烈度计台站远程监控系统

烈度计台站在地震预警中具有重要作用，对烈度计台站的远程监控是保证观测数据稳定可靠的前提。针对现有监控系统无法对台站供电、网络、设备状态等信息进行智能监控的问题，设计烈度计台站远程监控系统，实现对台站供电、网络、I/O开关量、烈度计状态等信息的采集及远程控制等功能，并在天津烈度计台网进行部署，提高了故障排查及维护效率，保证了烈度计台站数据的连续率。     

地震台站标准化中地震计防震加固装置试验分析

本文根据地震观测台站标准化对地震计等专业设备开展防震加固的要求, 对地震传感器加装防震装置后开展振动台测试与台站观测数据一致性分析。 振动台测试结果表明在振动台面出现PGA大于103.2 cm·s^-2时, 地震计出现了明显位移现象, 因此, 建议地处场地烈度大于Ⅶ度区台站地震计须加装防震装置; 我们采用平方相干方式对台站观测数据进行一致性分析, 通过频域与时域对近震和远震记录进行对比, 发现加装防震装置与未加防震装置地震计系统一致性无明显差异。     

山西地震台网运维智能管理系统

采用JAVA、MySQL设计并开发了山西地震台网运维智能管理系统。该系统功能主要包括台站和设备的信息管理、运行状态监控、自动更新JOPENS系统的台站日志和仪器参数、实时监控并计算台站噪声并导出图表。基于该系统,可以有效提高地震台网台站的运维工作效率,使日常工作流程化。     

南京地震台网可视化运维平台的设计与应用

针对南京市无人值守台站运维存在的不足,设计了一种基于GIS和3D台站模型的地震台站可视化运维平台。与目前台站维护系统相比,实现了台站设备监控信息多方位、多表现形式的展示,能够实时自动诊断台站故障,有效提高了南京市地震台网的管理水平。     

智能地震台站试验性研究

通过安装在台站的软硬件设备和远程测控平台,智能地震台站综合智能监控系统可以对无人职守地震台站设备的工作状态和环境进行实时监控,并能够自动判定台站故障点及发出报警信息,实现异地操作台站电源及观测设备等.试点运行结果表明,该系统运行稳定可靠,可以对台站的观测设备进行有效地保护,并极大地提升了数字地震台网中心的工作效能.     

克拉玛依无人值守地震监测站远程网络监控系统的实现

为解决克拉玛依无人值守地震监测站点的设备维护及场地巡视等难题,在不改变台站现有网络环境的前提下,使用网络摄像机和配套的监控软件等设备,通过合理配置实现了无人值守地震监测站点的远程网络视频监控,并在红浅监测站进行了实际验证,效果比较满意。该系统的实现,提高了克拉玛依台对无人值守站点的管控能力,对其他台站也有一定的借鉴意义。     

永安无人值守地震台远程网络监控系统

针对永安无人值守地震台设备维护及安全巡视等问题,利用地震台现有网络搭建方式,使用网络摄像机及相应监控系统软件,通过合理配置,实现无人值守地震台远程网络视频监控。该系统的实现,提高了永安地震台管控无人值守台站的能力,对其他地震台有一定借鉴意义。     

江苏省部分井下地震计监测能力差异初探

江苏部分地震台站在"十五"项目改造过程中安装了大动态、宽频带的高性能地震计—CMG-3TB井下地震计。笔者选取了溧阳台、南通台和盐城台作为研究样本,对比了三个台的监测能力并对地震计的监测能力进行了分析。还从各台台基噪声、测震监测设备和地震计安装三个方面对台站监测能力差异的原因进行了分析。     

用标定方法检测地震计的异常状态

以浙江省测震台网部分台站地震计为研究对象,选取一定时间窗口对阶跃标定波形进行计算,得出地震计在该时段内的周期和阻尼变化情况。结合台网台站运行维护工作,经过统计分析,表明利用此方法能够在一定程度上反映出台站地震计运行的异常状态。     

地震台站智能运维保障系统开发

针对浙江省地震监测台站不断增加,地震台站设备运维流程无序化、纸质化的管理现状,设计台站智能运维保障系统,实现台站运维智能化监控管理。与传统台站运维相比,该系统不仅实现台站运维资料的数字化管理,还通过引入抢修工单形式,保障台站抢修顺利进行。     

SCIENCE CHINA Earth Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Distribution of throughfall and stemflow in multi‐strata agroforestry,perennial monoculture,fallow and primary forest in central Amazonia,Brazil

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.     

A Monte Carlo study of rainfall forecasting with a stochastic model

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.     

Anthropogenic Eutrophication and Red Tide Outbreak in Lacustrine Systems of the Kashmir Himalaya

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.