关键词： 厄尔尼诺现象   气候变化   旱涝变化   降水量  

关键词： 中国东部   气候变化   农业生产   时间序列  

摘要： 研究中国东部近2000年来气候变化对农业生产的影响,不仅对揭示中国历史时期气候变化规律有重要意义,而且对今后中国农业生产的发展、农业政策的调整都有实际价值.该文在大量查阅史料文献和前人著作的基础上,分析了中国东部近2000年来的气候变化,表明气候变化既有冷暖和干湿的长期变迁,又有突发性的气候灾害,该文对中国东部2000年来的气候时期进行了划分.该文还以鄂尔多斯高原为例分析了2000年来干湿变化对农牧界线变迁的影响,表明气候寒冷干燥时,农牧过渡带的农业衰退,牧业兴起,农牧界线南退;气候温暖湿润时,农牧过渡带的农业发展,牧业受到抑制,农牧界线北移.该文根据陈高佣的《中国历代天灾人祸表》和张家诚的《历史上重大气候灾害简表》等基础资料,按不同时段建立2000年来水、旱、饥、寒的时间序列,对500御来的序列进行相关分析和功率谱分析.

关键词： Climate   Agricultural economics   Economic impact  

摘要： This study used a quadratic programming sector model to assess the integrated impacts of climate change on the agricultural economy of Egypt. Results from a dynamic global food trade model were used to update the Egyptian sector model and included socio-economic trends and world market prices of agricultural goods, In addition, the impacts of climate change from three bio-physical sectors - water resources, crop yields, and land resources - were used as inputs to the economic model. The climate change scenarios generally had minor impacts on aggregated economic welfare (sum of Consumer and Producer Surplus or CPS), with the largest reduction of approximately 6 percent. In some climate change scenarios, CPS slightly improved or remained unchanged. These scenarios generally benefited consumers more than producers, as world market conditions reduced the revenue generating capacity of Egyptian agricultural exporters but decreased the costs of imports. Despite increased water availability and only moderate yield declines, several climate change scenarios showed producers being negatively affected by climate change. The analysis supported the hypothesis that smaller food importing countries are at a greater risk to climate change, and impacts could have as much to do with changes in world markets as with changes in local and regional biophysical systems and shifts in the national agricultural economy.

关键词： simulation   EPIC   soil fertility   soil physical properties   climate change  

摘要： The agriculture of the Argentinean pampean region is undergoing a reconversion process as a result of a more intensive use of agrotechnologies. The ongoing changes are likely to overlap with the greenhouse warming-related climatic changes and atmospheric CO2 increase predicted for the next century. The goal of this study is to assess the potential impact of such changes on certain properties of soils of the Rolling Pampas, which support 10 to 15% of the national grain crop and oilseed production. Relation of wheat/soybean-maize crops in 45 agricultural soils was simulated using the EPIC model (Erosion/Productivity Impact Calculator;US Dept of Agriculture), which was previously calibrated and validated for local conditions, for the 1996 to 2050 period under 2 scenarios: (1) no climate change, and (2) climate change conditions derived from regional climate parameters projected by the GISS general circulation model combined with a CO2 concentration of 550 ppm. The 1971 to 1995 period was simulated under neutral conditions with the purpose of defining soil conditions for 1996. It was found that in the event of a change in climate, physical properties would change to a lesser degree than chemical properties. The soil bulk density would decrease by 8% with respect to the baseline scenario in soils under risk of erosion. In contrast, since it was assumed that the erosive storm pattern would remain unchanged, there would be no variations in the erosion rate. A general decrease in potential soil fertility of 6 to 10% for total organic N and 7 to 20% for organic C would take place after a 55 yr period. The sustainability of certain soils of the Carcarana River basin, particularly the Villa Eloisa series, would be at a higher risk.

关键词： climate change   Argentina   models   wheat   maize   soybean  

摘要： Agricultural production is one of the pillars of the Argentinean economy. The contribution of this sector is expected to keep growing in the near future as a consequence of the current technological development trend. However, the projected changes in climate and in the atmospheric concentration of CO2 in the coming years is likely to affect the productivity of crops, thus causing an impact on the national economy. This paper addresses climate change impact on the production of the main crops of the Argentinean pampean region by means of crop growth and development simulation models for wheat, maize and soybean included in DSSAT v. 3.0 (Dension Support System for Agrotechnology Transfer, Univ. of Hawaii, Honolulu). The weather data used includes temperature, global solar radiation and precipitation values from 23 sites within the region (current climate conditions) and the corresponding GISS general circulation model projections for the year 2050 (future climate) with CO2 concentrations of 330 and 550 ppm respectively. According to the results obtained, a generalized increase in soybean yield and a decrease in maize yield would occur. Wheat yield is likely to increase in the southern and the western parts of the region and decrease towards the north. Wheat and soybean production in the pampean region would increase by 3.6 and 20.7% respectively, while maize production would be reduced by 16.5%.

关键词： climate change   Latin America   agriculture   vulnerability   policy   economics  

摘要： The vulnerability of the agricultural sector in any region to future possible climate-change scenarios is determined to a great extent by the vulnerability of the sector to current climatic, economic and policy scenarios. Agricultural systems which are currently subject to extreme climatic interannual variability (drought, flood, storms, etc.) are likely to become even more vulnerable under the most commonly expected scenarios of climate change (i.e. increased temperatures, increased rainfall variability). Similarly, agricultural systems which are currently subject to drastic changes in economic and policy scenarios are also prone to become more vulnerable under expected climate-change conditions. The agricultural sector of Latin America has been subject to important variations in economical conditions and policies. These conditions have affected the structure of agricultural production, and resulted in a large reduction of the number of small farmers, who have migrated to poor metropolitan areas. Even for larger, commercial farmers, unstable and often inconsistent agricultural policies have increased the vulnerability of the sector. Additionally, large areas of Latin America are already affected by current interannual climatic variability related to the length of rainy seasons and the occurrence of extreme events (droughts, floods, etc.). The few studies conducted in the region to specifically assess the impact of climate change on agriculture have revealed expected reductions and increased variability in crop productivity. Similar results should be expected in the vast regions devoted to livestock production, since the systems are based on a fragile balance of nutrients, available water, stocking rates and pasture species. The characteristics of the current situation described in this article demonstrate the vulnerability of Latin American agriculture to climate change. Preparing the agricultural sector to mitigate the potential negative effects of climate change

关键词： 气候资源   农业生产潜力   气候变化  

摘要： 分析了西藏主要农区近30年气候资源的动态变化,结果表明气候变暖主要在冬季和夏季,尤以6月增温明显;积温增高,无霜期缩短;沿雅鲁藏布江一线、昌都年降水量每10年减少4～30mm,东南部年降水量呈递增趋势。80年代各农区光温生产潜力均高于60年代和70年代,30年平均每年上升11～62kg/hm^2。30年气候生产潜力最高的10年为70年代,最低的10年为80年代。

关键词： 气候变化   农业生产   农业气候  

关键词： 持续农业   气候变化   虫害   农业发展   持续治理  

摘要： 21世纪，随着世界人口的增加，首先将面临着对粮食及其它农产品的需求量的增加。要达到粮食稳定和人类的需求量，其制约的因素很多。本文就气候变化、有害生物的持续治理、对持续农业的影响进行了探讨。

关键词： 气候变化   冷凉型农业   农业发展   降水   气温  

摘要： 阐述了大兴安岭地区近４０年的气候变化，对未来１５年的气候进行了预测，提出了当地发展冷凉型农业的对策。