关键词： erosion productivity impact calculator (EPIC)   corn   wheat   alfalfa   crop yield   evapotranspiration   runoff  

摘要： A national assessment (NA) evaluated the potential consequences of climate change and variability, on the agriculture, water resources, as well as other economic and natural resource sectors in the United States. As part of this process, we used scenarios of the HadCM2 GCM and the EPIC agroecosystem. model to evaluate climate-change impacts on crop yields and ecosystem processes. Baseline climate data were obtained from national records for 1961-1990. The scenario runs for 2025-2034 and 2090-2099 were extracted from a HadCM2 run. EPIC was run on 204 representative farms under current climate and two 10-year periods centered on 2030 and 2095, each at CO2 concentrations of 365 and 560 ppm. Crops were simulated under both dryland and irrigated management, with irrigation water supply estimates taken from the HUMUS simulations in Paper 1. Texas, New Mexico, Colorado, Utah, Arizona, and California are projected to experience significant temperature increases by 2030. Slight cooling is expected by 2030 in Alabama, Florida, Maine, Montana, Idaho, and Utah. Larger areas are projected to experience increased warming by 2095. Uniform precipitation increases are expected by 2030 in the northeast. These increases are predicted to expand to the eastern half of the country by 2095. Regionally, dryland corn yields could increase, decrease or remain unchanged under the two scenarios. EPIC simulated yield increases for the Great Lakes, Corn Belt and Northeast regions. Simulated yields of irrigated corn were predicted to increase in almost all regions. Soybean yields could decrease in the Northern and Southern Plains, the Corn Belt, Delta, Appalachian, and Southeast regions and increase in the Lakes and Northeast regions. Simulated wheat yields exhibited upward trends under scenarios of climate-change. Evapotranspiration in dryland corn is expected to increase in both future periods while water-use efficiency will decrease. National corn production in 2030 and 2095 could be affected

关键词： global warming   irrigation   evapotranspiration   runoff   CO2-fertilization effect  

摘要： In response to a congressional mandate, the US Global Change Research Program organized a National Assessment of Climate Change focusing on geographic regions (e.g. Alaska, Great Plains) and sectors (e.g. public health, agriculture, water resources). This paper describes methodology and results of a study by researchers at the Pacific Northwest National Laboratory contributing to the water sector analysis. The subsequent paper makes use of the water supply results to estimate the climate change impacts on irrigated agriculture. The vulnerability of water resources in the conterminous US to climate changes in 10-year periods centered on 2030 and 2095 as. projected by the Hadley/United Kingdom Meteorological Office (UKMO) general circulation model (GCM;HadCM2) were modeled using the Hydrologic Unit Model for the United States (HUMUS). HUMUS, a biophysically based hydrology model, consists of a Geographical Information System (GIS) that provides data on soils, land use and climate to drive the Soil Water Assessment Tool (SWAT). The modeling was done at the scale of the eight-digit United States Geological Survey (USGS) Hydrologic Unit Area (HUA) of which there are 2101 in the conterminous US. Results are aggregated to the four- and two-digit (major water resource region, MWRR) scales for various purposes. Daily records of maximum/minimum temperature and precipitation (PPT) from 1961 to 1990 provided the baseline climate. Water yields (WY), used as a measure of water supply for irrigation, increases from the 1961-1990 baseline period over most of the US in 2030 and 2095. In 2030, WY increases in the western US and decreases in the central and southeast regions. Notably, WY increases by 139 turn (35%) from baseline in the Pacific Northwest. Driven by higher temperatures and reduced precipitation, WY is projected to decrease in the Lower Mississippi and Texas Gulf basins. The HadCM2 (2095) scenario projects a climate significantly wetter than baseline, resulting in water

关键词： 巴州农区   气候变化   农业生产   温度区域变化   拟合值   实况值   气温  

摘要： 分析了1960～2001年巴州农区年、季平均温度、降水的变化,结果表明:各地气候变化并不一致,大部分地区有温度升高、降水偏多的趋势。冬季的升温幅度明显大于其它季节,年平均温度的上升主要由冬季升温所致。

关键词： 温度   降水   气候变化   农业生产   锦州地区  

摘要： 通过对 195 1～ 2 0 0 2年锦州地区气候资料统计分析 ,得出近 5 0a由于锦州地区气候变化明显 ,对农业生产产生诸多有利和不利影响的结论。

关键词： 气候变化   农业收成   高分辨率   气候序列重建   西安  

摘要： 基于清代雨雪与农业收成等档案记载及现代气象观测记录,根据西安冬季降雪与平均气温之间的统计关系、降水入渗与水量平衡模型,分别重建了西安1736～2000年冬季平均气温与4季降水序列,并分析了该地区气候变化特征及其对1736～2000年农业收成的影响.主要结论如下:(1)西安的冷暖变化存在明显的百年际波动:其中18世纪相对温暖,19世纪寒冷,20世纪又转为温暖,且增暖趋势极为明显.(2)西安的降水变化存在明显的年代际波动.自1736年以来,共经历了6个多雨期与7个少雨期,其中多雨期的平均雨量比少雨期多16%.(3)气候变化对农业收成的影响极为明显.其中夏季降水量与秋收关系显著,而夏收又与前一年秋～当年春季的降水明显相关,且大多数严重歉收年均由降水明显偏少而致.虽然温度的年际变化与收成没有显著的联系,但温度年代际变化,即气候的冷暖阶段变化却与收成的阶段性变化关系密切.

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.