1991年江淮流域梅雨结束预报的分析与讨论

１９９１年江淮梅雨结束，在预报上具有相当难度。由于ＥＣＭＷＦ数值预报出现重大偏差，曾一度造成业务预报的重大分歧，增加了预报决策的困难。作者客观地反映当时预报的实况，其目的在于剖析预报分歧中的症结，并由此提出预报员的经验可以弥补单一预报工具的不足，修正数值预报产品的误差，从而提高预报准确率。     

1980～1994年台湾海峡两岸的地热涡与降水季度预报初探

利用１９８０～１９９４年大陆３．２ｍ深度和台湾３．０ｍ深度的地温资料,分析了１５ａ来的逐季地气图,统计了台湾海峡两岸的地热涡活动,发现平均每季有１个地热涡活动,其水平尺度比大陆内部的地热涡要小,生命史也要短,进入台湾地区的地热涡绝大多数是从西方和北方进入,其移动速度比大陆内部的要快得多。９０％以上的地热涡在同期有多雨区与其对应,热涡中心与多雨中心相距在１００ｋｍ以内者占６８％。最后给出了一个季度降水的定性预测方案,其步骤为：预报地热涡的中心位置、强度和水平尺度;推算降水正距平区的水平尺度、中心位置和强度;根据本区发生的地震等情况进行预报订正。     

Temporal and Spatial Scale Dependence of Precipitation Analysis over the Tropical Deep Convective Regime

Data from Goddard cumulus ensemble model experiment are used to study temporal and spatial scale dependence of tropical rainfall separation analysis based on cloud budget during Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment(TOGA COARE).The analysis shows that the calculations of model domain mean or time-mean grid-scale mean simulation data overestimate the rain rates of the two rainfall types associated with net condensation but they severely underestimate the rain rate of the rainfall type associated with net evaporation and hydrometeor convergence.     

水库汛期限制水位控制理论与观念的更新探讨

传统的水库汛限水位的控制,只利用了洪水的统计信息,使水库在汛期要时刻预防设计与校核洪水事件的发生,致使一些水库在汛期不敢蓄水而汛后又无水可蓄,造成洪水资源的浪费。提出水库汛限水位动态控制的新理念及其综合推理模式,适应当前预报技术的发展水平,考虑降雨径流洪水预报与一定时间内的短期降雨预报,排除不可能发生的洪水事件,预报可能发生的洪水,实施水库汛限水位的动态控制。但预报不可避免地存在误差,当小概率预报误差事件发生时,仍可采取弥补措施以确保大坝的防洪安全。     

香港大屿山残坡积土的残余强度试验研究

粘性土的残余强度是边坡稳定性评价、桩基与土的相互作用机理研究及填土边坡设计中的重要参数。本文在综述大量文献的基础上,结合香港大屿山火山岩风化残坡积土的残余强度试验研究,分析了残余强度的测试方法和影响残余强度的因素。研究结果表明,残余强度与有效法向应力间具有明显的非线性关系;与单剪测试结果相比,多级剪测试结果明显偏高。     

PRELIMINARY ANALYSES OF THE ACTIVITIES OF SOUTH CHINA SEA SUMMER MONSOON IN 1998

The NCEP reanalyzed data, OLR and SST observations are used to study the onset time and the multi-time scales features of the South China Sea (SCS) summer monsoon in 1998 and its interaction with the sea surface temperature and the effect on the precipitation in Guangdong province. It is found that the 1998 SCS summer monsoon set in on May 17 (in the fourth pentad of the month). The year witnesses a weak monsoon with the OLR oscillating at cycles of about 1 month and the Southwest Monsoon of about 1/2 month. The mon-soon over the Bay of Bengal and the cross-equatorial current near 105°are two driving forces for low-frequency variations of the SCS monsoon. The weak activity in the year was resulted from positive anomalies of SST in the equatorial eastern Pacific in early spring and subsequent formation of positive anomalies of SST in the SCS through the Arabian Sea.     

关于干旱监测评估指标的一种新探讨

从有效降水过程观点入手,针对降水过程次数、降水过程总量,尤其是降水过程的时间分布结构和效能,提出了一种新的干旱指数式。该结果在干旱研究分析、监测评估业务和决策服务中都有实用意义。     

多普勒天气雷达探测中气旋分析

利用南京多普勒天气雷达资料,对南京地区2003年7月8日出现的一次雷雨大风和短时强降水过程进行了分析,结果表明:这次强天气过程与多普勒天气雷达观测到的中气旋相联系,文中结合环境风场分析了中气旋的特征,计算了中气旋的主要参数。     

滁州地区不同类型特大暴雨过程的对比分析

利用常规探测资料、多普勒雷达资料和NCEP 1°×1°的再分析资料对安徽省滁州地区2008年8月1日减弱台风特大暴雨(简称"0808"过程)和2003年7月5日梅雨期特大暴雨(简称"0307"过程)进行了诊断对比分析。结果表明:超低空急流的增强对暴雨尤其是夜间暴雨的形成有提示作用;两次过程中都有次级环流的存在,作用方式有所不同,对高低空系统都有加强作用;其中"0808"过程中减弱台风携带的大量水汽对特大暴雨产生有重要作用,不需要很强的水汽输送就能产生强降水;特大暴雨强的水汽辐合中心都位于边界层内;冷空气的侵入对特大暴雨有重要作用;长时间降水回波的停滞是"0307"过程的主要原因。由强风暴造成的对流降水是"0808"过程在多普勒雷达产品上的主要特征。     

Causes of rockfalls in Al-Huwayshah area, Yemen

According to topography of Yemen, most areas and villages are located at obligated crest, toe of mountain and under cliffs. Therefore Al-Huwayshah consisting of Tawilah sandstone group is characterized by steep slope reach to 90° in some areas. This area is affected by strong tectonic movements and faults that occurred during the geological epochs. This effect enhances to find out fractures and joints as well as the rocks become brittle and ready to slide depending on the position of area. And there are some fractures and joints on the surface of the areas due to tectonic movement associated with opening the Red Sea and Gulf of Aden. The rainfalls, fractures, joints, earthquakes, gravity, vegetations, temperatures and human activities play a big role in the processes of rockfalls and landslides in this area. All those factors are considered as the basic causes and catalyzed factors for occurrence of rockfall in the studide area. In addition, the authors carried out laboratory test for many rock samples to get the physical properties of the rocks.