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701.
702.
ABSTRACT: An important international Niagara River management issue concerns allocation of the average 202,000 cubic feet per second river discharge for hydroelectric power and scenic purposes. Major water diversions from Niagara Falls are necessary for power production. Flow is allocated by the 1950 Niagara Treaty which is intended to maximize power benefits and preserve and enhance the scenic fals spectacle. This paper examines the extent to which the Treaty objectives have been achieved. Based on analyses of government documents, engineering data, and falls-viewing patterns, it is concluded that the 1950 Treaty led to enhancement of the falls spectacle and increased power generation. But significant additional power diversions probably are attainable without adverse effect upon the existing falls spectacle. Reducing daytime summer Horseshoe Falls flow and scheduling spring and autumn flow according to viewing patterns are possible means of increasing power diversions. Existing generating facilities could use considerably more water and the value of additional Niagara hydroelectricity is very high in terms of generation-cost savings over alternative power sources. Because of the cultural importance of the falls, Treaty modifications to permit increased power diversions are not recommended without prior public opinion sampling and on-site viewing experiments. These findings highlight the need for more careful study before long-term international agreements are concluded and illustrate the need for more flexible treaty arrangements to permit periodic adjustments for changing conditions. 相似文献
703.
Patrick Smallhorn-West Jan van der Ploeg Delvene Boso Meshach Sukulu Janet Leamae Mathew Isihanua Martin Jasper Janet Saeni-Oeta Margaret Batalofo Grace Orirana Alick Konamalefo Jill Houma Hampus Eriksson 《Ambio》2022,51(6):1504
Coastal fisheries are a critical component of Pacific island food systems; they power village economies and provide nutritious aquatic foods. Many coastal women and men actively fishing in this region rely on multi-species fisheries, which given their extraordinary diversity are notoriously difficult to both characterize, and to manage. Understanding patterns of fishing, diversity of target species and drivers of these patterns can help define requirements for sustainable management and enhanced livelihoods. Here we use a 12-month data set of 8535 fishing trips undertaken by fishers across Malaita province, Solomon Islands, to create fisheries signatures for 13 communities based on the combination of two metrics; catch per unit effort (CPUE) and catch trophic levels. These signatures are in turn used as a framework for guiding suitable management recommendations in the context of community-based resource management. While a key proximate driver of these patterns was fishing gear (e.g. angling, nets or spearguns), market surveys and qualitative environmental information suggest that community fishing characteristics are coupled to local environmental features more than the market value of specific species they target. Our results demonstrate that even within a single island not all small-scale fisheries are equal, and effective management solutions ultimately depend on catering to the specific environmental characteristics around individual communities.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01690-z. 相似文献
704.
705.
Jonathan B. Butcher 《Journal of the American Water Resources Association》2003,39(6):1521-1528
ABSTRACT: Most watershed water quality simulation models require the user to specify pollutant buildup and washoff rate parameters for pollutants, by land use. Buildup and washoff rates are difficult to measure directly, and only limited guidance and few observed data are available from the literature. Many studies, however, report storm event mean concentrations (EMCs). These EMCs must arise as a result of the buildup and washoff processes, but typically represent the net contribution from a variety of pervious and impervious surfaces. This paper explores the relationship between EMCs and buildup/washoff parameters. An assumption of the mathematical form of the buildup/washoff relationship gives an algebraic expression for the EMC consistent with model assumptions. This yields techniques to separate observed EMCs into contributions from different land uses and from pervious and impervious surfaces. Given this relationship, numerical optimization may be used to estimate site specific values of buildup and washoff parameters from observed storm EMCs for use in modeling. Use of this approach helps ensure that model parameters are consistent with observed data, providing a rational starting point for final model calibration. Several site examples demonstrate use of the method. 相似文献
706.
Douglas S. Kenney 《Journal of the American Water Resources Association》1999,35(3):493-503
ABSTRACT: The 1990s have featured a rapid proliferation of “watershed initiatives” in the western United States and elsewhere. Watershed initiatives are ad hoc, voluntary associations typically featuring both governmental and non-governmental actors organized together to collaboratively seek new strategies for addressing water and related natural resource problems at physically relevant regional scales. These efforts are a response to historical and sociopolitical trends that have resulted in increasingly ineffective forums and processes of resource management decision-making, and that have subordinated the role of local stakeholders in problem-solving efforts. In most cases, watershed initiatives appear to provide a pragmatic vehicle for resource managers and stakeholders to address common concerns in a more efficient manner than is otherwise possible, and as such, deserve further application and continued support. 相似文献
707.
J. Cameron C. Cincar M. Trudeau J. Marsalek K. Schaefer 《Journal of environmental management》1999,57(4):253
Stormwater management upgrade and maintenance costs in the province of Ontario are significant. As capital grant programs decline, municipalities are exploring alternative means for financing the abatement of stormwater quantity and quality problems. User pay financing represents one such option. The economic, institutional and legal issues related to implementing user pay financing of stormwater management in Ontario are addressed using the Regional Municipality of Ottawa-Carleton (RMOC) as a case-study. The paper reviews the experience with user pay stormwater management programs in Canada and the USA, and recent stormwater issues and financing needs in the RMOC. The presented spreadsheet rate model is based on stormwater quantity and quality considerations and best management practices (BMPs) for various land-use categories. The modelling results vary depending on the inclusion or exemption of certain land-use categories and whether BMPs are implemented. Preliminary results indicate the monthly stormwater user charges are comparable with those charged in USA programs. In Ontario, existing statutes provide the enabling legislation for stormwater user charges, and there are no legal or regulatory barriers to implementing them. However, program we start-up costs and public perception could be significant obstacles to instituting user charges. 相似文献
708.
Importance of information on tillage practices in the modelling of environmental processes and in the use of environmental indicators 总被引:1,自引:0,他引:1
Tillage has been and will always be integral to crop production. Tillage can result in the degradation of soil, water, and air quality. Of all farm management practices, tillage may have the greatest impact on the environment. A wide variety of tillage equipment, practices and systems are available to farmers, providing opportunities to enhance environmental performance. These opportunities have made tillage a popular focus of environmental policies and programs such as environmental indicators for agriculture. This paper provides a very brief examination of the role of tillage in crop production, its effect on biophysical processes and, therefore, its impact on the environment. Models of biophysical processes are briefly examined to demonstrate the importance of tillage relative to other farm management practices and to demonstrate the detail of tillage data that these models can demand. The focus of this paper is an examination of the use of information on tillage in Canada's agri-environmental indicators initiative, National Agri-environmental Health Analysis and Reporting Program (NAHARP). Information on tillage is required for several of the indicators in NAHARP. The type of data used, its source, and its quality are discussed. Recommendations regarding the collection of tillage data and use of tillage information are presented. 相似文献
709.
Herbert W. Greydanus 《Journal of the American Water Resources Association》1978,14(2):477-480
ABSTRACT: Most of California's precipitation falls at the wrong place in the wrong season in relation to the water needs. Redistribution and regulation are essential. Aquifer systems – groundwater basins – can provide a share of the future cyclic storage regulation. There are some differences in management concepts in using a full basin in comparison with a partially dewatered basin. Legal, water quality, and physical impacts on aquifer systems, including subsidence, are concerns. Storage may be for the benefit of overlying water users or for distant areas. Extraction during dry periods or recharge methods will require careful planning. Existing rights and uses and equitable treatment of all parties must be assured. Financial compensation may be involved. Changes in methods of operation or degree of self-determination by affected water agencies will require committed watermanship to resolve. Legislation or amendments to organic acts may be needed but much can be accomplished within existing statutes. Environmental impacts which can be avoided by not using large surface storage sites are important. Energy for pumping will be a key consideration. About 40 percent of California is underlain by aquifer systems. This resource offers major potential in overcoming the maldistribution of natural water resources. 相似文献
710.
Nora M. Znotinas Keith William Hipel 《Journal of the American Water Resources Association》1979,15(1):44-59
ABSTRACT: Procedures are presented for comparing and evaluating alternative engineering designs for a particular water resources project. By using certain aspects of fuzzy set theory, it is possible to introduce both quantitative and qualitative considerations into the decisionmaking process. In addition, the viewpoints of the various interest groups involved with the water resources development can be realistically incorporated by the evaluation techniques for the alternative designs. Methods are given for eliminating undesirable alternatives and thereby obtaining a reduced set of possible feasible solutions to the problem. Because of the flexibility of the evaluation methods, the viable alternatives should not only satisfy economical, technical. environmental and other types of constraints, but these possible solutions should be politically feasible as well. A method is formulated for checking the sensitivity of the feasible results with respect to the factors that are considered in the analysis. 相似文献