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141.
ABSTRACT: To quantify the effectiveness of best management practice (BMP) implementation on runoff, sediment, and nutrient yields from a watershed, the Nomini Creek watershed and water quality monitoring project was initiated in 1985, in Westmoreland County, Virginia. The changes in nonpoint source (NPS) loadings resulting from BMPs were evaluated by comparing selected parameters from data series obtained before, during, and after periods of BMP implementation. The results indicated that the watershed-averaged curve number, sediment, and nutrient (N and P) concentrations were reduced by approximately 5, 20, and 40 percent, respectively, due to BMP implementation. The nutrient yield model developed by Frere et al. (1980) was applied to the water quality parameters from 175 storms, but it failed to adequately describe the observed phenomena. Seasonal changes in nutrient availability factors were not consistent with field conditions, nor were they significantly different in the pm- and post-BMP periods. An extended period of monitoring, with intensive BMP implementation over a larger portion of the watershed, is required to identify BMP effectiveness.  相似文献   
142.
Future climate change is a source of growing concerns for the supply of energy and resources, and it may have significant impacts on industry and the economy. Major effects are likely to arise from changes to the freshwater resources system, due to the connection of energy generation to these water systems. Using future climate data downscaled by a stochastic weather generator, this study investigates the potential impacts of climate change on long‐term reservoir operations at the Chungju multipurpose dam in South Korea, specifically considering the reliability of the supply of water and hydropower. A reservoir model, Hydrologic Engineering Center‐Reservoir System Simulation (HEC‐ResSim), was used to simulate the ability of the dam to supply water and hydropower under different conditions. The hydrologic model Soil and Water Assessment Tool was used to determine the HEC‐ResSim boundary conditions, including daily dam inflow from the 6,642 km2 watershed into the 2.75 Gm3 capacity reservoir. Projections of the future climate indicate that temperature and precipitation during 2070‐2099 (2080s) show an increase of +4.1°C and 19.4%, respectively, based on the baseline (1990‐2009). The results from the models suggest that, in the 2080s, the average annual water supply and hydropower production would change by +19.8 to +56.5% and by +33.9 to 92.3%, respectively. Model simulations suggest that under the new climatic conditions, the reliability of water and hydropower supply would be generally improved, as a consequence of increased dam inflow.  相似文献   
143.
The objective of this research is to develop a desirable type III environmental declaration format for the industrial consumer. A total of five different scenarios were chosen for the presentation of life-cycle assessment results in a format that meets the requirements of a type III environmental declaration. Life-cycle assessment of an electronic component was performed for this purpose. Environmentally significant impact categories and input/output items of a product system derived from the life-cycle assessment are presented in this format. Presenting these information concisely in a standardized format would accelerate the communication of environmental aspects of materials and components in a product supply chain. Thus the type III environmental declaration can be a useful instrument for the manufacturing of an ecoproduct.  相似文献   
144.
A three‐dimensional hydrodynamic model was applied to Lake Paldang, South Korea. The lake has three inflows, of which Kyoungan Stream has the smallest flow rate and poorest water quality. Since all drinking water intake stations are located near the confluence of Kyoungan Stream within the lake, this contaminated tributary may have a significant impact on the quality of drinking water sources. The optimum drinking water intake location was determined from the applied model. The model was calibrated and verified using the data measured under different hydrological conditions. The model results were in reasonable agreement with the field measurements in both calibration and verification. The circulation and spreading patterns of the incoming flows in the lake, as well as their composition ratios to the drinking water intakes were determined from the model, and three alternative intake locations were proposed. The simulation results suggested that the horizontal and vertical relocations of the intake aqueduct could significantly decrease the composition ratio of the contaminated water. From this study, it was concluded that the three‐dimensional hydrodynamic model could successfully simulate the temporal and spatial mixing patterns of incoming flows and become a useful tool in determining the optimum water intake location in Lake Paldang.  相似文献   
145.
This study explored the public perceptions of mobile telecommunications development – new landscape elements installed to deliver new technology – in a protected area. It examined: (1) the perceived landscape impacts of such development; (2) the importance attached to the socio-economic value of mobile telecommunications; and (3) the factors underlying the perceived landscape impacts of mobile telecommunications development. A postal questionnaire survey was conducted in the Peak District National Park, England with 420 respondents drawn from National Park residents and visitors, urban dwellers and members of environmental organisations. The study suggests that: (1) there was a prevailing antipathy towards the landscape impacts of mobile telecommunications development in the National Park; (2) apart from emergency uses, the other socio-economic benefits of mobile telecommunications technology were thought to be relatively unimportant in the National Park; and (3) rather than socio-demographic characteristics, it was respondents' understandings of protected areas' needs for the technology and potential health risks that had significant effects on the perceived landscape impacts. Overall, this study suggests that the significance of National Park landscapes is respected by the public, even when setalongside the convenience of modern technology, which has substantial implications for landscape planning and management in protected areas.  相似文献   
146.
Greater emphasis is being placed on indicators of agri-environmental efficiency of organic production systems. Linking environmental measures with profitability measures based on net income is the only way to develop such indicators. A stochastic production frontier model that explicitly incorporates farm decisions about acquiring and managing organic soil-improving inputs is used to measure efficiency. The results confirm that on-farm self-sufficiency in soil-improving inputs is positively related to farm-level efficiency.  相似文献   
147.
Environmental Science and Pollution Research - In Jeju Island, multiple land-based aquafarms were fully operational along most coastal region. However, the effect of effluent on distribution and...  相似文献   
148.
Mercury emissions concentrations, emission factors, and the total national emission from major anthropogenic sources in Korea for the year 2007 were estimated. Uncontrolled and controlled mercury emission factors and the total emission from each source types are presented. The annual national mercury emission from major anthropogenic sources for the year 2007, on average was 12.8 ton which ranged from 6.5 to 20.2 ton. Averaged emissions of elemental, oxidized, and particulate mercury were estimated at 8.25 ton, 3.69 ton, and 0.87 ton, respectively. Due to the removal of a major portion of particulate and oxidized mercury species, elemental mercury was dominant in stack emission. About 54.8% of mercury emission was contributed by industrial sources, 45.0% by stationary combustion sources and 0.02% by mobile sources. Thermal power plants, oil refineries, cement kilns and incinerators (municipal, industrial, medical, sewage sludge) were the major mercury emitters, contributing about 26%, 25%, 21% and 20%, respectively to the total mercury emission. Other sources (crematory, pulp and paper manufacturing, nonferrous metals manufacturing, glass manufacturing) contributed about 8% of the total emission. Priority should be given in controlling mercury emissions from coal-fired power plants, oil refineries, cement kilns and waste incinerators. More measurements including natural and re-emission sources are to be carried out in the future in order to have a clear scenario of mercury emission from the country and to apply effective control measures.  相似文献   
149.
ABSTRACT: There is a long standing hypothesis that overdevelopment has occurred in the nation's floodplains due to imperfect information about the potential flood hazard, an expectation of disaster relief and anticipation of future structural protection. This hypothesis is investigated with multiple regression analysis of data for a case study area. In particular the question of whether floodplain residential property values are fully discounted for expected flood damages is addressed by considering the impact of the National Flood Insurance Program on property values. The extent to which flooding risk perceptions are based on low cost information such as distance from and elevation above the river is also considered. Finally, implications for floodplain management policy are discussed.  相似文献   
150.
Modified polycaprolactone was synthesized by melt reaction of PCL and reactive monomers such as glycidyl methacrylate (GMA) and maleic anhydride (MAH) in the presence of benzoyl peroxide in Brabender mixer. MAH showed a different grafting phenomenon compared to GMA. The reaction mechanism was discussed with different reactive monomers. Reactive blends of the PCL-g-GMA and the gelatinized starch with glycerin were prepared and their mechanical properties and biodegradabilities were investigated. Reactive blends of PCL-g-GMA and starch showed well-dispersed starch domain in the matrix and better mechanical strength than the unmodified PCL/starch blend. However, the reaction between PCL-g-GMA and starch induced a crosslinking during the reactive blending and this crosslinking in the blend lowered the biodegradation of the blend during the composting test. The biodegradability was investigated by the weight loss and surface morphology change of the blend in the composting medium.  相似文献   
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