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11.
The C-Lock system was developed to address the need for an improved method of quantifying and certifying project-level carbon emission reduction credits (CERC). It was designed to enable individual landowners to efficiently quantify, certify, pool, market and trade CERCs generated by agricultural management practices. We provide a general overview of the C-Lock system as it has been implemented for the USA State of South Dakota. C-Lock is comprised of four linked components: a web interface, a client database, a Geographic Information System (GIS) database of soil, climate and generalized land use history parameters, and the CENTURY soil carbon model. The user-friendly interface elicits generalized land-use and crop history information from the client from 1900 through 1989, then explicit annual information from 1990 onward. A climate-zone level landuse and crop management database is used to fill in gaps in the client-provided data. These data are used to drive the CENTURY model, which estimates annual changes in soil carbon stocks. Monte Carlo simulation is used to estimate uncertainty bounds, and these are applied to the CENTURY outputs in order to provide probabilistic estimates of accrued CERCs in a manner that is transparent and verifiable. In a demonstration application, CERCs are estimated for three different land-use scenarios on a representative field in eastern South Dakota: reduced tillage or conservation (no-till) management of a corn (maize)/wheat/soybean rotation, and enrollment in the Conservation Reserve Program, which entails establishing permanent grass cover. The credits are based on a business-asusual scenario of conventional tillage.  相似文献   
12.
ABSTRACT: Ground water flow and supply at the Whiteshell Research Area (WRA) in southeastern Manitoba and the advective movement of contaminants from a hypothetical nuclear fuel waste disposal vault to the adjacent biosphere and a nearby ground water supply well are simulated using finite-element modeling and numerical particle-tracking technique. The hypothetical vault is located at a depth of 500 m, below the water table, in low-permeability plutonic rock of the Canadian Shield. The rock mass is intersected by high-permeability fracture zones (aquifers), which also act as conduits for vault contaminants to migrate to the ground surface. The ground water resource is, therefore, limited in quantity and quality and should be explored with care. A 30 m deep well, which pumps water at a rate of 120 m3/yr from a low-dipping fracture zone, LD1, reduces natural discharge from the system to augment natural recharge. At this pumping rate, a 100 m or 200 m deep well neither reduces discharge nor induces recharge into the system. Thus, at the WRA, a 30 m deep domestic water supply well best meets the water requirements of a one-person household at the rate of 120 m3/yr. The 100 m and 200 m wells best meet the requirements of a family of six and a family of six with light irrigation, respectively, without capturing contaminants’pathways from the vault to the ground surface. By virtue of the proximity of the 200 m well intake to the hypothetical vault, this well performs best as a purge well at pumping rates of 0,000 m3/yr and greater. Finite-element modeling is useful in evaluating the water supply potential of a fractured rock environment in which a nuclear waste disposal vault is proposed to be sited.  相似文献   
13.
ABSTRACT: Federal and state storm water pollutant control regulations for industry require facilities to identify themselves and to implement appropriate controls specifically developed for each facility by its operators. Compliance is not directly observable from publicly reported information, and is believed to be low. Compliance requirements are divided into three stages: determination and notification of duty to comply; preparation of public reports and site-specific planning documents; and implementation of pollution prevention activities. Aggregate data show about 25 percent to 35 percent of metal plating facilities in California, and about 35 percent to 40 percent of facilities in the Los Angeles region, have recognized the need for first-stage compliance; the number required but failing to do so is not known. For second-stage compliance, between 77 percent and 88 percent of facilities submitted required annual reports from 1993 to 1995, while on-site water quality monitoring reports were submitted by about 60 percent of required facilities. Site investigations of ten Los Angeles area facilities showed variation in compliance with site-specific documentation and implementation requirements. Most facilities inadequately evaluated activities for potential storm water pollutants, and most prepared incomplete plans for storm water sampling and inspection procedures. Evaluation of third-stage compliance by evaluating quantitative effects of facility actions, beyond the scope of this research, is recommended.  相似文献   
14.
The United States Environmental Protection Agency (USEPA) recommends the use of Escherichia coli (E. coli) and enterococci as indicators of enteric pathogens in fresh waters; however, fecal coliform analyses will remain important by virtue of the large amount of historic data collected in prior years. In this study, we attempted, in a real-world situation (i.e., a rural inland watershed in the Piedmont of South Carolina) to compare different bacterial indicators and methods to one another. We compared fecal coliforms, enumerated by membrane filtration with E. coli, enumerated by a commercialized enzyme substrate method and observed E. coli/fecal coliform ratios of 1.63 and 1.2 for two separate tests. In the same watershed, we observed an E. coli/fecal coliform ratio of 0.84 when we used the commercialized enzyme substrate method for both enumerations. Given these results, users of such data should exercise care when they make comparisons between historic membrane filtration data and data acquired through the use of the more modern enzymatic methods. Some sampling and side-by-side testing between methods in a specific watershed may be prudent before any conversion factors between old and new datasets are applied.  相似文献   
15.
US environmental controls for industry include numerous regulations that rely on the regulated community to self-identify, monitor, report, or complete other requirements on their own recognizance. These include state- and federal-issued general permits for stormwater discharges associated with industrial activities, effective in 1992, with known incomplete compliance by 2004. Results demonstrate highly incomplete compliance with variation in effectiveness among studied states and urbanized regions. Texas and Oklahoma, administered by US EPA during the research period, have attained higher compliance rates than California, administered by a state agency, or Florida, also administered by US EPA. Specific program designs and implementation strategies employed by states are evaluated for impacts on states' compliance effectiveness.  相似文献   
16.
R-mode hierarchical cluster and principal component analysis (PCA) were simultaneously applied to surface water hydrochemical data from three different locations, Ankwaso, Dominase and Prestea, along the Ankobra Basin, Ghana, to extract principal factors corresponding to the different sources of variation in the hydrochemistry, with the objective of defining the main controls on the hydrochemistry at the basin scale. Using the Kaiser criterion, principal components (PC) were extracted from the data and rotated using varimax normalization, for each location. The varimax rotation ensured that variation in the data was maximized for easy interpretation of the results. The analysis reduced 30, 33 and 33 data points, respectively, for Ankwaso, Dominase and Prestea to four, three and four PC representing the sources of variation in the hydrochemistry at the three different locations. Though the PC analysis proved to be more robust at unveiling the sources of variation in the hydrochemistry than the R-mode hierarchical cluster analysis (HCA), the combined use of both techniques resulted in more reliable interpretations of the hydrochemistry. On the basis of these analyses, the hydrochemistry of the basin is controlled largely by the weathering of minerals (silicates, carbonates, gypsum and apatite) from the underlying meta-sediments of the Birimian and Tarkwaian Systems, and the decay of organic matter from the heavily forested regions. Concentrations of the major chemical parameters are within naturally acceptable limits and do not pose threats to the local ecology and humans. There is no strong evidence of high anthropogenic impacts on the major anions and cations used for this research, though there are variations at the different locations studied. The hydrochemistry at Ankwaso is principally controlled by the weathering of silicate minerals, whereas those of Dominase and Prestea are, respectively, influenced by precipitation and domestic wastewaters, and the decay of organic matter.  相似文献   
17.
A laboratory study of auctions for reducing non-point source pollution   总被引:2,自引:0,他引:2  
Non-point source pollution, such as nutrient runoff to waterways from agricultural production, is an environmental problem that typically involves asymmetric information. Land use changes to reduce pollution incur opportunity costs that are privately known to landholders, but these changes provide environmental benefits that may be more accurately estimated by regulators. This paper reports a testbed laboratory experiment in which landholder/sellers in sealed-offer auctions compete to obtain part of a fixed budget allocated by the regulator to subsidize abatement. In one treatment the regulator reveals to landholders the environmental benefits estimated for their projects, and in another treatment the regulator conceals the potential projects’ “environmental quality.” The results show that sellers’ offers misrepresent their costs more for high-quality projects when quality is revealed, so total abatement is lower and seller profits are higher when landholders know their projects’ environmental benefits. This suggests that concealing this information may improve regulatory efficiency.  相似文献   
18.
ABSTRACT: Nonstorm water discharges to municipal separate storm sewer systems (MS4s) are notable for spatial and temporal variability in volume, pollutant type, pollutant concentration, and activity of origin. The objective of this paper was to determine whether current technical knowledge and existing U.S. policy support an improved regulatory approach. The proposed policy would use type of discharge as a regulatory basis, merging the concepts of allowability of de minimis discharges and type-based statewide consistent rules. Specific research objectives were to comprehensively identify discharge types, characterize their prevalence in California, analyze relevant local and regional regulatory guidelines, and systematically evaluate opinions of experts about potential water quality impacts. Results demonstrate nonstorm water discharges were widespread in at least one sector, industrial facilities subject to a state permit; one discharge for every four facilities was reported in 1995, even though the permit explicitly prohibits such discharges. Clear consensus exists for minimal water quality concern for some discharge types when considering both municipal guidelines and experts’ opinions. In particular, condensate from a wide range of equipment and discharges from fire fighting equipment testing were found to be of low concern. Discharge types with consensus high concern were largely limited to discharges prohibited under other regulations, such as wastewater and hazardous waste management controls. Some discharge types where no consensus was identified, such as landscape irrigation, nevertheless generated concern for water quality impacts and appear to be relatively widespread. Available information supports technical feasibility of the proposed policy because at least some discharge types show strong consensus for de minimis impacts among regulatory guidelines and opinions of technical experts.  相似文献   
19.
The Fort Cobb Watershed in Oklahoma has diverse biogeophysical settings and provides an opportunity to explore the association of water quality with a diverse set of landscapes during both wet (April 2007‐December 2009) and dry (January 2005‐March 2007) periods. The objective of this work was to identify spatial patterns in phosphorus (P) (soluble reactive P [SRP] and bioavailable P [BAP]) associated with landscape metrics for two distinct streamflow regimes. Spatial autocorrelation of P was evaluated using contiguous (side‐by‐side) and upstream (upstream:downstream) connectivity matrices. Biogeophysical metrics were compiled for each contributing area, and were partitioned based on association to P concentrations. Results for both SRP and BAP indicated that spatial autocorrelation was present (< 0.05). There was more spatial autocorrelation and stream P concentrations were three to five times higher in the Wet phase than in the Dry phase (< 0.05). Analysis with recursive partitioning resulted in higher R2 with spatial autocorrelation than without spatial autocorrelation and indicated that lateral metrics (topography, soil, geology, management) were better predictors for SRP than instream metrics. During Wet phase, lateral metrics indicative of rapid surface and subsurface water movement were associated with higher P stream concentrations. This research demonstrated that we can detect landscapes more vulnerable to P losses and/or contaminations in either drought or very wet periods.  相似文献   
20.
ABSTRACT: Pollutants in urban storm water runoff, a significant and increasing fraction of pollutants in some waters of the U.S., originate from multiple activities. The industrial sector, one source category, is subject to federal and state-level storm water pollution prevention regulations, primarily General NPDES Permits that rely heavily on facility operators to identify themselves and develop appropriate site-specific pollutant controls. Degree of compliance is not readily determined and enforcement is inhibited because no publicly-available inventories contain data necessary to comprehensively identify facilities required to comply. This research evaluates the first stage of compliance, facility self-identification, concentrating on the motor-vehicle, transportation industry category using data at three scales: statewide, regional, and local or watershed. Data for California statewide and for the Los Angeles region show about 8 percent to 15 percent of motor-vehicle transportation facilities have complied with first-stage requirements. However, facility-specific evaluation in one Los Angeles County watershed suggests less than 50 percent of facilities in the industry conduct industrial activities of the kind covered by regulations; others need not comply. Results show strong variation by industry category. Second-stage compliance, follow-up reporting, is also evaluated for the Los Angeles region. About 17 percent to 34 percent of facilities completing first-stage requirements have also completed second-stage requirements.  相似文献   
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