青藏铁路沿线闪电活动的时空分布特征   总被引：6，自引：4，他引：2  

张廷龙  郄秀书  袁铁  熊亚军  张彤 《高原气象》2004,23(5):673-677

利用搭载于卫星上的闪电探测仪所获取的8年闪电资料,对青藏铁路沿线闪电活动的时空分布进行了研究。结果表明,青藏铁路沿线的闪电活动呈现出明显的季节变化和日变化。青藏铁路沿线的闪电活动主要发生在4～9月,其中以5～7月最为频繁,到10月份迅速消亡,而且闪电分布在南北向上变化较明显;青藏铁路沿线闪电活动在12：00～16：00(地方时,下同)最易发生。日闪电密度峰值出现在15：00左右。闪电密度的空间分布以那曲为最大,分别向南、北减小。另外,2003年夏季的地面观测资料还表明,那曲地区在傍晚还有一闪电活动峰值。  相似文献   

The Barranco de Arás flood of 7 August 1996 (Biescas, Central Pyrenees, Spain)     

Jordi Alcoverro  Jordi Corominas  Manuel Gmez 《Engineering Geology》1999,51(4):101-255

Geomorphic effects observed in the Barranco (creek) de Arás basin are used to characterize the flood. Sediment features allow to qualify the flood as essentially a water flow. Using the critical section method, the peak flood discharge is estimated to be between 400 and 600 m³ s⁻¹. Similar results were obtained using a paleohydraulic formula based on the size of the largest mobilized clasts. Using the rational method with available rainfall data, the discharge for a recurrence interval of 500 years is estimated to be between 150 and 200 m³ s⁻¹. These results agree with predictions obtained using curves of peak discharge versus basin area based on regional data. Several trenches dug on the fan showed that the size of boulders mobilized by the event is larger that those left by previous floods at the same place. When the estimated peak flood discharge is related to the basin area, values between 20 and 30 m³ s⁻¹ km⁻² are obtained, demonstrating that the Barranco de Arás flood was most unusual.  相似文献   

人工地震测深和天然地震流动观测兼用的轻便数字地震仪系统   总被引：8，自引：1，他引：7  

原秦喜  孙鸿 《中国地震》1999,15(2):159-166

本文介绍一种新的轻便数字地震仪ＤＡＳ－１。其设计特点是：双微处理器硬件结构;过采样ＡＤ转换技术的运用;线性相位和最小相位ＦＩＲ数字滤波的运用;大容量ＣＭＯＳ快闪存贮器作数据存储介质;ＧＰＳ授时和内部高精度数字钟相结合的时间服务系统;采集器功耗低于０．６５Ｗ。该仪器有３个信号输入通道,０￣４０Ｈｚ的带宽和１６位字长。它可方便地用于人工地震测深及天然地震流动观测。  相似文献   

Evolution of a debris-rock slide causing a natural dam: the flash flood of Río Santa Cruz,Province of San Juan—November 12, 2005     

Laura P. Perucca  M. Yanina Esper Angillieri 《Natural Hazards》2009,50(2):305-320

Between 2001 and 2005, a large debris rock slide occurred on the western slope of the Cordillera de Santa Cruz in the southeast Andean corner of the Province of San Juan (31°40′ S–70°16′ W). The landslide material accumulated in a downstream gorge as a natural dam of the Santa Cruz river, forming a large-volume lake. In November 2005, probably as a result of the increasing pressure of the water volume, this natural dam breached off with a violent and unexpected flash flood. In addition to life-threatening instances lived by some people downstream, this flood caused great economic loss to main localities of the Department of Calingasta, as well as considerable damage to one of the most relevant projects of the Province, the Caracoles Hydropower Project dam on the San Juan river. Considering the high costs of any physical remediation for a natural dam located in this high, remote, and inaccessible mountain area with no reliable road access, the main protective measures left to be pondered are the installation of a flash-flood early-warning system connected to downstream localities, along with a program of hydrological monitoring at the dam-forming area and annual satellital monitoring to verify the evolution of accumulated mass movements.  相似文献   

青藏高原闪电活动的时空分布特征   总被引：11，自引：1，他引：10       下载免费PDF全文

郄秀书  袁铁  谢毅然  马耀明 《地球物理学报》2004,47(6):997-1002

利用卫星上携带的闪电探测仪所获取的8年闪电资料(1995～2002)对青藏高原闪电活动的时空分布以及高原季风期间闪电活动对地面热力学特征的响应进行了研究.结果表明,高原上的平均闪电密度为3fl·a-1·km-2,并在高原中部（32°N, 88°E）出现闪电密度峰值5.1fl·a-1·km-2.闪电活动主要发生在6～8月,并在6月下旬至7月中旬最为活跃.大部分地区的闪电活动日变化峰值出现在14:00～16:00 LT,在中西部的显著高山地区早于这一时刻,而在显著低海拔的塔里木和柴达木盆地晚于这一时刻.夏季季风期间高原上的闪电活动明显依赖于地表的热力学特征,并与地表鲍恩比和感热通量呈明显的线性正相关,相关系数分别为0.7和0.6,鲍恩比有可能作为调整闪电产生效率的量度.  相似文献   

NaCl 溶液闪蒸效率特性数值研究     

王为术  闫广  李帅帅 《海洋科学》2012,36(10):68-72

盐水闪蒸技术广泛应用于海水淡化及海洋温差能发电,含盐质量分数、给盐液温度和闪蒸压力对闪蒸汽化率和热效率有很大影响。在质量分数为3.5%～20%、给盐液温度为30～95℃和闪蒸压力为1～30 kPa的范围内,对NaCl溶液闪蒸汽化率和热效率等闪蒸效率特性进行了定量计算研究,研究得到了盐水含盐质量分数、给盐液温度和闪蒸压力对闪蒸汽化率以及热效率影响的规律。结果表明,降低含盐质量分数,提高给盐液温度,降低闪蒸压力可提高闪蒸汽化率与热效率;含盐质量分数越高,造成的热损失越大,而提高给盐液温度会增大热损失。  相似文献   

Modest Maps的Flash网络地图发布与应用     

李木梓  徐柱 《测绘科学》2011,36(1):201-203

本文分析了Adobe Flash技术在网络地图发布前端技术上的优势和应用现状,选择开源Flash地图组件Modest Maps作为开发工具,在其上添加了一些组件模块,以"5.12地震信息显示"为示例,实现了基于Modest Maps的Falsh网络地图发布和简单的空间分析.  相似文献   

Flash flood sediment transport in a steep sand-bed ephemeral stream     

Paolo BILLI 《国际泥沙研究》2011,26(2):193-209

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基于Flash+ASP构建地质灾害隐患WebGIS初探          下载免费PDF全文

谢湛明  杨广斌 《贵州地质》2015,32(2):137-141

基于Flash+ASP技术方案,以黄平县为研究区,进行了广泛地野外勘测和室内各类空间、属性数据的整编,获取了黄平县域内地质灾害隐患点的时空信息,并结合数据库管理系统,从系统设计、空间数据库建立和系统功能设计等方面构建了黄平县地质灾害隐患WebGIS。该系统实现了地质灾害隐患点实时动态监测与灾情预测分析的网络化管理,为地质灾害防治工作提供有效辅助决策。  相似文献   

Mediterranean flash flood transfer through karstic area   总被引：1，自引：0，他引：1  

Vincent Bailly-Comte  Hervé Jourde  Axel Roesch  Séverin Pistre 《Environmental Geology》2008,54(3):605-614

Karstic aquifers influence flash floods propagation in Mediterranean countries. Near Montpellier, Southern France, discharge data are recorded on the Coulazou River upstream and downstream of the Aumelas Causse. Two gauging stations are used to describe the hydrodynamics of this binary karstic system. The first station characterizes the non-karstic catchment area. The second one is representative of the karstic part of the watershed. Records since April 2004 are used to understand how the river interacts with a karstic aquifer. Hydrograph analysis of three flash flood events is described. Corresponding discharge time series recorded at the two gauging stations are used to describe the modification of the hydrographs by auto- and crosscorrelations analyses. Finally, linear system analyses are used to provide the transfer functions of this binary karstic system according to the three flood events characteristics (initial conditions, volume, spatial distribution of rainfall, etc.). Theses functions summarize the hydrodynamic behaviour of the system: their shapes are indicative of the dynamics of the storage, the release and the contribution to surface waters.

Vincent Bailly-ComteEmail:

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