sandbar position (R = 0.75), suggesting that these end members of the nearshore sediment system are most strongly influenced by offshore wave forcing in a predictable, equilibrium-forced manner. The middle and inner bars are hypothesized to act as sediment transport pathways between the shoreline and the outer bar. Prediction of these more transient features by an equilibrium model was less skilful. Model coefficients reveal that these two end members (outer bar and shoreline) in the sediment system act in opposite directions to changes in the annual offshore wave forcing. During high wave events, sediment is removed from the shoreline and deposited in the nearshore sediment system with simultaneous landward retreat of the shoreline and offshore migration of the outer sandbar. While both end member features have cycles at annual and inter-annual scales, their respective equilibrium response factor differs by almost a factor of 10, with the shoreline responding around an inter-annual mean (ϕ = 1000 days) and the outer bar responding around a seasonal mean (ϕ = 170 days). The model accurately predicts shoreline response to both mild (e.g. 2004/05, 2008/09) and extreme (e.g. 2005/06, 2009/10) winter storms, as well as their summer recovery. The more mobile and dynamic outer sandbar is well-modelled during typical winters. Summer onshore sandbar migration of the outer bar in 2005 and 2006 is under-predicted as the system transitioned between a triple (winter) and

  5. Simulation of the landfall of the Deepwater Horizon oil on the shorelines of the Gulf of Mexico.

    Science.gov (United States)

    Boufadel, Michel C; Abdollahi-Nasab, Ali; Geng, Xiaolong; Galt, Jerry; Torlapati, Jagadish

    2014-08-19

    We conducted simulations of oil transport from the footprint of the Macondo Well on the water surface throughout the Gulf of Mexico, including deposition on the shorelines. We used the U.S. National Oceanic Atmospheric Administration (NOAA) model General NOAA Operational Modeling Environment (GNOME) and the same parameter values and input adopted by NOAA following the Deepwater Horizon (DWH) blowout. We found that the disappearance rate of oil off the water surface was most likely around 20% per day based on satellite-based observations of the disappearance rate of oil detected on the sea surface after the DWH wellhead was capped. The simulations and oil mass estimates suggest that the mass of oil that reached the shorelines was between 10,000 and 30,000 tons, with an expected value of 22,000 tons. More than 90% of the oil deposition occurred on the Louisiana shorelines, and it occurred in two batches. Simulations revealed that capping the well after 2 weeks would have resulted in only 30% of the total oil depositing on the shorelines, while capping after 3 weeks would have resulted in 60% deposition. Additional delay in capping after 3 weeks would have averted little additional shoreline oiling over the ensuing 4 weeks.

  6. Application of the AMBUR R package for spatio-temporal analysis of shoreline change: Jekyll Island, Georgia, USA

    Science.gov (United States)

    Jackson, Chester W.; Alexander, Clark R.; Bush, David M.

    2012-04-01

    The AMBUR (Analyzing Moving Boundaries Using R) package for the R software environment provides a collection of functions for assisting with analyzing and visualizing historical shoreline change. The package allows import and export of geospatial data in ESRI shapefile format, which is compatible with most commercial and open-source GIS software. The "baseline and transect" method is the primary technique used to quantify distances and rates of shoreline movement, and to detect classification changes across time. Along with the traditional "perpendicular" transect method, two new transect methods, "near" and "filtered," assist with quantifying changes along curved shorelines that are problematic for perpendicular transect methods. Output from the analyses includes data tables, graphics, and geospatial data, which are useful in rapidly assessing trends and potential errors in the dataset. A forecasting function also allows the user to estimate the future location of the shoreline and store the results in a shapefile. Other utilities and tools provided in the package assist with preparing and manipulating geospatial data, error checking, and generating supporting graphics and shapefiles. The package can be customized to perform additional statistical, graphical, and geospatial functions, and, it is capable of analyzing the movement of any boundary (e.g., shorelines, glacier terminus, fire edge, and marine and terrestrial ecozones).

  7. Integration of fluvial erosion factors for predicting landslides along meandering rivers

    Science.gov (United States)

    Chen, Yi-chin; Chang, Kang-tsung; Ho, Jui-yi

    2015-04-01

    River incision and lateral erosion are important geomorphologic processes in mountainous areas of Taiwan. During a typhoon or storm event, the increase of water discharge, flow velocity, and sediment discharge enhances the power of river erosion on channel bank. After the materials on toe of hillslope were removed by river erosion, landslides were triggered at outer meander bends. Although it has been long expected that river erosion can trigger landslide, studies quantifying the effects of river erosion on landslide and the application of river erosion index in landslide prediction are still overlooked. In this study, we investigated the effect of river erosion on landslide in a particular meanders landscape of the Jhoukou River, southern Taiwan. We developed a semi-automatic model to separate meandering lines into several reach segments based on the inflection points and to calculate river erosion indexes, e.g. sinuosity of meander, stream power, and stream order, for each reach segment. This model, then, built the spatial relationship between the reaches and its corresponding hillslopes, of which the toe was eroded by the reach. Based on the spatial relationship, we quantified the correlations between these indexes and landslides triggered by Typhoon Morakot in 2009 to examine the effects of river erosion on landslide. The correlated indexes were then used as landslide predictors in logistic regression model. Results of the study showed that there is no significant correlation between landslide density and meander sinuosity. This may be a result of wider channel dispersing the erosion at a meandering reach. On the other hand, landslide density at concave bank is significantly higher than that at convex bank in the downstream (stream order > 3), but that is almost the same in the upstream (stream order bank. In contrast, river sediment in the downstream is an erosion agent eroding the concave bank laterally, but also depositing on the concave side and protecting

  8. Charge-exchange wall physical erosion rates for a proposed INTOR/FED limiter

    International Nuclear Information System (INIS)

    Heifetz, D.; Schmidt, J.; Ulrickson, M.; Post, D.

    1983-01-01

    We have analyzed power deposition and physical erosion rates on the first wall and limiter due to charge-exchange neutrals in a proposed pump limiter design for the INTOR/FED tokamak. Plasma conditions were modeled using the one-dimensional plasma transport code baldur. Neutral transport was modeled using a two-dimensional, multispecies Monte Carlo algorithm. No chemical erosion or wall redeposition processes were included. Two possible plasma discharges with different edge densities and temperatures were modeled, a regime with T/sub e/ approx.300 eV and napprox.5 x 10 12 cm - 3 , and a hotter, less dense edge regime produced with pellet fueling. We found that the erosion of the stainless steel vacuum vessel wall was highly localized in each case to the two points just beyond the limiter tips, and to the point directly across from the neutralizer plate, with peak erosion rates approx.2 cm/yr, assuming a 40% duty cycle. The erosion of a carbon limiter, neglecting redeposition and chemical erosion, varied in the two cases from 1.6--4 cm/yr, for the same duty cycle. The hotter, less dense discharge produced less sputtering. However achieving truly tolerable physical sputtering rates may require a very low edge temperature, plasma

  9. Rainfall erosivity in Brazil: A Review

    Science.gov (United States)

    In this paper, we review the erosivity studies conducted in Brazil to verify the quality and representativeness of the results generated and to provide a greater understanding of the rainfall erosivity (R-factor) in Brazil. We searched the ISI Web of Science, Scopus, SciELO, and Google Scholar datab...

  10. Interrill soil erosion processes on steep slopes

    Science.gov (United States)

    To date interrill erosion processes and regimes are not fully understood. The objectives are to 1) identify the erosion regimes and limiting processes between detachment and transport on steep slopes, 2) characterize the interactive effects between rainfall intensity and flow depth on sediment trans...

  11. Soil erosion dynamics response to landscape pattern

    NARCIS (Netherlands)

    Ouyang, W.; Skidmore, A.K.; Hao, F.; Wang, T.

    2010-01-01

    Simulating soil erosion variation with a temporal land use database reveals long-term fluctuations in landscape patterns, as well as priority needs for soil erosion conservation. The application of a multi-year land use database in support of a Soil Water Assessment Tool (SWAT) led to an accurate

  12. Wind erosion modelling in a Sahelian environment

    NARCIS (Netherlands)

    Faye-Visser, S.M.; Sterk, G.; Karssenberg, D.

    2005-01-01

    In the Sahel field observations of wind-blown mass transport often show considerable spatial variation related to the spatial variation of the wind erosion controlling parameters, e.g. soil crust and vegetation cover. A model, used to predict spatial variation in wind erosion and deposition is a

  13. Reduction of soil erosion on forest roads

    Science.gov (United States)

    Edward R. Burroughs; John G. King

    1989-01-01

    Presents the expected reduction in surface erosion from selected treatments applied to forest road traveledways, cutslopes, fillslopes, and ditches. Estimated erosion reduction is expressed as functions of ground cover, slope gradient, and soil properties whenever possible. A procedure is provided to select rock riprap size for protection of the road ditch.

  14. Forest road erosion control using multiobjective optimization

    Science.gov (United States)

    Matthew Thompson; John Sessions; Kevin Boston; Arne Skaugset; David Tomberlin

    2010-01-01

    Forest roads are associated with accelerated erosion and can be a major source of sediment delivery to streams, which can degrade aquatic habitat. Controlling road-related erosion therefore remains an important issue for forest stewardship. Managers are faced with the task to develop efficient road management strategies to achieve conflicting environmental and economic...

  15. Past, Present, Future Erosion at Locke Island

    Energy Technology Data Exchange (ETDEWEB)

    Bjornstad, Bruce N.

    2006-08-08

    This report describes and documents the erosion that has occurred along the northeast side of Locke Island over the last 10 to 20 years. The principal cause of this erosion is the massive Locke Island landslide complex opposite the Columbia River along the White Bluffs, which constricts the flow of the river and deflects the river's thalweg southward against the island.

  16. Tools for Ephemeral Gully Erosion Process Research

    Science.gov (United States)

    Techniques to quantify ephemeral gully erosion have been identified by USDA Natural Resources Conservation Service (NRCS) as one of gaps in current erosion assessment tools. One reason that may have contributed to this technology gap is the difficulty to quantify changes in channel geometry to asses...

  17. Developing empirical relationship between interrill erosion, rainfall ...

    African Journals Online (AJOL)

    In order to develop an empirical relationship for interrill erosion based on rainfall intensity, slope steepness and soil types, an interrill erosion experiment was conducted using laboratory rainfall simulator on three soil types (Vertisols, Cambisols and Leptosols) for the highlands of North Shewa Zone of Oromia Region.

  18. Rethinking erosion on Java: a reaction

    NARCIS (Netherlands)

    Graaff, de J.; Wiersum, K.F.

    1992-01-01

    In a recent article (Diemont et al., 1991) about erosion on Java, it has been postulated that low inputs, not surface erosion, is the main cause of low productivity of upland food crops on this island. In this article it is argued that this hypothesis is too simple. An analysis of empirical field

  19. The erosive potential of candy sprays

    NARCIS (Netherlands)

    Gambon, D.L.; Brand, H.S.; Nieuw Amerongen, A.V.

    2009-01-01

    Objective To determine the erosive potential of seven different commercially available candy sprays in vitro and in vivo. Material and methods The erosive potential was determined in vitro by measuring the pH and neutralisable acidity. The salivary pH and flow rate were measured in healthy

  20. Dental erosion: prevalence, incidence, and distribution

    NARCIS (Netherlands)

    Jager, D.H.J.; Amaechi, B.T.

    2015-01-01

    Dental erosion is one of the most common dental diseases and it is a growing problem. Numerous epidemiological studies have investigated the prevalence of dental erosion. For these studies different cross sections of the population are investigated. Large differences were found between countries,

  1. Backward erosion piping : Initiation and progression

    NARCIS (Netherlands)

    Van Beek, V.M.

    2015-01-01

    Backward erosion piping is an internal erosion mechanism during which shallow pipes are formed in the direction opposite to the flow underneath water-retaining structures as a result of the gradual removal of sandy material by the action of water. It is an important failure mechanism in both dikes

  2. Automated lake-wide erosion predictions and economic damage calculations upstream of the Moses-Saunders power dam

    International Nuclear Information System (INIS)

    Zuzek, P.; Baird, W.F.; International Joint Commission, Ottawa, ON

    2008-01-01

    This presentation discussed an automated flood and erosion prediction system designed for the upstream sections of the Moses-Saunders power dam. The system included a wave prediction component along with 3-D maps, hourly run-ups, geographic information system (GIS) tools and a hazard analysis tool. Parcel, reach, township, and county databases were used to populate the system. The prediction system was used to develop detailed study sites of shore units in the study area. Shoreline classes included sand and cohesive buffs, low banks, coarse beaches, and cobble or boulder lags. Time series plots for Lake Ontario water and wave levels were presented. Great Lakes ice cover data were also included in the system as well as erosion predictions from 1961 to 1995. The system was also used to develop bluff recession equations and cumulative recession analyses for different regulation plans. Cumulative bluff recession and protection requirements were outlined. Screenshots of the flood and erosion prediction system interface were also included. tabs., figs

  3. Monitoring bank erosion at the Locke Island Archaeological National Register District: Summary of 1996/1997 field activities

    Energy Technology Data Exchange (ETDEWEB)

    Nickens, P.R. [ed.; Bjornstad, B.N.; Nickens, P.R.; Cadoret, N.A.; Wright, M.K.

    1998-08-01

    Locke Island is located in the Columbia River in south-central Washington. The US Department of Energy (DOE) owns Locke Island as part of its Hanford Site. In the 1960s and 1970s, as a result of intensive irrigation developments on the inland shoreline to the east of the island, the White Bluffs, which form the eastern boundary of the Columbia River channel in this area, began to show geological failures as excess irrigation water seeped out along the bluffs. One of the largest such failures, known as the Locke Island Landslide, is located just east of Locke Island. By the early 1980s, this landslide mass had moved westward into the river channel toward the island and was diverting the current at the island`s eastern perimeter. Erosion of the bank in the center of the island accelerated, threatening the cultural resources. By the early 1990s, the erosion had exposed cultural features and artifacts along the bank, leading to the beginning of intermittent monitoring of the cutbank. In 1994, DOE initiated more scheduled, systematic monitoring of island erosion to better understand the physical processes involved as well as mitigate ongoing loss of the archaeological record.

  4. Using airborne GAMMA-ray spectrometry (uranium, thorium, potassium) to quantify weathering and erosion processes

    International Nuclear Information System (INIS)

    Carrier, F.

    2005-01-01

    The airborne gamma-ray spectrometry survey carried out on the Armorican Massif provided soil contents in U, Th and K in ppm. Chemical and mechanical erosion processes within a homogeneous geological unit have been estimated using their variations and those of the 137 Cs. Our new approach, based on a multivariate analysis (hierarchic ascending classification), integrates the airborne gamma-ray spectrometry data, with their broad spatial distribution, together with precisely located station data (major elements, traces and isotopic geochemistry) resulting from a soil and river water erosion products survey. The total export of potassium was estimated in any point of an area catchment (50-m resolution) until 17+2 t/km 2 /a for a 50-m thick weathering profile. Erosion study by river sampling provide important biases, for the perennial river does not integrate the whole range of erosion products: the geochemical signature of the valleys is currently more represented than plateau areas. (author)

  5. Influence of Ultrasound Treatment on Cavitation Erosion Resistance of AlSi7 Alloy

    Directory of Open Access Journals (Sweden)

    Annalisa Pola

    2017-03-01

    Full Text Available Ultrasound treatment of liquid aluminum alloys is known to improve mechanical properties of castings. Aluminum foundry alloys are frequently used for production of parts that undergo severe cavitation erosion phenomena during service. In this paper, the effect of the ultrasound treatment on cavitation erosion resistance of AlSi7 alloy was assessed and compared to that of conventionally cast samples. Cavitation erosion tests were performed according to ASTM G32 standard on as-cast and heat treated castings. The response of the alloy in each condition was investigated by measuring the mass loss as a function of cavitation time and by analyzing the damaged surfaces by means of optical and scanning electron microscope. It was pointed out that the ultrasound treatment increases the cavitation erosion resistance of the alloy, as a consequence of the higher chemical and microstructural homogeneity, the finer grains and primary particles and the refined structure of the eutectic induced by the treatment itself.

  6. Influence of Ultrasound Treatment on Cavitation Erosion Resistance of AlSi7 Alloy.

    Science.gov (United States)

    Pola, Annalisa; Montesano, Lorenzo; Tocci, Marialaura; La Vecchia, Giovina Marina

    2017-03-03

    Ultrasound treatment of liquid aluminum alloys is known to improve mechanical properties of castings. Aluminum foundry alloys are frequently used for production of parts that undergo severe cavitation erosion phenomena during service. In this paper, the effect of the ultrasound treatment on cavitation erosion resistance of AlSi7 alloy was assessed and compared to that of conventionally cast samples. Cavitation erosion tests were performed according to ASTM G32 standard on as-cast and heat treated castings. The response of the alloy in each condition was investigated by measuring the mass loss as a function of cavitation time and by analyzing the damaged surfaces by means of optical and scanning electron microscope. It was pointed out that the ultrasound treatment increases the cavitation erosion resistance of the alloy, as a consequence of the higher chemical and microstructural homogeneity, the finer grains and primary particles and the refined structure of the eutectic induced by the treatment itself.

  7. Estimating the erosion and deposition rates in a small watershed by the 137Cs tracing method

    International Nuclear Information System (INIS)

    Li Mian; Li Zhanbin; Yao Wenyi; Liu Puling

    2009-01-01

    Understanding the erosion and deposition rates in a small watershed is important for designing soil and water conservation measures. The objective of this study is to estimate the net soil loss and gain at points with various land use types and landform positions in a small watershed in the Sichuan Hilly Basin of China by the 137 Cs tracing technique. Among various land use types, the order of erosion rate was bare rock > sloping cultivated land > forest land. The paddy field and Caotu (a kind of cultivated land located at the foot of hills) were depositional areas. The erosion rate under different landform was in this order: hillside > saddle > hilltop. The footslope and the valley were depositional areas. The 137 Cs technique was shown to provide an effective means of documenting the spatial distribution of soil erosion and deposition within the small watershed

  8. Regionalization of monthly rainfall erosivity patternsin Switzerland

    Science.gov (United States)

    Schmidt, Simon; Alewell, Christine; Panagos, Panos; Meusburger, Katrin

    2016-10-01

    One major controlling factor of water erosion is rainfall erosivity, which is quantified as the product of total storm energy and a maximum 30 min intensity (I30). Rainfall erosivity is often expressed as R-factor in soil erosion risk models like the Universal Soil Loss Equation (USLE) and its revised version (RUSLE). As rainfall erosivity is closely correlated with rainfall amount and intensity, the rainfall erosivity of Switzerland can be expected to have a regional characteristic and seasonal dynamic throughout the year. This intra-annual variability was mapped by a monthly modeling approach to assess simultaneously spatial and monthly patterns of rainfall erosivity. So far only national seasonal means and regional annual means exist for Switzerland. We used a network of 87 precipitation gauging stations with a 10 min temporal resolution to calculate long-term monthly mean R-factors. Stepwise generalized linear regression (GLM) and leave-one-out cross-validation (LOOCV) were used to select spatial covariates which explain the spatial and temporal patterns of the R-factor for each month across Switzerland. The monthly R-factor is mapped by summarizing the predicted R-factor of the regression equation and the corresponding residues of the regression, which are interpolated by ordinary kriging (regression-kriging). As spatial covariates, a variety of precipitation indicator data has been included such as snow depths, a combination product of hourly precipitation measurements and radar observations (CombiPrecip), daily Alpine precipitation (EURO4M-APGD), and monthly precipitation sums (RhiresM). Topographic parameters (elevation, slope) were also significant explanatory variables for single months. The comparison of the 12 monthly rainfall erosivity maps showed a distinct seasonality with the highest rainfall erosivity in summer (June, July, and August) influenced by intense rainfall events. Winter months have the lowest rainfall erosivity. A proportion of 62 % of

  9. Erosion testing of hard materials and coatings

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, Jeffrey A.

    2005-04-29

    Erosion is the process by which unconstrained particles, usually hard, impact a surface, creating damage that leads to material removal and component failure. These particles are usually very small and entrained in fluid of some type, typically air. The damage that occurs as a result of erosion depends on the size of the particles, their physical characteristics, the velocity of the particle/fluid stream, and their angle of impact on the surface of interest. This talk will discuss the basics of jet erosion testing of hard materials, composites and coatings. The standard test methods will be discussed as well as alternative approaches to determining the erosion rate of materials. The damage that occurs will be characterized in genera1 terms, and examples will be presented for the erosion behavior of hard materials and coatings (both thick and thin).

  10. Modelling rainfall erosion resulting from climate change

    Science.gov (United States)

    Kinnell, Peter

    2016-04-01

    It is well known that soil erosion leads to agricultural productivity decline and contributes to water quality decline. The current widely used models for determining soil erosion for management purposes in agriculture focus on long term (~20 years) average annual soil loss and are not well suited to determining variations that occur over short timespans and as a result of climate change. Soil loss resulting from rainfall erosion is directly dependent on the product of runoff and sediment concentration both of which are likely to be influenced by climate change. This presentation demonstrates the capacity of models like the USLE, USLE-M and WEPP to predict variations in runoff and erosion associated with rainfall events eroding bare fallow plots in the USA with a view to modelling rainfall erosion in areas subject to climate change.

  11. Erosion Pressure on the Danish Coasts

    DEFF Research Database (Denmark)

    Sørensen, Carlo Sass; Sørensen, Per; Kroon, Aart

    Coastlines around the world are receding due to coastal erosion.With rising sea levels and a potential climatic deterioration due to climate change, erosion rates are likely to increase at many locations in the future.Together with the current preference of people to settle near or directly...... by the ocean, coastal erosion issues become increasingly more important to the human values at risk. Along many Danish coastlines, hard structures already act as coastal protection in the form of groins, breakwaters, revetments etc. These eroding coasts however still lack sand and where the public, in general......, neglects the need for sand replenishment i.e. in the form of repeated sand nourishments. Here we present a conceptual model and method for dividing coastal erosion into acute and chronic erosion pressure, respectively. We focus on the model use for management and climate change adaptation purposes...

  12. Dietary assessment and counseling for dental erosion.

    Science.gov (United States)

    Marshall, Teresa A

    2018-02-01

    Dental erosion occurs after exposure to intrinsic or extrinsic acids. Exposure to intrinsic gastrointestinal acids is associated with anorexia nervosa, bulimia nervosa, rumination syndrome, or gastroesophageal reflux. Extrinsic dietary acids from foods or beverages also can cause erosion, particularly when exposure is prolonged by holding or swishing behaviors. Clinicians should screen patients exhibiting dental erosion for anorexia nervosa, bulimia nervosa, rumination syndrome, and gastroesophageal reflux disease. Clinicians should screen patients without a medical explanation for their erosion for exposure to acidic foods and beverages, particularly for habits that prolong exposure. Identification of intrinsic and extrinsic acid exposures and recommendations to minimize exposures are important to prevent erosion and maintain oral health. Copyright © 2018 American Dental Association. Published by Elsevier Inc. All rights reserved.

  13. Medication-related dental erosion: a review.

    Science.gov (United States)

    Thomas, Manuel S; Vivekananda Pai, A R; Yadav, Amit

    2015-10-01

    Dental erosion has become a major problem that affects the long-term health of the dentition. Among the various potential causes for erosive tooth wear, the different drugs prescribed for patients may be overlooked. Several therapeutic medications can directly or indirectly be associated with dental erosion. It is the responsibility of oral health providers to make both patients and colleagues aware of drugs that may contribute to this condition. Therefore, the purpose of this discussion is to provide an overview of the various therapeutic medications that can be related to tooth erosion. The authors also include precautionary measures-summarized as The 9 Rs-to avoid or at least reduce medication-induced erosion.

  14. Soil erosion processes on sloping land using REE tracer

    International Nuclear Information System (INIS)

    Shen Zhenzhou; Liu Puling; Yang Mingyi; Lian Zhenlong; Ju Tongjun; Yao Wenyi; Li Mian

    2007-01-01

    Sheet erosion is the main performance in the slope soil erosion process at the primary stage of natural rainfall. For three times of rainfall during experiment, the ratios of sheet erosion to total erosion account for 71%, 48% and 49% respectively, which showed that the sloping erosion was still at the primary stage from sheet erosion to rill erosion. With the rainfall going, the rill erosion amount increase. It showed that soil erosion was changing from sheet erosion to rill erosion. The sources of sediment from different sections of the plot were analyzed, and the results indicated that whatever the sheet erosion changed, the ratio erosion of upper part of surface soil was always lower than 10%. Sheet erosion came mainly from the lower section of surface soil. With the ratios to the amount of total rill erosion changes, the rill erosion amount of each section regularly changes too. The general conclusion is that when the rainfall ends, relative erosion of different slope element to the foot of slope is: 1 meter away accounts for 16%, 2-4 meters away is 6% and 5-9 meters away is 3%. The ratio of rill erosion amount of these three slope element is 5:2:1, which shows the rill erosion amount are mainly from the slope element of 4 meters from the foot of slope. (authors)

  15. Uncertainties in assessing tillage erosion - How appropriate are our measuring techniques?

    Science.gov (United States)

    Fiener, P.; Wilken, F.; Aldana-Jague, E.; Deumlich, D.; Gómez, J. A.; Guzmán, G.; Hardy, R. A.; Quinton, J. N.; Sommer, M.; Van Oost, K.; Wexler, R.

    2018-03-01

    Tillage erosion on arable land is a very important process leading to a net downslope movement of soil and soil constitutes. Tillage erosion rates are commonly in the same order of magnitude as water erosion rates and can be even higher, especially under highly mechanized agricultural soil management. Despite its prevalence and magnitude, tillage erosion is still understudied compared to water erosion. The goal of this study was to bring together experts using different techniques to determine tillage erosion and use the different results to discuss and quantify uncertainties associated with tillage erosion measurements. The study was performed in northeastern Germany on a 10 m by 50 m plot with a mean slope of 8%. Tillage erosion was determined after two sequences of seven tillage operations. Two different micro-tracers (magnetic iron oxide mixed with soil and fluorescent sand) and one macro-tracer (passive radio-frequency identification transponders (RFIDs), size: 4 × 22 mm) were used to directly determine soil fluxes. Moreover, tillage induced changes in topography were measured for the entire plot with two different terrestrial laser scanners and an unmanned aerial system for structure from motion topography analysis. Based on these elevation differences, corresponding soil fluxes were calculated. The mean translocation distance of all techniques was 0.57 m per tillage pass, with a relatively wide range of mean soil translocation distances ranging from 0.39 to 0.72 m per pass. A benchmark technique could not be identified as all used techniques have individual error sources, which could not be quantified. However, the translocation distances of the macro-tracers used were consistently smaller than the translocation distances of the micro-tracers (mean difference = - 26 ± 12%), which questions the widely used assumption of non-selective soil transport via tillage operations. This study points out that tillage erosion measurements, carried out under almost

  16. Soil erosion assessment of a Himalayan river basin using TRMM data

    Science.gov (United States)

    Pandey, A.; Mishra, S. K.; Gautam, A. K.; Kumar, D.

    2015-04-01

    In this study, an attempt has been made to assess the soil erosion of a Himalayan river basin, the Karnali basin, Nepal, using rainfall erosivity (R-factor) derived from satellite-based rainfall estimates (TRMM-3B42 V7). Average annual sediment yield was estimated using the well-known Universal Soil Loss Equation (USLE). The eight-year annual average rainfall erosivity factor (R) for the Karnali River basin was found to be 2620.84 MJ mm ha-1 h-1 year-1. Using intensity-erosivity relationships and eight years of the TRMM daily rainfall dataset (1998-2005), average annual soil erosion was also estimated for Karnali River basin. The minimum and maximum values of the rainfall erosivity factor were 1108.7 and 4868.49 MJ mm ha-1 h-1 year-1, respectively, during the assessment period. The average annual soil loss of the Karnali River basin was found to be 38.17 t ha-1 year-1. Finally, the basin area was categorized according to the following scale of erosion severity classes: Slight (0 to 5 t ha-1 year-1), Moderate (5 to 10 t ha-1 year-1), High (10 to 20 t ha-1 year-1), Very High (20 to 40 t ha-1 year-1), Severe (40 to 80 t ha-1 year-1) and Very Severe (>80 t ha-1 year-1). About 30.86% of the river basin area was found to be in the slight erosion class. The areas covered by the moderate, high, very high, severe and very severe erosion potential zones were 13.09%, 6.36%, 11.09%, 22.02% and 16.64% respectively. The study revealed that approximately 69% of the Karnali River basin needs immediate attention from a soil conservation point of view.

  17. A field experiment on the controls of sediment transport on bedrock erosion

    Science.gov (United States)

    Beer, A. R.; Turowski, J. M.; Fritschi, B.; Rieke-Zapp, D.; Campana, L.; Lavé, J.

    2012-12-01

    The earth`s surface is naturally shaped by interactions of physical and chemical processes. In mountainous regions with steep topography river incision fundamentally controls the geomorphic evolution of the whole landscape. There, erosion of exposed bedrock sections by fluvial sediment transport is an important mechanism forming mountain river channels. The links between bedload transport and bedrock erosion has been firmly established using laboratory experiments. However, there are only few field datasets linking discharge, sediment transport, impact energy and erosion that can be used for process understanding and model evaluation. To fill this gap, a new measuring setup has been commissioned to raise an appropriate simultaneous dataset of hydraulics, sediment transport and bedrock erosion at high temporal and spatial resolution. Two natural stone slabs were installed flush with the streambed of the Erlenbach, a gauged stream in the Swiss Pre-Alps. They are mounted upon force sensors recording vertical pressure und downstream shear caused by passing sediment particles. The sediment transport rates can be assessed using geophone plates and an automated moving basket system taking short-term sediment samples. These devices are located directly downstream of the stone slabs. Bedrock erosion rates are measured continuously with erosion sensors at sub-millimeter accuracy at three points on each slab. In addition, the whole slab topography is surveyed with photogrammetry and a structured-light 3D scanner after individual flood events. Since the installation in 2011, slab bedrock erosion has been observed during several transport events. We discuss the relation between hydraulics, bedload transport, resulting pressure forces on the stone slabs and erosion rates. The aim of the study is the derivation of an empirical process law for fluvial bedrock erosion driven by moving sediment particles.

  18. Fixed Points

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 5. Fixed Points - From Russia with Love - A Primer of Fixed Point Theory. A K Vijaykumar. Book Review Volume 5 Issue 5 May 2000 pp 101-102. Fulltext. Click here to view fulltext PDF. Permanent link:

  19. Tipping Point

    Medline Plus

    Full Text Available ... OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point ... 24 hours a day. For young children whose home is a playground, it’s the best way to ...

  20. Tipping Point

    Medline Plus

    Full Text Available ... 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash ...

  1. Erosion resistance comparison of alternative surface treatments

    Science.gov (United States)

    Česánek, Z.; Schubert, J.; Houdková, Š.

    2017-05-01

    Erosion is a process characterized by the particle separation and the damage of component functional surfaces. Thermal spraying technology HP/HVOF (High Pressure / High Velocity Oxygen Fuel) is commonly used for protection of component surfaces against erosive wear. Alloy as well as cermet based coatings meet the requirements for high erosion resistance. Wear resistance is in many cases the determining property of required component functioning. The application suitability of coating materials is particularly influenced by different hardness. This paper therefore presents an erosion resistance comparison of alloy and cermet based coatings. The coatings were applied on steel substrates and were subjected to the erosive test using the device for evaluation of material erosion resistance working on the principle of centrifugal erodent flow. Abrasive sand Al2O3 with grain size 212-250 μm was selected as an erosive material. For this purpose, the specimens were prepared by thermal spraying technology HP/HVOF using commercially available powders Stellite 6, NiCrBSi, Cr3C2-25%NiCr, Cr3C2-25%CoNiCrAlY, Hastelloy C-276 and experimental coating TiMoCN-29% Ni. Erosion resistance of evaluated coatings was compared with erosive resistance of 1.4923 high alloyed steel without nitridation and in nitrided state and further with surface treatment using technology PVD. According to the evaluation, the resulting erosive resistance depends not only on the selected erodent and surface protection, but also on the erodent impact angle.

  2. Dynamic Analysis of Soil Erosion in Songhua River Watershed

    Science.gov (United States)

    Zhang, Yujuan; Li, Xiuhai; Wang, Qiang; Liu, Jiang; Liang, Xin; Li, Dan; Ni, Chundi; Liu, Yan

    2018-01-01

    In this paper, based on RS and GIS technology and Revised Universal Soil Loss Equation (RUSLE), the soil erosion dynamic changes during the two periods of 1990 and 2010 in Bin County was analyzed by using the Landsat TM data of the two periods, so as to reveal the soil erosion spatial distribution pattern and spatial and temporal dynamic evolution rule in the region. The results showed that: the overall patterns of soil erosion were basically the same in both periods, mainly featuring slight erosion and mild erosion, with the area proportions of 80.68% and 74.71% respectively. The slight and extremely intensive erosion changing rates showed a narrowing trend; mild, moderate and intensive erosion was increasing, with a trend of increased soil erosion; mild and intensive erosion were developing towards moderate erosion and moderate and extremely intensive erosion were progressing towards intensive erosion.

  3. Providing support for day-to-day monitoring of shoreline cleanup operations

    International Nuclear Information System (INIS)

    Lamarche, A.; Tarpley, J.

    1997-01-01

    Experiences gained during the 'Cape Mohican' incident in October 1996, in San Francisco Bay, were recounted and proposed as a potential example of day-to-day monitoring, evaluation and reporting of shoreline cleanup effort. During this cleanup a set of communications procedures, progress reports and maps were developed which should be equally useful in other similar situations. The cartographic representations were specially highlighted as they focused on ways to provide a clear picture of the short term modifications in oiling conditions of the affected shoreline. The most important lesson learned from this oil spill was the importance of having personnel and equipment sufficiently matched to the task in order to evaluate oil conditions, produce cleanup recommendations, execute and communicate the status of the cleanup effort as fast, and as efficiently and effectively as possible. It was clearly demonstrated that unless the decision process is streamlined and supported with the best, most up-to-date information, the efforts of the cleanup team would be seriously undermined. 8 refs., 2 tabs., 6 figs

  4. Ikaite precipitation by mixing of shoreline springs and lake water, Mono Lake, California, USA

    Science.gov (United States)

    Bischoff, James L.; Stine, Scott; Rosenbauer, Robert J.; Fitzpatrick, John A.; Stafford, Thomas W., Jr.

    1993-08-01

    Metastable ikaite (CaCO 3·6H 2O) forms abundantly during winter months along the south shoreline of Mono Lake where shoreline springs mix with lake water. Ikaite precipitates because of its decreased solubility at low temperature and because of orthophosphate-ion inhibition of calcite and aragonite. During the spring some of the ikaite is transformed to anhydrous CaCO 3 and is incorporated into tufa, but most is dispersed by wave action into the lake where it reacts to form gaylussite (Na 2Ca(CO 3) 2· 5H 2O). Spring waters have low pH values, are dominantly Ca-Na-HCO 3, have low radiocarbon activities, and are mixtures of deep-seated geothermal and cold groundwaters. Chemical modeling reveals that precipitation of CaCO 3 can occur over a broad range of mixtures of spring and lake water with a maximum production occurring at 96% spring water and 4% lake water. Under these conditions all the Ca and a significant fraction of the CO 3 of the precipitate is spring supplied. A radiocarbon age of 19,580 years obtained on a natural ikaite sample supports this conclusion. With the springs supplying a large and probably variable portion of the carbonate, and with apparent 14C age of the carbonate varying from spring to spring, tufa of similar actual antiquity may yield significantly different 14C dates, making tufa at this location unsuitable for absolute age dating by the radiocarbon method.

  5. Potential urban runoff impacts and contaminant distributions in shoreline and reservoir environments of Lake Havasu, southwestern United States.

    Science.gov (United States)

    Wilson, Doyle C

    2018-04-15

    Heavy metal, nutrient, and hydrocarbon levels in and adjacent to Lake Havasu, a regionally significant water supply reservoir with a highly controlled, dynamic flow regime, are assessed in relation to possible stormwater runoff impacts from an arid urban center. Shallow groundwater and sediment analyses from ephemeral drainage (wash) mouths that convey stormwater runoff from Lake Havasu City, Arizona to the reservoir, provided contaminant control points and correlation ties with the reservoir environment. Fine-grain sediments tend to contain higher heavy metal concentrations whereas nutrients are more evenly distributed, except low total organic carbon levels from young wash mouth surfaces devoid of vegetation. Heavy metal and total phosphate sediment concentrations in transects from wash mouths into the reservoir have mixed and decreasing trends, respectively. Both series may indicate chemical depositional influences from urban runoff, yet no statistically significant concentration differences occur between specific wash mouths and corresponding offshore transects. Heavy metal pollution indices of all sediments indicate no discernible to minor contamination, indicating that runoff impacts are minimal. Nevertheless, several heavy metal concentrations from mid-reservoir sediment sites increase southward through the length of the reservoir. Continual significant water flow through the reservoir may help to disperse locally derived runoff particulates, which could mix and settle down gradient with chemical loads from upriver sources and local atmospheric deposition. Incorporating the shoreline environment with the reservoir investigation provides spatial continuity in assessing contaminant sources and distribution patterns. This is particularly acute in the investigation of energetic, flow-through reservoirs in which sources may be overlooked if solely analyzing the reservoir environment. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. A model integrating longshore and cross-shore processes for predicting long-term shoreline response to climate change

    Science.gov (United States)

    Vitousek, Sean; Barnard, Patrick; Limber, Patrick W.; Erikson, Li; Cole, Blake

    2017-01-01

    We present a shoreline change model for coastal hazard assessment and management planning. The model, CoSMoS-COAST (Coastal One-line Assimilated Simulation Tool), is a transect-based, one-line model that predicts short-term and long-term shoreline response to climate change in the 21st century. The proposed model represents a novel, modular synthesis of process-based models of coastline evolution due to longshore and cross-shore transport by waves and sea-level rise. Additionally, the model uses an extended Kalman filter for data assimilation of historical shoreline positions to improve estimates of model parameters and thereby improve confidence in long-term predictions. We apply CoSMoS-COAST to simulate sandy shoreline evolution along 500 km of coastline in Southern California, which hosts complex mixtures of beach settings variably backed by dunes, bluffs, cliffs, estuaries, river mouths, and urban infrastructure, providing applicability of the model to virtually any coastal setting. Aided by data assimilation, the model is able to reproduce the observed signal of seasonal shoreline change for the hindcast period of 1995-2010, showing excellent agreement between modeled and observed beach states. The skill of the model during the hindcast period improves confidence in the model's predictive capability when applied to the forecast period (2010-2100) driven by GCM-projected wave and sea-level conditions. Predictions of shoreline change with limited human intervention indicate that 31% to 67% of Southern California beaches may become completely eroded by 2100 under sea-level rise scenarios of 0.93 to 2.0 m.

  7. Modeling erosion and accretion along the Illinois Lake Michigan shore using integrated airborne, waterborne and ground-based method

    Science.gov (United States)

    Mwakanyamale, K. E.; Brown, S.; Larson, T. H.; Theuerkauf, E.; Ntarlagiannis, D.; Phillips, A.; Anderson, A.

    2017-12-01

    Sediment distribution at the Illinois Lake Michigan shoreline is constantly changing in response to increased human activities and complex natural coastal processes associated with wave action, short and long term fluctuations in lake level, and the influence of coastal ice. Understanding changes to volume, distribution and thickness of sand along the shore through time, is essential for modeling shoreline changes and predicting changes due to extreme weather events and lake-level fluctuation. The use of helicopter transient electromagnetic (HTEM) method and integration with ground-based and waterborne geophysical and geologic methods provides high resolution spatial rich data required for modeling the extent of erosion and accretion at this dynamic coastal system. Analysis and interpretation of HTEM, ground and waterborne geophysical and geological data identify spatial distribution and thickness of beach and lake-bottom sand. The results provide information on existence of littoral sand deposits and identify coastal hazards such as lakebed down-cutting that occurs in sand-starved areas.

  8. Mapping monthly rainfall erosivity in Europe.

    Science.gov (United States)

    Ballabio, Cristiano; Borrelli, Pasquale; Spinoni, Jonathan; Meusburger, Katrin; Michaelides, Silas; Beguería, Santiago; Klik, Andreas; Petan, Sašo; Janeček, Miloslav; Olsen, Preben; Aalto, Juha; Lakatos, Mónika; Rymszewicz, Anna; Dumitrescu, Alexandru; Tadić, Melita Perčec; Diodato, Nazzareno; Kostalova, Julia; Rousseva, Svetla; Banasik, Kazimierz; Alewell, Christine; Panagos, Panos

    2017-02-01

    Rainfall erosivity as a dynamic factor of soil loss by water erosion is modelled intra-annually for the first time at European scale. The development of Rainfall Erosivity Database at European Scale (REDES) and its 2015 update with the extension to monthly component allowed to develop monthly and seasonal R-factor maps and assess rainfall erosivity both spatially and temporally. During winter months, significant rainfall erosivity is present only in part of the Mediterranean countries. A sudden increase of erosivity occurs in major part of European Union (except Mediterranean basin, western part of Britain and Ireland) in May and the highest values are registered during summer months. Starting from September, R-factor has a decreasing trend. The mean rainfall erosivity in summer is almost 4 times higher (315MJmmha -1 h -1 ) compared to winter (87MJmmha -1 h -1 ). The Cubist model has been selected among various statistical models to perform the spatial interpolation due to its excellent performance, ability to model non-linearity and interpretability. The monthly prediction is an order more difficult than the annual one as it is limited by the number of covariates and, for consistency, the sum of all months has to be close to annual erosivity. The performance of the Cubist models proved to be generally high, resulting in R 2 values between 0.40 and 0.64 in cross-validation. The obtained months show an increasing trend of erosivity occurring from winter to summer starting from western to Eastern Europe. The maps also show a clear delineation of areas with different erosivity seasonal patterns, whose spatial outline was evidenced by cluster analysis. The monthly erosivity maps can be used to develop composite indicators that map both intra-annual variability and concentration of erosive events. Consequently, spatio-temporal mapping of rainfall erosivity permits to identify the months and the areas with highest risk of soil loss where conservation measures should be

  9. Detailed Project Report and Environmental Impact Assessment for Lakeshore Park, Ashtabula, Ohio Beach Erosion Control and Shoreline Protection Study. Stage III Documentation. Main Report.

    Science.gov (United States)

    1982-02-01

    lines of the Atlantic and Pacific Oceans, the Gulf of Mexico , the Great Lakes, and lakes, estuaries, and bays directly connected therewith." These...and only a small percentage would be suitable for beach fill. Un- depresent conditions the only damage found to be attributable to the harbor

  10. Anthropogenic effects on shoreface and shoreline changes: Input from a multi-method analysis, Agadir Bay, Morocco

    Science.gov (United States)

    Aouiche, Ismail; Daoudi, Lahcen; Anthony, Edward J.; Sedrati, Mouncef; Ziane, Elhassane; Harti, Abderrazak; Dussouillez, Philippe

    2016-02-01

    In many situations, the links between shoreline fluctuations and larger-scale coastal change embracing the shoreface are not always well understood. In particular, meso-scale (years to decades) sand exchanges between the shoreface and the shoreline, considered as important on many wave-dominated coasts, are rather poorly understood and difficult to identify. Coastal systems where sediment transport is perturbed by engineering interventions on the shoreline and shoreface commonly provide fine examples liable to throw light on these links. This is especially so where shoreface bathymetric datasets, which are generally lacking, are collected over time, enabling more or less fine resolution of the meso-scale coastal sediment budget. Agadir Bay and the city of Agadir together form one of the two most important economic development poles on the Atlantic coast of Morocco. Using a combined methodological approach based on wave-current modelling, bathymetric chart-differencing, determination of shoreline fluctuations, and beach topographic surveying, we highlight the close links between variations in the bed of the inner shoreface and the bay shoreline involving both cross-shore and longshore sand transport pathways, sediment budget variations and new sediment cell patterns. We show that the significant changes that have affected the bay shoreline and shoreface since 1978 clearly reflect anthropogenic impacts, notably blocking of alongshore sand transport by Agadir harbour, completed in 1988, and the foundations of which lie well beyond the depth of wave closure. Construction of the harbour has led to the creation of a rapidly accreting beach against an original portion of rocky shoreline updrift and to a net sand loss exceeding 145,000 m3/year between 1978 and 2012 over 8.5 km2of the bay shoreface downdrift. Shoreline retreat has been further exacerbated by sand extraction from aeolian dunes and by flattening of these dunes to make space for tourist infrastructure. Digital

  11. Dew Point

    OpenAIRE

    Goldsmith, Shelly

    1999-01-01

    Dew Point was a solo exhibition originating at PriceWaterhouseCoopers Headquarters Gallery, London, UK and toured to the Centre de Documentacio i Museu Textil, Terrassa, Spain and Gallery Aoyama, Tokyo, Japan.

  12. Tipping Point

    Medline Plus

    Full Text Available ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash ...

  13. Tipping Point

    Science.gov (United States)

    ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash ...

  14. Tipping Point

    Medline Plus

    Full Text Available ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head ... see news reports about horrible accidents involving young children and furniture, appliance and tv tip-overs. The ...

  15. Tipping Point

    Medline Plus

    Full Text Available ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head ... TV falls with about the same force as child falling from the third story of a building. ...

  16. Tipping Point

    Medline Plus

    Full Text Available ... Tipping Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture ... about horrible accidents involving young children and furniture, appliance and tv tip-overs. The force of a ...

  17. Lithosphere erosion atop mantle plumes

    Science.gov (United States)

    Agrusta, R.; Arcay, D.; Tommasi, A.

    2012-12-01

    Mantle plumes are traditionally proposed to play an important role in lithosphere erosion. Seismic images beneath Hawaii and Cape Verde show a lithosphere-asthenosphere-boundary (LAB) up to 50 km shallower than the surroundings. However, numerical models show that unless the plate is stationary the thermo-mechanical erosion of the lithosphere does not exceed 30 km. We use 2D petrological-thermo-mechanical numerical models based on a finite-difference method on a staggered grid and marker in cell method to study the role of partial melting on the plume-lithosphere interaction. A homogeneous peridotite composition with a Newtonian temperature- and pressure-dependent viscosity is used to simulate both the plate and the convective mantle. A constant velocity, ranging from 5 to 12.5 cm/yr, is imposed at the top of the plate. Plumes are created by imposing a thermal anomaly of 150 to 350 K on a 50 km wide domain at the base of the model (700 km depth); the plate right above the thermal anomaly is 40 Myr old. Partial melting is modeled using batch-melting solidus and liquidus in anhydrous conditions. We model the progressive depletion of peridotite and its effect on partial melting by assuming that the melting degree only strictly increases through time. Melt is accumulated until a porosity threshold is reached and the melt in excess is then extracted. The rheology of the partially molten peridotite is determined using viscous constitutive relationship based on a contiguity model, which enables to take into account the effects of grain-scale melt distribution. Above a threshold of 1%, melt is instantaneously extracted. The density varies as a function of partial melting degree and extraction. Besides, we analyze the kinematics of the plume as it impacts a moving plate, the dynamics of time-dependent small-scale convection (SSC) instabilities developing in the low-viscosity layer formed by spreading of hot plume material at the lithosphere base, and the resulting thermal

  18. X-ray diagnosis of erosive gastritis

    International Nuclear Information System (INIS)

    Taskov, A.; Krastin, A.

    1993-01-01

    A series of 602 patients are studied according to a standard protocol including double contrast examination, taking films with dosed compression and complete filling (accordingly 3+3+1 radiographs). A barium suspension at concentration 200.0 BaSO 4 in 100 ml water is used as a positive contrast medium, and effervescent powder or pills - as a negative contrast. Erosive gastritis is diagnosed in 48 patients (7.9%) of which 38 present complete erosions (79.2%), 6 (12.6%) - incomplete, and 4 (8.3%) - mixed erosions. In 35 cases (72.9%) erosions are differentiated in double-contrast films, while in 21 (43.8%) - in those with compression. The advantage of the double contrast technique consists in visualization of erosions of the body of the stomach and discovering of incomplete erosions. In 483 patients a comparative assessment is done of the X-ray and endoscopic findings. There are recorded 5 false-positive and 25 false-negative radiological results. The sensitivity of the X-ray study in terms of erosive gastritis amounts to 59.7%. 15 refs., 4 figs. (orig.)

  19. Erosion and stability of a mine soil

    International Nuclear Information System (INIS)

    Wu, T.H.; Stadler, A.T.; Low, C.

    1996-01-01

    Mine soils developed from mine spoils commonly have a wide range of particle size. The slopes of old spoil piles usually are marked by gullies due to years of uncontrolled erosion. These characteristics raise questions about applicability of available theories and models for estimating runoff and erosion. An investigation was made to determine whether available erosion models can work for mine soils and can account for gully erosion. The investigation at an abandoned surface mine consisted of measurement of soil and sediment properties, measurement of runoff and erosion, observations of armor by rock fragments on gully floor, and calculations with available theories of sediment transport and slope stability. The results at this site suggest that (1) predictions with the ANSWERS model have about the same accuracy as those made for agricultural lands; (2) armor provided by rock fragments are temporary as they are periodically removed by debris flows; (3) detachment by rainfall impact is the primary cause of erosion on short steep slopes; and (4) a simplified method can be used for estimating erosion on such slopes

  20. Soft drinks and in vitro dental erosion.

    Science.gov (United States)

    Gravelle, Brent L; Hagen Ii, Ted W; Mayhew, Susan L; Crumpton, Brooks; Sanders, Tyler; Horne, Victoria

    2015-01-01

    The purpose of this investigation was to determine to what extent the in vitro exposure of healthy teeth to various commonly consumed carbonated soft drinks may precipitate dental erosion. Forty-two healthy, extracted, previously unerupted human molars were weighed prior to, during, and after suspension in various sugared and diet or zero-calorie carbonated beverages for 20 days; the specimens were stored at room temperature while being stirred at 275 rpm. The percentage decrease in tooth weight from before to after exposure represented the weight loss due to enamel erosion; values in the experimental groups varied from 3.22% to 44.52% after 20 days' exposure. Data were subjected to analysis of variance and post hoc Scheffe testing at a level of α = 0.05. Nonsugared drinks (diet and zero-calorie) as a whole were more erosive than sugared beverages. A significant positive correlation was found between the amount of titratable acid and percentage of tooth erosion, while a significant negative correlation was revealed between the beverage pH and percentage of tooth erosion. No significant correlations were found between calcium or phosphate ion concentrations and the amount of erosion. It appears that enamel erosion is dependent on not only the beverage flow rate, pH, and amount of titratable acid, but also whether the soft drink is of the diet or zero-calorie variety, which reflects the type of artificial sweetener present.

  1. Human-induced C erosion and burial across spatial and temporal scales. (Invited)

    Science.gov (United States)

    van oost, K.

    2013-12-01

    Anthropogenic land cover change and soil erosion are tightly coupled: accelerated erosion and deposition of soil are inevitable consequences of the removal of vegetative cover and increased exposure of the soil surface to erosion. A significant portion of the earth surface has now been disturbed and this has locally accelerated erosion 10- to 100-fold. Although there is now growing awareness that the erosion-induced C flux may be an important factor determining global and regional net terrestrial ecosystem C balances, the significance of this disturbance for the past, present and future C cycle remains uncertain. In this paper, we argue that the significance for both past and present C budgets remains poorly quantified due to uncertainty about the contribution of biotic versus erosion-induced C fluxes because of their intrinsically different space and time scales. Carbon erosion research in agro-ecosystems has traditionally focused on short-term processes, i.e. single events to a few decades and longer-term observations of C and sediment dynamics are therefore rare. Likewise, C cycling is typically studied at the profile-scale while erosion processes operate over various spatial scales and whole-watershed approaches are therefore needed. We address this issue here by synthesizing 3 case studies where we report results of a measurement campaign to characterize the erosional control on vertical carbon fluxes from degraded land. First, using signatures in soil sedimentary archives, we integrate the effects of accelerated C erosion across point, hillslope and catchment scale for a temperate river catchment over the period of agriculture to demonstrate that accounting for the non-steady-state C dynamics in geomorphic active systems is pertinent to understand both past and future anthropogenic global change. Secondly, we report year-round soil respiration measurements with high temporal resolution along an erosion gradient on cultivated sloping land in the Chinese Loess

  2. Estimating surface soil erosion losses and mapping erosion risk for Yusufeli micro-catchment (Artvin

    Directory of Open Access Journals (Sweden)

    Mustafa Tüfekçioğlu

    2016-10-01

    Full Text Available Sheet erosion, one of the most important types of water erosion, takes place on the top soil as tiny soil layer movement that affects lake and stream ecosystem. This type of erosion is very important because the productive soil layer on the top soil can be lost in a very short period of time. The goal of this study was to quantify the amount of surface (sheet and rill soil erosion, and to identify areas under high erosion risk within the study area at Yusufeli province in Artvin by using RUSLE erosion methodology. As a result of the study it was found that the average annual potential soil loss by surface erosion was 3.6 ton ha-1yr-1. Additionally, the maps produced and conclusions reached by the study revealed that the areas of high erosion risk were identified spatially and measures to control erosion on some of these high risk areas can be possible with appropriate erosion control techniques.

  3. Erosion by rain in the western Congo

    International Nuclear Information System (INIS)

    Ploey, J. de

    1967-01-01

    Vast expanses of the western part of central and southern Africa are covered with uniform, sandy formations of the Kalahari type. The topography of these areas and their present morphological characteristics are mainly the result of erosion by rain. Information on the hydrology of the surface waters in these areas is fairly limited and is insufficient to permit any conclusions regarding the way in which erosion by rain takes place. To obtain a better understanding of these phenomena, the author devised a series of experiments based on the use of 46 Sc-labelled radioactive sand. These experiments began at the beginning of the 1964/65 rainy season and are continuing. The experimental plot corresponds to convex and rectilinear portions of a hillside with a slope varying between 0 and 12 degrees. The vegetation consists of grassy savannah of substeppe appearance and secondary forests. Series of labelled samples were placed successively on the surface of the experimental plot and the erosive effect of rain was determined by measuring the residual concentrations after rainfall. Some samples were placed below a shield so as to eliminate the effects of splash and reveal the part played by runoff. Radiographic films were used to study the dispersion of labelled particles in the surrounding area. This radiographic method made it possible to determine the scale of erosion by splash for different rainfall conditions. The erosion diagrams obtained from these experiments show the correlations that exist between the intensity and duration of the rainfall and the erosion of the soil. Examination of the erosion diagrams and the shielded samples and analysis of the radiographs showed that erosion by rain on Kalahari ground covered with substeppe savannah is caused mainly by splash erosion and by dispersed, intermittent runoff. Sheet wash plays no part if the slope is less than 12 degrees. (author) [fr

  4. Shoreline change after 12 years of tsunami in Banda Aceh, Indonesia: a multi-resolution, multi-temporal satellite data and GIS approach

    Science.gov (United States)

    Sugianto, S.; Heriansyah; Darusman; Rusdi, M.; Karim, A.

    2018-04-01

    The Indian Ocean Tsunami event on the 26 December 2004 has caused severe damage of some shorelines in Banda Aceh City, Indonesia. Tracing back the impact can be seen using remote sensing data combined with GIS. The approach is incorporated with image processing to analyze the extent of shoreline changes with multi-temporal data after 12 years of tsunami. This study demonstrates multi-resolution and multi-temporal satellite images of QuickBird and IKONOS to demarcate the shoreline of Banda Aceh shoreline from before and after tsunami. The research has demonstrated a significant change to the shoreline in the form of abrasion between 2004 and 2005 from few meters to hundred meters’ change. The change between 2004 and 2011 has not returned to the previous stage of shoreline before the tsunami, considered post tsunami impact. The abrasion occurs between 18.3 to 194.93 meters. Further, the change in 2009-2011 shows slowly change of shoreline of Banda Aceh, considered without impact of tsunami e.g. abrasion caused by ocean waves that erode the coast and on specific areas accretion occurs caused by sediment carried by the river flow into the sea near the shoreline of the study area.

  5. Predicted erosion and sediment delivery of fallout plutonium

    International Nuclear Information System (INIS)

    Foster, G.R.; Hakonson, T.E.

    1984-01-01

    Plutonium (Pu) from fallout after atmospheric explosion of nuclear weapons in the 1950s and 1960s is being redistributed over the landscape by soil erosion and carried on sediment by streams to oceans. Erosion rates computed with the Universal Soil Loss Equation for about 200,000 sample points on nonfederal land across the US were used to estimate Pu removal rates by soil erosion by water, Pu delivery in several major rivers, and concentration of Pu on the transported sediment. Estimates of average annual Pu delivery on sediment ranged from 0.002% of the initial fallout Pu inventory for the Savannah River basin to 0.08% for the Mississippi River basin. If the deposition of Pu had been uniformly 37 Bq/m 2 , the estimated Pu activity on suspended sediment ranged from about 0.26 Bq/kg of sediment for the Savannah River basin to 0.52 Bq/kg for the Columbia and Rio Grande river basins. After 1000 yr, about 9 to 48% of the initial Pu inventory will remain in US soils that are eroding. Much of the Pu on eroded sediment will travel only a short distance from its origin before its host sediment particles are deposited and permanently located, at least for a few hundred years. As much as 90% of the initially deposited Pu will remain, redistributed over the landscape by erosion and deposition. Although the delivery rate of Pu by rivers will not decrease greatly in the next 100 yr, a significant decrease will likely occur by 1000 yr

  6. Effect of endurance training on dental erosion, caries, and saliva.

    Science.gov (United States)

    Frese, C; Frese, F; Kuhlmann, S; Saure, D; Reljic, D; Staehle, H J; Wolff, D

    2015-06-01

    The aim of this investigation was to give insights into the impact of endurance training on oral health, with regard to tooth erosion, caries, and salivary parameters. The study included 35 triathletes and 35 non-exercising controls. The clinical investigation comprised oral examination, assessment of oral status with special regard to caries and erosion, saliva testing during inactivity, and a self-administered questionnaire about eating, drinking, and oral hygiene behavior. In addition, athletes were asked about their training habits and intake of beverages and sports nutrition. For saliva assessment during exercise, a subsample of n = 15 athletes volunteered in an incremental running field test (IRFT). Athletes showed an increased risk for dental erosion (P = 0.001). No differences were observed with regard to caries prevalence and salivary parameters measured during inactivity between athletes and controls. Among athletes, a significant correlation was found between caries prevalence and the cumulative weekly training time (r = 0.347, P = 0.04). In athletes after IRFT and at maximum workload, saliva flow rates decreased (P = 0.001 stimulated; P = 0.01 unstimulated) and saliva pH increased significantly (P = 0.003). Higher risk for dental erosions, exercise-dependent caries risk, and load-dependent changes in saliva parameters point out the need for risk-adapted preventive dental concepts in the field of sports dentistry. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Modeling Megacusps and Dune Erosion

    Science.gov (United States)

    Orzech, M.; Reniers, A. J.; Thornton, E. B.

    2009-12-01

    Megacusps are large, concave, erosional features of beaches, of O(200m) alongshore wavelength, which sometimes occur when rip channel bathymetry is present. It is commonly hypothesized that erosion of the dune and back beach will be greater at the alongshore locations of the megacusp embayments, principally because the beach width is narrower there and larger waves can more easily reach the dune toe (e.g., Short, J. Geol., 1979, Thornton, et al., Mar. Geol., 2007). At present, available field data in southern Monterey Bay provide some support for this hypothesis, but not enough to fully confirm or refute it. This analysis utilizes XBeach, a 2DH nearshore sediment transport model, to test the above hypothesis under a range of wave conditions over several idealized rip-megacusp bathymetries backed by dunes. Model results suggest that while specific wave conditions may result in erosional hot spots at megacusp embayments, other factors such as tides, wave direction, and surf zone bathymetry can often play an equal or stronger role.

  8. [Gastric band erosion: Alternative management].

    Science.gov (United States)

    Echaverry-Navarrete, Denis José; Maldonado-Vázquez, Angélica; Cortes-Romano, Pablo; Cabrera-Jardines, Ricardo; Mondragón-Pinzón, Erwin Eduardo; Castillo-González, Federico Armando

    2015-01-01

    Obesity is a public health problem, for which the prevalence has increased worldwide at an alarming rate, affecting 1.7 billion people in the world. To describe the technique employed in incomplete penetration of gastric band where endoscopic management and/or primary closure is not feasible. Laparoscopic removal of gastric band was performed in five patients with incomplete penetrance using Foley catheterization in the perforation site that could lead to the development of a gastro-cutaneous fistula. The cases presented include a leak that required surgical lavage with satisfactory outcome, and one patient developed stenosis 3 years after surgical management, which was resolved endoscopically. In all cases, the penetration site closed spontaneously. Gastric band erosion has been reported in 3.4% of cases. The reason for inserting a catheter is to create a controlled gastro-cutaneous fistula, allowing spontaneous closure. Various techniques have been described: the totally endoscopic, hybrid techniques (endoscopic/laparoscopic) and completely laparoscopic. A technique is described here that is useful and successful in cases where the above-described treatments are not viable. Copyright © 2015. Published by Masson Doyma México S.A.

  9. Tungsten erosion and redeposition in the all-tungsten divertor of ASDEX Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, M; Krieger, K; Matern, G; Neu, R; Rasinski, M; Rohde, V; Sugiyama, K; Wiltner, A [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, 85748 Garching (Germany); Andrzejczuk, M; Fortuna-Zalesna, E; Kurzydlowski, K J; Zielinski, W [Faculty of Materials Science and Engineering, Warsaw University of Technology, Association EURATOM-IPPLM, 02-507 Warsaw (Poland); Hakola, A; Koivuranta, S; Likonen, J [VTT Materials for Power Engineering, EURATOM Association, PO Box 1000, FI-02044 VTT (Finland); Ramos, G [CICATA-Qro, Instituto Politecnico Nacional, Queretaro (Mexico); Dux, R, E-mail: matej.mayer@ipp.mpg.de

    2009-12-15

    Net erosion and deposition of tungsten (W) in the ASDEX Upgrade divertor were determined after the 2007 campaign by using thin W marker stripes. ASDEX Upgrade had full-W plasma-facing components during this campaign. The inner divertor and the roof baffle were net W deposition areas with a maximum deposition of about 1x10{sup 18} W-atoms cm{sup -2} in the private flux region below the inner strike point. Net erosion of W was observed in the whole outer divertor, with the largest erosion close to the outer strike point. Only a small fraction of the W eroded in the main chamber and in the outer divertor was found in redeposits in the inner divertor, while a large fraction was either redeposited at unidentified places in the main chamber or has formed dust.

  10. Characterizing Low-Z erosion and deposition in the DIII-D divertor using aluminum

    Directory of Open Access Journals (Sweden)

    C.P. Chrobak

    2017-08-01

    Full Text Available We present measurements and modeling of aluminum erosion and redeposition experiments in separate helium and deuterium low power, low density L-mode plasmas at the outer divertor strike point of DIII-D to provide a low-Z material benchmark dataset for tokamak erosion-deposition modeling codes. Coatings of Al ∼100nm thick were applied to ideal (smooth and realistic (rough surfaces and exposed to repeat plasma discharges using the DiMES probe. Redeposition in all cases was primarily in the downstream toroidal field direction, evident from both in-situ spectroscopic and post-mortem non-spectroscopic measurements. The gross Al erosion yield was estimated from film thickness change measurements of small area samples, and was found to be ∼40–70% of the expected erosion yield based on theoretical physical sputtering yields after including sputtering by a 1–3% carbon impurity. The multi-step redeposition and re-erosion process, and hence the measured net erosion yield and material migration patterns, were found to be influenced by the surface roughness and/or porosity. A time-dependent model of material migration accounting for deposit accumulation in hidden areas was developed to reproduce the measurements in these experiments and determine a redeposition probability distribution function for sputtered atoms.

  11. Compressor Impeller Erosion Resistant Surface Treatment

    National Research Council Canada - National Science Library

    Riley, Michael

    2000-01-01

    ...). Coatings based on tungsten carbide tantalum carbide. titanium carbide all with a cobalt matrix were evaluated for high velocity particle erosion in conventional wear test studies as well as wind tunnel testing...

  12. Puerto Rico Relative Vulnerability to Erosion

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical factors, such as the slope of the land, the texture of the soil, and the precipitation regime influence erosion in an area. Parts of Puerto Rico are very...

  13. Paradiaphyseal calcific tendinitis with cortical bone erosion.

    Science.gov (United States)

    Fritz, P; Bardin, T; Laredo, J D; Ziza, J M; D'Anglejan, G; Lansaman, J; Bucki, B; Forest, M; Kuntz, D

    1994-05-01

    To determine the clinical, radiologic, and histologic features of calcific tendinitis with cortical bone erosion. The records of 6 patients with paradiaphyseal calcific tendinitis and adjacent bone cortex erosion were reviewed. Calcific tendinitis involved the linea aspera in 4 patients, the bicipital groove in 1 patient, and the deltoid insertion in another. Calcium deposits were associated with cortical bone erosions, revealed on plain radiographs in 4 patients and computed tomography scans in 2. Bone scans were performed in 2 patients and showed local hyperfixation of the isotope. In 4 patients, suspicion of a neoplasm led to a biopsy. Calcium deposits appeared to be surrounded by a foreign body reaction with numerous giant cells. Apatite crystals were identified by transmission electron microscopy and elemental analysis in 1 surgical sample. Paradiaphyseal calcific tendinitis with cortical bone erosion is an uncommon presentation of apatite deposition disease.

  14. Emission Facilities - Erosion & Sediment Control Facilities

    Data.gov (United States)

    NSGIC Education | GIS Inventory — An Erosion and Sediment Control Facility is a DEP primary facility type related to the Water Pollution Control program. The following sub-facility types related to...

  15. Understanding and Predicting Gun Barrel Erosion

    National Research Council Canada - National Science Library

    Johnston, Ian A

    2005-01-01

    The Australian Defence Force will soon have to contend with gun barrel erosion issues arising from the use of new low-vulnerability gun propellants, the acquisition of new ammunition and gun systems...

  16. Puerto Rico Relative Erosion Potential (REP) - 2000

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The relative erosion potential is an indicator of sediment and pollution runoff from land based on slope, soil type, land cover (circa 2000) and (maximum monthly)...

  17. Puerto Rico Relative Erosion Potential (REP) - 1990

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The relative erosion potential is an indicator of sediment and pollution runoff from land based on slope, soil type, land cover (circa 1990) and (maximum monthly)...

  18. Definition of tolerable soil erosion values

    Directory of Open Access Journals (Sweden)

    G. Sparovek

    1997-09-01

    Full Text Available Although the criteria for defining erosion tolerance are well established, the limits generally used are not consistent with natural, economical and technological conditions. Rates greater than soil formation can be accepted only until a minimum of soil depth is reached, provided that they are not associated with environmental hazard or productivity losses. A sequence of equations is presented to calculate erosion tolerance rates through time. The selection of equation parameters permits the definition of erosion tolerance rates in agreement with environmental, social and technical needs. The soil depth change that is related to irreversible soil degradation can be calculated. The definition of soil erosion tolerance according to these equations can be used as a guideline for sustainable land use planning and is compatible with expert systems.

  19. PROBLEMS OF SOIL PROTECTION FROM EROSION

    Directory of Open Access Journals (Sweden)

    M. Voloshuk

    2007-10-01

    Full Text Available In this article the problems of soil protection from erosion in Moldova are considered. The history (evolution of erosive processes is generalized, the first items of information on presence washed off soils are marked. Purposeful study of soil erosion, development of measures of struggle with it were begun in Moldova at the end of 40 years. In connection with transition to new economic methods of conducting economy (farmers, rent, privatization of land before pedologist, the experts of design organizations put forward the new requirements to study of erosive processes, development of soil protection, ecologo-adaptive systems of landscape agriculture. The tasks for improvement of a soil cover, restoration of fertility soil and their protection are put forward which are necessary for deciding in a near future.

  20. Rain Erosion/Measurement Impact Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The FARM Rain Erosion/Impact Measurement Lab develops solutions for deficiencies in the ability of materials, coatings and designs to withstand a severe operational...