点源两层大地三维地电模型视电阻率边界元解   总被引：2，自引：1，他引：2  

毛先进  钱家栋 《地震工程学报》1994,16(1):1-11

本文用两层均匀大地人工点源作用下的空间电位分布作为基本解，导出了下伏基岩中陷含三维地质体情况下，关于电位的边界积分方程组，用边界单元法解积分方程求得地表电位，从而求得了一定装置下的视电阻率。本文方法的独特优点是积分只须在异常体边界面上进行了测线可以沿任意方向。用联剖法计算了均匀半空间下含球形异常体的ρｓ曲线，所得结果与其他学者用解析方法所求得的结果一致。用中间梯度法计算下层基岩中含有一长方体，测线  相似文献   

长江三峡狮子口地区重力滑动构造研究     

宋利好  杨森楠  任建业  吴树仁 《吉林大学学报(地球科学版)》1995,(2)

长江三峡工程坝址西南约１０ｋｍ的狮子口地区，发育一个长约８ｋｍ、宽约３ｋｍ的重力滑动构造系统。它由下伏系统、滑动系统和前缘推挤带构成，是一个典型的多层次滑褶型重力滑动构造。它形成时的温、压条件为１３０．５～１９３．７℃和１８０～２３０ＭＰａ；ｌ；形成深度约５～１０ｋｍ；总体岩层收缩量３２．２％；总滑移距离１０６０ｍ；活动时间上限１２７．６５士３８．２９万年。它是燕山运动期间南北向挤压体制下，在黄陵背斜东、西两侧应力屏蔽区内派生的近东西向拉伸构造应力场的产物。  相似文献   

新疆钻孔应变异常特征及其与地震三要素关系研究     

蒋靖祥  许风柱  闫均科 《内陆地震》1995,(2)

将新疆高精度钻孔应变仪１０年来观测到的应变异常划分为趋势异常、短期异常、临震异常三类，并对这三种异常的特征进行了分析总结．认为，地震三要素与应变异常参量关系密切，震级与异常量级、震中距有着确定性关系。  相似文献   

TWO DIMENSIONAL FINITE ELEMENT-BOUNDARY ELEMENT COUPLING MODEL OF MAGNETOTELLURIC SOUNDING          下载免费PDF全文

Luo Huan-yen  Zhang Shu-xia 《地震地质》1987,9(2):9

This paper describes how to apply the boundary element method to solve 2-D magneto-telluric sounding problem and then couple the BEM with finite element method to deal with inhomogeneous geological structure and its relation to regional stress regime. The BEM is able to calculate precisely the derivative of field variables. Such a new approach can more flexibly than others set up the upper boundary condition of the air region. Two practical examples are given. One is the study of topographical effect on the MT fields using boundary element method. There is an inverse relationship between the change of apparent resistivity and the topographical variation. The other is a coupled model of a basin in Nei Monngol Autonomous Region. A lower resistivity zone must exist in the crust and should be thicker below the central portion of the basin. This seems to agree with the regional stress regime changed from extension in Mesozoic to compression in Cenozoic  相似文献   

三维地理信息数据在移动通信网络规划和优化系统中的应用     

滕艳敏 《中国地名》2007,(4)

随着移动通信的迅猛发展,网络规模不断扩大,借助数字地图,尤其是三维地理信息数据进行网络规划和优化已变得越来越重要。本文主要介绍三维地理信息数据在建立移动通信网络规划和优化系统中的应用。  相似文献   

长江三峡库区云阳-巫山段斜坡坡度对滑坡的贡献率   总被引：4，自引：0，他引：4  

乔建平  吴彩燕  田宏岭 《山地学报》2007,25(2):207-211

三峡库区滑坡发育与多种因素相关,在它的内部因子中除了地层、斜坡高差和坡向等重要因素外,斜坡的坡度是一个非常重要的条件。为了研究坡度与滑坡发育的关系,借助于GIS技术,利用贡献率法重点研究了三峡库区斜坡坡度对滑坡发育的影响,并且定量地给出了二者的相关关系,即坡度对滑坡发育的贡献。该方法是将坡度划分为若干区间,分析每一区间对滑坡发育所起到的贡献作用,并定量评价了其贡献率的大小。所得研究结果与实际情况较吻合,为库区的滑坡防治规划提供了依据。  相似文献   

Prediction of surface horizontal displacements, and gravity and tilt changes caused by filling the Three Gorges Reservoir   总被引：11，自引：0，他引：11  

H. Wang  H. T. Hsu  Y. Z. Zhu 《Journal of Geodesy》2002,76(2):105-114

 Horizontal displacements, and gravity and tilt changes induced by filling the Three Gorges Reservoir are modeled using elastic loading Green functions. When the water surface reaches its highest level, the effects become maximum on the reservoir banks. The longitudinal and latitudinal components of the horizontal displacements reach −8.2 and 7.7 mm respectively, gravity is increased by up to 3.4 mGal, and the prime vertical and meridian components of the tilt changes are −7.8 and −17.5 arcseconds respectively. Accordingly, the filling of the reservoir will influence values observed from global positioning system (GPS), gravimetry and tilt measurements in the area. The results given can be used to provide important corrections for extracting earthquake-related signals from observed data. Received: 19 January 2001 / Accepted: 3 September 2001  相似文献   

空间信息可视化的现状与趋势   总被引：10，自引：0，他引：10  

刘纪平  常燕卿等 《测绘学院学报》2002,19(3):207-210

对空间信息可视化的现状进行了较为细致的总结，分析了目前空间信息可视化存在的问题。在此基础上，讨论了空间信息可视化的完整概念，提出了空间信息可视化位置特征、交互性、多维性和可视化多样性的本质特征，概括了数据组织与调度、静态可视化、过程模拟与探索性分析等空间信息可视化基本过程。最后，提出未来空间信息可视化主要关键技术。  相似文献   

Geopositioning Accuracy of Ikonos Imagery: Indications from Two Dimensional Transformations   总被引：1，自引：0，他引：1  

Harry B. Hanley  & Clive S. Fraser 《The Photogrammetric Record》2001,17(98):317-329

Earth observation satellites with 1m resolution, such as Space Imaging's Ikonos system, offer the photogrammetric and remote sensing communities a significant new means for geospatial information collection. These satellites possess the potential for pixel-level geopositioning precision and promise timely, highly automated generation of two dimensional (2D) and three dimensional (3D) spatial information products. This paper concentrates on the pursuit of optimal accuracy and considers an essential first step in the evaluation of the Ikonos imaging system, namely the metric integrity of the sensor system. In the absence of sensor calibration information (the camera model), an empirical evaluation approach has been adopted. This involves an assessment of 2D transformations between image and planar object space. It is shown that based on results obtained in the Melbourne Ikonos Testfield, 2D geopositioning to 0.5 m accuracy is possible from the base-level "Geo"product when a modest amount of good quality ground control is available and sub-pixel image mensuration is achieved. These findings are applicable to both near-nadir imagery and oblique stereo images. Moreover, the results obtained suggest that there are no significant geometric perturbations in the sensor system and initial image processing, which augurs well for the successful application of non-collinearity based 3D orientation and triangulation models for Ikonos imagery.  相似文献   

南海及邻区地壳上地幔三维S波速度结构的面波波形反演>.   总被引：13，自引：3，他引：13       下载免费PDF全文

曹小林  朱介寿  赵连锋  曹家敏  洪学海 《地震学报》2001,23(2):113-124

对南海及邻区中国数字地震台网４个台站接收到的328条长周期地震记录的面波波形进行分块波形反演．分块波形反演把大尺度的优化问题转化为小尺度的优化问题，采用非线性优化方法求解，从而得到南海及邻区22网格划分、从地表深至430ｋｍ 的地壳上地幔三维S波速度结构，并用检验板法进行了分辨率分析．结果表明，海域、岛弧和大陆在速度分布、岩石圈和软流圈存在明显的结构差异．   相似文献