938 resultados para Coastal and estuarine stations


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Owing to their high vulnerability and low adaptive capacity, Caribbean islands have legitimate concerns about their future, based on observational records, experience with current patterns and consequences of climate variability, and climate model projections. Although emitting less than 1% of global greenhouse gases, islands from the region have already perceived a need to reallocate scarce resources away from economic development and poverty reduction, and towards the implementation of strategies to adapt to the growing threats posed by global warming (Nurse and Moore, 2005). The objectives of this Report are to conduct economic analyses of the projected impacts of climate change to 2050, within the context of the IPCC A2 and B2 scenarios, on the coastal and marine resources of the British Virgin Islands (BVI). The Report presents a valuation of coastal and marine services; quantitative and qualitative estimates of climate change impacts on the coastal zone; and recommendations of possible adaptation strategies and costs and benefits of adaptation. A multi-pronged approach is employed in valuing the marine and coastal sector. Direct use and indirect use values are estimated. The amount of economic activity an ecosystem service generates in the local economy underpins estimation of direct use values. Tourism and fisheries are valued using the framework developed by the World Resources Institute. Biodiversity is valued in terms of the ecological functions it provides, such as climate regulation, shoreline protection, water supply erosion control and sediment retention, and biological control, among others. Estimates of future losses to the coastal zone from climate change are determined by considering: (1) the effect of sea level rise on coastal lands; and (2) the effect of a rise in sea surface temperature (SST) on coastal waters. Discount rates of 1%, 2% and 4% are employed to analyse all loss estimates in present value terms. The overall value for the coastal and marine sector is USD $1,606 million (mn). This is almost 2% larger than BVI’s 2008 GDP. Tourism and recreation comprise almost two-thirds of the value of the sector. By 2100, the effects of climate change on coastal lands are projected to be $3,988.6 mn, and $2,832.9 mn under the A2 and B2 scenarios respectively. In present value terms, if A2 occurs, losses range from $108.1-$1,596.8 mn and if B2 occurs, losses range from $74.1-$1,094.1 mn, depending on the discount rate used. Estimated costs of a rise in SST in 2050 indicate that they vary between $1,178.0 and $1,884.8 mn. Assuming a discount rate of 4%, losses range from $226.6 mn for the B2 scenario to $363.0 mn for the A2 scenario. If a discount rate of 1% is assumed, estimated losses are much greater, ranging from $775.6-$1,241.0 mn. Factoring in projected climate change impacts, the net value of the coastal and marine sector suggests that the costs of climate change significantly reduce the value of the sector, particularly under the A2 and B2 climate change scenarios for discount rates of 1% and 2%. In contrast, the sector has a large, positive, though declining trajectory, for all years when a 4% discount rate is employed. Since the BVI emits minimal greenhouse gases, but will be greatly affected by climate change, the report focuses on adaptation as opposed to mitigation strategies. The options shortlisted are: (1) enhancing monitoring of all coastal waters to provide early warning alerts of bleaching and other marine events; (2) introducing artificial reefs or fish-aggregating devices; (3) introducing alternative tourist attractions; (4) providing retraining for displaced tourism workers; and (5) revising policies related to financing national tourism offices to accommodate the new climatic realities. All adaptation options considered are quite justifiable in national terms; each had benefit-cost ratios greater than 1.

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O estudo de comunidades de peixes estuarinos tem recebido a atenção de pesquisadores, pelo fato destes ecossistemas apresentarem uma grande variedade e abundância de peixes. Muitas destas espécies possuem interesse comercial, constituido-se numa ferramenta fundamental para a avaliação dos estoques pesqueiros, contribuindo também para a conservação dos ambientes estuarinos e costeiros. O estuário do rio Curuçá localiza-se na costa norte, região do salgado paraense, apesar da pesca ser a principal atividade econômica das cidades da região, existem poucos estudos a respeito da ictiofauna local. O objetivo principal deste trabalho foi de caracterizar a ictiofauna demersal dos canais principais do estuário do rio Curuçá, identificando as variações anuais e espaciais na composição, densidade e biomassa, bem como os fatores abióticos que influenciam nestas variações. Para isto, foram realizadas coletas bimestrais, utilizando uma rede de arrasto de fundo, nos dois canais principais do estuário. Ao final do estudo foram capturados 18.989 indivíduos, pertecentes a 73 espécies, destas Ophichthus cylindroideus, Hippocampus reidi, Sygnathus pelagicus e Butis koilomatodon ainda não haviam sido registradas para a costa norte. As famílias Sciaenidae, Engraulidae e Ariidae, foram as mais representativas em número de espécies, densidade e biomassa, dominando as capturas. As 20 espécies classificadas como estuarinas foram a maioria, e apresentaram as maiores densidades e biomassa em todos os meses e estações de coleta. A densidade média (0,12 ind/m²) foi significativamente maior na estação chuvosa, já para a biomassa (1,11 g/m²) não houve diferenças significativas entre os meses de coleta. Entre os perfis, Curuçá apresentou uma maior riqueza de espécies, densidade e biomassa. Esta diferença está relacionada principalmente a uma maior heterogenidade de substratos deste perfil, fazendo com que este possua uma maior disponibilidade de microhabitat. Os parâmetros físicos-químicos da água se apresentaram homogêneos ao longo dos pontos de coletas tendo pouca influência sobre a distribuição espacial da ictiofauna. O fato de encontrarmos novos registros de espécies para a região, reforça a importância de novos estudos para uma maior compreensão da ictiofauna local, que é um importante recurso econômico para as populações locais.

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The Camamu Bay (CMB) is located on the narrowest shelf along the South American coastline and close to the formation of two major Western Boundary Currents (WBC), the Brazil/North Brazil Current (BC/NBC). These WBC flow close to the shelf break/slope region and are expected to interact with the shelf currents due to the narrowness of the shelf. The shelf circulation is investigated in terms of current variability based on an original data set covering the 2002-2003 austral summer and the 2003 austral autumn. The Results show that the currents at the shelf are mainly wind driven, experiencing a complete reversal between seasons due to a similar change in the wind field. Currents at the inner-shelf have a polarized nature, with the alongshore velocity mostly driven by forcings at the sub-inertial frequency band and the cross-shore velocity mainly supra-inertially forced, with the tidal currents playing an important role at this direction. The contribution of the forcing mechanisms at the mid-shelf changes between seasons. During the summer, forcings in the two frequency bands are important to drive the currents with a similar contribution of the tidal currents. On the other hand, during the autumn season, the alongshore velocity is mostly driven by sub-inertial forcings and tidally driven currents still remain important in both directions. Moreover, during the autumn when the stratification is weaker, the response of the shelf currents to the wind forcing presents a barotropic signature. The meso-scale processes related to the WBC flowing at the shelf/slope region also affect the circulation within the shelf, which contribute to cause significant current reversals during the autumn season. Currents at the shelf-estuary connection are clearly supra-inertially forced with the tidal currents playing a key role in the generation of the along-channel velocities. The sub-inertial forcings at this location act mainly to drive the weak ebb currents which were highly correlated with both local and remote wind forcing during the summer season. (C) 2010 Elsevier Ltd. All rights reserved.

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The New World genus Cathorops in the family Ariidae (Sea Catfishes) includes species that inhabit estuarine and coastal waters as well as freshwaters, playing an important role in Neotropical coastal and estuarine fisheries. The relatively conserved external morphology coupled with the marked sexual dimorphism and ontogenetic variation makes it difficult to recognize and diagnose the species. One of the major problems concerns the nomenclatural and geographical limits, of C. spixii, described from tropical Brazil and often treated as the only coastal marine species in the genus from the Western Atlantic. Examination of types of nominal species as well as comprehensive collections of non-types from Caribbean and Atlantic South America, lead us to conclude that C. spixii is restricted to Brazil and that C. nuchalis is a valid species, ranging from Venezuela to Guyana. The nominal species Arius laticeps, Arius nigricans, and Arius variolosus are synonyms of C. nuchalis, C. spixii, and C. arenatus, respectively. We also describe a new species in the Cathorops mapale species group from Colombia and Venezuela.

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Two of the indicators of the UN Millennium Development Goals ensuring environmental sustainability are energy use and per capita carbon dioxide emissions. The increasing urbanization and increasing world population may require increased energy use in order to transport enough safe drinking water to communities. In addition, the increase in water use would result in increased energy consumption, thereby resulting in increased green-house gas emissions that promote global climate change. The study of multiple Municipal Drinking Water Distribution Systems (MDWDSs) that relates various MDWDS aspects--system components and properties--to energy use is strongly desirable. The understanding of the relationship between system aspects and energy use aids in energy-efficient design. In this study, components of a MDWDS, and/or the characteristics associated with the component are termed as MDWDS aspects (hereafter--system aspects). There are many aspects of MDWDSs that affect the energy usage. Three system aspects (1) system-wide water demand, (2) storage tank parameters, and (3) pumping stations were analyzed in this study. The study involved seven MDWDSs to understand the relationship between the above-mentioned system aspects in relation with energy use. A MDWDSs model, EPANET 2.0, was utilized to analyze the seven systems. Six of the systems were real and one was a hypothetical system. The study presented here is unique in its statistical approach using seven municipal water distribution systems. The first system aspect studied was system-wide water demand. The analysis involved analyzing seven systems for the variation of water demand and its impact on energy use. To quantify the effects of water use reduction on energy use in a municipal water distribution system, the seven systems were modeled and the energy usage quantified for various amounts of water conservation. It was found that the effect of water conservation on energy use was linear for all seven systems and that all the average values of all the systems' energy use plotted on the same line with a high R 2 value. From this relationship, it can be ascertained that a 20% reduction in water demand results in approximately a 13% savings in energy use for all seven systems analyzed. This figure might hold true for many similar systems that are dominated by pumping and not gravity driven. The second system aspect analyzed was storage tank(s) parameters. Various tank parameters: (1) tank maximum water levels, (2) tank elevation, and (3) tank diameter were considered in this part of the study. MDWDSs use a significant amount of electrical energy for the pumping of water from low elevations (usually a source) to higher ones (usually storage tanks). The use of electrical energy has an effect on pollution emissions and, therefore, potential global climate change as well. Various values of these tank parameters were modeled on seven MDWDSs of various sizes using a network solver and the energy usage recorded. It was found that when averaged over all seven analyzed systems (1) the reduction of maximum tank water level by 50% results in a 2% energy reduction, (2) energy use for a change in tank elevation is system specific, and (2) a reduction of tank diameter of 50% results in approximately a 7% energy savings. The third system aspect analyzed in this study was pumping station parameters. A pumping station consists of one or more pumps. The seven systems were analyzed to understand the effect of the variation of pump horsepower and the number of booster stations on energy use. It was found that adding booster stations could save energy depending upon the system characteristics. For systems with flat topography, a single main pumping station was found to use less energy. In systems with a higher-elevation neighborhood, however, one or more booster pumps with a reduced main pumping station capacity used less energy. The energy savings for the seven systems was dependent on the number of boosters and ranged from 5% to 66% for the analyzed five systems with higher elevation neighborhoods (S3, S4, S5, S6, and S7). No energy savings was realized for the remaining two flat topography systems, S1, and S2. The present study analyzed and established the relationship between various system aspects and energy use in seven MDWDSs. This aids in estimating the amount of energy savings in MDWDSs. This energy savings would ultimately help reduce Greenhouse gases (GHGs) emissions including per capita CO 2 emissions thereby potentially lowering the global climate change effect. This will in turn contribute to meeting the MDG of ensuring environmental sustainability.

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In this paper, we present a map describing the main geomorphological features of the coastal and marine area between the towns of Albenga and Savona (Ligurian Sea, NW Mediterranean) corresponding to a coastal stretch of ~40 km. To produce this map, we collated data from the literature, orthophotos, perspective photos, multibeam and side scan sonar data, and undertook direct surveys to ground truth data obtained using indirect techniques. We divided the information into nine thematic layers, including bathymetry, natural coastal types, geomorphological elements, seafloor coverage (both geological and biological), coastal and nearshore dynamics, human influence on coastal and marine environments, coastal occupation and protected areas.

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Reconstructing terrestrial water budgets is of prime importance for understanding past climate and environment. To shed more light on how plant-wax derived n-alkanes may be used for this purpose we investigated the distribution and stable isotopic compositions of hydrogen (dD) and carbon (d13C) of plant-wax derived n-C29 and -C31 alkanes in terrestrial, coastal and offshore surface sediments in relation to hydrology along a NW-SE transect east of the Italian Apennines from the Po River to the Eastern Gulf of Taranto. The plant wax average chain length increases southward and may relate to increasing temperature and/or aridity. The plant wax dD of the terrestrial and coastal samples also increases southward and mainly reflects changes in the dD of precipitation. The d13C of plant waxes is primarily interpreted in terms of C3 vegetation changes rather than varying contributions by C4 plants. The plant wax d13C-dD composition of the Po River and Apennine rivers differs considerably from that in southern Italy, and suggests a mainly southern source for plant waxes in marine sediments of the Gulf of Taranto. This calibration provides a basis for the reconstruction of past changes in the Italian water balance and n-alkane source areas.

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The determination of the strain and velocity behaviour of the ice surface near the two German Antarctic Stations on Filchner/Ronne and Ekström ice shelves was performed by the use of various geodetic measuring techniques. The relative positions and heights of control points valid for reference data were deduced from terrestrial observations (horizontal and vertical angle selectro optical distances). After a second sampling of data, these values served as the basis for the deformation analyses. Doppler-Satellite-observations (Navy Navigation Satellite System) made absolute positioning (latitude, longitude, height) of special points possible. These Doppler observations, supported by azimuth measurements (gyro-theodolite and sun observations) provided the datum of control networks (translations and orientation). After the repetition of these observations, the drift rates and azimuths of the control points as wenas the rotanon rates of the surface elements could be given. From vertical angles and horizontal distances differences in height end refraction coefficients were calculated. On days without clouds the refraction coefflcients increased by arnounts of up to 3.0 (in extreme cases up to 5.0). Distances over 1 km have to be subdivided to reach a standard deviation level of an heigh: difference better than 0.05 m. In order to determine the heterögeneity of refraction, some height differences should be measured with higher accuracy end-by subdivision of distances.

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The present dataset is part of an interdisciplinary project carried out on board the RV Southern Surveyor off New South Wales (Australia) from the 15th to the 31st October 2010. The main objective of the research voyage was to evaluate how the East Australian Current (EAC) affects the optical, chemical, physical, and biological water properties of the continental shelf and slope off the NSW coast.

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Vol. for 29th, 1915 includes the 4th: Land Grant College Engineering Association. Proceedings of the ... annual convention of the Land Grant College Engineering Association ...; in 1915 the Land Grant College Engineering Association united with the Association of American Agricultural Colleges and Experiment Stations.