关键词： 重庆   三峡库区   农业气候   气候变化   气候周期性   非周期性   东部降水量   灰色系统模型  

摘要： 对重庆三峡库区 1961～ 2 0 0 0年气候周期性和非周期性变化研究分析发现 ,各种气温、日照均具有 2 0年的主要周期 ,库区东部气温非周期性变化平均增加 2 .0℃ ,东部降水量平均减少 181.5mm ,较中、西部变化显著。建立了GM (1,1)灰色系统模型 ,对未来 10年库区各段农业气候生态变化进行预测 ,库区东部和西部生长季气温将升高 0 .5～ 1.0℃ ,中部则略有下降 ,东部日照将增加 2 0 0h左右 ,中、西部将减少 0～ 2 0 0h ,降水量中部将减少2 0 0mm左右 ,东、西部将增加 10 0～ 50 0mm。

关键词： climate change   agricultural water cycle   water-balance model   yield index   China  

摘要： Climate change would have a major impact on the hydrological cycle and consequently on available water resources, the potential for flood and drought, and agricultural productivity. In this study, the impacts of climate change on the agricultural water cycle and their implications for agricultural production in the 2020s were assessed by water-balance calculations for Chinese croplands. Temporal and spatial changes in potential evapotranspiration, actual evapotranspiration, soil-moisture, soil-moisture deficit, yield index, and cropland surface runoff under the baseline climate and a HADCM2 general circulation model (GCM) climate-change scenario were mapped on a grid of 0.5degrees latitude/longitude resolution. According to the analysis, agricultural water demand in south China is projected to decrease generally, and the cropland soil-moisture deficit would decrease due to climate change. However, in north China, agricultural water demand is expected to increase, and the soil-moisture deficit would increase generally. The changes in the water resources would have consequent impacts on the yield index. Cropland surface runoff during the growing period is expected to increase on some sloping croplands in the southwest mountain areas and in some areas along the south coast. These changes would have important implications for agricultural production. Particularly the rain-fed crops in the north China plain and northeast China would face water-related challenges in coming decades due to the expected increases in water demands and soil-moisture deficit,and decreases in precipitation. (C) 2002 Elsevier Science B.V. All rights reserved.

关键词： 农业生产   气候变化   本溪县   气象资料   统计分析   降水   气温  

摘要： 利用本溪县 195 8～ 2 0 0 0年气象资料进行统计分析 ,归纳出近 2 0a本溪县气候变化特点是 :温度呈上升 ,降水呈减少趋势 ;根据气候变化的特点分析对农业生产的影响 ,提出了应对措施。

关键词： 济阳县   气候变化   农业   气象灾害   气温   降水量   大风   霜冻  

摘要： 分析了济阳县近 4 0年气候变化特征及农业气象灾害的变化趋势 ,为合理开发气候资源和防灾减灾提供依据 ,对当地农业发展和种植制度改革有积极的意义。

关键词： Climate change   Agriculture   Environmental impact  

摘要： We examined the impacts on U.S. agriculture of transient climate change as simulated by 2 global general circulation models focusing on the decades of the 2030s and 2090s. We examined historical shifts in the location of crops and trends in the variability of U.S. average crop yields, finding that non-climatic forces have likely dominated the north and westward movement of crops and the trends in yield variability. For the simulated future climates we considered impacts on crops, grazing and pasture, livestock, pesticide use, irrigation water supply and demand, and the sensitivity to international trade assumptions, finding that the aggregate of these effects were positive for the U.S. consumer but negative, due to declining crop prices, for producers. We examined the effects of potential changes in El Nino/Southern Oscillation (ENSO) and impacts on yield variability of changes in mean climate conditions. Increased losses occurred with ENSO intensity and frequency increases that could not be completely offset even if the events could be perfectly forecasted. Effects on yield variability of changes in mean temperatures were mixed. We also considered case study interactions of climate, agriculture, and the environment focusing on climate effects on nutrient loading to the Chesapeake Bay and groundwater depletion of the Edward's Aquifer that provides water for municipalities and agriculture to the San Antonio, Texas area. While only case studies, these results suggest environmental targets such as pumping limits and changes in farm practices to limit nutrient run-off Would need to be tightened if current environmental goals were to be achieved under the climate scenarios we examined.

关键词： 气候变化   农业   二氧化碳浓度   作物生产力   水分利用  

摘要： 全球气候变化过程加剧。阐述了CO_2浓度升高及气候变化对农业的影响,包括CO_2浓度升高对作物生产力的影响,CO_2浓度与温度升高相互影响以及CO_2浓度与水分利用之间相互影响。研究表明随CO_2浓度的升高,作物生产力如生物量、经济产量以及水分利用效率均将有所提高,但高温对作物生产力可能产生不利影响,并指出今后研究重点。

ISBN: (纸本)750293541X

关键词： 气候变化-气候影响-生态农业-研究-中国  

关键词： 菏泽市   气候变化   农业生产   农业气候资源   农业气象灾害   气候要素   影响  

摘要： 依据菏泽市气象台47年的观测资料,找出了近20年以来气象要素、农业气候资源以及气象灾害较前27年发生的变化,分析了这种变化对农业生产的可能影响,提出了菏泽市未来农业面临的气候问题及建议。

关键词： Climate change   Agriculture   Water pollution  

摘要： Research on climate change and agriculture has largely focused on production, food prices, and producer incomes. However, societal interest in agriculture is much broader than these issues. The objective of this paper is to analyze the potential impacts of climate change on an important negative externality from agriculture, water quality. We construct a simulation model of maize production in twelve watersheds within the U. S. Chesapeake Bay Region that has economic and watershed components linking climate to productivity, production decisions by maize farmers, and nitrogen loadings delivered to the Chesapeake Bay. Maize is an important crop to study because of its importance to the region's agriculture and because it is a major source of nutrient pollution. The model is run under alternative scenarios regarding the future climate, future baseline (without any climate change), whether farmers respond to climate change, whether there are carbon dioxide (CO2) enrichment effects on maize production, and whether agricultural prices facing the region change due to climate change impacts on global agricultural commodity markets. The simulation results differ from one scenario to another on the magnitude and direction of change in nitrogen deliveries to the Chesapeake Bay. The results are highly sensitive to the choice of future baseline scenario and to whether there are CO2 enrichment effects. The results are also highly sensitive to assumptions about the impact of climate change on commodity prices facing farmers in the Chesapeake Bay region. The results indicate that economic responses by farmers to climate change definitely matter. Assuming that farmers do not respond to changes in temperature, precipitation, and atmospheric CO2 levels could lead to mistaken conclusions about the magnitude and direction of environmental impacts.