关键词： nitrous oxide   agriculture   CO2   fertilization   nitrogen use efficiency  

摘要： Nitrous oxide (N2O) is an important greenhouse gas and ozone depleting substance. Previous projections of agricultural N2O(the dominant anthropogenic source) show emissions changing in tandem, or at a faster rate than changes in nitrogen (N) consumption. However, recent studies suggest that the carbon dioxide (CO2) fertilization effect may increase plant N uptake, which could decrease soil N losses and dampen increases in N2O. To evaluate this hypothesis at a global scale, we use a process-based land model with a coupled carbon-nitrogen cycle to examine how changes in climatic factors, land-use, and N application rates could affect agricultural N2O emissions by 2050. Assuming little improvement in N use efficiency (NUE), the model projects a 24%-31% increase in global agricultural N2O emissions by 2040-2050 depending on the climate scenario-a relatively moderate increase compared to the projected increases in N inputs (42%-44%) and previously published emissions projections (38%-75%). This occurs largely because the CO2 fertilization effect enhances plant N uptake in several regions, which subsequently dampens N2O emissions. And yet, improvements in NUE could still deliver important environmental benefits by 2050: equivalent to 10 PgCO(2) equivalent and 0.6 Tg ozone depletion potential.

关键词： Climate change   Agricultural drought   Adaptation   Cropping pattern   The Barind tract   Bangladesh  

摘要： The north-western part of Bangladesh especially the Barind region is considered as a drought-prone area. The objective of this paper is to find out the adaptation measures practised by farmers to cope with climate change and agricultural drought in two drought-prone villages of the north-western Bangladesh. The primary data for this study were collected from a structured questionnaire survey conducted on 130 households selected from 192 through simple random sampling. The present study finds that agriculture of this area is recurrently disrupted by frequent drought events. Moreover, the climate change will increase both frequency and magnitude of extreme drought events in this region. This paper identifies that the impacts of drought on agriculture are difficulties in irrigation, disruption in cropping pattern, depletion of ground water table, problem in fish cultivation and so on. On the other hand, analyses unveil that respondents practised a range of adjustment strategies to combat adverse impacts of drought such as adoptions of drought-tolerant crop varieties, rainwater harvesting, mango and jujube intercropping with rice, kitchen gardening, weed control and reducing water loss, constructing water control structures, irrigation and cultivation of fast-growing fish species. Therefore, the present study recommends proper drought early warning system, reserving surface water, managing supplemental irrigation, tree plantation, re-excavation of canals and traditional ponds, credit support to the farmers, preparedness and awareness rising to ensure the future sustainable agricultural development in the study areas.

关键词： mathematical sector modelling national adaptation programme   net annual return   water use return  

摘要： This research paper highlights the adverse effects of climate change on the agricultural sector in Saudi Arabia and the actions taken to adapt to these adverse effects. Special focus was given to the potential to optimise the reallocation of scarce water resources among the competitive advantage date palm cropping regions in Saudi Arabia using a mathematical sector modelling approach. The results showed great potential for Saudi Arabia to adapt to the adverse effects of climate change by optimising the date palm cropping pattern in accordance with its scarce water resources and limited cultivated lands. The optimised scenario would result in a high net annual return, equivalent to about 881.76 million US$ year(-1), and an increase on the water use return from about 0.97 US$ cm(-1) in the base year to approximately 1.31 US$ cm(-1). The optimised scenario would also provide the opportunity to reduce the allocated date palm cropping area by approximately 4% (from approximately 118,250 hectares to approximately 113,446 hectares) and to reduce the water demand by approximately 1% (from 681.06 million cubic metres (MCM) per year to approximately 674.28 MCM per year).

关键词： CLIMATE change   RISK assessment   GRAZING   GENERAL circulation model   EMISSIONS (Air pollution)  

摘要： A risk management approach to assessing climate change impacts was completed for grazing, wheat and sorghum production systems in eastern Australia. This 'risk matrix' approach for wheat and sorghum was compared to results from simulation modelling of the impacts of projected climate change from general circulation models (GCM's). In the modelling we used five GCM's, the A1FI emissions scenario and a baseline climate (historical, 1960-2010);both the 'risk matrix' approach and modelling used a time horizon of 2030. While some people find the risk matrix process a highly effective tool for assessing climate change impacts others question its utility without the support of quantitative data such as that produced from integrated climate and agricultural models. Here we show the impacts of climate change on wheat and sorghum production systems using both approaches, and also show the risk, adaptation responses and vulnerability of all three production systems using the 'risk matrix' approach. Advantages and disadvantages of each approach are identified. The independent assessment showed the two approaches produced similar results. The 'risk matrix' showed little overall impact, risk or vulnerability for the central slopes from climate change using the adaptation strategies currently available for yield, protein levels, pests and disease, weeds and soil condition. The simulation modelling showed no statistically significant impact on yield, drainage, erosion and runoff, although more high-end extremes were evident. The risks to 2030 from anthropogenic climate change can largely be managed by continuing to implement best management practice and managing the risks already posed by climate variability. The 'risk matrix' approach was a useful tool under these circumstances to assess the impacts, adaptation, risk and vulnerability of climate change in the absence of local modelling information, and demonstrates the power of expert opinion to help understand and respond to clim

关键词： Climate change   Hydrological modeling   Mexico   Semiarid   SWAT   Water management  

摘要： In northern Mexico, water resources management has become a challenging task, aggravated by the vulnerability of this region to climate change. The semiarid Guadalupe River Basin is under additional pressure due to wine production and drinking water supply. We have applied the SWAT model to the upper section of this basin to assess the impacts of several climate change scenarios on its water availability. An overall good performance was obtained (daily and monthly NSE values of 0.66 and 0.86 for calibration;0.52 and 0.76 for validation). Water balance and flow components prediction was satisfactory. However, although peak flows were well represented, the model overestimated discharge during low flow periods. Once evaluated, high and low emissions climate change scenarios were simulated using projections based on CMIP3 for both scenarios and for short (2010-2039) and long term (2070-2099) obtained from the Baja California Climate Change Action Program. Noticeable impacts of climate change on river flow were obtained, with runoff reductions around -45% in the short term, but up to -60% in the long term. Main drives seem to be precipitation reduction, in addition to an increasing water loss- in percentage-via evapotranspiration. Aquifer recharge is expected to decrease up to -74%, with a consequent reduction of groundwater flow. We also quantified the differentiating impacts during dry, normal and wet years. The latter was the most affected (annual streamflow reduction up to -72%), especially during winter and spring. On the contrary, a slight runoff increase is expected during dry years, especially during summer. These runoff reductions were supposed to be a huge problem for a region where pressure on water resources is already very strong. Our model framework may provide water managers with an approximation of how climate change possibly can affect water availability, serving as a tool to test further scenarios. (C) 2015 Elsevier B.V. All rights reserved.

关键词： 气候变化   农业生产   影响   评价  

摘要： 在我国的经济发展中,农业占据着极其重要的地位,而农业生产在很大程度上受到气候变化的影响。近年来,我国气候发生了一定的变化,气温呈现出逐年上升的趋势,极端恶劣天气频频发生,对农业生产造成了很大影响。对于气候对农业影响的评价,学术界进行了较为深入的研究,本文对这些评价方法进行综述。

关键词： SWAT  

摘要： Modeling impacts of agricultural scenarios and climate change on surface water quantity and quality provides useful information for planning effective water, environmental and land use policies. Despite the significant impacts of agriculture on water quantity and quality, limited literature exists that describes the combined impacts of agricultural land use change and climate change on future bioenergy crop yields and watershed hydrology. In this study, the soil and water assessment tool (SWAT) eco-hydrological model was used to model the combined impacts of five agricultural land use change scenarios and three downscaled climate pathways (representative concentration pathways, RCPs) that were created from an ensemble of eight atmosphere-ocean general circulation models (AOGCMs). These scenarios were implemented in a well-calibrated SWAT model for the intensively farmed and tiled Raccoon River watershed (RRW) located in western Iowa. The scenarios were executed for the historical baseline, early century, mid-century and late century periods. The results indicate that historical and more corn intensive agricultural scenarios with higher CO2 emissions consistently result in more water in the streams and greater water quality problems, especially late in the 21st century. Planting more switchgrass, on the other hand, results in less water in the streams and water quality improvements relative to the baseline. For all given agricultural landscapes simulated, all flow, sediment and nutrient outputs increase from early-to-late century periods for the RCP4.5 and RCP8.5 climate scenarios. We also find that corn and switchgrass yields are negatively impacted under RCP4.5 and RCP8.5 scenarios in the mid-and late 21st century.

关键词： 中国农业科学院   科技工作者   气候变化   参数反演   农业遥感   农业区划   农业资源   研究员  

摘要： 毛克彪，1977年生，博士，中国农业科学院农业资源与农业区划研究所研究员（优秀青年一级人才），湖南科技大学兼职教授，安徽农业大学客座教授。多年来致力于农业遥感水热参数反演及空间气候变化前沿研究，积极主动参与国家重大自然灾害监测工作并作出了突出贡献。主持或参与各类国家重大、重点等科研项目近20项。

关键词： 邯郸   农业   脆弱性   气候变化   对策  

摘要： 本文选取邯郸主要农作物小麦、玉米、棉花为代表,通过分析三种农作物产量与温度和降水的关系,对农业生产的脆弱性进行了评价,针对全球变暖趋势下小麦、玉米、棉花生产存在的脆弱性问题,提出了合理调整农作物的种植制度和时间,以充分利用热量资源,提高农作物的产量;加强农业基础设施的建设,积极抵御气象灾害;建立完善的应对气象灾害的预警机制;选择适应性强的新的农作物的品种的适应对策,加强农作物对气象灾害的抵御能力,提高农业抵抗自然灾害的能力,稳定农业生产。

关键词： 农业   水稻   气候变化   适应   碳减排   进展与前瞻  

摘要： 以水稻作物为特定对象,围绕气候变化与作物生产,梳理和分析了气候变化对水稻产业影响的研究动态,以及基于"减排"和基于"适应"的水稻生产分别对气候变化响应的学术观点。分析发现:在当前的相关研究中,包括水稻作物在内的关于中国农作物碳排放核算体系存在着标准模糊和范围偏窄的问题,关于"减排"与"适应"协同的响应策略的研究较为缺乏。加强对这一问题的研究将有助于深化和完善农业或作物与气候变化双向互动机制的研究成果。