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651.
ABSTRACT: As part of the National Assessment of Climate Change, the implications of future climate predictions derived from four global climate models (GCMs) were used to evaluate possible future changes to Pacific Northwest climate, the surface water response of the Columbia River basin, and the ability of the Columbia River reservoir system to meet regional water resources objectives. Two representative GCM simulations from the Hadley Centre (HC) and Max Planck Institute (MPI) were selected from a group of GCM simulations made available via the National Assessment for climate change. From these simulations, quasi-stationary, decadal mean temperature and precipitation changes were used to perturb historical records of precipitation and temperature data to create inferred conditions for 2025, 2045, and 2095. These perturbed records, which represent future climate in the experiments, were used to drive a macro-scale hydrology model of the Columbia River at 1/8 degree resolution. The altered streamflows simulated for each scenario were, in turn, used to drive a reservoir model, from which the ability of the system to meet water resources objectives was determined relative to a simulated hydrologic base case (current climate). Although the two GCM simulations showed somewhat different seasonal patterns for temperature change, in general the simulations show reasonably consistent basin average increases in temperature of about 1.8–2.1°C for 2025, and about 2.3–2.9°C for 2045. The HC simulations predict an annual average temperature increase of about 4.5°C for 2095. Changes in basin averaged winter precipitation range from -1 percent to + 20 percent for the HC and MPI scenarios, and summer precipitation is also variously affected. These changes in climate result in significant increases in winter runoff volumes due to increased winter precipitation and warmer winter temperatures, with resulting reductions in snowpack. Average March 1 basin average snow water equivalents are 75 to 85 percent of the base case for 2025, and 55 to 65 percent of the base case by 2045. By 2045 the reduced snowpack and earlier snow melt, coupled with higher evapotranspiration in early summer, would lead to earlier spring peak flows and reduced runoff volumes from April-September ranging from about 75 percent to 90 percent of the base case. Annual runoff volumes range from 85 percent to 110 percent of the base case in the simulations for 2045. These changes in streamflow create increased competition for water during the spring, summer, and early fall between non-firm energy production, irrigation, instream flow, and recreation. Flood control effectiveness is moderately reduced for most of the scenarios examined, and desirable navigation conditions on the Snake are generally enhanced or unchanged. Current levels of winter-dominated firm energy production are only significantly impacted for the MPI 2045 simulations.  相似文献   
652.
ABSTRACT: A wide variety of regional assessments of the water-related impacts of climatic change have been done over the past two decades, using different methods, approaches, climate models, and assumptions. As part of the Water Sector research for the National Assessment of the Implications of Climatic Variability and Change for the United States, several major summaries have been prepared, looking at the differences and similarities in results among regional research projects. Two such summaries are presented here, for the Colorado River Basin and the Sacramento River Basin. Both of these watersheds are vitally important to the social, economic, and ecological character of their regions; both are large snowmelt-driven basins; both have extensive and complex water management systems in place; and both have had numerous, independent studies done on them. This review analyzes the models, methods, climate assumptions, and conclusions from these studies, and places them in the context of the new climate scenarios developed for the National Assessment. Some significant and consistent impacts have been identified for these basins, across a wide range of potential climate changes. Among the most important is the shift in the timing of runoff that results from changes in snowfall and snowmelt dynamics. This shift has been seen in every regional result across these two basins despite differences in models and climate change assumptions. The implications of these impacts for water management, planning, and policy are discussed.  相似文献   
653.
ABSTRACT: The U.S. Army Corps of Engineers conducted an assessment of Great Lakes water resources impacts under transient climate change scenarios. The integrated model linked empirical regional climate downscaling, hydrologic and hydraulic models, and water resource use sub-models. The water resource uses include hydropower, navigation, shoreline damages, and wetland area. The study is unique in that both steady-state 2°CO2 and transient global circulation model (GCM) scenarios were used and compared to each other. The results are consistent with other impact studies in that high scatter in regional climate among the GCM scenarios lead to high uncertainty in impacts. Nevertheless, the transient scenarios show that in the near-term (approximately 20 years) significant changes could occur. This result only adds to the urgency of creating more flexible and robust management of water resources uses.  相似文献   
654.
水资源定价方法的初步探讨   总被引:9,自引:0,他引:9  
谢标  杨永岗 《环境科学》1999,20(3):100-103
根据水资源的特点,分析了开展水资源定价研究的目的和意义,设计了水资源存在价值及其经济价值确定方法的研究思路,研究认为,探讨水资源存在价值应考虑其本身的价值和环境容量虚幻成本2方面;水资源经济价值则包括水淘汰存在价值和水资源转化为水资源商品后物化的使用价值,这里的使用价值又包含水资源污染治理及损害成本、稀缺性价值、边际运行成本和边际时间成本等4个方面,在以上分析的基础上,给出了水资源定价的计算模型,  相似文献   
655.
对广东省平远县稀土矿开采对土地资源的影响进行了初步的调查和分析。同时在已进行的植被恢复措施的基础上,对其效应作了初步的分析,评价了恢复措施对水土流失和土壤理化性质的影响,并据此提出了比较适合的植被恢复措施。  相似文献   
656.
海南省农业能值分析   总被引:1,自引:0,他引:1  
应用OdumHT创立的能值分析理论和方法,对海南省农业进行了分析和评价,结果表明:由于自然条件得天独厚,环境资源对农业的贡献很大,环境资源能值占能值利用率的30%,高于全国平均值(13%);净能值产出率为1.27,高于日本和意大利,可以作为一种能值来源;农牧渔业产品的宏观经济价值远大于市场价值,农业生产中有相当大一部分环境资源无偿投入;环境承载指标为2.44,远低于日本和意大利,环境压力较小,发展潜力很大。进而提出促进农业持续发展的有关建议与设想。  相似文献   
657.
云南省土著民族在长期生产实践中积累了丰富的知识,形成了特有的习俗。这些知识和习俗对保护当地生态环境和资源发挥了重大作用。本文从宗教信仰、民俗、耕作制度、栽培、选种等方面进行归纳,以期从中汲取有益于农业持续发展的精华。  相似文献   
658.
由于地质和地理条件的特殊性,沿海地区生态环境极其脆弱和敏感。水资源短缺、水环境污染、海水入侵、地面沉降、生态环境退化和海平面上升,已构成我国沿海地区实现可持续发展战略面临的重大资源和环境问题。水资源和生态环境的持续利用,已成为我国沿海地区一项极其重要的战略任务。根据可持续发展理论,通过建立适应水资源持续利用的管理体制、政策和运行机制,采取生态环境可持续保护策略,可完全达到水资源和生态环境的持续利用,并有效实现中国沿海地区资源、环境与经济、社会的有机协调及经济、社会的持续、稳定、健康发展  相似文献   
659.
江苏海岸湿地水质污染特征与海陆一体化调控   总被引:6,自引:0,他引:6  
2000年江苏海岸湿地人海河流河口淡水监测断面有30%的水质处于劣Ⅴ类,满足Ⅲ类水质的仅占10%;近岸海域海水监测断面有50%的水质处于Ⅳ标准。人类扰动的频率与强度的日益加大是水质污染的主要原因,而河流携带大量污染物是水质污染的主要途径。江苏海岸湿地水质污染防治的关键在于流域海陆水环境系统的一体化调控,侧重点是调控技术路线和水质污染控制层次的设计。环境管理控制区划的方案是:横向上由陆向海划分为上游流域、近岸陆域、海岸湿地和离岸海域4个环境控制带;纵向上自北向南以水系汇流特征、行政区划特征、海域特点划分为Ⅳ类环境功能区及若干亚区。  相似文献   
660.
Wildlife conservation and management (WCM) practices have been historically drawn from a wide variety of academic fields, yet practitioners have been slow to engage with emerging conversations about animals as complex beings, whose individuality and sociality influence their relationships with humans. We propose an explicit acknowledgement of wild, nonhuman animals as active participants in WCM. We examined 190 studies of WCM interventions and outcomes to highlight 3 common assumptions that underpin many present approaches to WCM: animal behaviors are rigid and homogeneous; wildlife exhibit idealized wild behavior and prefer pristine habitats; and human–wildlife relationships are of marginal or secondary importance relative to nonhuman interactions. We found that these management interventions insufficiently considered animal learning, decision-making, individuality, sociality, and relationships with humans and led to unanticipated detrimental outcomes. To address these shortcomings, we synthesized theoretical advances in animal behavioral sciences, animal geographies, and animal legal theory that may help conservation professionals reconceptualize animals and their relationships with humans. Based on advances in these fields, we constructed the concept of animal agency, which we define as the ability of animals to actively influence conservation and management outcomes through their adaptive, context-specific, and complex behaviors that are predicated on their sentience, individuality, lived experiences, cognition, sociality, and cultures in ways that shape and reshape shared human–wildlife cultures, spaces, and histories. Conservation practices, such as compassionate conservation, convivial conservation, and ecological justice, incorporate facets of animal agency. Animal agency can be incorporated in conservation problem-solving by assessing the ways in which agency contributes to species’ survival and by encouraging more adaptive and collaborative decision-making among human and nonhuman stakeholders.  相似文献   
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