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221.
Smallholder farmers’ coping and adaptation strategies to climate change and variability in the central highlands of Ethiopia 总被引:1,自引:0,他引:1
This study describes the different coping and adaptation strategies used by smallholder farmers to mitigate the adverse impacts of climate change and variability in the central highlands of Ethiopia. A distinction was made between coping and adaptation strategies, respectively, as short-term and longer term measures. The study surveyed 200 farm households in three districts, and three focus group discussions and three key informant interviews were conducted in each district. All the surveyed farmers perceived at least one aspect of change in the local climate. Their perception of an increasing trend of temperature was supported by meteorological records, while their perception of declining annual rainfall was not supported by actual records in two of the three districts, where positive trends in rainfall were observed. Farmers identified changes in rainfall and drought as their major climate change-related risks. In response, farmers used different strategies to mitigate the adverse effects of climate change and variability. The most widely used coping strategy was selling livestock (85% of the respondents), followed by changing consumption pattern (76% of the respondents). Changing crop planting dates was the most preferred adaptation option (89% of the respondents), while irrigation as an adaptation strategy was used only by 10% of the surveyed farmers. Shortage of water for irrigation (83% of the respondents) and shortage of money to buy necessary inputs (77% of the respondents) were the major barriers to effective adaptation frequently cited in the study area. We conclude that adaptation policy should build on existing coping and adaptation strategies and focus on addressing barriers to the adoption of coping and adaptation measures at different scales. 相似文献
222.
我国农田农药流失现状及减控策略 总被引:1,自引:0,他引:1
农业面源污染已经成为全球水污染的主要来源,其中具有生物毒性的农药污染物对人体健康和生态环境安全构成了严重威胁。分析了我国农田农药流失现状,指出流失的主要农药品种与用药历史和特点密切相关,水体中检出的有机氯农药主要源于早期农药残留,检出的有机磷农药和长残效除草剂部分种类目前仍在使用。提出从影响农药流失的各个环节入手,制定严密的减控策略。植物缓冲带是拦截农药流失的常用措施,可以实现对农业面源污染的可持续治理。建议实行生态功能区划,严格限制高毒农药的施用,减少化学农药施用量,规范农药喷洒器械和施药技术,从源头上控制农药流失,从而降低农业非点源污染带来的危险。 相似文献
223.
Joanne L. Pottier Hans P. Deuel Sara C. Pryor 《Environmental monitoring and assessment》2000,65(1-2):459-467
Modelled and measured indicator species ratios of O3/NOz, O3/NOy, H2O2/HNO3, HCNO/NOy for the Lower Fraser Valley were compared with VOC-NOx-O3 sensitivity threshold values reported in previous studies. Modelled region - specific indicator ratio thresholds derived from 50% NOx and 50% VOC reduction scenarios are provided. They show strongest agreement with the H2O2/HNO3 ratio values found elsewhere. A clear transition region for the LFV from VOC to NOx sensitivity could not be identified, but there is evidence that O3 concentrations in the western valley, dominated by metropolitan Vancouver, are VOC sensitive, and the more rural eastern valley O3 concentrations exhibit greater NOx sensitivity. The UAM-V Process Analysis utility was used to identify physical and chemical mechanisms which contributed to O3 formation and destruction and indicate the key importance of entrainment from elevated layers generated by the highly complex meteorological conditions in determining near surface O3 concentrations. 相似文献
224.
Non-aggressive mate guarding by the blue-footed booby: a balance of female and male control 总被引:3,自引:1,他引:2
Thirteen pairs of blue-footed boobies (Sula nebouxii) were observed on their colony. Pairs courted frequently and, on average, copulated 24 times during the 30 days before laying,
with 38% of those copulations occurring in the last 5 days (presumed fertile period). Males and females increased attendance
at the nest site as laying approached. Seven females performed an average seven extra-pair copulations, with 1–2 paired male
neighbors, but these were less concentrated in the presumed fertile period than within-pair copulations, and the last two
copulations of all 7 females were with their social mates. Rates of female extra-pair copulations were six times lower when
their social mate was present, and during the presumed fertile period, no female performed an extra-pair copulation in the
presence of her mate. Males did not respond to infidelity of social mates with aggression, prompt copulation, retaliatory
copulation, or increase in copulation. Seven of 13 males performed an average of five extra-pair copulations, with 1–3 paired
female neighbors, before their own mates began egg-laying. The males' extra-pair copulations represented only 4% of their
total copulations during their own mates' presumed fertile periods. Females, the larger sex, apparently control sexual access
and copulate with extra males to achieve extra-pair fertilization. Males pursue a mixed strategy: they copulate with extra
females, mostly outside their own mate's presumed fertile period, and they copulate increasingly with their social mate as
laying approaches, probably assuring some paternity by mate guarding, involving attendance and courtship. Behavior of males
and females is also consistent with other hypotheses for extensive joint nest site attendance: pairbonding, copulation access,
and territory acquisition.
Received: 14 November 1997 / Accepted after revision: 16 May 1998 相似文献
225.
中国生物多样性保护适应气候变化的对策 总被引:1,自引:0,他引:1
基于气候变化对生物多样性影响的总结分析,初步提出了我国生物多样性保护适应气候变化的对策。气候变化对生物物候、分布、迁移活动、群落结构、栖息地质量、生态系统和景观多样性都产生了一定影响,未来将产生更深刻的影响。我国生物多样性保护适应气候变化需要从物种有效保护、自然保护区规划与管理、灾害防御等方面进行。 相似文献
226.
Yvonne Andersson-Sköld Pascal Suer Ramona Bergman Helena Helgesson 《Local Environment》2016,21(1):85-104
A decision support tool aiming to facilitate discussion and transparency in land-use planning processes has been developed. It includes process steps initiating with an analysis of the current situation, identification of relevant actions and sustainability analysis steps. The sustainability was subdivided into human health and environment, resources, and social and economic impacts. The main difference between this risk analysis tool and others is the allowance of comparisons of present risks and consequences of measures early in the process. It also includes assessments from short- and long-term perspectives, such as taking into account climate change. It combines classic risk analysis with life-cycle assessment procedure. It has been developed and tested in co-operation with municipalities. The tests show that the tool is applicable and can be relevant in the planning process. It offers an iterative discussion framework that is systematic, condensed and yet a simplistic way of describing consequences. The criticism is that it is regarded as time demanding, but this can be managed by preparatory work. 相似文献
227.
The accumulated knowledge and perceptions of communities 'at risk' are key elements in managing disaster risk at the local level. This paper demonstrates that local knowledge of flood hazards can be structured systematically into geographic information system (GIS) outputs. When combined with forecasting models and risk scenarios, they strengthen the legitimacy of local knowledge of at-risk populations. This is essential for effective disaster risk reduction practices by external actors, local non-governmental organisations (NGOs) and municipal authorities. The research focused on understanding coping strategies and 'manageability' of flood hazards as defined by communities. 'Manageability' is how people experience flooding in relation to their household capacity and the coping mechanisms available. The research in the Philippines highlights the significance of localised factors, including socioeconomic resources, livelihoods, seasonality and periodicity, for understanding manageability. The manageability concept improves practice at the municipal level by legitimising local coping strategies, providing better indicators, and developing understanding of flooding as a recurrent threat. 相似文献
228.
Complementing institutional with localised strategies for climate change adaptation: a South-North comparison 总被引:1,自引:0,他引:1
Climate change and disasters pose a serious risk to sustainable development. In the South, local coping strategies are an important element of adaptation to climate and disaster risk. Such strategies have emerged because of the limited assistance provided by urban actors and associated social security and governance systems. In the North, in contrast, local coping strategies are comparatively poorly developed. However, the extent of the changing climatic conditions is also reducing the capacity of Northern institutions to deal with climatic extremes and variability, which emphasises the need for more local-level engagement in the North. This paper analyses the differences in local and institutional responses to climate change and disasters in a Southern and a Northern city (San Salvador, El Salvador, and Manchester, United Kingdom, respectively), and highlights how the lessons learned might be translated into an improved distributed governance system; that is, an 'integrated engagement model', where local and institutionalised responses support rather than hinder each other, as is currently the case. 相似文献
229.
Changing household responses to drought in Tharaka, Kenya: vulnerability, persistence and challenge 总被引:2,自引:0,他引:2
Drought is a recurring challenge to the livelihoods of those living in Tharaka District, Kenya, situated in the semi-arid zone to the east of Mount Kenya, from the lowest slopes of the mountain to the banks of the Tana River. This part of Kenya has been marginal to the economic and political life of Kenya from the colonial period until the present day. A study of more than 30 years of change in how people in Tharaka cope with drought reveals resilience in the face of major macro-level transformations, which include privatisation of landownership, population growth, political decentralisation, increased conflict over natural resources, different market conditions, and environmental shifts. However, the study also shows troubling signs of increased use of drought responses that are incompatible with long-term agrarian livelihoods. Government policy needs to address the challenge of drought under these new macro conditions if sustainable human development is to be achieved. 相似文献
230.
陈印军 《中国人口.资源与环境》2000,10(2):52-53
在党中央和国务院的关怀下 ,西部大开发的序幕即将拉开 ,全国人民为之振奋。如何保障西部大开发的顺利实施 ?本文认为必须转变传统观念 ,实施新的开发战略。 相似文献