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长治地区暴雨中小尺度触发系统的分析王光天,侯彩红,张晋保(长治市气象局046000)1引言长治地区为山西省暴雨多发区,且雨量分布极不均匀,降水强度大,突发性强。如1975年8月4~8日,壶关县石窟滩、杏村的雨量达1150.0mm,是当地年平均降水量的... 相似文献
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盛夏中国北方的超强区域性持续暴雨 总被引:2,自引:0,他引:2
将“63.8暴雨”与“75.8暴雨”的天气学特征作了系统的对比分析。研究表明:尽管这两次暴雨相隔12年,主要暴雨落区相距500km以上,发生暴雨的低气压系统分别来自西南与东南等差别,而形成暴雨的基本天气学过程是非常相似的。概括这两次暴雨的环一种盛夏出现在中国北方的超强区域在气的概念模型。 相似文献
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北京城市暴雨和雨型的研究 总被引:18,自引:0,他引:18
暴雨是北京洪水的主要成因,同时也是水资源补给的重要来源。本文编制了北京的五塔寺站(下称北京站)T=5,10,15,20,30,45,60,90,120min及3,6,12,24h等13个时段,N=200,100,50,20,10,5,2等7个不同重视现期的设计暴雨公式。同时,以10min,1和2h为单位时段,统计分析出120min,12和24h的设计雨型。本成果能满足北京城近效区水利工程,地下雨洪 相似文献
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WANG Yunfeng WANG Bin HAN Yueqi ZHU Min HOU Zhiming ZHOU Yi LIU Yudi KOU Zheng 《大气科学进展》2004,21(4):587-596
The numerical forecasts of mei-yu front rainstorms in China has been an important issue. The intensity and pattern of the frontal rainfall are greatly influenced by the initial fields of the numerical model. The 4-dimensional variational data assimilation technology (4DVAR) can effectively assimilate all kinds of observed data, including rainfall data at the observed stations, so that the initial fields and the precipitation forecast can both be greatly improved. The non-hydrostatic meso-scale model (MM5) and its adjoint model are used to study the development of the mei-yu front rainstorm from 1200 UTC 25 June to 0600 UTC 26 June 1999. By numerical simulation experiments and assimilation experiments, the T106 data and the observed 6-hour rainfall data are assimilated. The influences of many factors, such as the choice of the assimilated variables and the weighting coefficient, on the precipitation forecast results are studied. The numerical results show that 4DVAR is valuable and important to mei-yu front rainfall prediction. 相似文献
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DIAGNOSTIC ANALYSIS OF A RAINSTORM IN SHANDONG PENINSULA INFLUENCED BY A DISTANT TROPICAL DEPRESSION
Based on the observational data as well as data of satellite, NCEP reanalysis and moist potential vortex, the heavy rainfall event that occurred away from the outer cycle of tropical depression Kaemi (No.0605) on July 27, 2006 in Shandong Peninsula has been analyzed. The results show that there are three severe convective cloud clusters during the heavy rainfall. The uprightness of coupling pattern between upper-layer jet and low jet and a divergence area, which appeared in the right of upper-layer jet, provided favorable environmental conditions for convective cloud clusters. The strong convective weather happens over the prefrontal warm sector and the storm rainfall mainly distributes in the front of a high-energy area.Positive vorticity distribution and transportation of warm advection in low levels provide dynamic and thermal conditions for the rainstorm. The spatial-temporal evolvements of physical variable fields and MPV2 as the horizontal component of moist potential vorticity show that the rain intensity change is determined by upper and low level jets and the area of MPV2>0 occurs at the front of the low jet cores. 相似文献
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A newly-discovered GPD-GEV relationship together with comparing their models of extreme precipitation in summer 总被引:3,自引:0,他引:3
It has been theoretically proven that at a high threshold an approximate expression for a quantile of GEV (Generalized Extreme Values) distribution can be derived from GPD (Generalized Pareto Distribution). Afterwards, a quantile of extreme rainfall events in a certain return period is found using L-moment estimation and extreme rainfall events simulated by GPD and GEV, with all aspects of their results compared. Numerical simulations show that POT (Peaks Over Threshold)-based GPD is advantageous in its simple operation and subjected to practically no effect of the sample size of the primitive series, producing steady high-precision fittings in the whole field of values (including the high-end heavy tailed). In comparison, BM (Block Maximum)-based GEV is limited, to some extent, to the probability and quantile simulation, thereby showing that GPD is an extension of GEV, the former being of greater utility and higher significance to climate research compared to the latter. 相似文献
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近期国家出台了诸多关于调控房地产业的新政策,“国六条”、“十五条意见”……可见,中央加大规范房地产市场行为的力度和决心,从严管理土地已势在必行。新政策的出台预示着新一轮房地产“战役”已经打响,本次房地产宏观调控能否顺利达到预期效果,让我们拭目以待…… 相似文献