Quantification of the Attenuation of Storm Surge Components by a Coastal Wetland of the US Mid Atlantic     

Anne-Eleonore Paquier  Jana Haddad  Seth Lawler  Celso M. Ferreira 《Estuaries and Coasts》2017,40(4):930-946

Coastal wetlands are receiving increased consideration as natural defenses for coastal communities from storm surge. However, there are gaps in storm surge measurements collected in marsh areas during extreme events as well as understanding of storm surge processes. The present study evaluates the importance and variation of different processes (i.e., wave, current, and water level dynamics with respect of the marsh topography and vegetation characteristics) involved in a storm surge over a marsh, assesses how these processes contribute to storm surge attenuation, and quantifies the storm surge attenuation in field conditions. During the Fall of 2015, morphology and vegetation surveys were conducted along a marsh transect in a coastal marsh located at the mouth of the Chesapeake Bay, mainly composed of Spartina alterniflora and Spartina patens. Hydrodynamic surveys were conducted during two storm events. Collected data included wave characteristics, current velocity and direction, and water levels. Data analysis focused on the understanding of the cross-shore evolution of waves, currents and water level, and their influence on the overall storm surge attenuation. Results indicate that the marsh area, despite its short length, attenuates waves and reduces current velocity and water level. Tides have a dominant influence on current direction and velocity, but the presence of vegetation and the marsh morphology contribute to a strong reduction of current velocity over the marsh platform relative to the currents at the marsh front. Wave attenuation varies across the tide cycle which implies a link between wave attenuation and water level and, consequently, storm surge height. Storm surge reduction, here assessed through high water level (HWL) attenuation, is linked to wave attenuation across the front edge of the marsh; this positive trend highlights the reduction of water level height induced by wave setup reduction during wave propagation across the marsh front edge. Water level attenuation rates observed here have a greater range than the rates observed or modeled by other authors, and our results suggest that this is linked to the strong influence of waves in storm surge attenuation over coastal areas.  相似文献   

Large wood load and transport in a flood-free period within an inter-dam reach: a decade of monitoring the Dyje River,Czech Republic     

Zdeněk Máčka  Ondřej Kinc  Matej Hlavňa  David Hortvík  Lukáš Krejčí  Jana Matulová  Pavel Coufal  Pavel Zahradníček 《地球表面变化过程与地形》2020,45(14):3540-3555

This study examined the large wood (LW) load and transport during the non-flood period (2009–2018) following major floods that occurred in 2002 and 2006 within the inter-dam reach of the Dyje River (Czech–Austrian border). The LW load was examined in 36 river corridor segments scattered within the reach in the 2009–2018 period. Two whole-reach surveys (2011 and 2019) on LW frequency and distribution were conducted, and the export of LW to the downstream reservoir was analysed between June 2013 and December 2018. In the period of non-flood discharges, the recruitment and depletion of LW were highly variable processes in space and time, leading to a considerable change in the total LW quantity. Whereas the total number of LW pieces decreased, the total LW volume increased because of the increasing dimensions of newly recruited pieces. The annual variability in the quantity of newly recruited pieces was better explained by the variation in the maximum annual discharges (y = 41.043ln(x) + 3.2737, R² = 0.5352) than by the variability in the number of days with wind gusts >17.2 m/s (y = 1.5004x + 82.096, R² = 0.118). The land use change with the abandonment of human settlements after World War II and the progressive expansion of forest was the major historical factor driving the increased recruitment of LW to the river corridor. While the 2006 (>100-year RI) flood brought approximately 1,250 LW pieces to the reservoir, the 2013 (1.5-year RI) flood delivered 45 pieces. The long-term average monthly input of LW to the reservoir was 7.7 pieces. The exceptional low-magnitude flood of 2013, which occurred at the beginning of the monitoring period, was shown to be a threshold above which the number of LW pieces that floated to the dam significantly increased. © 2020 John Wiley & Sons, Ltd.  相似文献   

The COVID-19 pandemic and global environmental change: Emerging research needs     

Robert Barouki  Manolis Kogevinas  Karine Audouze  Kristine Belesova  Ake Bergman  Linda Birnbaum  Sandra Boekhold  Sebastien Denys  Celine Desseille  Elina Drakvik  Howard Frumkin  Jeanne Garric  Delphine Destoumieux-Garzon  Andrew Haines  Anke Huss  Genon Jensen  Spyros Karakitsios  Jana Klanova  Paolo Vineis 《Chemie der Erde / Geochemistry》2012

The outbreak of COVID-19 raised numerous questions on the interactions between the occurrence of new infections, the environment, climate and health. The European Union requested the H2020 HERA project which aims at setting priorities in research on environment, climate and health, to identify relevant research needs regarding Covid-19. The emergence and spread of SARS-CoV-2 appears to be related to urbanization, habitat destruction, live animal trade, intensive livestock farming and global travel. The contribution of climate and air pollution requires additional studies. Importantly, the severity of COVID-19 depends on the interactions between the viral infection, ageing and chronic diseases such as metabolic, respiratory and cardiovascular diseases and obesity which are themselves influenced by environmental stressors. The mechanisms of these interactions deserve additional scrutiny. Both the pandemic and the social response to the disease have elicited an array of behavioural and societal changes that may remain long after the pandemic and that may have long term health effects including on mental health. Recovery plans are currently being discussed or implemented and the environmental and health impacts of those plans are not clearly foreseen. Clearly, COVID-19 will have a long-lasting impact on the environmental health field and will open new research perspectives and policy needs.  相似文献   

Thermally induced alterations of minerals during measurements of the temperature dependence of magnetic susceptibility: a case study from the hydrothermally altered Soultz-sous-Forêts granite,France     

Jana?JustEmail author  Agnes?Kontny 《International Journal of Earth Sciences》2012,101(3):819-839

Identification of magnetic minerals using the temperature dependence of magnetic susceptibility in low field (κ–T) combined with optical microscopy, microprobe, X-ray diffraction, and chemical analysis provided new constraints on the alteration of Fe-bearing minerals of the magnetite-bearing Soultz-sous-Forêts granite from the EPS-1 borehole (upper Rhine Graben, France). While relatively fresh granite shows largely reversible κ–T curves typical of magnetite, the altered granite revealed a wide variety of irreversible heating and cooling curves, which allowed an assignment to different alteration stages under specific geochemical conditions. Though paramagnetic minerals like Fe-bearing carbonates, pyrite, or antiferromagnetic hematite could not be detected according to their Curie or Neél temperature, they were identified due to reactions to new ferrimagnetic phases during the heating/cooling experiments at specific temperatures. Mineral reactions were proved by measurements of the single mineral phases hematite, Fe-carbonates, and illite. Our mineralogical results combined with the thermomagnetic measurements imply that first faulting of the granite occurred already during cooling of the magma, which caused a first magnetite oxidation event. During uplift of the granitic body and exposure to a paleo-erosion surface, strongly acidic fluids, emerged from pyrite oxidation, caused a decomposition of Fe-bearing minerals like martite (hematite derived from magnetite oxidation) and Fe-carbonates and an ongoing transformation of magnetite to martite. Subsequently, precipitation of fine-grained hematite was restricted only to the upper part of the pluton. In the deeper part of the borehole, pyrite was preserved from oxidation. In an active fault, zone martite was reduced back to magnetite, which can be explained with the occurrence of organic matter transported by fluids.  相似文献   

Isolation and identification of cadmium- and lead-resistant lactic acid bacteria for application as metal removing probiotic     

J. N. Bhakta  Y. Munekage  K. Ohnishi  B. B. Jana 《International Journal of Environmental Science and Technology》2012,9(3):433-440

The purpose of the present study was to isolate and identify the metal-resistant lactic acid bacteria from sediments of coastal aquaculture habitats for removal of cadmium and lead from ambience. Collected sediment samples were used to isolate the cadmium- and lead-resistant bacterial colonies by spread plate technique using agar media (De Man, Rogosa and Sharpe) supplemented with cadmium or lead at 50?mg/l. Isolates were identified by bacterial colony polymerase chain reaction and sequencing of 16S ribosomal deoxyribonucleic acid. Metal removing probiotic was determined by characterizing the lactic acid yield in culture media, viability in fish intestine, metal-resistant and metal-removal efficiencies. 16S ribosomal deoxyribonucleic acid sequencing data of five (Cd10, Cd11, Pb9, Pb12 and Pb18) and other all isolates clearly showed 99?% similarities to Enterococcus faecium and Bacillus cereus, respectively. The Pb12 exhibited higher lactic acid yield (180?mmol) than that of the remaining E. faecium strains and excellent viability without pathogenicity; therefore, further study was carried out using Pb12 strain. The selected Pb12 strain showed elevated metal resistant (minimum inhibitory concentrations 120 and 800?mg/l for cadmium and lead, respectively) and removal efficiencies [Cadmium 0.0377?mg/h/g and lead 0.0460?mg/h/g of cells (wet weight)]. From the viability and metal removal points of view, it can be concluded that isolated metal-resistant E. faecium Pb12 strains might be used as potential probiotic strains for removing heavy metals from fish intestinal milieu to control the progressive bioaccumulation of heavy metals in the fish.  相似文献   

Stardust-NExT,Deep Impact,and the accelerating spin of 9P/Tempel 1     

Michael J.S. Belton  Karen J. Meech  Steven Chesley  Jana Pittichová  Brian Carcich  Michal Drahus  Alan Harris  Stephen Gillam  Joseph Veverka  Nicholas Mastrodemos  William Owen  Michael F. A’Hearn  S. Bagnulo  J. Bai  L. Barrera  Fabienne Bastien  James M. Bauer  J. Bedient  B.C. Bhatt  Hermann Boehnhardt  H. Zhao 《Icarus》2011,213(1):345-368

The evolution of the spin rate of Comet 9P/Tempel 1 through two perihelion passages (in 2000 and 2005) is determined from 1922 Earth-based observations taken over a period of 13 year as part of a World-Wide observing campaign and from 2888 observations taken over a period of 50 days from the Deep Impact spacecraft. We determine the following sidereal spin rates (periods): 209.023 ± 0.025°/dy (41.335 ± 0.005 h) prior to the 2000 perihelion passage, 210.448 ± 0.016°/dy (41.055 ± 0.003 h) for the interval between the 2000 and 2005 perihelion passages, 211.856 ± 0.030°/dy (40.783 ± 0.006 h) from Deep Impact photometry just prior to the 2005 perihelion passage, and 211.625 ± 0.012°/dy (40.827 ± 0.002 h) in the interval 2006–2010 following the 2005 perihelion passage. The period decreased by 16.8 ± 0.3 min during the 2000 passage and by 13.7 ± 0.2 min during the 2005 passage suggesting a secular decrease in the net torque. The change in spin rate is asymmetric with respect to perihelion with the maximum net torque being applied on approach to perihelion. The Deep Impact data alone show that the spin rate was increasing at a rate of 0.024 ± 0.003°/dy/dy at JD2453530.60510 (i.e., 25.134 dy before impact), which provides independent confirmation of the change seen in the Earth-based observations.The rotational phase of the nucleus at times before and after each perihelion and at the Deep Impact encounter is estimated based on the Thomas et al. (Thomas et al. [2007]. Icarus 187, 4–15) pole and longitude system. The possibility of a 180° error in the rotational phase is assessed and found to be significant. Analytical and physical modeling of the behavior of the spin rate through of each perihelion is presented and used as a basis to predict the rotational state of the nucleus at the time of the nominal (i.e., prior to February 2010) Stardust-NExT encounter on 2011 February 14 at 20:42.We find that a net torque in the range of 0.3–2.5 × 10⁷ kg m² s^?2 acts on the nucleus during perihelion passage. The spin rate initially slows down on approach to perihelion and then passes through a minimum. It then accelerates rapidly as it passes through perihelion eventually reaching a maximum post-perihelion. It then decreases to a stable value as the nucleus moves away from the Sun. We find that the pole direction is unlikely to precess by more than ～1° per perihelion passage. The trend of the period with time and the fact that the modeled peak torque occurs before perihelion are in agreement with published accounts of trends in water production rate and suggests that widespread H₂O out-gassing from the surface is largely responsible for the observed spin-up.  相似文献   

Redacted in Nebraska: the noises of conspiracy around nuclear power problems     

John Eyles  Jana Fried  Emily Catherine Eyles 《GeoJournal》2014,79(3):329-342

This paper investigates a ‘small story’, the problems around the Fort Calhoun nuclear power plant (Nebraska) in the wet summer of 2011. Relying on materials from digital media, it presents the official and an alternative version of events. Utilizing a constructionist approach, it identifies the search for moral certainty, as well as the importance of blame and conspiracy theories, from which emerges the ‘big story’. Highlighting the important role of on-line media and digital communication, we document not only the official story but also an opposing version based on a coherent worldview emphasising the problems of big government, liberal views and denial of American individual rights—all framed as a conspiracy covering-up a threatening, human-made technology failure. We suggest why this worldview occurs, stressing a widespread emphasis on American values and history, ‘failed journalism’, public uncertainty, the complexity of nuclear technology, and the specific uses of digital communication.  相似文献   

Confirmation of Cometary Features of Newly Discovered Bodies     

Miloš Tichý  Jana Tichá  Michal Kočer 《Earth, Moon, and Planets》2002,90(1-4):507-513

The majority of new ground-based discoveries of comets comes from large surveys devoted, predominantly, to Near Earth Asteroids. The first step in distinguishing these newly discovered members of the population of cometary bodies consists inconfirmatory astrometric observations along with detection of their cometaryfeatures. Although both amateur and professional stations take part in suchconfirmatory observations, only some of them do a preliminary analysis of thecometary activity of a particular newly discovered body. A timely recognitionof cometary features of a particular body having an unusual orbit can help inplanning further observing campaigns.A main goals of the Klet Observatory NEO astrometric follow-upprogramme consists of an analysis of possible cometary activity of newlydiscovered unusual bodies. Here, we describe several examples (comets C/1999 S4 (LINEAR) and so on). We also mention an extension of our programme to fainterobjects after the completion ofa new 1-m telescope at the Klet Observatory.  相似文献   

Reconstruction of a complex late Quaternary glacial landscape in the Cordillera de Cochabamba (Bolivia) based on a morphostratigraphic and multiple dating approach     

Jan-Hendrik May  Jana Zech  Frank Preusser  Jaime Argollo  Heinz Veit 《Quaternary Research》2011,76(1):106-118

Although glacial landscapes have previously been used for the reconstruction of late Quaternary glaciations in the Central Andes, only few data exist for the Eastern Cordillera in Bolivia. Here, we present results from detailed morphostratigraphic mapping and new data of surface exposure dating (SED), optically stimulated luminescence (OSL), and radiocarbon dating (¹⁴C) from the Huara Loma Valley, Cordillera de Cochabamba (Bolivia). Discrepancies between individual dating methods could be addressed within the context of a solid geomorphic framework. We identified two major glaciations. The older is not well constrained by the available data, whereas the younger glaciation is subdivided into at least four major glacial stages. Regarding the latter, a first advance dated to ~ 29-25 ka occurred roughly contemporaneous with the onset of the global last glacial maximum (LGM) and was followed by a less extensive (re-)advance around 20-18 ka. The local last glacial maximum (LLGM) in the Huara Loma Valley took place during the humid lateglacial ~ 17-16 ka, followed by several smaller readvances until ~ 10-11 ka, and complete deglaciation at the end of the Early Holocene.  相似文献   

Strategic coupling in ‘next wave cities’: Local institutional actors and the offshore service sector in the Philippines     

Jana Maria Kleibert 《Singapore journal of tropical geography》2014,35(2):245-260

The outsourcing and offshoring of services to developing countries has created new opportunities for economic development for countries in the global South. This paper looks at the scope for agency of local institutional actors in the investment attraction of business process outsourcing companies. Drawing on empirical work from the Philippines, an analysis of the process of integrating lower‐tier cities into global service production networks is presented. Specifically, the roles of local institutional actors in facilitating FDI attraction and strategically coupling local assets with the needs of multinational service corporations are discussed. Two contrasting cases, the cities of Baguio and Bacolod, show that considerable scope for intervention rests with local institutional actors. The findings have implications for policymaking and research concerned with the newest phase of outsourcing and offshoring in developing countries.  相似文献