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611.
Climate forcing is forecasted to influence the Adriatic Sea region in a variety of ways, including increasing temperature, and affecting wind speeds, marine currents, precipitation and water salinity. The Adriatic Sea is intensively developed with agriculture, industry, and port activities that introduce pollutants to the environment. Here, we developed and applied a Level III fugacity model for the Adriatic Sea to estimate the current mass balance of polychlorinated biphenyls in the Sea, and to examine the effects of a climate change scenario on the distribution of these pollutants. The model’s performance was evaluated for three PCB congeners against measured concentrations in the region using environmental parameters estimated from the 20th century climate scenario described in the Special Report on Emission Scenarios (SRES) by the IPCC, and using Monte Carlo uncertainty analysis. We find that modeled fugacities of PCBs in air, water and sediment of the Adriatic are in good agreement with observations. The model indicates that PCBs in the Adriatic Sea are closely coupled with the atmosphere, which acts as a net source to the water column. We used model experiments to assess the influence of changes in temperature, wind speed, precipitation, marine currents, particulate organic carbon and air inflow concentrations forecast in the IPCC A1B climate change scenario on the mass balance of PCBs in the Sea. Assuming an identical PCBs’ emission profile (e.g. use pattern, treatment/disposal of stockpiles, mode of entry), modeled fugacities of PCBs in the Adriatic Sea under the A1B climate scenario are higher because higher temperatures reduce the fugacity capacity of air, water and sediments, and because diffusive sources to the air are stronger. 相似文献
612.
When local resource users detect, understand, and respond to environmental change they can more effectively manage environmental
resources. This article assesses these abilities among artisanal fishers in Roviana Lagoon, Solomon Islands. In a comparison
of two villages, it documents local resource users’ abilities to monitor long-term ecological change occurring to seagrass
meadows near their communities, their understandings of the drivers of change, and their conceptualizations of seagrass ecology.
Local observations of ecological change are compared with historical aerial photography and IKONOS satellite images that show
56 years of actual changes in seagrass meadows from 1947 to 2003. Results suggest that villagers detect long-term changes
in the spatial cover of rapidly expanding seagrass meadows. However, for seagrass meadows that showed no long-term expansion
or contraction in spatial cover over one-third of respondents incorrectly assumed changes had occurred. Examples from a community-based
management initiative designed around indigenous ecological knowledge and customary sea tenure governance show how local observations
of ecological change shape marine resource use and practices which, in turn, can increase the management adaptability of indigenous
or hybrid governance systems. 相似文献
613.
Matthew Alexander 《补救:环境净化治理成本、技术与工艺杂志》2020,30(2):25-35
In situ bioremediation was selected in the Record of Decision (ROD) as the remedial technology for a 29‐acre dilute, acidic and aerobic, chlorinated solvent plume (principally trichloroethylene [TCE] and 1,1‐dichloroethylene) for a Superfund site located in central New Jersey. Implementation of the remedy at full‐scale began in late 2010, using reductive dechlorination and bioaugmentation, and treatment has continued steadily over the last 9 years. The amendments injected include electron donor and alkaline (bicarbonate) buffer solution and, once anaerobic aquifer conditions became established, a bioaugmentation culture. Amendment injections occurred in multilevel injection wells (IWs), to maintain control over the vertical interval of amendment delivery. The areal coverage of the plume has been reduced by 59% based on the 10 µg/L TCE isocontour and the contaminant mass has been reduced by 79% through the 9 years of treatment. Lessons learned from this project include the need for bioaugmentation in the acidic aquifer and an efficient and effective manner of well construction and amendment injection using multiscreen single casing IWs and packer systems. Additional lessons learned include differences in longevity of the electron donor amendment versus the bicarbonate neutralization additive, and the need for varied amendment delivery techniques (IWs, direct injection, horizontal well installation) in selected lower permeable zones to attain treatment. 相似文献
614.
Knook Jorie Dynes Robyn Pinxterhuis Ina de Klein Cecile A. M. Eory Vera Brander Matthew Moran Dominic 《Environmental management》2020,65(2):243-256
Environmental Management - Although the link between agriculture and diffuse water pollution has been understood for decades, there is still a need to implement effective measures to address this... 相似文献
615.
Matthew P. Miller Paul D. Capel Ana María García Scott W. Ator 《Journal of the American Water Resources Association》2020,56(1):100-112
In response to concerns regarding the health of streams and receiving waters, the United States Environmental Protection Agency established a total maximum daily load for nitrogen in the Chesapeake Bay watershed for which practices must be in place by 2025 resulting in an expected 25% reduction in load from 2009 levels. The response of total nitrogen (TN) loads delivered to the Bay to nine source reduction and land use change scenarios was estimated using a Spatially Referenced Regression on Watershed Attributes model. The largest predicted reduction in TN load delivered to the Bay was associated with a scenario in which the mass of TN as fertilizer applied to agricultural lands was decreased. A 25% decrease in the mass of TN applied as fertilizer resulted in a predicted reduction in TN loading to the Bay of 11.3%, which was 2.5–5 times greater than the reductions predicted by other scenarios. Eliminating fertilizer application to all agricultural land in the watershed resulted in a predicted reduction in TN load to the Bay of 45%. It was estimated that an approximate 25% reduction in TN loading to the Bay could be achieved by eliminating fertilizer applied to the 7% of subwatersheds contributing the greatest fertilizer‐sourced TN loads to the Bay. These results indicate that management strategies aimed at decreasing loading from a small number of subwatersheds may be effective for reducing TN loads to the Bay, and similar analyses are possible in other watersheds. 相似文献
616.
Luca Delle Monache Jeffrey Weil Matthew Simpson Marty Leach 《Atmospheric environment (Oxford, England : 1994)》2009,43(36):5807-5821
A new urban parameterization for a fast-running dispersion prediction modeling system suitable for emergency response situations is introduced. The parameterization represents the urban convective boundary layer in the dispersion prediction system developed by the National Atmospheric Release Advisory Center (NARAC) at Lawrence Livermore National Laboratory. The performance of the modeling system is tested with data collected during the field campaign Joint Urban 2003 (JU03), held in July 2003 in Oklahoma City, Oklahoma. Tests were performed using data from three intense operating periods held during daytime slightly unstable to unstable conditions. The system was run in operational mode using the meteorological data that would be available operationally at NARAC to test its effectiveness in emergency response conditions. The new parameterization considerably improves the performance of the original modeling system, by producing a better degree of pattern of correspondence between predictions and observations (as measured by Taylor diagrams), considerably reducing bias, and better capturing directional effects resulting in plume predictions whose shape and size better resemble the observations (via the measure of effectiveness). Furthermore, the new parameterization shows similar skills to urban modeling systems of similar or greater complexity. The parameterization performs the best at the three JU03 sensor arcs (1, 2, and 4 km downwind the release points), with fractional bias values ranging from 0.13 to 0.4, correlation values from 0.45 to 0.71, and centered root-mean-square error being reduced more than 50% in most cases. The urban parameterization has been tested with grid increments of 125, 250, 500 and 1000 m, performing best at 250 and 500 m. Finally, it has been found that representing the point source by a Gaussian distribution with an initial spread of particles leads to a better representation of the initial spread induced by near-source buildings, resulting in lower bias and improved correlation in downtown Oklahoma City. 相似文献
617.
Michael B. Griffith F. Bernard Daniel Matthew A. Morrison Michael E. Troyer James M. Lazorchak Joseph P. Schubauer‐Berigan 《Journal of the American Water Resources Association》2009,45(6):1475-1492
Griffith, Michael B., F. Bernard Daniel, Matthew A. Morrison, Michael E. Troyer, James M. Lazorchak, and Joseph P. Schubauer‐Berigan, 2009. Linking Excess Nutrients, Light, and Fine Bedded Sediments to Impacts on Faunal Assemblages in Headwater Agricultural Streams. Journal of the American Water Resources Association (JAWRA) 45(6):1475‐1492. Abstract: Biological impairments in streams are typically defined by regulatory agencies in terms of altered invertebrate or fish assemblages. While nutrients, canopy cover, and sediment fines contribute to these impairments, these stressors are often defined, at least in part, by their impacts on periphyton. Path analysis can extend these assessments to impacts on invertebrates and fish by characterizing the direct and indirect relationships among variables along defined model pathways. With data from headwater tributaries in the Little Miami River, Ohio, we tested models of the impacts of nutrients [total nitrogen (TN), total phosphorus (TP), and the nitrogen to phosphorus (N/P) ratio], the percentage of (%) open canopy, and the % sand and fines on three periphyton metrics [periphytic ash‐free dry mass (AFDM), the percent abundance of cyanobacteria (% cyanobacteria), and the percent abundance of Chlorophyta (% Chlorophyta)] and, in turn, on selected invertebrate or fish metrics. Our objective was to develop and evaluate a statistical model that assesses the direct and indirect impacts of excess nutrients on macroinvertebrate and fish in these streams and demonstrate how this approach might be applicable elsewhere. The results suggest indirect pathways for the influences of nutrients, canopy cover, and fine bedded sediments on invertebrates or fish that are mediated by their influences on periphyton. This is in addition to any direct impacts of these stressors on the invertebrate and fish metrics. In most models, all three periphyton metrics increased with % open canopy. Periphytic AFDM increased with TN, while % cyanobacteria decreased. The % cyanobacteria also decreased with % sand and fines, but % Chlorophyta increased. The metrics, percent abundance of (%) three most dominant (macroinvertebrate) taxa, % Trichoptera, and % herbivorous fish all increased with periphytic AFDM, while % climbers, % swimmers, and %Lepomis cyanellus Rafinesque decreased. Lepomis cyanellus is an indicator species, because it is generally common in these streams and relatively tolerant to various common environmental stressors. The % three most dominant macroinvertebrate taxa increased while % Hydropsychidae (Trichoptera) and %L. cyanellus decreased with % cyanobacteria. The % Trichoptera and %L. cyanellus increased with % Chlorophyta. Some macroinvertebrate metrics, such as the % burrowers and number of burrower taxa, did not have any statistically significant relationships with the periphyton metrics but did exhibit a direct pathway with % sand and fines. These analyses illustrate how path analysis can be used to estimate the relationships among the variables in a conceptual model, modify the model, assess the relative importance of different paths, and explore responses resulting from stressors with interacting and indirect impacts. 相似文献
618.
Noreen McDonald Author Vitae Matthew Trowbridge Author Vitae 《Journal of Safety Research》2009,40(3):177-183
Problem
Motor vehicle crashes are the most common cause of death for American adolescents. However, the impact of where teens live on when they begin driving has not been studied.Method
Data from the 2001 National Household Travel Survey were used to estimate the effect of residential density on the driver status of teens aged 16 to 19 years after matching on demographic characteristics.Results
Controlling for demographic characteristics, 16 and 17 year old teens in high density neighborhoods had driver rates 15 percentage points below teens living in less dense areas (p < 0.001). The effect for 18 and 19 year olds was a 9 percentage point decrease (p < 0.001).Summary
These results suggest teens living in less dense and more sprawling communities initiate driving at a younger age than comparable teens in compact areas, placing them at increased risk for crash related injuries. Impact on Industry: The role of environmental factors, such as neighborhood walkability and provision of transit, should be considered in young driver programs. 相似文献619.
620.
Following international interventions in Bosnia-Herzegovina(1) and Iraq, non-governmental organisations (NGOs) have played a central role in delivering humanitarian relief, encouraging participation in new systems of government, and advocating on behalf of marginalised groups. Although intervening agencies have framed such autonomous organisations as unquestionably virtuous, scholars have increasingly questioned the agency of NGOs, pointing to the constraining effects of funding and regulatory mechanisms. This paper contributes to this body of work by offering a detailed examination of legislation requiring NGOs to register with nascent state institutions. Drawing on case study material from Bosnia and Iraq, it argues that NGO registration should not be dismissed as a technical or legal matter, but that it should be embraced as a significant political practice embedded in relations of power. Registration legislation has increased the transparency of NGO funding origins and institutional practices, yet it has simultaneously acted as a barrier to smaller organisations and led to the transmission of international objectives through civil society entities. 相似文献