首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   635篇
  免费   81篇
  国内免费   4篇
安全科学   25篇
环保管理   167篇
综合类   235篇
基础理论   140篇
环境理论   1篇
污染及防治   62篇
评价与监测   8篇
社会与环境   62篇
灾害及防治   20篇
  2025年   14篇
  2024年   25篇
  2023年   20篇
  2022年   26篇
  2021年   35篇
  2020年   34篇
  2019年   33篇
  2018年   28篇
  2017年   29篇
  2016年   57篇
  2015年   39篇
  2014年   39篇
  2013年   41篇
  2012年   34篇
  2011年   48篇
  2010年   33篇
  2009年   35篇
  2008年   26篇
  2007年   27篇
  2006年   25篇
  2005年   18篇
  2004年   20篇
  2003年   13篇
  2002年   7篇
  2001年   4篇
  2000年   3篇
  1999年   1篇
  1998年   1篇
  1987年   1篇
  1985年   2篇
  1982年   1篇
  1970年   1篇
排序方式: 共有720条查询结果,搜索用时 15 毫秒
561.
Linking GIS-based models to value ecosystem services in an Alpine region   总被引:11,自引:1,他引:11  
Planning frequently fails to include the valuation of public goods and services. This can have long-term negative economic consequences for a region. This is especially the case in mountainous regions such as the Alps, which depend on tourism and where land-use changes can negatively impact key ecosystem services and hence the economy. In this study, we develop a semi-automatic procedure to value ecosystem goods and services. Several existing process-based models linked to economic valuation methods are integrated into a geographic information system (GIS) platform. The model requires the input of a digital elevation model, a land-cover map, and a spatially explicit temperature dataset. These datasets are available for most regions in Europe. We illustrate the approach by valuing four ecosystem services: avalanche protection, timber production, scenic beauty, and habitat, which are supplied by the “Landschaft Davos”, an administrative district in the Swiss Alps. We compare the impacts of a human development scenario and a climate scenario on the value of these ecosystem services. Urban expansion and tourist infrastructure developments have a negative impact on scenic beauty and habitats. These impacts outweigh the benefits of the developments in the long-term. Forest expansion, predictable under a climate change scenario, favours natural avalanche protection and habitats. In general, such non-marketed benefits provided by the case-study region more than compensate for the costs of forest maintenance. Finally, we discuss the advantages and disadvantages of the approach. Despite its limitations, we show how this approach could well help decision-makers balance the impacts of different planning options on the economic accounting of a region, and guide them in selecting sustainable and economically feasible development strategies.  相似文献   
562.
新型农村社区建设是改善农民的生产和生活环境,推进城乡关系良性互动与城乡一体化的有效途径。经实地调研考察确定规划区范围内共有旅游资源7大类、17个亚类、35个基本类型,结合秦皇岛柳河圈新农村建设规划的实践,提出应把新社区空间规划建设与旅游景区建设融于一体,将葡萄酒休闲旅游产业融合社区发展,新型社区住宅建设要彰显地方特色建设,社区产业规划、新社区文化规划应彰显旅游文化特色等具有本地区特色的新型农村社区的建设路径,以期促进秦皇岛农村社会经济的发展。  相似文献   
563.
旅游公共服务市场化与政府的作用研究   总被引:1,自引:0,他引:1  
旅游公共服务是我国公共服务建设的基本领域,也是一个需要逐步完善的系统。旅游公共服务市场化,是顺应旅游行政改革和建设服务型政府的内在要求。结合旅游公共服务的实践,在分析旅游公共服务市场化的内涵、可行性以及旅游公共服务市场化条件和效率的基础上,提出旅游公共服务市场化的途径选择,最后探讨了政府在旅游公共服务市场化过程中应发挥的作用。  相似文献   
564.
In recent decades, significant progress has been made toward reconstructing the past climate record based on environmental proxies, such as tree rings and ice core records. However, limited examples of research that utilizes such data for water resources decision-making and policy exist. Here, we use the reconstructed record of Palmer Drought Severity Index (PDSI), dating back to 1138AD to understand the nature of drought occurrence (severity and duration) in the state of Maine. This work is motivated by the need to augment the scientific basis to support the water resources management and the emerging water allocation framework in Maine (Maine Department of Environmental Protection, Chapter 587). Through a joint analysis of the reconstructed PDSI and historical streamflow record for twelve streams in the state of Maine, we find that: (a) the uncertainties around the current definition of natural drought in the Chapter 587 (based on the 20th century instrumental record) can be better understood within the context of the nature and severity of past droughts in this region, and (b) a drought index provides limited information regarding at-site hydrologic variations. To fill this knowledge gap, a drought index-based risk assessment methodology for streams across the state is developed. Based on these results, the opportunities for learning and challenges facing water policies in a changing hydroclimate are discussed.  相似文献   
565.
ABSTRACT/ The aim of this study is to analyze the antecedents of urban waste recycling behavior. To achieve this goal, a concrete urban waste management program was chosen. The study focuses on the Selective Collection Program (SCP) in Zaragoza, a medium-sized city in northeastern Spain. The research starts with a conceptual model in which the variables that potentially affect recycling behavior can be classified into two groups: incentives and barriers. Moreover, the sociodemographic characteristics of the individuals are included in our study. Given that the proposed model requires specification of latent variables or constructs, the analysis is based on the Structural Equation Models (SEM) methodology. The results revealed that environmental awareness, knowledge of the environmental impact of urban waste, and the positive perception of management by local government exercise a positive effect on individual recycling behavior, while perceived personal difficulties (space and time availability) and distance to and from the container have a negative effect. As regards sociodemographic variables, this study found that annual family income sustains a negative relationship with recycling behavior, while age maintains a positive one. The results obtained clearly show the important role that the public authorities play, especially municipal governments, in achieving the waste recycling objectives established in accordance with international legislation.  相似文献   
566.
China’s new Classification-Based Forest Management (CFM) is a two-class system, including Commodity Forest (CoF) and Ecological Welfare Forest (EWF) lands, so named according to differences in their distinct functions and services. The purposes of CFM are to improve forestry economic systems, strengthen resource management in a market economy, ease the conflicts between wood demands and public welfare, and meet the diversified needs for forest services in China. The formative process of China’s CFM has involved a series of trials and revisions. China’s central government accelerated the reform of CFM in the year 2000 and completed the final version in 2003. CFM was implemented at the provincial level with the aid of subsidies from the central government. About a quarter of the forestland in China was approved as National EWF lands by the State Forestry Administration in 2006 and 2007. Logging is prohibited on National EWF lands, and their landowners or managers receive subsidies of about 70 RMB (US$10) per hectare from the central government. CFM represents a new forestry strategy in China and its implementation inevitably faces challenges in promoting the understanding of forest ecological services, generalizing nationwide criteria for identifying EWF and CoF lands, setting up forest-specific compensation mechanisms for ecological benefits, enhancing the knowledge of administrators and the general public about CFM, and sustaining EWF lands under China’s current forestland tenure system. CFM does, however, offer a viable pathway toward sustainable forest management in China.  相似文献   
567.
生态系统服务是人类生存和可持续发展的物质基础和自然资本,对其进行量化评估可以为管理者当局保护和管理湿地提供重要的参考依据.以泸沽湖湿地和邛海湿地为研究对象,通过实地调查,综合运用生态经济学、环境经济学和资源经济学方法,对2个湿地的生态系统服务功能价值进行了评估.结果表明:泸沽湖的间接使用价值为153 214.60万元,占总价值的82.785%,远大于直接使用价值,而邛海的直接使用价值为94 050万元,占总价值的75.250%,远大于间接使用价值;湿地的主要服务功能价值是水调节功能、科考旅游功能和水质净化功能的价值.最后对2个湿地的生态系统服务功能的价值构成进行了分析,并提出了相应的保护管理策略.  相似文献   
568.
  总被引:1,自引:0,他引:1  
Developing nature-based tourism in private lands calls for new mechanisms to consolidate the interests of the tourism industry, visitors, and landowners. This choice experiment study elaborates on the heterogeneity of visitors’ preferences and willingness to pay (WTP) for enhanced forest amenities and ecosystem services. The survey, targeting domestic and foreign tourists visiting the Ruka-Kuusamo area in Finland, considered four attributes: landscape quality, outdoor routes, forest biodiversity, and carbon sequestration. For observed heterogeneity, the visitors were grouped by their attitudes towards forest management. Unobserved heterogeneity in visitors’ choice behaviour and WTP was examined with the latent class model. While most visitors had environmentally friendly attitudes and were willing to pay, especially for enhanced landscape quality and biodiversity, considerable heterogeneity was revealed in terms of three segments with distinctive attitudes, choice behaviour and WTP. The variation in WTP has important implications for the design of a scheme of payments for environmental management.  相似文献   
569.
    
The biodiversity crisis necessitates a global implementation of effective, equitable, and feasible conservation strategies. Public land acquisitions (PLAs) for watershed protection can produce co-benefits for basic human needs and biodiversity, but there are concerns that acquiring land is not scalable or may not protect threatened biodiversity. PLA programs are rare, allowing for limited opportunities to assess these concerns. We investigate a unique policy that has legally mandated PLAs in the Colombian Andes, a tropical biodiversity hotspot, since 1993. Using a novel dataset of >7000 PLAs, along with surveys and in-person interviews, we study the scale, spatial allocation, and constraints on PLA implementation, and examine its potential conservation benefits. More than 300,000 ha were acquired through PLAs, but economic and institutional factors such as land cost, government income, and land tenure informality were main drivers in the degree of PLA implementation. Acquisitions were thus directed mostly toward cheaper, less threatened ecosystems.  相似文献   
570.
根据Costanza等人对全球生态系统服务价值的测算结果,分析了1996-2003年邹城市土地利用和生态系统服务价值变化.结果表明,邹城市的耕地、园地和林地土地面积在减少,建设用地和水域用地面积在增加.由于水域单位面积生态系统服务价值较高,7年间邹城市区域生态系统服务价值处于增加状态.邹城市生态系统服务价值从1996年的95.9704×106美元增加到2003年的104.5830×106美元,7年间增加8.6126×106美元,变化率达到8.97%.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号