A habitat-specific fish-based approach to assess the ecological status of Mediterranean coastal lagoons   总被引：1，自引：0，他引：1  

Anita Franco  Patrizia Torricelli  Piero Franzoi 《Marine pollution bulletin》2009,58(11):1704-1717

A habitat approach was promoted in the framework of ecological status assessment of transitional waters, assuming the importance of habitat heterogeneity to the overall system status. The approach was applied to the use of fish-based multimetric indices by adapting them to seagrass and marsh habitats in the Venice lagoon, Italy, through selection of appropriate metrics and reference conditions. While for marsh habitats, no clear patterns resulted, the index response for seagrass was consistent with the habitat degradation and loss recorded in the lagoon between 2002 and 2005 and with the higher habitat disturbance in southern and central lagoon sub-basins. The assessment of individual habitats is presented as a first step in the process of evaluating the overall condition of a Mediterranean lagoon environment, which should also take account of the diversity of habitats and their availability within the system to properly define an overall index of ecological status.  相似文献   

Characterization of alkanes, hopanes, and polycyclic aromatic hydrocarbons (PAHs) in tar-balls collected from the East Coast of Peninsular Malaysia   总被引：1，自引：0，他引：1  

Chandru K  Zakaria MP  Anita S  Shahbazi A  Sakari M  Bahry PS  Mohamed CA 《Marine pollution bulletin》2008,56(5):950-962

The East Coast of Peninsular Malaysia faces the South China Sea and is vulnerable to oil pollution because of intense petroleum production activities in the area. The South China Sea is also a favored route for supertankers carrying crude oil to the Far East. Consequently, oil spills can occur, causing pollution and contamination in the surrounding areas. Residual oil spills stranded on coastal beaches usually end up as tar-balls. Elucidating the sources of tar-balls using a molecular marker approach is essential in assessing environmental impacts and perhaps settling legal liabilities for affected parties. This study utilizes a multimodal molecular marker approach through the use of diagnostic ratios of alkanes, hopanes, and polycyclic aromatic hydrocarbons (PAHs) to determine the source, distribution and weathering of tar-balls. Hopane ratios (e.g., C29/C30, and summation C31-C35/C30 ratios) were used to identify the sources of tar-balls. The weathering effects were distinguished by using alkanes, namely the unresolved complex mixture (UCM) and low molecular weight/high molecular weight (L/H) ratios. Similarly, PAHs were also used for the determination of weathering processes undergone by the tar-balls. This multimodal molecular marker gave a very strong indication of the sources of tar-balls in this study. For example, 16 out of 17 samples originated from South East Asian Crude Oil (SEACO) with one sample from Merang, Terengganu originating from North Sea Oil (Troll). The TRME-2 sample may have come from a supertanker's ballast water discharge. The second possibility is that the tar-ball may have been transported via oceanographic currents. All 'weathered' sample characterizations were based on the presence of UCM and other ratios. The multimodal molecular marker approach applied in this study has enabled us to partially understand the transport behavior of tar-balls in the marine environment and has revealed insights into the weathering process of tar-balls.  相似文献   

Can soil piping impact environment and society? Identifying new research gaps     

Anita Bernatek-Jakiel  Estela Nadal-Romero 《地球表面变化过程与地形》2023,48(1):72-86

Soil piping is a widespread, although often overlooked land degradation process. So far, subsurface soil erosion studies have been focused on the importance of soil piping in hydrological and geomorphological processes, and factors controlling piping processes. Nowadays, the environmental changes being caused by the Anthropocene have clearly demonstrated that society depends on soil more than ever before, so the traditional studies of soil erosion processes need to be redefined. In that sense, geomorphologists face to overcome new piping-related problems. In this article we identify new possible areas of research: (i) soil pipes and pipe collapses (PCs) as natural hazards, (ii) role of soil piping in carbon cycle, (iii) soil pipes and PCs and their relationships with biodiversity, and (iv) piping-affected areas as geodiversity sites. Only better recognition of natural hazards driven by soil piping, such as land subsidence and degradation, landslides, flooding and off-site sediment effects may result in better prevention and control measures in piping-affected areas. Moreover, in the context of Global Change the role of soil piping in carbon cycle should be raised. Land-use and land-cover changes, as well as climate change may affect piping dynamics in different morphoclimatic regions and soil loss due to piping may lead to carbon loss. Soil pipes and PCs are closely interlinked with biodiversity, both positively and negatively. Piping erosion may directly and indirectly destroy vegetation and animals, although in some cases piping erosion may create new habitats and provide favourable conditions for some species. However, soil piping is not only an environmental and societal problem, but it may also contribute to the world geodiversity, which is clearly observed in badland sites. Piping erosion may have a significant impact on environment and society, thus further research with new questions is essential to provide knowledge for sustainable development.  相似文献   

The effect of tides and storms on the sediment transport across a Dutch barrier island          下载免费PDF全文

Daan Wesselman  Renske de Winter  Anita Engelstad  Robert McCall  Ap van Dongeren  Piet Hoekstra  Albert Oost  Maarten van der Vegt 《地球表面变化过程与地形》2018,43(3):579-592

Under natural conditions, barrier islands might grow vertically and migrate onshore under the influence of long‐term sea level rise. Sediment is transported onshore during storm‐induced overwash and inundation. However, on many Dutch Wadden Islands, dune openings are closed off by artificial sand‐drift dikes that prevent the influx of sediment during storms. It has been argued that creating openings in the dune row to allow regular flooding on barrier islands can have a positive effect on the sediment budget, but the dominant hydrodynamic processes and their influence on sediment transport during overwash and inundation are unknown. Here, we present an XBeach model study to investigate how sediment transport during overwash and inundation across the beach of a typical mesotidal Wadden Sea barrier island is influenced by wave, tide and storm surge conditions. Firstly, we validated the model XBeach with field data on waves and currents during island inundation. In general, the XBeach model performed well. Secondly, we studied the long‐term sediment transport across the barrier island. We distinguished six representative inundation classes, ranging from frequently occurring, low‐energy events to infrequent, high‐energy events, and simulated the hydrodynamics and sediment transport during these events. An analysis of the model simulations shows that larger storm events cause larger cross‐shore sediment transport, but the net sediment exchange during a storm levels off or even becomes smaller for the largest inundation classes because it is counteracted by larger mean water levels in the Wadden Sea that oppose or even reverse sediment transport during inundation. When taking into account the frequency of occurrence of storms we conclude that the cumulative effect of relatively mild storms on long‐term cross‐shore sediment transport is much larger than that of the large storm events. © 2017 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.  相似文献   

Developing observational methods to drive future hydrological science: Can we make a start as a community?     

Keith Beven  Anita Asadullah  Paul Bates  Eleanor Blyth  Nick Chappell  Stewart Child  Hannah Cloke  Simon Dadson  Nick Everard  Hayley J. Fowler  Jim Freer  David M. Hannah  Kate Heppell  Joseph Holden  Rob Lamb  Huw Lewis  Gerald Morgan  Louise Parry  Thorsten Wagener 《水文研究》2020,34(3):868-873

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Treatment of Crystal Violet from Synthetic Solution Using Membranes Doped with Natural Fruit Extract          下载免费PDF全文

Simona Caprarescu  Alexandra R. Miron  Violeta Purcar  Anita‐Laura Radu  Andrei Sarbu  Cristian Andi Nicolae  Mihaela Pascu  Daniela Ion‐Ebrasu  Valentin Raditoiu 《洁净——土壤、空气、水》2018,46(7)

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The impact of a storm surge on business establishments in the Houston MSA     

Anita R. Schiller 《Natural Hazards》2011,56(1):331-346

This paper examines the possible storm surge damage from a major hurricane to hit the Houston Metropolitan Statistical Area (MSA.) Using storm surge analysis on a unique data set compiled from the Texas Workforce Commission (QCEW), the paper estimates the expected industry-level damage for each county in the Houston MSA. The advantages of using GIS to analyze the expected storm surge damage estimation is that it provides an accurate estimation of the number of affected employees and probable wages losses, by industry and county, based on QCEW data. The results indicate that the ‘Basic Chemical Manufacturing’ and ‘Oil and Gas Extraction’ industries incur the highest employee and payroll losses while the ‘Restaurants and Eateries’ has the largest establishment damage if a major hurricane were to hit the Houston MSA.  相似文献   

Assessment of institutional capacity to adapt to climate change in transboundary river basins     

Anita Milman  Lisa Bunclark  Declan Conway  William Neil Adger 《Climatic change》2013,121(4):755-770

Responses to climate change in transboundary river basins are believed to depend on national and sub-national capacities as well as the ability of co-riparian nations to communicate, coordinate, and cooperate across their international boundaries. We develop the first framework for assessing transboundary adaptive capacity. The framework considers six dimensions of transboundary river basins that influence planning and implementation of adaptation measures and represents those dimensions using twelve measurable indicators. These indicators are used to assess transboundary adaptive capacity of 42 basins in the Middle East, Mediterranean, and Sahel. We then conduct a cluster analysis of those basins to delineate a typology that includes six categories of basins: High Capacity, Mediated Cooperation, Good Neighbour, Dependent Instability, Self-Sufficient, and Low Capacity. We find large variation in adaptive capacity across the study area; basins in Western Europe generally have higher capacities to address the potential hazards of climate change. Our basin typology points to how climate change adaptation policy interventions would be best targeted across the different categories of basins.  相似文献   

Development of Atlantic cod (Gadus morhua) exposed to produced water during early life stages: Effects on embryos, larvae, and juvenile fish     

Sonnich Meier  H. Craig Morton  Gunnar Nyhammer  Bjrn Einar Grsvik  Valeri Makhotin  Audrey Geffen  Stepan Boitsov  Karen Anita Kvestad  Anneli Bohne-Kjersem  Anders Goksyr  Arild Folkvord  Jarle Klungsyr  Asbjrn Svardal 《Marine environmental research》2010,70(5):383-394

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Dynamic tensile strength of terrestrial rocks and application to impact cratering     

Huirong‐Anita Ai  Thomas J. Ahrens 《Meteoritics & planetary science》2004,39(2):233-246

Abstract— Dynamic tensile strengths and fracture strengths of 3 terrestrial rocks, San Marcos gabbro, Coconino sandstone, and Sesia eclogite were determined by carrying out flat‐plate (PMMA and aluminum) impact experiments on disc‐shaped samples in the 5 to 60 m/sec range. Tensile stresses of 125 to 300 MPa and 245 to 580 MPa were induced for gabbro and eclogite, respectively (with duration time of ?1 μs). For sandstone (porosity 25%), tensile stresses normal to bedding of ?13 to 55 MPa were induced (with duration times of 2.4 and ?1.4 μs). Tensile crack failure was detected by the onset of shock‐induced (damage) P and S wave velocity reduction. The dynamic tensile strength of gabbro determined from P and S wave velocity deficits agrees closely with the value of previously determined values by post‐impact microscopic examination (?150 MPa). Tensile strength of Coconino sandstone is 20 MPa for a 14 μs duration time and 17 MPa for a 2.4 μs duration time. For Sesia eclogite, the dynamic tensile strength is ?240 MPa. The fracture strength for gabbro is ?250 MPa, ?500 MPa for eclogite, and ?40 MPa for sandstone. Relative crack‐induced reduction of S wave velocities is less than that of post‐impact P wave velocity reductions for both gabbro and eclogite, indicating that the cracks were predominantly spall cracks. Impacts upon planetary surfaces induce tensile failure within shock‐processed rocks beneath the resulting craters. The depth of cracking beneath impact craters can be determined both by seismic refraction methods for rocks of varying water saturation and, for dry conditions (e.g., the Moon), from gravity anomalies. In principle, depth of cracking is related to the equations‐of‐state of projectile and target, projectile dimension, and impact velocity. We constructed a crack‐depth model applicable to Meteor Crater. For the observed 850 m depth of cracking, our preferred strength scaling model yields an impact velocity of 33 km/s and impactor radius of 9 m for an iron projectile.  相似文献