基于地图空间数据的空间信息多级网格生成方法

简要介绍了空间信息多级网格的核心思想以及网格编码系统,利用Visual Basic开发工具和美国ESRI公司的MapObjects控件,通过空间点坐标、基本网格行列号、网格级别和编码间的转换关系,实现了在地图空间数据基础上生成多级网格的方法.     

基于3D GIS的城市空间规划分析方法研究

分析了福州三山视线控制线规划,采用了基础空间数据和ArcGIS 9.0平台,实现了快速建立数字高程模型与建筑物三维框架模型.     

SHRIMP U-Pb Zircon Age of the Ka''''erjiao Intrusion in the Sawur Region in West Junggar,Xinjiang

Acid intrusions are widespread in the Sawur region, Xinjiang. The Ka'erjiao intrusion is mainly composed of albite granite porphyry, K-feldspar granite porphyry, ivernite and granite porphyry. Being a transitional product between magma intrusion and eruption in the Sawur region, the Ka'erjiao intrusion was formed at the telophase of the late Carboniferous to the begining of early Permian as determined by the SHRIMP U-Pb zircon dating, with an age of 302.6±7.6 Ma (1σ). The intrusion consists of alkali-enriched rock, whose REE distribution patterns are of the LREE enrichment type, theδEu value is low and Nd, Sr, Pb isotopes reflect its mantle source characteristics. Theδ18O value of intrusion is low as a result of isotope exchange with meteoric water. The geochemical characteristics show that it was formed in a post-collisional tectonic setting. Taking combined considerations of current studies of A-type granites and Permian volcanic rocks, we think that in the telophase of the late Carboniferous to the beginning of the early Permian, the Sawur region was within the extension or compressional to extensional period of a post-collisional stage. The Ka'erjiao intrusion from mantle sources can confirm the vertical continental crust growth in the late Paleozoic. The Sawur region in west Junggar is consistent with east Junggar in post-collisional tectonic evolution process.     

广西"十五"数字测震台网信道建设与系统集成

通过实施广西"十五"数字测震台网建设项目,在保证地震速报能力的前提下,根据广西区域数字测震台的布局,合理选择台站不同数据传输模式和台网集成方案,以取得系统的优良性价比.     

关于公皋井地下流体数字化观测资料应用的思考与探讨

本文对朝阳地震台公皋井地下流体数字化资料进行了详细的分析,对如何将这些观测资料应用于地震预报进行了探讨。     

地震数据采集器中△-∑AD转换器512kHz数据流的仿真

根据△-∑AD转换器原理，通过编程将给定的输入信号转换为1位串行△-∑数据流。用此数据流可以仿真地震数据采集器中的滤波抽样过程，检验设计构造的各级滤波参数能否满足地震观测的需要。为了证明该仿真程序的正确性，本文介绍了利用CS5376A公布的数字滤波参数对数据流进行滤波验证。     

逐步逼近曲化平方法研究

位场资料的常规处理解释方法是建立在平面数据理论之上的，然而实际的位场数据大多为曲面数据，若把曲面数据当成平面数据进行处理，必然导致很大的误差，因此有必要进行“曲化平”处理. 曲化平目前存在的主要问题是计算精度低、计算量大，因此，研究快速、精度高且适合大数据量处理的曲化平方法具有重要的价值. 本文在已有的泰勒级数曲化平方法基础上提出了逐步逼近技术和平均平面技术，使得曲面位场资料处理的精度得到了很大提高. 最后通过理论模型和实际资料的处理验证了该方法的应用效果.     

京津冀地区地下流体数字化观测数据完整率及其地震前兆监测有效性的调查与分析

在北京、天津、河北二市一省部分地区抽样调查了13口井水位、11口井水温、5口井气氡、2口井气汞、2口井氦气数字化观测现状,统计分析了其数据完整率及观测断记次数与数据缺失量;在调查观测数据断记及其原因的基础上,进一步统计分析了数据缺失的主要原因,分析了连续完整的数据系列在地震前兆监测中的有效性。研究结果表明,除了氦气之外,水位、水温、气氡与气汞4大主要测项的运行,总体上是正常的;但多数井多数测项存在断记与数据缺失的问题,其主要原因是仪器故障与运行不正常,其次是停电、通信线路故障与雷击,此外还存在原因不明的断记与缺数的问题;以井统计,约有1/2的水位与水温观测井可在地震中期与短临前兆中发挥作用,而气氡、气汞等化学量观测只在地震短临前兆监测中,约有一半的井有可能发挥一定效能。     

Analysis and modeling of the seasonal South China Sea temperature cycle using remote sensing

The present paper describes the analysis and modeling of the South China Sea (SCS) temperature cycle on a seasonal scale. It investigates the possibility to model this cycle in a consistent way while not taking into account tidal forcing and associated tidal mixing and exchange. This is motivated by the possibility to significantly increase the model’s computational efficiency when neglecting tides. The goal is to develop a flexible and efficient tool for seasonal scenario analysis and to generate transport boundary forcing for local models. Given the significant spatial extent of the SCS basin and the focus on seasonal time scales, synoptic remote sensing is an ideal tool in this analysis. Remote sensing is used to assess the seasonal temperature cycle to identify the relevant driving forces and is a valuable source of input data for modeling. Model simulations are performed using a three-dimensional baroclinic-reduced depth model, driven by monthly mean sea surface anomaly boundary forcing, monthly mean lateral temperature, and salinity forcing obtained from the World Ocean Atlas 2001 climatology, six hourly meteorological forcing from the European Center for Medium range Weather Forecasting ERA-40 dataset, and remotely sensed sea surface temperature (SST) data. A sensitivity analysis of model forcing and coefficients is performed. The model results are quantitatively assessed against climatological temperature profiles using a goodness-of-fit norm. In the deep regions, the model results are in good agreement with this validation data. In the shallow regions, discrepancies are found. To improve the agreement there, we apply a SST nudging method at the free water surface. This considerably improves the model’s vertical temperature representation in the shallow regions. Based on the model validation against climatological in situ and SST data, we conclude that the seasonal temperature cycle for the deep SCS basin can be represented to a good degree. For shallow regions, the absence of tidal mixing and exchange has a clear impact on the model’s temperature representation. This effect on the large-scale temperature cycle can be compensated to a good degree by SST nudging for diagnostic applications.     

Analysis of Fog Probability from a Combination of Satellite and Ground Observation Data

The Cloud Type product, developed by the Satellite Application Facility to support to nowcasting and very short-range forecasting (SAFNWC) of EUMETSAT and based on Météosat-8/SEVIRI, identifies cloud categories, and especially low and very low clouds which are first estimates of areas where fog is likely to occur. This cloud type is combined with precipitation information from radar data and with hourly diagnostic analyses of 2-metre relative humidity and 10-metre wind to elaborate an hourly analysis of fog probability. This analysis provides four levels of fog probability with a 3-kilometre horizontal resolution: No risk, low-level risk, medium-level risk and high-level risk. An evaluation of such fog probability analyses versus a one-year set of French hourly SYNOP reports shows encouraging results (potential of detection = 0.73 for low and medium and high-level risks), even if false alarm ratios remain high. Most of the non-detections occur at twilight and are due to satellite non-detections. Eventually, we show case studies that clearly illustrate the high potential of the method.