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641.
Chen, Limin, Sujoy B. Roy, and Robert A. Goldstein, 2012. Projected Freshwater Withdrawals Under Efficiency Scenarios for Electricity Generation and Municipal Use in the United States for 2030. Journal of the American Water Resources Association (JAWRA) 1‐16. DOI: 10.1111/jawr.12013 Abstract: Water withdrawals in the United States (U.S.) have been relatively uniform over the past two decades on a nationally aggregated basis, although on a more highly resolved geographical basis, increases have occurred, largely associated with growth in population and the cooling needs for new electricity generation. Using recent county‐level water use data, we develop projections for five different scenarios, bracketing a range of future conditions, and representing different levels of efficiency in the municipal and electricity generation sectors, where the municipal sector includes public and self‐supplied domestic withdrawals. Starting with the 2005 estimate of 347 billion gallons per day (bgd) of freshwater withdrawal in the continental U.S., our analysis shows that under a business‐as‐usual scenario of growth, there will be a need for additional water over current levels: 11 bgd in the municipal sector, with a smaller requirement for new electricity generation (1 bgd). However, we also estimate that withdrawals could be reduced significantly over current levels, through increased water use efficiencies in the electric power and municipal sectors. The study shows that if water withdrawals are to be held at their current levels for the thermoelectric and municipal sectors individually at a county level over the next 25 years, large improvements in efficiency will be needed in many parts of the Southeast and Southwest.  相似文献   
642.
Future climate and land‐use changes and growing human populations may reduce the abundance of water resources relative to anthropogenic and ecological needs in the Northeast and Midwest (U.S.). We used output from WaSSI, a water accounting model, to assess potential changes between 2010 and 2060 in (1) anthropogenic water stress for watersheds throughout the Northeast and Midwest and (2) native fish species richness (i.e., number of species) for the Upper Mississippi water resource region (UMWRR). Six alternative scenarios of climate change, land‐use change, and human population growth indicated future water supplies will, on average across the region, be adequate to meet anthropogenic demands. Nevertheless, the number of individual watersheds experiencing severe stress (demand > supplies) was projected to increase for most scenarios, and some watersheds were projected to experience severe stress under multiple scenarios. Similarly, we projected declines in fish species richness for UMWRR watersheds and found the number of watersheds with projected declines and the average magnitude of declines varied across scenarios. All watersheds in the UMWRR were projected to experience declines in richness for at least two future scenarios. Many watersheds projected to experience declines in fish species richness were not projected to experience severe anthropogenic water stress, emphasizing the need for multidimensional impact assessments of changing water resources.  相似文献   
643.
Water‐level trends spanning 20, 30, 40, and 50 years were tested using month‐end groundwater levels in 26, 12, 10, and 3 wells in northern New England (Maine, New Hampshire, and Vermont), respectively. Groundwater levels for 77 wells were used in interannual correlations with meteorological and hydrologic variables related to groundwater. Trends in the contemporary groundwater record (20 and 30 years) indicate increases (rises) or no substantial change in groundwater levels in all months for most wells throughout northern New England. The highest percentage of increasing 20‐year trends was in February through March, May through August, and October through November. Forty‐year trend results were mixed, whereas 50‐year trends indicated increasing groundwater levels. Whereas most monthly groundwater levels correlate strongly with the previous month's level, monthly levels also correlate strongly with monthly streamflows in the same month; correlations of levels with monthly precipitation are less frequent and weaker than those with streamflow. Groundwater levels in May through August correlate strongly with annual (water year) streamflow. Correlations of groundwater levels with streamflow data and the relative richness of 50‐ to 100‐year historical streamflow data suggest useful proxies for quantifying historical groundwater levels in light of the relatively short and fragmented groundwater data records presently available.  相似文献   
644.
Understanding the impacts that influence water quality is critical to the development of best management practices at the large watershed scale. This study describes the spatiotemporal variation in surface water quality and identifies their main impact in the Haihe River basin, China. Multivariate statistical techniques are applied to analyze the similarities among the sampling sites and to identify the main pollution sources in surface water. Results show that: (1) the basin can be clustered into two regions, water quality being better in the mountainous vs. plain regions; (2) water quality improves due to implementation of a strict state policy on environmental pollution control, prodded by the hosting of the Olympic games in the cities of Beijing and Tianjin; and (3) agricultural and residential land uses as well as livestock‐breeding are the main sources affecting water quality in the mountainous regions, whereas rural waste discharge — including domestic waste sewage, human and animal feces, and solid waste — significantly influences water quality in the plain regions. The waste discharge of industrial factories may be a significant source of water pollution in the plain regions. Results indicate that the environmental management from pollution sinks and sources, long‐lasting legal framework, and adequate economic incentives should be improved to optimize the large‐scale watershed management under the background of the rapid development of countries like China.  相似文献   
645.
The methods used to simulate flood inundation extents can be significantly improved by high‐resolution spatial data captured over a large area. This paper presents a hydraulic analysis methodology and framework to estimate national‐level floodplain changes likely to be generated by climate change. The hydraulic analysis was performed using existing published Federal Emergency Management Agency 100‐year floodplains and estimated 100‐ and 10‐year return period peak flow discharges. The discharges were estimated using climate variables from global climate models for two future growth scenarios: Representative Concentration Pathways 2.6 and 8.5. River channel dimensions were developed based on existing regional United States Geological Survey publications relating bankfull discharges with channel characteristics. Mathematic relationships for channel bankfull topwidth, depth, and side slope to contributing drainage area measured at model cross sections were developed. The proposed framework can be utilized at a national level to identify critical areas for flood risk assessment. Existing hydraulic models at these “hot spots” could be repurposed for near–real‐time flood forecasting operations. Revitalizing these models for use in simulating flood scenarios in near–real time through the use of meteorological forecasts could provide useful information for first responders of flood emergencies.  相似文献   
646.
ABSTRACT: Fecal‐indicator bacteria were sampled at 14 stream sites in Anchorage, Alaska, USA, as part of a study to determine the effects of urbanization on water quality. Population density in the subbasins sampled ranged from zero to 1,750 persons per square kilometer. Higher concentrations of fecal‐coliform, E. coli, and enterococci bacteria were measured at the most urbanized sites. Although fecal‐indicator bacteria concentrations were higher in summer than in winter, seasonal differences in bacteria concentrations generally were not significant. Areas served by sewer systems had significantly higher fecal‐indicator bacteria concentrations than did areas served by septic systems. The areas served by sewer systems also had storm drains that discharged directly to the streams, whereas storm sewers were not present in the areas served by septic systems. Fecal‐indicator bacteria concentrations were highly variable over a two‐day period of stable streamflow, which may have implications for testing of compliance to water‐quality standards.  相似文献   
647.
Abstract: Tradable permits have been applied in many areas of environmental policy and may be a response to increasing calls for flexible conservation instruments that successfully conserve biodiversity while allowing for economic development. The idea behind applying tradable permits to conservation is that developers wishing to turn land to economic purposes, thereby destroying valuable habitat, may only do so if they submit a permit to the conservation agency showing that habitat of at least the equivalent ecological value is restored elsewhere. The developer himself does not need to carry out the restoration, but may buy a permit from a third party, thus allowing a market to emerge. Nevertheless, the application of tradable permits to biodiversity conservation is a complex issue because destroyed and restored habitats are likely to differ. There may be various trade‐offs between the ecological requirements that destroyed and restored habitats be as similar as possible, and the need for a certain level of market activity to have a functioning trading system. The success of tradable permits as an instrument for reconciling the conflicts between economic development and conservation depends on the existence of certain economic, institutional, and ecological preconditions, for example, a functioning institutional framework, sufficient expert knowledge, and adequate monitoring and enforcement mechanisms.  相似文献   
648.
ABSTRACT: A distributed watershed model combining kinematic wave routing, 1‐D dynamic channel‐flow routing, and 2‐D diffusive overland‐flow routing has been developed to simulate flooding and inundation levels of large watersheds. The study watershed was linked to a GIS database and was divided into an upstream mountainous area and a downstream alluvial plain. A kinematic wave routing was adopted at the mountainous area to compute the discharge flowing into the alluvial plain. A 1‐D dynamic channel routing solving the St. Venant equations by the Preissmann method was performed for the main channel of the alluvial plain, whereas a 2‐D overland‐flow routing solving the diffusion wave equation with the Alternating Direction Explicit scheme was used for floodplains. The above two routings were connected by weir‐link discharge formula. The parameters in the model were calibrated and independently verified by single‐event storms. An example application of flooding/inundation analysis was conducted for the Taichung station and the Woozi depot (Taiwan High Speed Rail). Suggested inundation‐proofing measures ‐ including raising ground surface elevation of the station and depot and building a waterproofing exterior wall and their combination ‐ were investigated. It was concluded that building the waterproofing exterior wall had a strong tendency to decrease peak inundation depth.  相似文献   
649.
This meta‐analysis builds upon a previous meta‐analysis by (1) including 65 per cent more studies that have over twice the sample size to estimate the relationships between emotional intelligence (EI) and job performance; (2) using more current meta‐analytical studies for estimates of relationships among personality variables and for cognitive ability and job performance; (3) using the three‐stream approach for classifying EI research; (4) performing tests for differences among streams of EI research and their relationships with personality and cognitive intelligence; (5) using latest statistical procedures such as dominance analysis; and (6) testing for publication bias. We classified EI studies into three streams: (1) ability‐based models that use objective test items; (2) self‐report or peer‐report measures based on the four‐branch model of EI; and (3) “mixed models” of emotional competencies. The three streams have corrected correlations ranging from 0.24 to 0.30 with job performance. The three streams correlated differently with cognitive ability and with neuroticism, extraversion, openness, agreeableness, and conscientiousness. Streams 2 and 3 have the largest incremental validity beyond cognitive ability and the Five Factor Model (FFM). Dominance analysis demonstrated that all three streams of EI exhibited substantial relative importance in the presence of FFM and intelligence when predicting job performance. Publication bias had negligible influence on observed effect sizes. The results support the overall validity of EI. Copyright © 2010 John Wiley & Sons, Ltd. Note: Correction added on 22 July 2010 after first publication online on 29 June 2010. The affiliations for Ronald H. Humphrey and Thomas H. Hawver have been corrected in this version of the article.  相似文献   
650.
Lee, Se‐Yeun, Alan F. Hamlet, Carolyn J. Fitzgerald, and Stephen J. Burges, 2011. Methodology for Developing Flood Rule Curves Conditioned on El Niño‐Southern Oscillation Classification. Journal of the American Water Resources Association (JAWRA) 47(1):81‐92. DOI: 10.1111/j.1752‐1688.2010.00490.x Abstract: Regional climate varies on interannual and decadal time scales that in turn affect annual streamflows, flood risks, and reservoir storage deficits in mid‐summer. However, these variable elements of the climate system are generally not included in water resources operating policies that attempt to preserve a balance between flood risk and other water resources system objectives. A methodology for incorporating El Niño‐Southern Oscillation (ENSO) information in designing flood control curves is investigated. An optimization‐simulation procedure is used to develop a set of ENSO‐conditioned flood control rule curves that relate streamflow forecasts to flood control evacuation requirements. ENSO‐conditioned simulated flood risk and storage deficits under current operating policy are used to calibrate a unique objective function for each ENSO classification. Using a case study for the Columbia River Basin, we demonstrate that ENSO‐conditioned flood control curves constructed using the optimization‐simulation procedure consistently reduce storage deficits at a number of interrelated projects without increasing flood risk. For the Columbia Basin, the overall improvements in reservoir operations are relatively modest, and (in isolation) might not motivate a restructuring of flood control operations. However, the technique is widely applicable to a wide range of water resources systems and/or different climate indices.  相似文献   
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