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   222篇
  免费   12篇
  国内免费   3篇
安全科学   4篇
废物处理   1篇
环保管理   89篇
综合类   25篇
基础理论   59篇
环境理论   1篇
污染及防治   14篇
评价与监测   6篇
社会与环境   16篇
灾害及防治   22篇
  2024年   1篇
  2023年   1篇
  2022年   1篇
  2021年   4篇
  2020年   2篇
  2019年   5篇
  2018年   5篇
  2017年   12篇
  2016年   12篇
  2015年   6篇
  2014年   10篇
  2013年   29篇
  2012年   7篇
  2011年   16篇
  2010年   6篇
  2009年   17篇
  2008年   11篇
  2007年   12篇
  2006年   13篇
  2005年   7篇
  2004年   11篇
  2003年   8篇
  2002年   4篇
  2001年   4篇
  2000年   5篇
  1999年   3篇
  1998年   3篇
  1997年   2篇
  1996年   3篇
  1993年   2篇
  1987年   3篇
  1986年   6篇
  1984年   1篇
  1982年   1篇
  1981年   2篇
  1977年   1篇
  1972年   1篇
排序方式: 共有237条查询结果,搜索用时 609 毫秒
61.
ABSTRACT: Drought has been a hazard in parts of Africa throughout historic times, and in all likelihood prior to that time as well. In recent years the hazard of drought has been increasing in frequency and areal extent. A drought that occured from 1968 to 1974 in Sub-Saharan Africa directly affected millions of people, and directly or indirectly cost the lives of tens of thousands of people. The mechanism involved in the widespread problem is the manner of adjustment of the human population to climatic cycles of short duration, in the face of rapidly growing human and animal numbers. A rapid collapse of the grasslands and an expansion of the Sahara Desert southward into more humid areas has resulted from the increasing pressure on the land from largely subsistance farming and herding. Present social, economic, and political conditions indicate that the process is going to continue to accelerate, affecting ever-increasing numbers of people in the Sub-Saharan Africa region.  相似文献   
62.
The relationship between migration and deforestation in the developing world continues to receive significant attention. However beyond direct population increase, the precise mechanisms that operate within the intersection of migrant/host land rights remain largely unexamined. Where migrants are provided with land and rights by the State and/or local communities, how such rights are perceived by the migrants is of primary importance in their interaction with land resources, and in aggregate it impacts the development opportunities and environmental repercussions of migration. The authors analyze the operative aspects of land rights reception (as opposed to provision) by migrant populations, and the relationship between this reception and deforestation. The article examines a case in Zambia to analyze how tenurial constructs, emerging from the way rights are perceived by migrants, lead to the continued clearing of areas much larger than needed for cultivation, even when the arrangement appears counter‐productive in terms of land rights provision and labour allocation. While valuable policy efforts have focused on providing resource rights to migrants, how such rights are received and the relationship of this reception to resource management needs greater policy attention.  相似文献   
63.
Among the world's poor, approximately 75% of those in extreme poverty live and work in rural areas and two‐thirds of them depend mainly on farming or farm labour for their livelihood. Policies to grant the rural poor secure access to land and water for irrigation — and to improve the economic efficiency of small‐scale agriculture — can thus play a critical role in the implementation of rural development strategies, including efforts to combat rural poverty. Since inadequate access to arable land is probably the most important cause of rural poverty, redistributive land reform is increasingly seen as crucial for socio‐economic development and poverty alleviation in many developing countries with substantial amounts of (unused) arable state land or (under‐utilized) large private landholdings. This article argues that market‐based land redistribution schemes, such as the one being implemented in South Africa, can be considered one of the most innovative approaches to land reform that have emerged over the last decade. These schemes thus provide a useful alternative to more conventional, state‐controlled land redistribution programmes. The article concludes, however, that when countries opt for market‐based approaches to land redistribution, the State still has an important role to play, without necessarily deciding which land parcels change hands.  相似文献   
64.
Past global efforts at dealing with the problem of global warming concentrated on mitigation, with the aim of reducing and possibly stabilizing greenhouse gas (GHG) concentrations in the atmosphere. With the slow progress in achieving this, adaptation was viewed as a viable option to reduce the vulnerability to the anticipated negative impacts of global warming. It is increasingly realized that mitigation and adaptation should not be pursued independent of each other but as complements. This has resulted in the recent calls for the integration of adaptation into mitigation strategies. However, integrating mitigation and adaptation into climate change concerns is not a completely new idea in the African Sahel. The region is characterized by severe and frequent droughts with records dating back into centuries. The local populations in this region, through their indigenous knowledge systems, have developed and implemented extensive mitigation and adaptation strategies that have enabled them reduce their vulnerability to past climate variability and change, which exceed those predicted by models of future climate change. However, this knowledge is rarely taken into consideration in the design and implementation of modern mitigation and adaptation strategies. This paper highlights some indigenous mitigation and adaptation strategies that have been practiced in the Sahel, and the benefits of integrating indigenous knowledge into formal climate change mitigation and adaptation strategies. Incorporating indigenous knowledge can add value to the development of sustainable climate change mitigation and adaptation strategies that are rich in local content, and planned in conjunction with local people.  相似文献   
65.
In most of sub‐Saharan Africa, where the agricultural sector experiences dismal performance and is characterized by a gloomy picture, the cotton sub‐sector in Côte d’Ivoire is often mentioned as a “success story” given the spectacular rise in the quantity of cotton production and the profile of the crop within the farming system. What are the historical and political antecedents of the development of cotton and the factors responsible for the feat accomplished in the midst of general failures in the same continent? To what extent can cotton be regarded as a “success story” and, what lessons can be drawn for agricultural development strategies based on the Ivorian case study? This paper traces the historical and socio‐political background of cotton development in Côte d’Ivoire and identifies key policy and institutional interventions that have influenced the rise of cotton production and its emergence as the dominant crop in the farming systems of the country. Four stages in Ivorian cotton development are identified: planning, take off, crisis and the renaissance phases. The study demonstrates how a combination of good planning, technological advancement and appropriate policy and institutional conditions have contributed significantly to the rise of cotton production and its influence on the agricultural economy of northern Côte d’Ivoire. The study also highlights how the sustainability of agricultural development has been impacted by domestic and international policies and political events over which smallholder farm families have little control, and can at best only respond to. Important questions about cotton development in Côte d'Ivoire are raised that need to be answered before the program can be categorized conclusively as a success story. The study shows that there are no quick fixes to agricultural development in the sub‐region. Rather, good planning and putting the necessary building blocks in place are important prerequisites. It is recommended that agricultural development efforts in the continent take cognizance of the complexity of the sector and address the inter‐relationships that exist among the technical, policy, market and institutional factors that combine individually and collectively to influence African agriculture.  相似文献   
66.
The use of mercury in small-scale gold mining has been a growing concern in many parts of Africa. However, although the negative effects of mercury pollution are increasingly reported, little has been written about how labour relationships and gold production challenges in mining communities affect mercury management practices. This article provides an integrative analysis of small-scale gold extraction processes, labour challenges, and mercury use at gold mills in Zimbabwe, focusing on a gold rush area in Mashonaland West Province. It examines practices employed by miners who have limited economic capacities to upgrade technologies, and how the complex relationships between miners, mill owners and government regulators affect environmental performance. The study draws attention to how poor environmental management practices relate to labour inequities, low gold recovery as well as the informal gold trade dynamics amid the country's economic crisis. Results of a United Nations-supported stakeholder consultation process are discussed, with proposals for improving labour conditions and reducing environmental risk. The article highlights why the government should develop and support local programs to assist miners, as well as the decisive roles mill owners could take in ensuring improved standards on their sites.  相似文献   
67.
Carbon sequestration through forestry and agroforestry can help mitigate global warming. For Africa, carbon sequestration also represents an opportunity to fund sustainable development through financial inflows. However, with a low share of global carbon trade, there are strong concerns that African countries are losing out on this valuable opportunity. Through a comprehensive review of 23 carbon sequestration projects across 14 countries, this paper discusses ways to overcome critical challenges to scale up carbon investments in Africa. These projects are expected to sequester 26.85 million tCO2 beyond the baseline situation. Within the continent, East Africa is the preferred destination for carbon investors. Most projects are non‐Kyoto compliant and represent voluntary emission reductions. While project benefits such as increased local incomes and improved natural resources are promising, there are concerns that conversion of grasslands into tree plantations can harm local ecosystems. Insecure land tenure constrains new investments and increases the risk that local communities will lose access to forests. Another challenge is that projects with smallholders have high transaction costs. These costs can be overcome by building strong community institutions and simplifying project guidelines. To attract more projects, African governments will need to build their capacity to identify relevant opportunities.  相似文献   
68.
Comanagement has recently become the most popular approach for reconciling land claims and biodiversity conservation in South Africa and beyond. Following the resolution of land claims on protected areas in South Africa, comanagement arrangements have been created between the relevant conservation authorities and the land claimant communities who are legally awarded tenure rights to the land. However, it is doubtful that these partnerships constitute success for the former land claimants. Using the case of a “resolved” land claim in Mkambati Nature Reserve, Eastern Cape Province, as well as insights from comanagement literature, this paper identifies and discusses three key possible reasons for the unimpressive performance of comanagement in reconciling land restitution and conservation. The first one is the origins of the comanagement idea in the conservation of high value natural resources (e.g., fisheries, forestry), rather than in or including concerns for resource rights. The second reason is the neglect of key conditions for successful comanagement, as discussed in the comanagement literature. The final reason is the ambiguity in settlement agreements, including the use of terminology and concepts that reinforce unequal power relationships, with the state emerging as the powerful partner. This paper concludes that, unless there is a serious reassessment of the comanagement idea as a way of reconciling land reform and conservation, and a possible review of settlement agreements that have relied on comanagement, both the integrity of the “successful land claimant’s rights” and that of conservation remain under threat.  相似文献   
69.
This paper presents a qualitative assessment of the participatory water management strategies implemented at the community level in rural Mali through a water supply project — The West Africa Water Initiative (WAWI) — coordinated by World Vision International, a non‐governmental and humanitarian organization. Data for the study were generated through a combination of primary and secondary sources in three villages. Results of the study indicate that while community‐based rural water supply is a positive step in responding to the needs of rural Malians, the installation of boreholes with hand pumps informed merely by consultative participatory approaches and limited extension involvement will not necessarily proffer sustainable rural water supply in the region. A “platform” approach to rural water supply management that can mobilize the assets and insights of different social actors to influence decision making at all stages, including the design and choice‐of‐technology stages, in water supply interventions is instead advocated.  相似文献   
70.
Global environmental crisis narratives about biodiversity loss promote conservation research on how human activities impact natural resources and link scientific findings to protectionist policies. This paper critiques how local knowledge, over space and through time, is constructed for these studies and integrated with ecological measures and qualitative interpretations of biodiversity conditions. As a case example, we describe how ethnoecological research at Mt. Kasigau, a biodiversity hot spot in Southeastern Kenya, changes ‘scientific’ views on human–resource relations. Species richness in woody plants and local knowledge about trees show resource continua on the mountain that question the designation of diverse undisturbed forests and degraded human‐utilized lands. Local narratives document spatially dynamic and adaptive relationships between the Kasigau Taita and their plant resources as they moved up and down the mountain in response to environmental conditions and extra local forces. We argue that greater ‘local learning’ about local places is important to hypothesizing and potentially guiding ‘global action’ for biodiversity conservation.  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