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841.
Probabilistic Flood Prediction in the Upper Huaihe Catchment Using TIGGE Data 总被引:1,自引:0,他引:1
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ZHAO Linn QI Dan TIAN Fuyou WU Hao DI Jingyue WANG Zhi LI Aihua 《Acta Meteorologica Sinica》2012,26(1):62-71
Based on the precipitation and temperature data obtained from THORPEX (The Observing System Research and Predictability Experiment) Interactive Grand Global Ensemble (TIGGE)-China Meteorological Administration (CMA) archiving center and the raingauge data,the three-layer variable infiltration capacity (VIC-3L) land surface model was employed to carry out probabilistic hydrological forecast experiments over the upper Huaihe River catchment from 20 July to 3 August 2008.The results show that the performance of the ensemble probabilistic prediction from each ensemble prediction system (EPS) is better than that of the deterministic prediction.Especially,the 72-h prediction has been improved obviously.The ensemble spread goes widely with increasing lead time and more observed discharge is bracketed in the 5th-99th quantile.The accuracy of river discharge prediction driven by the European Centre (EC)-EPS is higher than that driven by the CMA-EPS and the US National Centers for Environmental Prediction (NCEP)-EPS,and the grand-ensemble prediction is the best for hydrological prediction using the VIC model.With regard to Wangjiaba station,all predictions made with a single EPS are close to the observation between the 25th and 75th quantile.The onset of the flood ascending and the river discharge thresholds are predicted well,and so is the second rising limb.Nevertheless,the flood recession is not well predicted. 相似文献
842.
基于超级集合思想的数值预报产品变权集成方法探讨 总被引:5,自引:3,他引:2
针对目前地方气象台站能获取的国内外数值预报产品种类多、数量大、质量参差不齐的实际情况,探讨了几种基于超级集合思想的多模式数值预报动态变权集成处理方法.该方法经济、简便、有效,为预报员从海量的数值产品信息中提取更为准确和精细的集成形势场、物理量场、降水预报、冷空气活动预报、集成矩、特征线路图等多种具有较高质量的集成统计新产品,能动态反映各类数值预报模式的预报能力变化,在一定程度上提高了不同时间、不同区域的精细化预报水平和数值产品的利用效率,为业务预报提供了有价值的参考. 相似文献
843.
In 2003–2008, highly accurate photoelectric and CCD observations of the close binary system DI Her were performed in the V band. The light curves of three primary and three secondary eclipses were constructed. These observations, along with the highly accurate photoelectric observations of other authors obtained in different years from 1963 to 1986, have confirmed the difference between the observed (1 . o 3 ± 0 . o 1/100 yr) and theoretical (4 . o 3/100 yr) rates of apsidal motion. Our photometric data are indicative of a possible variability in the system with period P′ = 1.175 days and amplitude A′ = 0 . m 011, which is probably related to the pulsations of one of the components. There may be a third body in the system that produces in-phase variations in the times of primary and secondary minima with a period of 10.5 yr and an amplitude of 1 . m 5. 相似文献
844.
N. N. Samus’ V. P. Goranskii O. V. Durlevich A. V. Zharova E. V. Kazarovets E. N. Pastukhova M. L. Hazen T. M. Tsvetkova 《Astronomy Letters》2002,28(3):174-181
We present a new electronic version of the first volume of the General Catalogue of Variable Stars (GCVS), fourth edition, which contains data on 10558 variable stars in Andromeda-Crux (the constellations are ordered in the Catalog according to the Latin alphabet). This version incorporates the name lists of variable stars from no. 67 to no. 76 for the same constellations. The main distinctive feature of the new version is that it provides improved equatorial J2000.0 coordinates for 10349 stars (including those for 4587 stars corrected for proper motions). These are based on identifications with positional catalogs using finding charts and on our new measurements. We searched for a number of stars on original plates from the plate collections of several observatories. The version also includes a file of remarks to the first GCVS volume and a preliminary version of the file of bibliographic references to the entire fourth edition of the GCVS. Apart from a complete update of the positional information, the new version incorporates all the other corrections that were found to be necessary after the first GCVS volume was published (1985). 相似文献
845.
Two Precambrian Shield zero‐order catchments were monitored from January 2003 to July 2004 to characterize their hydrological and biogeochemical characteristics prior to a forest management experiment. Hydrometric observations were used to examine temporal trends in hillslope‐wetland connectivity and the hillslope runoff processes that control wetland event response. The hillslope groundwater flux from the longer transect (E1) was continuous throughout the study period. Groundwater fluxes from a shorter and steeper hillslope (E0) were intermittent during the study period. Large depression storage elements (termed micro‐basins) located on the upper hillslope of the E1 catchment appeared to be at least partly responsible for the observed rapid wetland runoff responses. These micro‐basins were hydrologically connected to a downslope wetland by a subsurface channel of glacial cobbles that functioned as a macropore channel during episodic runoff events. The runoff response from the hilltop micro‐basins is controlled by antecedent water table position and water is quickly piped to the wetland fringe through the cobble channel during high water table conditions. During periods of low water table position, seepage along the bedrock–soil interface from the hilltop micro‐basin and other hillslopes maintained hillslope–wetland connectivity. The micro‐basins create a dynamic variable source‐area runoff system where the contributing area expands downslope during episodic runoff events. The micro‐basins occupied 30% of the E1 catchment and are a common feature on the Precambrian Shield. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
846.
B. N. Rustamov 《Astronomy Letters》2001,27(1):34-38
We present the equivalent widths of the Hβ and Hγ absorption lines in the spectrum of V1057 Cyg measured from 1978–1990 spectrograms. The mean equivalent widths of these lines decreased approximately twofold during 1978–1985 and somewhat increased during 1987–1990. Using published UBV photometry, we show that there has been a correlation between the Hβ equivalent width and the ?U-B? color since 1983, with ?W λ(Hβ)? increasing with decreasing?U-B? Based on our spectroscopic and photometric observations in 1978–1990, we assume that V1057 Cyg has passed to a qualitatively new stage of its development after 1985. 相似文献
847.
Simultaneousinversionofvelocitydistribu┐tionandinterfacepositionsSONG-LINLI1)(李松林)NING-YUANWU2)(吴宁远)ZHAN-LONGSONG1)(宋占隆)JIN-... 相似文献
848.
廖洞贤 《南京气象学院学报》1996,19(3):267-275
设计了一个以均匀网格差分模式为基础的变网格差分模式,如证明:如前者满足一定条件并具有质量和能量守恒性质,以及与连续情况一致的动,位能之间的转换关系,则变网格模式也同样具有,而且,把前者改变为后者增加的运算量很小,也非常方便。 相似文献
849.
徐贵章 《武汉大学学报(信息科学版)》1996,(4)
在分析变截面杆件形常数微机实现方法的基础上,利用有限元先处理定位向量法,形成变截面结构关于独立结点位移坐标的结构刚度矩阵,经静力缩聚得到关于集中质量水平动力自由度的侧向刚度矩阵,由Stodola迭代法和规范地震反应谱完成抗震动力分析和振型组合计算 相似文献
850.