关键词： SEDIMENTATION & deposition   PREHISTORIC agriculture   CLIMATIC changes   CROPS & climate   STRATIGRAPHIC geology -- Holocene   FLUVISOLS   ARCHAEOLOGICAL geology  

摘要： Despite the importance of understanding the effect of land use on floodplains in eastern North America, few studies have directly addressed the possibility and extent of prehistoric indigenous land use on floodplain development. Here we report geoarchaeological evidence of increasing floodplain sedimentation and prehistoric land-use intensification in the Delaware River Valley (eastern United States) during the Medieval Climate Anomaly-Little Ice Age transition. The evidence of this anthropogenic sedimentation event, documented throughout eastern North America, is designated here as pre-colonial sediment (PCS), ca. A. D. 1100-1600. The data demonstrate that the combined effects of prehistoric land use and climate change affected eastern North American floodplain development several hundred years prior to the onset of major European settlement.

关键词： Farmers   Perceptions   Agronomy   Climate change   Drought  

摘要： This paper investigates farmers' perceptions of climate change and variability in southwest Uganda and compares them with daily rainfall and temperature measurements from the 1960s to the present, including trends in daily rainfall and temperature, seasonality: changing probability of risk and intensity of rainfall events. Statistical analyses and modelling of rainfall and temperature were performed and contrasted with qualitative data collected through a semi-structured questionnaire. The fieldwork showed that farmers perceived regional climate to have changed in the past 20 years. In particular, farmers felt that temperature had increased and seasonality and variability had changed, with the first rainy season between March and May becoming more variable. Farmers reported detailed accounts of climate characteristics during specific years, with recent droughts in the late 1990s and late 2000s confirming local perceptions that there has been a shift in climate towards more variable conditions that are less favourable to production. There is a clear signal that temperature has been increasing in the climate data mid, to a lesser extent, evidence that the reliability of rains in the first season has decreased slightly However, rainfall measurements do not show a downward trend in rainfall amount, a significant shift in the intensity of rainfall events or in the start and end of the rainy seasons. We explore why there are some differences between farmers' perceptions and die climate data due to different associations of risk between ideal rainfall by farmers, including the amount and distribution needed for production, meteorological definitions of normal rainfall or the long-term statistical mean and its variation, and the impact of higher temperatures. The paper reflects on the methodological approach and considers the implications for communicating information about risk to users in order to support agricultural innovation.

关键词： AGRICULTURE -- United States   CLIMATIC changes  

摘要： The article focuses on how agriculture can adapt to climate change in the U.S.

关键词： AGRICULTURE   RISK assessment   FOOD security   CROPPING systems   ECONOMETRIC models  

摘要： The Intergovernmental Panel on Climate Change (IPCC) assessment of major risks for African agriculture and food security caused by climate change during coming decades is confirmed by a review of more recent climate change impact assessments (14 quantitative, six qualitative). Projected impacts relative to current production levels range from -100% to +168% in econometric, from -84% to +62% in process-based, and from -57% to +30% in statistical assessments. Despite large uncertainty, there are several robust conclusions from published literature for policy makers and research agendas: agriculture everywhere in Africa runs some risk to be negatively affected by climate change;existing cropping systems and infrastructure will have to change to meet future demand. With respect to growing population and the threat of negative climate change impacts, science will now have to show if and how agricultural production in Africa can be significantly improved.

关键词： 农业安全生产   气候变化   农业结构战略性调整   可持续发展道路   保障   自然灾害   生产任务   粮食安全  

摘要： 农业是应对自然灾害最脆弱的产业，受气候变化的影响最大。目前我国处于农业结构战略性调整的关键时期，粮食安全生产任务艰巨，未来的气候变化对农业生产的影响还存在相当大的不确定性，因此迫切需要探索一条可持续发展道路，以适应和减缓气候变化对农业产生的影响。

关键词： 气候变化   低碳农业   可持续发展  

摘要： 气候变化给我国自然生态系统和经济社会发展带来了现实的威胁，主要体现在农牧业、林业、自然生态系统、水资源等领域以及沿海和生态脆弱地区，适应气候变化已成为中国的迫切任务。我国是农业自然灾害频发的国家，气候变化使我国更加频繁地出现极端天气，如强暴雨、强雷暴、干旱化等。倨国家减灾委、民政部统计，截至2010年8月6日，洪涝灾害造成全国2亿人（次）受灾，

关键词： 气候变化   农业气象灾害   本溪山区  

摘要： 利用本溪地区1953-2008年温度、降水和主要农业气象灾害资料,根据农业气象学原理和农业气象灾害指标,整理、统计、分析相应的气象要素。采用气候倾向率和Mann-kendall方法,对气象要素变化特征进行诊断分析。结果表明:本溪山区温度呈上升趋势、降水呈下降趋势变化,年平均气温线性倾向率为0.29℃/10a,四季中,冬季线性倾向率最大,为0.61℃/10a;年降水量的线性倾向率为-26.11mm/10a,春季线性倾向率为2.88mm/10a,其他各季呈减少趋势变化。暴雨日数呈现减少趋势变化,但是灾害损失呈现增加趋势,洪涝频率减少,干旱频率增加。通过对气候变化与主要气象灾害研究,为合理开发山区气候资源,调整产业结构提供科学的气象依据。

关键词： 气候变化   农业科技   安徽省   社会主义新农村建设   农业现代化   国家方案   科技厅  

摘要： 为推进农业应对气候变化，加快农业现代化和社会主义新农村建设，日前，安徽省科技厅根据《中国应对气候变化国家方案》《安徽省应对气候变化方案》，出台了《安徽省农业科技应对气候变化方案》。

关键词： 气候变化   农业   影响评估   不确定性   模型模拟  

摘要： 模型模拟是研究气候波动对作物影响的重要手段,也是评估未来气候变化对农业可能影响的主要途径.由于科学认识和模拟技术上的不确定性,当前的气候变化对农业潜在影响评估结果一致性很差,为农业应对气候变化的决策制定带来了极大困难.基于不同层次的影响评估中不确定性,本文从气候预估、影响评估建模过程及气候模式与作物模型的连接3个方面,系统总结了气候变化对农业影响评估中不确定性的来源及传播过程;并介绍了针对多层次、多样化的不确定性源及不确定性传播的处理技术与方法,指出了当前不确定性处理中的缺陷与不足.最后对如何准确地实施气候变化对农业影响的评估,进一步减小气候变化对农业影响评估潜在的不确定性也提出了改进的建议.

关键词： 气候变化   气温   降水量   受灾面积  

摘要： 全球气候变化对农业生产和灾害管理产生了深远和持久的影响。本文根据1951—2009年全国160个气象观测站点季度平均气温、降水量数据和当年农业受灾面积数据,采用线性回归分析方法,定量地分析了气候变化对我国农业受灾面积的影响。结果表明,第一,近60年来,农业受灾面积一般达到总播种面积的30%左右,其中水、旱灾受灾面积合计占到总受灾面积的80%左右,旱灾的受灾面积要大于水灾的面积。第二,春季平均气温、降水量对农业总受灾面积有较高的解释力。春季降水量每增加1毫米,总受灾面积将减少25万公顷;平均气温每上升0.1℃,总受灾面积增加39万公顷。夏季平均气温和降水量对旱灾受灾面积有较高的解释力,同时上年的受灾面积对本年度的受灾面积有相当大的解释力。第三,气候变化对农业生产造成不利影响的一个重要方面是气温上升导致旱灾面积逐年扩大。最后本文提出了这些结论的政策性启示。