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为了进一步提升青藏高原地震监测能力,中国地震局在青海、西藏和新疆3个地区建设地震台站。为确保高质量产出地震数据,以青海地区新增16个地震台站为例,围绕观测数据的完整性和可靠性,基于数据连续率、台基噪声水平和事件波形记录质量,对地震观测数据质量进行评价,结果发现:青海地区新增地震台站观测环境较好,总体运行稳定,数据连续率较高,适合进行宽频带数字地震观测;地震台站空间分布更加均匀,青海省中西部地区理论地震监测能力从约MS 4.5提升到MS 2.0,地震监测能力提升。本项工作的开展,为我国青藏高原地震监测能力提升提供了业务化支撑。 相似文献
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朱元清 《地震地磁观测与研究》2002,23(2)
地震台阵是为监测微弱地震信号而发展起来的一种地震观测系统。特别是近 2 0年来 ,随着地震观测技术、电子技术、通讯技术和计算机技术的飞跃进步 ,地震台阵又有了更快更新的发展 ,在全球范围内逐步形成了多种台阵广泛分布的局面。当前 ,地震台阵已成为全球地震活动监测网的重要组成部分。地震台阵观测系统 ,采用独特的地震数据处理方法 ,将台阵内若干子台的数据汇聚在一起 ,以达到压低干扰背景 (如地面噪声 ) ,提高信噪比 ,突出地震信号 ,从而获得比单一地震台站更强 (数倍于单一地震台站 )的地震检测能力 ,是一种先进的地震观测技术。通过… 相似文献
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1 地震数据存储器的功能近年来,我国的数字地震观测技术和设备有了很大发展,特别是通过实施“八五”国家科技攻关项目,全面系统地研制出一批数字地震观测所需的仪器设备和软件,并正在“九五”项目中发挥重要作用。在实施的“九五”项目中,地震数据的记录和存储主要以实时传输记录和小容量的FRAM内存为主(庄灿涛等,1995),这样的记录存储方式对不一定必须实时分析数据的研究工作,例如,大数量子台的台阵观测,流动观测,勘址观测就显得既费用高又不方便,对于这类工作,实时传输记录并不是优选的记录和存储方式。从目前数字地震观测技术发展看,… 相似文献
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龚永俭 《地震地磁观测与研究》2012,33(3):235-239
地震观测数据的准确性和连续性,不仅取决于观测仪器、观测方法和观测技术水平,在很大程度上还依赖于良好的地震观测环境。客观、全面地对地震台站的观测环境进行调查评估,并建立地震观测环境监控体系,对于观测数据的质量控制、地震预报水平的提高和地震行政执法均具有重要意义。 相似文献
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地震台站的数据共享和安全访问是基于IPv4的地震观测网络系统急需解决的关键技术问题,由于IPv4的地址局限,缺乏安全认证和数据加密措施,现有的地震观测网络系统建立在私有IP地址的行业局域网,只能实现基于台网级的数据共享访问。下一代互联网IPv6协议取代IPv4是必然趋势,本研究以实现台站级数据访问为目标,构建在IPv6网络环境下地震观测网络系统的安全组网模型,同时针对现有观测系统的特点,探讨IPv4地震观测系统过渡到IPv6的系统模型,为下一步IPv6技术在地震行业的推广应用打下基础。 相似文献
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“十五”期间中国地震观测系统得到了迅速的发展, 中国地震局地球物理研究所于2007年底完成“中国数字地震观测网络”项目“国家数字测震台网数据备份中心”技术系统的建设.该数据备份中心可以准实时地接收并存储全国1000多个固定地震台站的信号,具备海量数据校验、数据格式转换、以用户定制方式截取地震事件波形数据和数据网络下载的功能.到目前为止,已累计为国内10多个科研单位开展的70多项研究提供了近70TB海量波形数据的服务,特别在快速开展的汶川特大地震震后相关研究中提供了重要的数据支撑和保障作用.本文介绍了“国家数字测震台网数据备份中心”技术系统建设、汶川特大地震数据服务快速响应、大地震快速响应波形数据自动截取系统建设,以及对地震学及相关科学研究的数据支持情况. 相似文献
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M. N. French R. L. Bras W. F. Krajewski 《Stochastic Environmental Research and Risk Assessment (SERRA)》1992,6(1):27-45
A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities. 相似文献
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Gtz Schroth Luciana Ferreira Da Silva Marc‐Andree Wolf Wenceslau Geraldes Teixeira Wolfgang Zech 《水文研究》1999,13(10):1423-1436
The partitioning of rain water into throughfall, stemflow and interception loss when passing through plant canopies depends on properties of the respective plant species, such as leaf area and branch angles. In heterogeneous vegetation, such as tropical forest or polycultural systems, the presence of different plant species may consequently result in a mosaic of situations with respect to quantity and quality of water inputs into the soil. As these processes influence not only the water availability for the plants, but also water infiltration and nutrient leaching, the understanding of plant effects on the repartitioning of rain water may help in the optimization of land use systems and management practices. We measured throughfall and stemflow in a perennial polyculture (multi‐strata agroforestry), monocultures of peach palm (Bactris gasipaes) for fruit and for palmito, a monoculture of cupuaçu (Theobroma grandiflorum), spontaneous fallow and primary forest during one year in central Amazonia, Brazil. The effect on rain water partitioning was measured separately for four useful tree species in the polyculture and for two tree species in the primary forest. Throughfall at two stem distances, and stemflow, differed significantly between tree species, resulting in pronounced spatial patterns of water input into the soil in the polyculture system. For two tree species, peach palm for fruit (Bactris gasipaes) and Brazil nut trees (Bertholletia excelsa), the water input into the soil near the stem was significantly higher than the open‐area rainfall. This could lead to increased nutrient leaching when fertilizer is applied close to the stem of these trees. In the primary forest, such spatial patterns could also be detected, with significantly higher water input near a palm (Oenocarpus bacaba) than near a dicotyledonous tree species (Eschweilera sp.). Interception losses were 6·4% in the polyculture, 13·9 and 12·3% in the peach palm monocultures for fruit and for palmito, respectively, 0·5% in the cupuaçu monoculture and 3·1% in the fallow. With more than 20% of the open‐area rainfall, the highest stemflow contributions to the water input into the soil were measured in the palm monocultures and in the fallow. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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M. A. Kahn 《洁净——土壤、空气、水》2000,28(2):95-101
Red tide, a recurrent phenomenon has become conspicuous in several Kashmir lake ecosystems since 1991. The responsible organism (Euglena pedunculata), a rare flagellate rediscovered in the Kashmir Himalaya (Khan 1993) caused first and unprecedented red tide outbreak, constituting a maximum of 96% of resident numerical phytoplankton density in Dal Lake. At present, conflicting hypotheses exist on the generation of causal assemblage(s) imparting redness to waters: Jeeji Bai (1991) linked its origin to acid precipitation – a fallout of burning oil‐fields during the Gulf War – whilst Khan (1993) holds local factor(s) responsible. Field/experimental studies support the latter contention that the influx of untreated sewage, in unison with warm temperatures, high levels of PhAR, iron and interruption to hydrological flow‐pattern together with absence/or reduction in grazing activity created conducive environmental milieu for red tide outbreak. Dal Lake “red tide” drifted the bloom‐inoculum to other waters, including Lake Wular, where additional ecological niches were carved out, threatening the aesthetic value and biological diversity of Kashmir lakes. Ecological monitoring indicates frequent seasonal red tide occurrence in Dal Lake (including summer‐autumn event of 1998) which testifies its unabated eutrophication status. Further studies are needed on ecological adaptability and biogeographic distribution of this rare and unique red tide‐causing flagellate. 相似文献