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211.
Ana J. Abascal Sonia Castanedo Paula Núñez Adam Mellor Annika Clements Beatriz Pérez Mar Cárdenas Helios Chiri Raúl Medina 《Marine pollution bulletin》2017,114(1):302-314
This paper presents a high-resolution operational forecast system for providing support to oil spill response in Belfast Lough. The system comprises an operational oceanographic module coupled to an oil spill forecast module that is integrated in a user-friendly web application. The oceanographic module is based on Delft3D model which uses daily boundary conditions and meteorological forcing obtained from COPERNICUS and from the UK Meteorological Office. Downscaled currents and meteorological forecasts are used to provide short-term oil spill fate and trajectory predictions at local scales. Both components of the system are calibrated and validated with observational data, including ADCP data, sea level, temperature and salinity measurements and drifting buoys released in the study area. The transport model is calibrated using a novel methodology to obtain the model coefficients that optimize the numerical simulations. The results obtained show the good performance of the system and its capability for oil spill forecast. 相似文献
212.
Castañeda Javiera V. Bronfman Nicolás C. Cisternas Pamela C. Repetto Paula B. 《Natural Hazards》2020,103(2):1881-1904
Natural Hazards - Understanding the culture of preparedness is essential to improve public policies and programs aimed to promote population preparedness to cope with natural hazards. The present... 相似文献
213.
Marengo Jose A. Cunha Ana Paula M. A. Nobre Carlos A. Ribeiro Neto Germano G. Magalhaes Antonio R. Torres Roger R. Sampaio Gilvan Alexandre Felipe Alves Lincoln M. Cuartas Luz A. Deusdará Karinne R. L. Álvala Regina C. S. 《Natural Hazards》2020,103(2):2589-2611
Natural Hazards - Historically, during periods of extreme drought, food security in the drylands of the semiarid region of Northeast Brazil (NEB) is under severe risk due to agricultural collapse.... 相似文献
214.
Stefano Cannicci Fabrizio Bartolini Farid Dahdouh-Guebas Sara Fratini Carlos Litulo Adriano Macia Elisha J. Mrabu Gil Penha-Lopes Jos Paula 《Estuarine, Coastal and Shelf Science》2009,84(3):305
Mangrove forests are known to accomplish crucial ecosystem functions and services. They are nursery areas for fish, prawns and crabs, which provide coastal communities with a variety of food, timber and chemicals, and protect coasts from catastrophic events, such as tsunamis. Recently, a novel ecological service has been proposed for mangrove systems, namely natural wastewater treatment wetlands. This hypothesis was based on experimental data collected mainly in Chinese mangrove systems, which proved that mangrove soils were efficient in absorbing nutrients. Moreover, sewage loading seemed harmless to both plants and benthic communities in these systems. However, before promoting the use of natural mangroves as pollution buffers, or constructed mangrove wetlands as sewage treatment facilities, more data are needed on their overall tolerance to organic loading. Differences in macrobenthos patterns were thus investigated between peri-urban mangroves and sites not affected by sewage disposal in East Africa. We assessed differences in epifaunal assemblages, comprising crabs and molluscs, employing multivariate ACI unbalanced analyses to compare peri-urban mangrove swamps with those characteristic of non-urban mangroves with similar ecological traits. The sampling design was spatially nested, replicates being assessed at equatorial (southern Kenya) and subtropical (southern Mozambique) sites. The results manifested a consistent increase in crab biomass at the peri-urban sites in both Kenya and Mozambique. Moreover, the peri-urban systems were richer than the non-urban mangroves, both in terms of fiddler crabs (Uca spp.) which feed on benthic microalgae and bacteria, and sesarmids, such as Perisesarma guttatum and Neosarmatium meinerti, which feed on both substratum and leaf litter. The abundance of gastropods, in contrast, decreased significantly, especially in Kenya, mainly due to the disappearance of the mud whelk Terebralia palustris. The results thus indicate that, in East African mangrove systems, domestic wastewater has detectable effects on crabs and molluscs, suggesting their usefulness as bioindicators of its effects in mangroves. Transformed benthic patterns at the peri-urban sites indicated the need for further study of the actual potential of natural mangrove forests to absorb pollution in sewage treatment. 相似文献
215.
Gil Penha-Lopes Steven Bouillon Perrine Mangion Adriano Macia Jos Paula 《Estuarine, Coastal and Shelf Science》2009,84(3):318-325
Population structure and distribution of Terebralia palustris were compared with the environmental parameters within microhabitats in a monospecific stand of Avicennia marina in southern Mozambique. Stable carbon and nitrogen isotope analyses of T. palustris and potential food sources (leaves, pneumatophore epiphytes, and surface sediments) were examined to establish the feeding preferences of T. palustris. Stable isotope signatures of individuals of different size classes and from different microhabitats were compared with local food sources. Samples of surface sediments 2.5–10 m apart showed some variation (−21.2‰ to −23.0‰) in δ13C, probably due to different contributions from seagrasses, microalgae and mangrove leaves, while δ15N values varied between 8.7‰ and 15.8‰, indicating that there is a very high variability within a small-scale microcosm. Stable isotope signatures differed significantly between the T. palustris size classes and between individuals of the same size class, collected in different microhabitats. Results also suggested that smaller individuals feed on sediment, selecting mainly benthic microalgae, while larger individuals feed on sediment, epiphytes and mangrove leaves. Correlations were found between environmental parameters and gastropod population structure and distribution vs. the feeding preferences of individuals of different size classes and in different microhabitats. While organic content and the abundance of leaves were parameters that correlated best with the total density of gastropods (>85%), the abundance of pneumatophores and leaves, as well as grain size, correlated better with the gastropod size distribution (>65%). Young individuals (height < 3 cm) occur predominantly in microhabitats characterized by a low density of leaf litter and pneumatophores, reduced organic matter and larger grain size, these being characteristic of lower intertidal open areas that favour benthic microalgal growth. With increasing shell height, T. palustris individuals start occupying microhabitats nearer the mangrove trees characterized by large densities of pneumatophores and litter, as well as sediments of smaller grain size, leading to higher organic matter availability in the sediment. 相似文献
216.
Understanding the movement of marine fish larvae in coastal habitats requires an assessment of active swimming abilities. The critical speed (U-crit) and endurance swimming of late-stage larvae of Diplodus capensis and Sarpa salpa (Family Sparidae), common inshore recreational linefish species, were measured in a laboratory swimming chamber. Postflexion and settlement-stage larvae were collected from the wild in a small bay on the warm temperate coast of South Africa. Larvae were allowed to acclimate in captivity and were tested soon after capture. For the endurance tests a speed of 18 cm s−1 was selected, as this approximated the mean current speed observed in the coastal environment of the area. The mean U-crit value (maximum swimming speed) for D. capensis (19 cm s−1) was similar to that of S. salpa (18 cm s−1), and similarly mean endurance (km swum) for S. salpa (8 km) was similar to that of D. capensis (6 km). The increase in critical speed and endurance swimming abilities with standard length was best described by a linear relationship. At lengths between 12 and 15 mm BL, D. capensis was the better swimmer, whereas S. salpa was the better swimmer between 15 and 16 mm BL. Of all the larvae that swam at critical speed, 90% were in an inertial environment. These swimming speeds exceed the modal current velocities observed in the shallow nearshore of the study region where these larvae occur abundantly. These swimming abilities provide larvae with the potential to influence their dispersal trajectories and ultimately influence their distribution in their nearshore nursery areas. 相似文献
217.
Steven D. Andrews Audrey Decou Bill Braham Simon R. A. Kelly Paula Robinson Andrew C. Morton John E. A. Marshall Fiona Hyden 《Basin Research》2020,32(5):1213-1233
Previous work has demonstrated the presence of a number of exhumed hydrocarbon traps in central East Greenland. Re-evaluation of the stratigraphy alongside detailed investigation of the occurrence of bitumen within the Mols Bjerge and Laplace Bjerg exhumed hydrocarbon traps provides new perspectives on these structures, as well as the petroleum geology of East Greenland and the wider North Atlantic. Sedimentological and stratigraphic studies, augmented with palynological and provenance investigations, have constrained the dating and correlation of the strata exposed in the Mols Bjerge and Laplace Bjerg. Petrographic analysis, alongside analysis of the bitumen identified, has highlighted a much wider distribution of hydrocarbon than previously recognized. It was previously considered that Jurassic strata formed the main reservoir interval within the Mols Bjerge and Laplace Bjerg exhumed hydrocarbon traps. It is shown here that the reservoir intervals in the Laplace Bjerg trap lie within the Late Triassic Ørsted Dal and Vega Sund members, which contain up to 18% pyrobitumen and were previously misidentified as Jurassic. The Jurassic Bristol Elv Formation is the most extensively bitumen stained unit in the Mols Bjerge trap. However, occurrences of pyrobitumen (up to 3%) are recorded throughout the Triassic stratigraphy, including the Early Triassic Wordie Creek Formation. Faults, thick calcrete development and regionally continuous mudstone units play an important role in compartmentalizing the palaeohydrocarbon accumulations. 相似文献
218.
In this study, we investigate the response of a Regional Climate Model (RCM) to errors in the atmospheric data used as lateral
boundary conditions (LBCs) using a perfect-model framework nick-named the “Big-Brother Experiment” (BBE). The BBE has been
designed to evaluate the errors due to the nesting process excluding other model errors. First, a high-resolution (45 km)
RCM simulation is made over a large domain. This simulation, called the Perfect Big Brother (PBB), is driven by the National
Centres for Environmental Prediction (NCEP) reanalyses; it serves as reference virtual-reality climate to which other RCM
runs will be compared. Next, errors of adjustable magnitude are introduced by performing RCM simulations with increasingly
larger domains at lower horizontal resolution (90 km mesh). Such simulations with errors typical of today’s Coupled General
Circulation Models (CGCM) are called the Imperfect Big-Brother (IBB) simulations. After removing small scales in order to
achieve low-resolution typical of today’s CGCMs, they are used as LBCs for driving smaller domain high-resolution RCM runs;
these small-domain high-resolution simulations are called Little-Brother (LB) simulations. The difference between the climate
statistics of the IBB and those of PBB simulations mimic errors of the driving model. The comparison of climate statistics
of the LB to those of the PBB provides an estimate of the errors resulting solely from nesting with imperfect LBCs. The simulations
are performed over the East Coast of North America using the Canadian RCM, for five consecutive February months (from 1990
to 1994). It is found that the errors contained in the large scales of the IBB driving data are transmitted to and reproduced
with little changes by the LB. In general, the LB restores a great part of the IBB small-scale errors, even if they do not
take part in the nesting process. The small scales are seen to improve slightly in regions with important orographic forcing
due to the finer resolution of the RCM. However, when the large scales of the driving model have errors, the small scales
developed by the LB have errors as well, suggesting that the large scales precondition the small scales. In order to obtain
correct small scales, it is necessary to provide the accurate large-scale circulation at the lateral boundary of the RCM. 相似文献
219.
Paula Meth 《Geoforum》2009,40(5):853-863
Men living in the informal settlement of Cato Crest, Durban, South Africa, where violence and crime are high, are marginalised in a variety of ways, but also cling to patriarchal ideals. These relations of power are witnessed through the expression of a range of emotions which point to the interconnections between emotions, place, politics and performances of masculinity. This paper contributes to debates over the significance of politics in analyses of emotions, as well as broadening attention to geographies of emotions of, and beyond, fear. Using an example from the global South, the particular politics informing marginalisation and their relations with emotion are examined. This is achieved through a focus on three key government policy agendas shaping these men’s lives, namely housing, gender and employment. 相似文献
220.