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利用2014—2018年4—6月福建省及周边地区实测降水量和ECMWF模式降水量预报产品资料,采用目标识别方法,设定降水量阈值α,选取合适的特征尺度D0和邻近度阈值β,分别识别实况降水场的主雨带和预报降水场的所有雨带,并选取匹配度阈值进行目标配对,确定与实况降水场主雨带最匹配的预报降水场主雨带。改进SAL空间检验方法,将模式主雨带预报误差用主雨带的强度（指降水极值和降水量阈值）、位置（指重心点位置）、形态（指主轴、次轴特征长度和轴向角度）属性的预报误差来表示。结果表明：预报主雨带的降水极值比实况小,但降水量阈值比实况大;预报主雨带的重心点位置与实况相比,4月偏西、偏南,5月、6月偏西、偏北,预报主雨带的重心位置多是滞后于实况,位于实况主雨带的上游;主雨带大都呈窄长带状分布,预报主雨带比实况更窄长,且预报时效越长越窄长。预报主雨带轴向角度比实况略小,总体均呈东偏北走向。以上分析结果可为模式主雨带预报误差的订正提供依据。 相似文献
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浅谈测井方法在工程勘察中的应用 总被引：1，自引：0，他引：1
地球物理测井应用于工程勘察中,能够较好地解决用钻探不易解决的问题,如有效判别薄夹层、寻找井旁隐伏断裂破碎带、判断孔内土层稳定性以及测定土层的速度等。其中自然伽马测井曲线在判定含砾粘土夹层及软弱薄粘土夹层等方面具有较高的准确性;声波、井径、自然γ、视电阻率等测井方法可有效查找井旁隐伏断裂破碎带,特别是声波测井曲线异常更为明显;另外跨孔实测剪切波速还可进行地基土加固效果检验。 相似文献
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Based on ERA5 reanalysis data and multi-source observations, including polarimetric radar and automatic weather stations, this study analyzes the formation mechanism and microphysical characteristics of a warm-sector heavy rainfall event caused by a convective system with multiple-rain-bands organizational mode over the western coast of south China. In the early stage, under the influence of coastal convergence and topography, convection was triggered in the coastal mountainous areas and moved n... 相似文献
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台风暴雨作为台风引起的最主要灾害之一,一直被人们关注。台风常被认为是对称结构,但从实际状况来看台风的非对称性非常明显,所以有必要研究斜压性涡度在台风中的表现。在高分辨率数值模拟的基础上,通过引入斜压涡度的概念,分析和总结了斜压涡度在2009年台风“莫拉克”暴雨过程中的表现。通过模拟与分析得到如下的结果:斜压涡度和MPV对比,可以看出在登陆前和登陆后,明显低层斜压涡度有更强的异常信号,围绕台风内核呈现正负正的位相特点;从沿着台风中心时间剖面可以看出,登陆前斜压涡度低层多为负正负的位相,并且随着时间的推移,斜压涡度有从大气的高层向台风的移动中心传递的趋势,即在台风即将到达时原先的正涡度被替换为负涡度,所以对其移动有一定指示意义;在台风“莫拉克”过台湾岛时,其斜压涡度表现为负涡度消失,在山地附近有正涡度生成,完成过岛,台风中心被替换;斜压涡度的异常值主要位于大气的低层时,一般会产生较强的降水。 相似文献
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地理信息系统已逐渐向智能移动端延伸,桌面端使用的数据类型并不适用于移动端,切片数据和离线矢量数据可以用在移动端供用户观看、查询与分析。因此,本文设计了面向移动GIS的数据处理工具来快速批量生产移动端使用的数据。 相似文献
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During the April-June raining season,warm-sector heavy rainfall(WR) and frontal heavy rainfall(FR) often occur in the south of China,causing natural disasters.In this study,the microphysical characteristics of WR and FR events from 2016 to 2022 are analyzed by using 2-dimensional video disdrometer(2DVD) data in the south of China.The microphysical characteristics of WR and FR events are quite different.Compared with FR events,WR events have higher concentration of D<5.3 mm(especially D <1 ... 相似文献
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Warm-sector heavy rainfall (WR), shear-line heavy rainfall (SR), and frontal heavy rainfall (FR) are three types of rainfall that frequently occur during the pre-summer rainy season in south China. In this research, we investigated the differences in microphysical characteristics of heavy rainfall events during the period of 10-15 May 2022 based on the combined observations from 11 S-band polarimetric radars in south China. The conclusions are as follows: (1) WR has the highest radar echo top height, the strongest radar echo at all altitudes, the highest lightning density, and the most active ice-phase process, which suggests that the convection is the most vigorous in the WR, moderate in the FR, and the weakest in the SR. (2) Three types of rainfall are all marine-type precipitation, the massweighted mean diameter (Dm, mm) and the intercept parameter (Nw, mm-1 m-3 ) of the raindrops in the WR are the largest. (3) The WR possesses the highest proportion of graupel compared with the FR and SR, and stronger updrafts and more abundant water vapor supply may lead to larger raindrops during the melting and collision-coalescence processes. (4) Over all the heights, liquid and ice water content in the WR are higher than those in the SR and FR, the ratio of ice to liquid water content in the WR is as high as 27% when ZH exceeds 50 dBZ, definitely higher than that in the SR and FR, indicating that the active ice-phase process existing in the WR is conducive to the formation of heavy rainfall. 相似文献