首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
Regional Environmental Change - The threat of flooding poses a considerable challenge for justice. Not only are more citizens becoming exposed to risk, but they are expected to play increasingly...  相似文献   

2.
This paper discusses the linkages between population change, land use, and deforestation in the Amazon regions of Brazil, Bolivia, Colombia, Ecuador, Perú, and Venezuela. We begin with a brief discussion of theories of population–environment linkages, and then focus on the case of deforestation in the PanAmazon. The core of the paper reviews available data on deforestation, population growth, migration and land use in order to see how well land cover change reflects demographic and agricultural change. The data indicate that population dynamics and net migration exhibit to deforestation in some states of the basin but not others. We then discuss other explanatory factors for deforestation, and find a close correspondence between land use and deforestation, which suggests that land use is loosely tied to demographic dynamics and mediates the influence of population on deforestation. We also consider national political economic contexts of Amazon change in the six countries, and find contrasting contexts, which also helps to explain the limited demographic-deforestation correspondence. The paper closes by noting general conclusions based on the data, topics in need of further research and recent policy proposals.Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue  相似文献   

3.
4.
Environment, Development and Sustainability - The human pressure on nature makes it imperative understanding how environmental issues can influence the world view of society. The aim of the current...  相似文献   

5.
Flow regulation causes various environmental impacts in the downstream reaches of impounded rivers. The S?o Francisco River (SF) basin is Brazil’s third most important watershed. Several dams have been built in its course in the last four decades, mostly for flow regulation and hydropower generation. This paper presents an evaluation of historical changes in the flood regime. Three regions of the SF River basin, which are under the influence of different levels of regulation, were studied: the lower, middle, and upper SF River. The components of magnitude, frequency, and duration of floods were quantified for each region from 1940 to 1960 (prior to the construction of the first dam) and from 1986 to 2006 (after the last dam). The results have shown the inexistence of big floods in the downstream areas, decreasing durations of small floods as well as significant changes in the annual seasonality of floods. Reductions in the flood frequency were verified in all stretches, even in non-regulated systems, such as the lower Velhas River. The climate variation, which occurred in both period, was not able to explain the changes in the flood regime of S?o Francisco River; therefore, dams and other anthropogenic activity are the main factors promoting the temporal variability of streamflows in the S?o Francisco basin.  相似文献   

6.
Statistical data shows that the increase in disasters due to natural hazards over the past 20 years has, for the most part, been caused by meteorological and hydrological events. This increase has been largely assigned to climate change [Centre for Research on the Epidemiology of Disasters (CRED), 2010, http://www.emdat.be/Database/Trends/trends.html], that is, with climate-related hazards being major triggers for the majority of disasters. Consequently, there is obvious concern about how a changing climate will exacerbate the situation in the future (McBean and Ajibade in Curr Opin Environ Sustain 1:179–186, 2009). However, the attribution of a single hazard event or specific losses to climate change is still difficult, if not impossible, due to the complexity of factors that generate disaster losses. Disaster risk is a product of the interaction of the hazard (event) and the vulnerability conditions of the society or elements exposed. As a result, the need for a systematic linkage between disaster risk reduction (DRR) and climate change adaptation (CCA) to advance sustainable development, and finally human security is being discussed within the ongoing climate change negotiations as well as within the disaster risk community, for example, in the framework of the Intergovernmental Panel on Climate Change special report on ‘Managing the risks of extreme events and disasters to advance climate change adaptation’. However, crucial differences between DRR and CCA exist that have widely limited or hampered their integration in practice. A review of existing literature on the topic and current national and local adaptation strategies, as well as 38 expert interviews conducted between April and May 2009, have led the authors to hypothesise that most of these differences and challenges can be categorised with respect to different spatial and temporal scales, the knowledge base, and norm systems. This paper examines the reasons for the practical barriers when linking CCA and DRR according to these three aspects. Finally, we outline recommendations and measures that need to be adopted in order to overcome existing barriers. In addition, quality criteria are formulated that should be applied in order to constantly monitor and evaluate adaptation strategies designed to simultaneously meet DRR requirements and vice versa.  相似文献   

7.
The Ouémé River is one of the most important rivers in the Republic of Bénin. It is 510 km long and its catchment drains 75% of the country. In this study, organochlorine and organophosphorous pesticide residues were measured in more than 35 sediment samples collected on nine locations along the Ouémé River from upstream to downstream. Except for one location, Tanéka-Koko, all areas were contaminated by more than 20 pesticides. Organochlorine pesticides identified in sediment samples included pp'-DDE, op'-DDD, pp'-DDD, op'-DDT, pp'-DDT, alpha-endosulfan, beta-endosulfan, endosulfan sulphate, alpha-HCH, beta-HCH, lindane, aldrin, dieldrin, endrin, telodrin, isodrin, cis- and trans-heptachlorepoxide, hexachlorbutadiene, hexachlorobenzene and octachlorostyrene. The organophosphorous pesticide chlorpyrifos, used in a new formulation to protect cotton, was also identified. In some areas, the concentrations of organochlorine pesticides in the sediment of the Ouémé River exceeded environmental quality standards and are reason for concern.  相似文献   

8.
In Southeast Asia, inland fish resources are crucial for small-scale fishing households. Their decline, due to overfishing and a set of socio-ecological factors, jeopardises aquatic ecosystems and the livelihoods of fishing communities. Singkarak Lake (West Sumatra) exemplifies this sustainability challenge. The paper proposes a multi-disciplinary analysis of the situation. First, it identifies and documents the primary livelihood systems and the strategic adaptations involved in fishing communities. Based upon a sample of 200 households and the implementation of multivariate analyses, a typology is developed. Three household types are identified. Type I comprises better-off farming fishers that have high fishing capitals and income but the lowest returns on fishing and land assets. Type II includes poor fishing farmers with higher farming income; they show the highest return on land assets. Type III is composed of poorer, younger fishers with the highest return on fishing assets and fishing costs. They have little land, low farming income, and diversified livelihood sources. Second, the technical efficiency (TE) of fishing households is studied using a data envelopment analysis. The results show that the average TE is low, but marked differences exist between the types. Type I households have the lowest TE in fishing, confirming an extensification and overcapitalisation strategy. Type II households show a high technical fishing efficiency. They have developed on-farm diversification with a combined, balanced livelihood system. Type III households are the most efficient fishers. They developed an intensification strategy together with off-farm diversification. Different livelihood strategies and economic portfolio have been developed as the response to the limited resources, uncertainty, fluctuating environment and other source of vulnerability. The fishers built up their livelihood based on their assets’ ownership, access to other resource out of fishing and their socio-economic status. In this context, understanding livelihood diversity among small-scale fishers, different socio-economic, their efficiency, constraints and opportunities emerge as important factor in policy formulation to enhance support to small-scale fishing communities and improved management of both the resources and local development. Finally, the paper suggests a focus on people and community-related solutions and proposes a threefold approach of resource conservation, livelihood improvements and restructured governance.  相似文献   

9.
Policy-making in social-ecological systems increasingly looks to iterative, evolutionary approaches that can address the inherent complexity of interactions between human wellbeing, provision of goods, and the maintenance of ecosystem services. Here, we show how the analysis of available time-series in tropical delta regions over past decades can provide important insight into the social-ecological system dynamics in deltaic regions. The paper provides an exploratory analysis of the recent changes that have occurred in the major elements of three tropical deltaic social-ecological systems, such as demography, economy, health, climate, food, and water. Time-series data from official statistics, monitoring programmes, and Earth observation data are analysed to explore possible trends, slow and fast variables, and observed drivers of change in the Amazon, Ganges–Brahmaputra–Meghna and Mekong deltas. In the Ganges–Brahmaputra–Meghna delta zone, increasing gross domestic product and per capita income levels since the 1980s mirror rising levels of food and inland fish production. In contrast, non-food ecosystem services, such as water availability, water quality, and land stability appear to be deteriorating. In the Amazon delta, natural and anthropogenic perturbations are continuously degrading key ecosystem services, such as carbon storage in biomass and soils, the regulation of water balance, and the modulation of regional climate patterns. In the Mekong delta, rapid economic development, changing land-use practices, and salinity intrusion are progressively putting more pressure on the delivery of important provisioning services, such as rice and inland aquaculture production, which are key sources of staple food, farm incomes, and export revenue. Observed changes in many key indicators of ecosystem services point to a changing dynamic state and increased probability of systemic threshold transformations in the near future.  相似文献   

10.
Activity profiles of excess 210Pb determined in three sediment cores from Amazon River mouth, Macapá city, Brazil, provided the evaluation of sedimentation rates, contributing to a better knowledge of the hydrological conditions in the site that is the capital of Amapá State and is drained by the waters of the huge Amazon River. Chemical data were also determined in the sediments, allowing identify signatures coupled to anthropogenic inputs held in the past in Amapá State. Significant direct relationships between LOI (loss on ignition) and organic matter were found for all sediments profiles. Silica was found to be inversely related to organic matter in the three profiles; its decrease accompanied an increase on the specific surface of the sediments. This relationship was confirmed by a great number of inverse significant correlations among silica and oxides Na2O, K2O, CaO, MgO, Al2O3, P2O5, Fe2O3 and MnO. It was possible to identify the role of organic matter on adsorption of several oxides in the core sediments profiles. Apparent sediment mass accumulation rates corresponding to values between 450 and 2510 mg cm−2 yr−1 were obtained, and are compatible with the results of others studies. The 210Pb activities in one sampling point suggested the occurrence of anthropogenic inputs related to the initial period of the mining activities conducted in Serra do Navio, Amapá State, for the commercialization of Mn ores. This was reinforced by the abrupt fluctuations in chemical data obtained for the sediments and composition of the interstitial waters occurring there. The Atlantic hurricane activity also appeared to affect the sedimentation rates in the area, as two different values were recorded in each profile.  相似文献   

11.
Climate change is a global challenge that has a particularly strong effect on developing countries such as Nepal, where adaptive capacity is low and where agriculture, which is highly dependent on climatic factors, is the main source of income for the majority of people. The nature and extent of the effects of climate change on rural livelihoods varies across Nepal in accordance with its highly diverse environmental conditions. In order to capture some of this variability, a comparative study was performed in two different ecological regions: Terai (lowland) and Mountain (upland) in the western development region of Nepal. The study focuses on perceptions of, and on adaptations to climate change by farmers. Information was collected from both primary and secondary data sources. Climate data were analyzed through trend analysis. Results show that most farmers perceive climate change acutely and respond to it, based on their own indigenous knowledge and experiences, through both agricultural and non-agricultural adaptations at an individual level. The study also shows that there is a need to go beyond the individual level, and to plan and provide support for appropriate technologies and strategies in order to cope with the expected increasing impacts of climate change.  相似文献   

12.
Regional Environmental Change - The Brazilian Northeastern semi-arid region’s history has been characterized by drought, water scarcity, and poor living conditions. For the last...  相似文献   

13.
14.
Tropical delta regions are at risk of multiple threats including relative sea level rise and human alterations, making them more and more vulnerable to extreme floods, storms, surges, salinity intrusion, and other hazards which could also increase in magnitude and frequency with a changing climate. Given the environmental vulnerability of tropical deltas, understanding the interlinkages between population dynamics and environmental change in these regions is crucial for ensuring efficient policy planning and progress toward social and ecological sustainability. Here, we provide an overview of population trends and dynamics in the Ganges–Brahmaputra, Mekong and Amazon deltas. Using multiple data sources, including census data and Demographic and Health Surveys, a discussion regarding the components of population change is undertaken in the context of environmental factors affecting the demographic landscape of the three delta regions. We find that the demographic trends in all cases are broadly reflective of national trends, although important differences exist within and across the study areas. Moreover, all three delta regions have been experiencing shifts in population structures resulting in aging populations, the latter being most rapid in the Mekong delta. The environmental impacts on the different components of population change are important, and more extensive research is required to effectively quantify the underlying relationships. The paper concludes by discussing selected policy implications in the context of sustainable development of delta regions and beyond.  相似文献   

15.
The conservation and sustainable use of forests in the twenty-first century pose huge challenges for forest management and policy. Society demands that forests provide a wide range of ecosystem services, from timber products, raw materials and renewable energy to sociocultural amenities and habitats for nature conservation. Innovative management and policy approaches need to be developed to meet these often-conflicting demands in a context of environmental change of uncertain magnitude and scale. Genetic diversity is a key component of resilience and adaptability. Overall, forest tree populations are genetically very diverse, conferring them an enormous potential for genetic adaptation via the processes of gene flow and natural selection. Here, we review the main challenges facing our forests in the coming century and focus on how recent progress in genetics can contribute to the development of appropriate practical actions that forest managers and policy makers can adopt to promote forest resilience to climate change. Emerging knowledge will inform and clarify current controversies relating to the choice of appropriate genetic resources for planting, the effect of silvicultural systems and stand tending on adaptive potential and the best ways to harness genetic diversity in breeding and conservation programs. Gaps in our knowledge remain, and we identify where additional information is needed (e.g., the adaptive value of peripheral populations or the genetic determinism of key adaptive traits) and the types of studies that are required to provide this key understanding.  相似文献   

16.
Summary This article identifies responses of stakeholders to future management of the Rhine River Basin, notably to the plan Rhine In The Future. This plan foresees the construction of a bypass between the rivers Rhine and IJssel, the Green River. The Green River would be a nature reserve area that can be flooded during high water discharges. The inhabitants of the area would be permanently relocated. Their defence of stakes will be coloured by patterns of acting and thinking that belong to respectively postmodernity, modernity and pre-modernity. These different colourings show in negotiation skills, levels of organisations, alertness, power positions, and access to local and outside resources. Most local stakeholders appreciate the postmodern environmentalism that leads to the greening of river management, but regret the loss of their strong, pre-modern, social cohesion. Whereas they consider national interests in a rather balanced way, they doubt the necessity of the bypass for safety reasons. They have confidence in financial compensations for relocation, but will negotiate about these compensations with skill and determination. Their tactics will be reinforced by collective efforts that stem from their social cohesion.One professor says it will be dryer, the other one says it will be wetter.We all have mobile telephones so we know it when the water comes.The social cohesion of this community will be lost forever.When youre not bought out youll be the real victim.We like to have a nature reserve area around here.  相似文献   

17.

As financing protection against mountain hazards becomes increasingly challenging and therefore investments have to be prioritized, dilemmas of justice emerge: some local governments and individuals benefit from natural hazard protection schemes, whereas others loose. Decisions on whom to protect often caused contradicting concepts of political understanding, which differ in interpretations of fair resource allocation and distribution. This paper analyses the impact of different philosophical schools of social justice on mountain hazard management in Austria. We used data from a spatially explicit, object-based assessment of elements at risk and compared potential distributional effects of three political jurisdictions. We found that—depending on the respective political direction—various local governments gain and others loose within the actual distributional system of mitigation strategies. The implementation of a utilitarian policy approach would cause that high income communities in hazard-prone areas would mainly benefit. Consequently, this policy direction would encourage the public administration to ignore their own failure in the past natural hazards management and prevention. On the other hand, following a Rawlsians approach mainly peripheral communities would gain from new policy direction who often show besides natural hazards problem mainly large socio-economic challenges. Finally, the most radical change would include the implementation of a liberalism policy, whereabouts the state only provides hazard information, but no further mitigation measures. These findings highlight the distributional consequences of future mountain hazard management strategies and point to the crucial selection of policy direction in navigating the selection of various adaptation schemes.

  相似文献   

18.
19.
20.

The South American country Brazil is one of the richest countries in terms of natural resources, representing 14 percent of the world’s total biocapacity. However, the biocapacity (biosphere’s ability to generate resources and sequester waste) per capita in Brazil has shown a massive decline over the last five decades, while economic growth and urbanization have rapidly increased for the same period. Brazil is one of the largest creditors of biocapacity to the world, and biocapacity loss in Brazil can lead to devastating environmental consequences. Therefore, this work empirically investigates the influence of urbanization, economic growth, and industrialization on biocapacity controlling human capital from 1961 to 2016 in Brazil. The Bayer and Hack cointegration test, the Autoregressive Distributed Lag (ARDL) technique, and Hacker and Hatemi-J (J Econ Stud 39:144–160, 2012) causality tests are employed. The findings unfolded a U-shaped relationship between economic growth and biocapacity, evidencing that economic growth reduces biocapacity, but after achieving a threshold level, it promotes biocapacity. Urbanization has a negative relationship with biocapacity per capita, indicating that urbanization is a significant driver of the biocapacity loss in Brazil. Further, urbanization and economic growth Granger cause biocapacity. Lastly, relevant policy implications are proposed to overcome the reduction in biocapacity.

  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