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   743篇
  免费   36篇
  国内免费   18篇
测绘学   50篇
大气科学   132篇
地球物理   13篇
地质学   127篇
海洋学   110篇
综合类   26篇
自然地理   339篇
  2024年   1篇
  2023年   17篇
  2022年   59篇
  2021年   58篇
  2020年   50篇
  2019年   56篇
  2018年   43篇
  2017年   64篇
  2016年   42篇
  2015年   41篇
  2014年   55篇
  2013年   70篇
  2012年   28篇
  2011年   25篇
  2010年   24篇
  2009年   35篇
  2008年   23篇
  2007年   25篇
  2006年   17篇
  2005年   14篇
  2004年   15篇
  2003年   7篇
  2002年   8篇
  2001年   3篇
  2000年   3篇
  1999年   4篇
  1998年   1篇
  1996年   2篇
  1995年   1篇
  1993年   1篇
  1992年   1篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
排序方式: 共有797条查询结果,搜索用时 243 毫秒
181.
Located on the Caribbean coast of Central America and flanked by the second longest barrier reef in the world, Belize is a nation reliant upon marine resources. Each year, the country’s predominantly small-scale fisheries generate an estimated US$22 million in revenue – 1.8%of GDP – and employ 3000 people. However, the nation’s fishing communities are facing an unprecedented challenge. Existing threats posed by declining fish stocks have been exacerbated by the introduction of the invasive alien red lionfish Pterois volitans in 2008. This Indo-Pacific predator has the potential to cause significant losses to the recruitment of native fish, in turn disrupting coral reef community dynamics in the Belize Barrier Reef Reserve System, a UNESCO World Heritage Site. Howefver, targeted lionfish fishing may offer a cost effective means to control the invasion, while also creating an alternative livelihood solution and improving food security among Belize's coastal fishing communities. This study summarises the recent history of the lionfish invasion in Belize, describes the multi-sector approach being used to address the invasion, and presents preliminary research summarising the characteristics of invasive alien lionfish in Belize. Data from Belize's nascent ‘lionfishery’ are also presented, demonstrating that demand for lionfish is outweighing supply – largely as a result of awareness-raising initiatives – and highlighting the strong potential for replication of this approach elsewhere in the Caribbean. The study concludes by discussing the barriers and potential solutions to this market-based approach to invasive species management.  相似文献   
182.
Adaptive management and related fields have theorized new governance strategies that embrace complexity and are able to respond effectively to changing and unpredictable biophysical dynamics. However, this body of work pays inadequate attention to important on-the-ground realities, including feasibility of implementation and the power dynamics embedded in multi-scalar systems of environmental governance. This paper presents findings from a research project on challenges to adaptive management in the variable wetland ecosystem of the Okavango Delta, Botswana. Many residents of this rural region rely on transitional agricultural practices, shifting between dryland and floodplain farming in response to dynamic precipitation and flooding patterns. Higher than average floods in 2009–2011 inundated many floodplain fields past the point of production, causing farmers to shift to the dryland for multiplem seasons. At the same time, the highly centralized Government of Botswana began to implement stricter regulations over floodplain resources, which stemmed in part from a new adaptive management plan developed for the region. As a result, many farmers felt pressured by the government to abandon transitional livelihood practices and to shift permanently to dryland agriculture even though many preferred to continue floodplain farming. This loss of a responsive livelihood strategy will likely result in decreased long-term adaptive capacity for many residents. Drawing on these findings, this paper advances the argument that if adaptive management is to become a viable option for communities in changing environments, more attention must be given to the role of unequal power relations in multi-scalar systems of environmental governance.  相似文献   
183.
Natural disasters present a multitude of entangled societal challenges beyond the realms and capacities of single actors. Prior research confirms that effective collaboration is of critical significance to address such complex collective action problems. Yet, studies rarely investigate if patterns of collaboration are appropriately aligned (‘fit’) with how different challenges (tasks) are interdependent, or how levels of fit influence collective action performance. We develop a set of hypotheses specifying what constitutes a good fit between collaborative networks and task interdependency. Using unique empirical data from the response to a major wildfire in Sweden, we examine how individual actors select collaboration partners and tasks during the formation the collaborative crisis response network. Then we test if levels of fit in the established network influence performance. We show that patterns of actor and task interdependency influence the formation of collaborative networks and that a good fit seems to be associated with more effective collaboration. Our data even suggest that a good fit is more important for performance than actors’ prior crisis management experience and level of professionalization. Further, we show that actors only partially engage in actor-task configurations conducive to high performance. Our study probes the limitations of simplified accounts of collaborative disaster management by enabling more precise and theoretically informed empirical inquiries regarding the mechanisms that shape the structure and performance of collaborative networks.  相似文献   
184.
Interest in obtaining a more accurate snapshot of irrigation management from a geographical perspective is increasingly relevant. This proposal is based on existing qualitative approaches in combination with an alternative method (the territorial irrigation management model) to identify and present key stakeholders attitudes and perceptions in the Segarra-Garrigues irrigation system in Spain. Advantages are (1) the focus on interrelations and context, (2) the applicability and extrapolation of the irrigation system, and (3) the irrigator-driven rather than researcher-driven perspective. Results revealed that there are conceptual and practical heterogeneities between the preferences of stakeholders' groups regarding water resources management, environmental protection, and agricultural challenges.  相似文献   
185.
Many difficulties have arisen from top-down approaches to the design and implementation of global environmental initiatives. The concept of translation and other analytical features of Actor-Network Theory (ANT) can offer a way of conceptualising these difficulties and their practical effects. By translation, we refer to what happens in-between the formulation of international goals and the results of implementation, and more specifically, relations and negotiations within this broader process. We examine several aspects of translation in the case of Reducing Emissions from Deforestation and Forest Degradation (REDD+), a prominent global environmental initiative. Using an ethnographic approach, we explore local responses in Central Kalimantan province, Indonesia, to REDD+ ideas and goals that originate at international and national levels. Following selection in 2010 as the official REDD+ pilot province, Central Kalimantan became a site for the convergence of actors and projects with varied sources of funding. The study identifies a central tension that emerged between an initial vision of Central Kalimantan as a pioneer, and local concerns about being used as an experimental subject or ‘guinea pig’ for the testing of externally designed schemes. Results show that greater flexibility in the design of programs and initiatives is needed, to provide space for local inputs. Implementation should pay attention to how local actors are included in planning processes that inform decision-making at higher jurisdictional levels. To bring about intended changes in land use, programs like REDD+ need to extend beyond a focus on short-term projects and targets, to instead emphasise long-term investments and forms of collective action that support learning.  相似文献   
186.
The water-energy-food nexus has become a popular concept in environmental change research and policy debates. Proponents suggest that a nexus approach promotes policy coherence through identifying optimal policy mixes and governance arrangements across the water, energy and food sectors. Although the nexus literature identifies some barriers to achieving coherence it does not clearly explain why the barriers are present, what influences them, and how they can be acted upon. These gaps disconnect the nexus literature from the governance processes it ultimately seeks to influence. This paper examines how the integrative environmental governance literature can help to close these gaps. It extracts insights from seven streams of research literature and discusses their relevance for the nexus literature. We argue that connecting the nexus to decision-making processes requires: i) rethinking the boundaries of nexus analysis vis-à-vis other sectors and levels; ii) elaboration of shared principles that can guide decision-making towards policy coherence − or an appropriate form of fragmentation − in different contexts; iii) viewing policy coherence as a continuous process of changing values and perception rather than as an outcome.  相似文献   
187.
The Kyoto Protocol's Clean Development Mechanism (CDM) is a carbon credit trading scheme intended to reduce anthropogenic greenhouse gas emissions and promote ‘sustainable development’. Hundreds of CDM‐sponsored hydroelectric dams have been constructed in southwest China's Yunnan Province, where carbon finance contributes substantial financial incentives to hydropower expansion. This article investigates whether riparian Handai farmers settled near the Madushan hydropower plant on the Chinese section of Red River have experienced positive outcomes from this project's participation in the CDM. I assess how Handai individuals' access to core livelihood assets has been modified following dam completion and probe how the CDM reconfigures scalar relations among the various stakeholders involved in hydropower governance in Yunnan. Though the CDM facilitates hydropower expansion, it fails to produce development that is more sustainable than ‘business as usual’ from a local perspective. Rather, the CDM consolidates hydropower governance in the same way as it unfolded in Yunnan before the province became an active participant in this scheme. The CDM also facilitates a national development campaign fostering specific socio‐economic modernization patterns in China's western provinces.  相似文献   
188.
Svein Jentoft   《Marine Policy》2006,30(6):671-680
This paper has two main sources of inspiration. Firstly, building on Flyvbjerg's “Making Social Science Matter”[Flyvbjerg B. Making social science matter: why social inquiry fails and how it can succeed again. Cambridge: Cambridge University Press; 2003], I argue that the contribution of the social sciences to fisheries resource management must essentially be “phronetic” (after Aristotle's phronesis, i.e. practical wisdom), in contrast to the “scientific” (Aristotle: episteme) contribution of the natural sciences. Secondly, inspired by the recent publication “Fish for Life: Interactive Governance for Fisheries” [Kooiman J, Jentoft S, Pullin R, Bavinck M, editors. Fish for life: interactive governance for fisheries. Amsterdam: Amsterdam University Press; 2005], I hold that phronesis is basically what the notion of governance adds to management. Governance is the broader concept, inviting a more reflexive, deliberative and value-rational methodology than the instrumental, means-end oriented management concept. I claim that for interdisciplinarity to work in fisheries it is essential to recognize the fundamental methodological differences that exist between the social and natural sciences.  相似文献   
189.
Multilevel governance is regarded as a promising approach to deal with the multidimensional nature of climate change adaptation. However, the policy context in which it is implemented is very often complex and fragmented, characterised by interacting climate and non-climate strategies. An understanding of multilevel decision-making and governance is particularly important, if desired adaptation outcomes are to be achieved. This paper examines how climate change adaptation takes place in a complex multilevel system of governance, in the context of Australia's Great Barrier Reef (GBR) region. It examines over one hundred adaptation strategies at federal, state, regional and local levels in terms of type, manifestation, purposefulness, drivers and triggers, and geographic and temporal scope. Interactions between strategies are investigated both at the same level of governance and across governance levels. This study demonstrates that multilevel approach is a necessary, but not a sufficient condition in responding to complex multiscale and multisector issues, such as climate change adaptation. Short-term adaptation measures; a predominant incremental, sectoral, top-down approach to adaptation; and the lack of a framework for managing interactions are major threats to effective climate adaptation in the GBR region. Coping with such threats will require long-term transformative action, establishing enabling conditions to support local adaptation, and, most important, creating and maintaining strategic interactions among adaptation strategies. Coordinating and integrating climate and non-climate strategies across jurisdictions and policy sectors are the most significant and challenging tasks for multilevel governance in the GBR region and elsewhere.  相似文献   
190.
Abstract

Collaborative conservation has been touted as a viable option for addressing contentious natural resource stewardship issues in a way that represents the diverse voices impacted by, and involved in, conservation decisions. Engaging meaningfully in collaborative conservation involves overcoming a unique set of challenges while also realizing opportunities. In this special issue, we use the term collaborative conservation evaluation to encompass research and evaluation related to collaborative governance and collaborative natural resource management projects, programs, or decision-making processes that leverage a participatory approach, involve multiple stakeholders, and incorporate a range of contemporary evaluation approaches. Here, we provide a series of articles and tools intended to highlight different approaches to evaluation that utilize a variety of methodologies adapted for different contexts. We intend for these articles to spark further conversation and inspire future directions in evaluating collaborative conservation for researchers and practitioners.  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