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861.
Because watershed collaborations connect economic and environmental concerns, they are of interest to students of sustainable economic development. The economic outcomes of such collaborations are difficult to study because socio-economic data collection areas do not generally correspond to collaboration boundaries and also because of the simultaneity of economic stimuli and restrictions in collaborative arrangements. This case study of New York City’s Watershed Collaboration in its Catskill Delaware Watershed used a mapping program to create a database of Watershed residents from the 1990 and 2000 census. It provides a heretofore unavailable socioeconomic portrait of the Watershed and trends in indicators relevant to Collaboration effectiveness such as age, demographic pressures, and economic welfare. Through the use of national, state, regional and rural controls, the study also explores the impact of the agreement on the Watershed. Results do not provide evidence of a net negative impact and are consistent with a net positive impact. Several trends which work against agreement effectiveness are identified.  相似文献   
862.
Mountain socio-ecological systems produce valuable but complex ecosystem services resulting from biomes stratified by altitude and gravity. These systems are often managed and shaped by smallholders whose marginalization is exacerbated by uncertainties and a lack of policy attention. Human–environment interfaces in mountains hence require holistic policies. We analyse the potential of the Global Mountain Green Economy Agenda (GMGEA) in building awareness and thus prompting cross-sectoral policy strategies for sustainable mountain development. Considering the critique of the green economy presented at the Rio + 20 conference, we argue that the GMGEA can nevertheless structure knowledge and inform regional institutions about the complexity of mountain socio-ecological systems, a necessary pre-condition to prompt inter-agency collaboration and cross-sectoral policy formulation. After reviewing the content of the GMGEA, we draw on two empirical cases in the Pakistani and Nepali Himalayas. First, we show that lack of awareness has led to a sequence of fragmented interventions with unanticipated, and unwanted, consequences for communities. Second, using a green economy lens, we show how fragmentation could have been avoided and cross-sectoral policies yielded more beneficial results. Project fragmentation reflects disconnected or layered policies by government agencies, which inherently keep specialized agendas and have no incentive to collaborate. Awareness makes agencies more likely to collaborate and adopt cross-sectoral approaches, allowing them to target more beneficiaries, be more visible, and raise more funds. Nevertheless, we also identify four factors that may currently still limit the effect of the GMGEA: high costs of inter-agency collaboration, lack of legitimacy of the green economy, insufficiently-secured smallholder participation, and limited understanding of the mechanisms through which global agendas influence local policy.  相似文献   
863.
A multimedia environmental fate model was developed to study the temporal dynamics and spatial distribution of a chemical pollutant at watershed scale. The theoretical considerations and implementation of the model were described in the accompanying paper (Part I). This paper presents the result of a test simulation on the transport of trichloroethylene (TCE) in the Connecticut River Basin. The simulation results were reported as time series of concentrations and inter-media transport fluxes in the compartments of atmosphere, plant, soil, surface water, and sediment. Predicted concentrations from the test simulation were compared with published field data or predictions by validated models. The temporal trends in TCE predictions were evaluated by comparing the simulation results with monthly TCE concentrations in various environmental compartments and monthly fluxes of inter-media transport processes. Results indicated that the simulation results were in reasonable agreement with reported data in the literature. The results also revealed that the mass transport of TCE from the atmosphere compartment to soil and surface water was a major route of TCE dispersion in the environment.  相似文献   
864.
Institutions are the rules and norms that guide societal behavior. As societies evolve—with more diverse economies, increased populations and incomes, and more water scarcity—new and more complex water management institutions need to be developed. This evolution of water management institutions may also be observed across different constituencies, with different societal needs, in the same time period. The Red River of the North basin is particularly well suited for research on water management issues. A key feature of water management in the Red River Basin is the presence of three completely different sets of water law. Minnesota’s water law is based upon riparian rights. North Dakota’s water law is based upon prior appropriation. Manitoba has a system of water allocation that features provincial control. Because the basin is fairly homogeneous in terms of land use and geographic features, its institutional diversity makes this an excellent case study for the analysis of local water institutions. This article reviews the local water management institutions in the Red River Basin and assesses the ongoing institutional evolution of local water management.  相似文献   
865.
This article provides an overview of the use of risk-based analysis (RBA) in flood damage assessment, and it illustrates the use of Geographic Information Systems (GIS) in identifying flood-prone areas, which can aid in flood-mitigation planning assistance. We use RBA to calculate expected annual flood damages in an urban watershed in the state of Rhode Island, USA. The method accounts for the uncertainty in the three primary relationships used in computing flood damage: (1) the probability that a given flood will produce a given amount of floodwater, (2) the probability that a given amount of floodwater will reach a certain stage or height, and (3) the probability that a certain stage of floodwater will produce a given amount of damage. A greater than 50% increase in expected annual flood damage is estimated for the future if previous development patterns continue and flood-mitigation measures are not taken. GIS is then used to create a map that shows where and how often floods might occur in the future, which can help (1) identify priority areas for flood-mitigation planning assistance and (2) disseminate information to public officials and other decision-makers.  相似文献   
866.
Despite rapid growth in river restoration, few projects receive the necessary evaluation and reporting to determine their success or failure and to learn from experience. As part of the National River Restoration Science Synthesis, we interviewed 39 project contacts from a database of 1,345 restoration projects in Michigan, Wisconsin, and Ohio to (1) verify project information; (2) gather data on project design, implementation, and coordination; (3) assess the extent of monitoring; and (4) evaluate success and the factors that may influence it. Projects were selected randomly within the four most common project goals from a national database: in-stream habitat improvement, channel reconfiguration, riparian management, and water-quality improvement. Roughly half of the projects were implemented as part of a watershed management plan and had some advisory group. Monitoring occurred in 79% of projects but often was minimal and seldom documented biological improvements. Baseline data for evaluation often relied on previous data obtained under regional monitoring programs using state protocols. Although 89% of project contacts reported success, only 11% of the projects were considered successful because of the response of a specific ecological indicator, and monitoring data were underused in project assessment. Estimates of ecological success, using three criteria from Palmer and others (2005), indicated that half or fewer of the projects were ecologically successful, markedly below the success level that project contacts self-reported, and sent a strong signal of the need for well-designed evaluation programs that can document ecological success.  相似文献   
867.
旅游作为一种日渐兴旺的人类活动,在带来旅游城市经济增长的同时也不可避免地引起水体的氮污染问题.研究旅游城市水体氮负荷的特征,对提高水环境质量具有重要意义.以丽江市漾弓江流域为例,基于物质流分析方法(MFA)探讨旅游城市的水环境氮负荷变化特征及其主要来源,并用回归分析方法探究流域水体氨氮浓度与旅游人次的关系.结果表明,2015—2019年漾弓江流域水体氮负荷呈波动式递减状态,总量为1200~1400 t.人类生活和农作物种植系统是漾弓江流域水体氮负荷的主要贡献者,其中,游客生活子系统的水体氮负荷增速尤为 显著,本地居民生活系统增速缓慢,其他子系统排放量呈下降趋势.旅游旺季及雨季、施肥等的叠加影响使得6月和7月水环境质量最差,表现为水体氨氮浓度值和超标率最高.针对近年来漾弓江流域水环境氮负荷的排放特征及水质超标特点,因时制宜制定减排对策将有助于减少 氮污染,提高旅游城市水环境质量.  相似文献   
868.
对国际议程间的关联性分析已经成为全球治理中的重要问题。特别是,由联合国引领的全球发展与应对气候变化问题,已经占据了当前国际政治议程的首要位置,两者的协同直接影响到全球治理的有效性。《2030年可持续发展议程》与《巴黎气候协定》不仅具有共同的规范性基础,而且两者通过议题衔接和叠加已经形成了密切的治理关系,国际制度关联性日益突出。从目前来看,这种关联性体现了以下特点:第一,嵌入关系。可持续发展议程的目标之一是应对全球气候变化,《巴黎协定》的治理目标已经嵌入联合国可持续发展议程之中,但也与一些目标存在矛盾,因此,协同治理具有必要性。第二,指标对应。《巴黎协定》下的“国家自主贡献”细化项目与可持续发展议程中的大部分指标已经形成对应关系,治理具有同质性。第三,制度间倡议交叉与功能外溢。其协同治理关系具体表现在诸多层面上,特别是在联合国系统内的协调、治理模式的趋同、资金渠道的整合、围绕联合国可持续发展议程所进行的发展机构改革,以及联合进行政策倡议、规则建构及政策制定等方面。从制度关系演变的角度来看,两者协同治理的类型正在发生变化,制度互动在不同层次上不断累积,并逐渐转向伙伴型的协同治理模式。  相似文献   
869.
Deteriorated watersheds can be restored: A case study   总被引:1,自引:0,他引:1  
A project in west-central Colorado demonstrated that a watershed dissected by a dense gully network can be stabilized and rehabilitated. Check dam systems, aided by improved vegetative cover through reduced cattle grazing and plantings, stabilized not only the structurally treated gullies, but also gullies within the network that were not structurally treated. Comparison with untreated gullies located outside of the project area, showed that the outside gullies widened three times as much as the structurally untreated inside gullies. Statistical analysis indicated that precipitation was normal during the treatment and evaluation period.Check dams decreased gully depth by accumulating sediment deposits. In turn, gully bank stabilization was hastened and alluvial aquifer volumes increased. This increase, plus higher infiltration rates as a result of denser vegetation, led to renewed perennial streamflow after 7 treatment years.Within 11 years after treatment, check dam systems and improved vegetation reduced sediment loads in the flows by more than 90 percent, providing a substantial benefit to farmlands and ponds downstream.From this work we are able to conclude that only part of a gully network requires structural treatment. The mainstem gully, and those tributaries controlling the local base levels of others, are the critical segments that should be structurally treated.  相似文献   
870.
Historically, management strategies in Canada's boreal forest have focused on forest polygons and terrestrial biodiversity to address ecological considerations in forest management. The Forest Watershed and Riparian Disturbance (FORWARD) project examines the problem from a watershed perspective rather than a forest polygon viewpoint. The main objective of this study was to devise an artificial neural network (ANN) modeling tool that can predict flow and total phosphorus (TP) concentration for ungauged watersheds (where daily flow is not monitored). This dictates that all inputs should be easily accessed via a public domain database, like the Environment Canada weather database, without the need to install flow gauges in each modeled watershed. Daily flow and TP concentration for two of the project watersheds were modeled using ANNs. The two watersheds (1A Creek, 5.1 km2 and Willow Creek, 15.6 km2) were chosen to reflect variations in wetland area and composition in the study area. Flow was modeled with a feed-forward multilayer perceptron ANN trained with the error back-propagation algorithm. Simulated values for flow were then used, as inputs, to model TP concentration using the same neural networks algorithm. One hidden layer with three slabs; each operating with a different activation function was utilized to simulate the conceptual differences between base flow, snowmelt, and storm events. Time domain analysis was conducted to identify possible model time-lagged inputs reflecting the time dependency of the modeled variables. Spectral analysis was used to address data hystereses. Our results highlight the capabilities of ANN in modeling complex ecosystems and highly correlated variables. Results also indicated that more research towards the phosphorus dynamics in wetlands is required to better represent the impact of wetland area and composition on the water-phase phosphorus in ANN modeling.  相似文献   
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