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黄河中游吴堡—龙门段河道洪水概化预报研究
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作者 黄华平 侯博 +2 位作者 梁忠民 李彬权 王军 《人民黄河》 CAS 北大核心 2018年第6期34-37,共4页
将洪水过程模式概化与支持向量回归机相结合,提出了一种逐时段更新的河道洪水概化预报方法。以黄河中游吴堡—龙门段河道洪水预报为例,根据龙门站1980—2000年28场洪水过程资料概化出典型洪水模式,采用支持向量回归机算法构建洪峰流量... 将洪水过程模式概化与支持向量回归机相结合,提出了一种逐时段更新的河道洪水概化预报方法。以黄河中游吴堡—龙门段河道洪水预报为例,根据龙门站1980—2000年28场洪水过程资料概化出典型洪水模式,采用支持向量回归机算法构建洪峰流量与洪水历时的预报模型,根据逐时段洪峰流量/洪水历时的预报结果,对概化的典型洪水模式进行缩放,实现了龙门站洪水过程主要特征的概化预报。对2001—2006年5场洪水的预报检验结果表明:随着逐时段资料的更新,该方法的预报精度逐步提升,且涨水阶段的预报结果已能较好地展示整场洪水过程的发展趋势。 展开更多
关键词 支持向量回归机 概化预报 洪水 吴堡—龙门区间 黄河中游
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Impacts and uncertainty analysis of elevated temperature and CO_2 concentration on wheat biomass 被引量:1
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作者 刘玉洁 陶福禄 《Journal of Geographical Sciences》 SCIE CSCD 2012年第6期1002-1012,共11页
Impacts of climatic change on agriculture and adaptation are of key concern of scientific research. However, vast uncertainties exist among global climates model output, emission scenarios, scale transformation and cr... Impacts of climatic change on agriculture and adaptation are of key concern of scientific research. However, vast uncertainties exist among global climates model output, emission scenarios, scale transformation and crop model parameterization. In order to reduce these uncertainties, we integrate output results of four IPCC emission scenarios of A1 FI, A2, B1 and B2, and five global climatic patterns of HadCM3, PCM, CGCM2, CSIRO2 and ECHAM4 in this study. Based on 20 databases of future climatic change scenarios from the Climatic Research Unit (CRU) , the scenario data of the climatic daily median values are generated on research sites with the global mean temperature increase of 1℃(GMT+ID), 2℃(GMT+2D) and 3℃(GMT+3D). The impact of CO2 fertilization effect on wheat biomass for GMT+I D, GMT+2D and GMT+3D in China's wheat-producing areas is studied in the process model, CERES-Wheat and probabilistic forecasting method. The research results show the CO2 fertilization effect can compensate reduction of wheat biomass with warming temperature in a strong compensating effect. Under the CO2 fertilization effect, the rain-fed and irrigated wheat biomasses increase respectively, and the increment of biomass goes up with temperature rising. The rain-fed wheat biomass increase is greater than the irrigated wheat biomass. Without consideration of CO2 fertilization effect, both irrigated and rain-fed wheat biomasses reduce, and there is a higher probability for the irrigated wheat biomass than that of the rain-fed wheat biomass. 展开更多
关键词 rising temperature CO2 concentration wheat biomass probabilistic projection
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