GRAPES_Meso和ECMWF模式对郴州地区2019年汛期降水预报对比检验

利用GRAPES_Meso和ECMWF模式降水量预报、实况降水量等资料,计算2019年汛期两种模式的晴雨预报准确率(PC)、风险评分(TS)、漏报率(PO)、空报率(FAR)、真实技巧评分(TSS)和预报偏差(BIAS)几个量,对模式降水量预报进行了统计检验.研究结果表明:对于郴州10个国家站,GRAPES_Meso整体优于ECMWF模式,两种模式对所有气象站降水均存在预报过度的现象,其中ECMWF模式更明显;ECMWF模式的漏报率低于GRAPES_Meso模式,但其空报率高于后者;两种模式都对资兴到永兴一带的预报效果最好,对西南部预报效果最差,ECMWF模式在桂东站表现较好,GRAPES_Meso模式则对汝城站预报效果更优;对暴雨及以上量级的降水预报效果ECMWF模式明显优于GRAPES_Meso模式,而对小雨量级来说,后者更佳;两种模式对9月的预报效果最差,4月和5月较好.     

监测预报暴雨，提升防灾能力——“我国梅雨锋暴雨遥感监测技术与数值预报模式系统”项目

1998年汛期由于持续的梅雨锋暴雨,造成长江流域发生全流域的洪涝灾害,国家损失人民币三千多亿元,一千多人在这次洪涝里丧生。由于梅雨锋暴雨具有突发性和持续性特点,我国气象部门对暴雨出现时间、地点与强度很难做出准确预报,显示出我国对梅雨锋暴雨的监测与预测能力的对相薄弱。于是在倪允琪教授带领下的国家973项目对"我国梅雨锋暴雨遥感监测技术与数值预报模式系统"从1999年正式开始研究,并于2006年获得了国家科学技术进步二等奖。该项目为暴雨监测与预报提供了一系列理论和方法,为提升国家减灾防灾能力以及为人民生命财产提供气象保障起了重要作用。     

暴雨短期预报专家系统

本文总结了肇庆地区前汛期（4～6月）暴雨短期预报专家系统研究的初步成果．专家系统中，天气形势部分是根据肇庆气象台多年来对暴雨研究的主要成果及预报经验给出的，同时对850hPa上华南高度场进行了切比雪夫多项式展开；物理条件部份是根据1980～1989年实时资料及预报经验归纳得出．在预报时，主要应用热带有限区域数值模式产品本系统在微机上实现，人机对话及预报结论等均用中文显示。     

大-暴雨天气预报方法研究

拟利用1980—2000年气象资料和历史天气图,研究产生大一暴雨的影响系统和环流特征,建立天气模型,为今后的预报提供参考。     

桂西北强对流天气的能量分析及预报

桂西北的暴雨和冰雹大风天气，其总能量演变都具有明显的特征。建立主要天气系统与总能量相结合的暴雨和冰雹大风短期预报方案，对暴雨和冰雹大风具有一定预报能力。     

咸阳地区"04-08-10"区域性暴雨成因分析

对2004年8月10日成阳区域性暴雨从气候背景、天气形势、物理量场、成阳地形等方面进行分析，揭示了这次暴雨形成的直接原因和突出的前兆反映，为提高此类区域性暴雨预报准确率提供了参考依据。     

清远市前汛期24小时暴雨预报

本文对1983～1991年前讯期（4～6月）850hPa亚欧图的分析，根据850hPa上切变线的位置与性质．把清远前汛期切变线型暴雨分为4种类型，并对这4种尖型总结出若干条预报指标．为清远前汛期暴雨24h预报提供了比较成功的预报方法．     

桂西北暴雨的短时定量预报方法

本文根据产生桂西北暴雨的物理机制，提出了一个确定雨量预报的计算公式，并对1987～1992年河池市6年的暴雨进行试报，效果较好。     

绥化市近年灾害性天气过程分析

本文针对绥化市近年灾害性天气个例,从气候学角度对近年绥化市暴雨、干旱、雷雨大风等灾害性天气过程进行气候分析,得出绥化市近年灾害性天气的时空分布特点。利用MICAPS1.0、MICAPS2.0常规资料、雷达回波、自动雨量站资料进行天气学分析,从高低空环流形势、影响系统、卫星云图特点等方面入手,寻求灾害性天气预报的思路和方法,抓住预报着眼点,较为准确监测和判断灾害性天气的发生、发展规律,提高预报的准确率,为防灾减灾,减少灾害造成的损失提供科学预报依据。     

楚雄州暴雨的时空分布特征分析

本文用1961—2002年楚雄州10个站逐日雨量资料及历史天气图，统计分析了楚雄州暴雨的时空分布特征，得到的结果在暴雨预报及防灾减灾及气候区划方面有一定的参考价值。     

Sand-Dust Storm Ensemble Forecast Model Based on Rough Set

To improve the accuracy of sand-dust storm forecast system, a sand-dust storm ensemble forecast model based on rough set (RS) is proposed. The feature data are extracted from the historical data sets using the self-organization map (SOM) clustering network and single fields forecast to form the feature values with low dimensions. Then, the unwanted attributes are reduced according to RS to discretize the continuous feature values. Lastly, the minimum decision rules are constructed according to the remainder attributes, namely sand-dust storm ensemble forecast model based on RS is constructed. Results comparison between the proposed model and the back propagation neural network model show that the sand-storm forecast model based on RS has better stability, faster running speed, and its forecasting accuracy ratio is increased from 17.1% to 86.21%.     

Numerical Model of Storm Surge and Inundation in Bohai Bay

A two-dimensional numerical model of extratropical storm surge and inundation in Bohai Bay was built based on the unsteady flow Navier-Stokes equations. The model included two sections, one was for the simulation of storm surge tidal level and the other for the simulation of storm surge inundation in the coastal area. While simulating the storm surge tidal level, the alternating direction implicit (ADI) method was applied to dispersing and solving 2D storm surge equations. In the simulation of storm surge inundation, the 2D unsteady flow equations were dispersed and solved using the structureless grids of finite volume method (FVM). A coupling calculation mode of the process of inundation and storm surge tidal level variation was proposed, therefore the storm surge inundation process and area could be calculated while simulating and forecasting the process of storm surge tidal setup. Furthermore, an extratropical storm surge and inundation in Bohai Bay were simulated using this numerical model. Simulation results are in good agreement with the measured data, which shows that this numerical model provides a new method of simulating and forecasting storm surge and inundation in Bohai Bay.     

Comprehensive risk analysis of storm surge flood based on WebGIS

The comprehensive risk analysis of storm surge flood is vital to the safety management of sea embank- ment, the scientific assessment of storm surge disaster and the improvement of emergent treatment in storm surge haz- ard. Based on the research of disaster-causing, disaster-pregnant and disaster-bearing factors, the influencing factors of storm surge risk are concluded to be flood natural risk, embankment position, embankment width and height. The membership degree of the factors of storm surge risk is firstly determined by storm surge flood evolution based on WebGIS, and the comprehensive risk membership and risk grade of each influencing factor are obtained. Then the effects of a single factor on comprehensive risk and sensitivity analysis are discussed, and the storm surge flood risk map is obtained. Finally, the storm surge of Tianjin Binhai New Area is taken as a case. The results show that the in- fluencing degree of the factors on the comprehensive risk membership is in decreasing order of flood natural risk, em- bankment position, embankment width and height. The flood risk map of the case is drawn, which is useful to decrease losses caused by storm surge disaster.     

关于沙尘暴沙粒在高空运动的数学模型及分析

文章从物理学的流体力学出发,运用相关的因素进行分析,建立沙尘暴颗粒扩散的数学模型,分析了沙尘颗粒扩散的内在因素,并且试图寻找减少沙尘暴危害的方法。     

Soundbites

“在暴风雨中，明智的人会向上帝乞求让自己从恐惧中解放出来而不是乞求让自己从危险中解脱出来。是内心的风暴使他害怕而不是外界。” ——拉尔夫·沃尔多·爱默生强调内心的恐惧远比外界的危险更能对个人造成危害。     

校园网广播风暴的成因与防治

由于网络拓扑的设计和连接问题,或网络上设备越来越多,广播所占用的时间也越来越多。当数量达到一定程度时,就会对网络上的正常信息传递产生影响,导致网络性能下降,甚至网络瘫痪,这就是广播风暴。广播风暴已成为校园网故障的头号杀手。     

3D simulation of storm surge disaster based on scenario analysis

The occurrence of storm surge disaster is often accompanied with floodplain, overflow, dike breach and other complex phenomena, while current studies on storm surge flooding are more concentrated on the 1D/2D numerical simulation of single disaster scenario(floodplain, overflow or dike breach), ignoring the composite effects of various phenomena. Therefore, considering the uncertainty in the disaster process of storm surge, scenario analysis was firstly proposed to identify the composite disaster scenario including multiple phenomena by analyzing key driving forces, building scenario matrix and deducing situation logic. Secondly, by combining the advantages of k-ω and k-ε models in the wall treatment, a shear stress transmission k-ω model coupled with VOF was proposed to simulate the 3D flood routing for storm surge disaster. Thirdly, risk degree was introduced to make the risk analysis of storm surge disaster. Finally, based on the scenario analysis, four scenarios with different storm surge intensity(100-year and 200-year frequency) were identified in Tianjin Binhai New Area. Then, 3D numerical simulation and risk map were made for the case.     

调整经营理财策略 增强企业抗击金融风暴能力

从企业目标的角度分析金融风暴对企业的影响,运用经济周期理论阐述企业应对金融风暴经营理财策略。     

试析《雷雨》第三幕环境描写

恰到好处的雷雨环境描写是《雷雨》第三幕戏的一大特色。本幕中雷雨环境描写对衬托人物心理状态、推动情节发展、加剧戏剧冲突产生了极大的功效和强烈的艺术魅力。     

System development for storm surge hazard assessment based on WebGIS for Tianjin Binhai New Area

It is imperative to develop a risk assessment system for quickly predicting storm surge disaster due to the vulnerability of Tianjin Binhai New Area. The flood routing model with user-defined breaches was firstly established based on the seed spread algorithm in order to achieve a rapid forecasting of storm surge flood information. Furthermore, fuzzy mathematics was utilized to identify the storm disaster grade, and the hazard mapping was conducted to visually obtain the hazard spatial and temporal distribution. Finally, the flood routing visualization method was proposed based on numerical simulation of storm surge to achieve the reappearance scene of dynamic evolution process. The developed system can play a vital role in the management and decision-making of sea dyke mitigation engineering in Tianjin Binhai New Area.