曲面搜索法推求暴雨强度公式参数

目的为解决暴雨强度公式参数在传统推求方法中所存在的非线性函数拟合的问题．方法应用黄金分割法将参数b和n的值固定，即将非线性函数进行线性化，并在由这两个参数所确定的曲面上，通过计算机的特性来搜索参数A1和C的最优值．结果通过对线性函数的拟合，可以依次得到4个参数的值，近而推得暴雨强度公式．结论经过对多个城市的暴雨强度公式推求与比较，曲面搜索法能够快速、精确地得出计算结果．有效地解决了传统推求方法存在的诸多弊端，计算误差远远小于国家规范要求．     

Experimental and discrete element numerical analysis of side slope instability induced by fissure water underlying impervious bed

1 Introduction The in situ observations and analysis on the landslide events indicate that water is one of the key factors which induce landslide of the mountain mass[1―8]. The mechanism offissure water inducing landslide can be generalized into three aspects: (1) the softening influence of water weakens the strength of materials on the slip surface[9―11]; (2) the cleft water pressure towards the slide slope free face increases sliding force[12―15]; (3) water pressure on the slip surface lo…     

Numerical analysis of rainfall infiltration in the slope with a fracture

1 Introduction It has been widely accepted that the rainfall infiltration through fractures is one of the most probable factors for slope failure. Recent studies have focused on the relationships between rainfall and slope failure, but the mechanisms of rainfall-induced slope failures have not been fully understood. As a result, many experiments and theoretical studies have been carried out to simulate the infiltration in the fractured soil[1—3]. Aimed at the infiltration in unsaturated rock …     

森林林冠对降雨量截留的实验分析

以实测资料为基础，分析了林冠对降雨量的截留量。     

JJS1型翻斗雨量传感器校准仪

叙述了JJS1型翻斗雨量传感器校准仪的研制、开发及解决的主要技术问题，找出了校准过程中的误差来源，分析并给出了现场校准和测试的可行性及理论依据。     

SL2-1型雨量传感器测量误差调整方法探讨

SL2—1型雨量传感器是—种在借鉴国外先进技术的基础上研发出的一种新型单翻斗雨量传感器，它以结构布局合理、科学，测量准确度高而倍受广大用户的推崇。我国气象装备部门研发的单雨量自动观测站，有相当一部分采用该雨量传感器作为测量降雨量的基本传感器。为保证全国范围内所有雨量自动观测站所观测到的雨量准确、可靠，以及其观测数据具有可比性，定期开展雨量传感器的检定与维护，将雨量观测值的误差控制在允许范围内，是气象计量保障中的一项非常重要的工作。本文从单翻斗雨量传感器的结构原理入手，重点介绍传感器的超差调整方法和日常维护，作为实际观测和检定时为参考。     

基于ECMWF和WRF的嘉陵江流域面雨量预报精度评估

将降雨数值预报产品运用到水文预报中已经逐渐成为提高洪水作业预报的预见期的重要手段。为充分了解ECMWF(European Centre for Medium Range Weather Forecasts)和WRF(Weather Research and Forecasting model)2种数值天气预报产品对嘉陵江研究区面雨量预报的预报精度和误差分布,且为增强洪水预报精度的稳健性提供科学支持,采用TS评分、空报率、漏报率、正确率等指标,对嘉陵江地区7个气象分区内的2016年汛期面雨量预报结果进行了检验,分析了不同分区内各检验指标与预报时效的关系。结果表明:ECMWF数值预报产品和WRF数值预报产品均可用于该地区晴雨预报,且2种产品的预报精度随降水等级的增大呈增大趋势,随预报时效的增加呈减小趋势。综合而言,ECMWF数值预报产品对嘉陵江研究区的预报效果更好。     

Climate Change and Future Long-Term Trends of Rainfall at North-East of Iraq

Iraq is facing water shortage problem despite the presence of the Tigris and Euphrates Rivers. In this research, long rainfall trends up to the year 2099 were studied in Sulaimani city northeast Iraq to give an idea about future prospects. The medium high （A2） and medium low B2 scenarios have been used for purpose of this study as they are more likely than others scenarios, that beside the fact that no climate modeling canter has performed GCM （global climate model） simulations for more than a few emissions scenarios （HadCM3 has only these two scenarios） otherwise pattern scaling can be used for generating different scenarios which entail a huge uncertainty. The results indicate that the average annual rainfall shows a significant downward trend for both A2 and B2 scenarios. In addition, winter projects increase/decrease in the daily rainfall statistics of wet days, the spring season show very slight drop and no change for both scenarios. However, both summer and autumn shows a significant reduction in maximum rainfall value especially in 2080s while the other statistics remain nearly the same. The extremes events are to decrease slightly in 2080s with highest decrease associated with A2 scenario. This is due to the fact that rainfall under scenario A2 is more significant than under scenario B2. The return period of a certain rainfall will increase in the future when a present storm of 20 year could occur once every 43 year in the 2080s. An increase in the frequency of extreme rainfall depends on several factors such as the return period, season of the year, the period considered as well as the emission scenario used.     

基于摄像视频分析的降雨量测量方法

提出一种新颖的基于视频的降雨量测量方法。首先 根据雨图亮度变化特征检测雨滴;其次,为解决雨滴离摄像机距离信息未知情况下的雨滴尺 寸估计问题,在雨滴成像光度模型中融入散聚焦因素, 构建了基于亮度差和色彩张量响应特征的散聚焦雨滴判别方法;然后,根据透视成像关系计 算聚焦雨滴的尺寸并根据气象学 雨滴谱的定义来构建观测雨滴谱;最后,为抑制观测雨滴谱中的噪声,采用气象学Gamma模 型拟合观测雨滴谱,并由模型参 数计算降雨量。在不同程度的降雨环境下实验检验算法,并与雨量计记 录数据对比,测量结果较为一致。     

Proposal of a semi-probabilistic approach for storage facility design

Storage facilities are key devices in mitigating the urban drainage impact on receiving water bodies, but their design is still affected by high uncertainty. The analytical-probabilistic approach has recently raised interest, because the facility performances are directly related to probability. Starting from statistically independent storm events, distributions of the meteorological variables must be fitted. Rainfall series, recorded in three Italian raingauges, were examined for appraising two main concerns: the choice of proper probability distributions for rainfall volume and the sample sensitivity with respect to the analysis criterion. The analytical derivation of the model is then finally discussed.