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A quantitative scheme is put forward in our work of forecasting the storm rainfall of typhoons for specific sites.Using the initial parameters,weather situations and physical quantities as well as numerical weather prediction products,the scheme constructs multivariate,objective and similarity criteria for environmental factors for the time between the current and forthcoming moment within the domain of forecast.Through defining a non-linear similarity index,this work presents a comprehensive assessment of the similarity between historical samples of typhoons and those being forecast in terms of continuous dynamic states under the multivariate criteria in order to identify similar samples.The historical rainfall records of the similar samples are used to run weighted summarization of the similarity index to determine site-specific and quantitative forecasts of future typhoon rainfall.Samples resembling the typhoon being forecast are selected by defining a non-linear similarity index composed of multiple criteria.Trial tests have demonstrated that this scheme has positive prediction skill. 相似文献
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广州飞龙世界游乐城关闭的原因与启示 总被引:2,自引:1,他引:2
广州番禺“飞龙世界游乐城”是广州市首座主题公园,在1995年元月开业前后,各种新闻媒体普作过大量宣传,实际景点建设、经营运作声势浩大,一度名扬粤港澳,但在营业4年后,却被广州番禺法院封闭停业了。文中从旅游科学和旅游业实践的角度,通过实地调查研究,认为其失败的主要原因是:(1)景点建设背离主题,贪大求全;(2)市场定位盲目乐观,大量设施空置;(3)经营管理上未能扬长避短,蛇系列产品未能适销对路进入园国际市场;(4)投资机制上靠贷款建设,经营严重亏损,并从中得到几点启迪,供今后创办主题公园借鉴。 相似文献
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一次强对流风暴含水量的雷达反演和数值模拟结果的对比分析 总被引:2,自引:9,他引:2
利用多普勒天气雷达探测的反射率因子Z与含水量M的Z-M经验关系式,反演含水量,并构建等高平面位置显示CAPPI和垂直剖面VCS两种显示方式。计算域定为以雷达站为中心的,水平边长为150 km,垂直高度为30 km的长方体箱区,分辨率是1 km×1 km×1 km。同时应用中国科学院大气物理研究所建立的完全弹性三维雹云数值模式(IAP-CSM3D),以2004年4月23日发生在湖南省境内的一次强对流风暴过程为例,模拟该风暴云体的含水量分布。雷达反演含水量和数值模拟结果的对比分析表明,不论在风暴的发展阶段还是在强盛阶段,反演得到的含水量等值线分布和模式输出总体相似,风暴中心的强度和高度位置吻合得很好,较好地反映了该风暴云的结构,反演效果较好。 相似文献
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广东大峡谷河床壶穴形态的形成与发育 总被引:1,自引:0,他引:1
The goal of this study is to provide information on the process of pothole growth on a gorge streambed. Pothole geometries
were measured in a reach of the Dabu river bed at the head of a gorge more than 200 m deeply incising into a 650–750 m high
planation surface formed in the middle Miocene in northern Guangdong, China. Geometric and derivative data of the potholes
obtained from fieldwork were interpreted using standard statistical methodologies. Our study shows that the formation and
development of a stream pothole were only related to local conditions of a stream reach where the pothole occurs; the weaknesses,
which are usually intersect fractures, typically interconnected vertical joints, or triangular pits generated by hitting of
rock fragments during floods, initiate the pothole development on a streambed; the geometrical dimensions of the potholes
are controlled by tectonic joints developed in bedrock of the stream reach; the radius and the depth of potholes are strongly
(log) positive correlated; the pothole shapes and the flow patterns are inconstant during pothole growth; a pothole can be
formed within a short period, but cannot be fully developed and maintained for a long time in a strong incision streambed.
The finding in our study can improve the understanding of Quaternary environment in Guangdong.
Foundation: National Natural Science Foundation of China, No.40871020; Guangdong Natural Science Foundation, No.7005836
Author: Wang Wei (1956–), Ph.D and Professor, specialized in Quaternary geology and geomorphology. 相似文献
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降水天气现象自动化观测是实现地面自动化观测的重要内容之一,为了克服人工观测的主观性,提高降水现象观测资料的完整性和实时性,中国气象局气象探测中心遴选了6家厂家18台雨滴谱降水现象仪分别在北京站和长沙站进行为期3个月的降水天气现象仪对比试验。主要从试验的选址、原理、标准、方法及参试设备的试验数据进行分析,结果表明:参试设备对雨强大于0.1mm/h的平均捕获率不低于97%,对雨强小于0.1mm/h的平均捕获率不低于84%;各参试设备吻合率随着降水强度的逐渐增大,经历了一个先升后降的过程;参试设备对冰雹现象观测结果较为理想,所有参试设备对冰雹现象平均错报率均低于0.5%,而对毛毛雨和未知现象的观测仍需改进;参试设备的漏报率与雨强大小呈负相关,雨强越小,漏报率越高。 相似文献
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VIL中心区自动识别、跟踪和临近预报 总被引:18,自引:0,他引:18
利用多普勒天气雷达体扫数据资料计算垂直累积液态含水量(VIL),用逐步增大初始阈值法识别VIL中心区;利用动态预测面积比法、分类跟踪法以及中心区面积守恒原则相结合的方法对中心区进行跟踪;运用线性最小二乘法、线性集成法和线性外推法对中心区的重心位置进行临近预报。实例结果表明:所使用的方法能很好地识别、跟踪和预报VIL中心区。 相似文献