数字填图技术在区域地质调查中应用实例--以民和试点图幅为例

文章根据2002年中国地调局在青海省民和幅进行区域地质调查数字填图技术试点,结合实践,详细介绍了数字填图技术在区域地质调查中从野外到至内以最终阶段成果的PRB过程,证明了区域地质调查填图数字化是切实可行的。     

CODA Q estimates for Kumaun Himalaya

CodaQ (Q _c) estimates for the Kumaun Himalaya region have been obtained in high frequency range. Local earthquakes, recorded by a digital seismic network in the region, which fall in the epicentral distances range of 10 to 80 km and with a local magnitude range of 1.4 to 2.8, have been used. The coda waves of 30 sec window length, filtered at seven frequency bands centered at 1.5, 3, 6, 9, 12, 18 and 24Hz, have been analysed using the single backscattering model. The values ofQ _c estimates vary from 65 to 283 at 1.5 Hz to 2119 to 3279 at 24.0 Hz which showed thatQ _c is frequency dependent and its value increases as frequency increases. A frequency-dependentQ _c relationship,Q _c = (92 ± 4.73)f^(1.07±.023), is obtained for the region representing the average attenuation characteristics of seismic waves for Kumaun Himalaya region.     

Flooding in the Red River Basin – Lessons from Post Flood Activities

Flood of 1997 affected a large number of residents in the Red River Basin. Life disruption, economic damage, lengthy recovery process, physical and emotional trauma motivated a number of main initiatives to improve the level of preparedness in case of future floods. This review will focus on the involvement of the International Joint Commission (IJC). Personal experience is used in this review to emphasize a number of important lessons, of special relevance to Canadian portion of the basin, from the post flood activities. Level of preparedness for, and potential damage from future floods will benefit from focusing very serious effort on the improvement of the Canadian database, exchange of data with the U.S. and standardization of data collection, exchange and use. Tools for sustainable floodplain management are improving. However, the Red River Basin with its characteristics requires a special set of sophisticated tools that will enhance flood flow forecasting, planning of new flood control measures (structural and non-structural) and emergency operations of existing flood protection system. City of Winnipeg, being the largest population centre in the basin deserves a special attention. Additional protection of 670,000 people is required that will take into consideration temporal and spatial distribution of economic and social costs and benefits.     

基于GIS的数字地图的应用

文章概述了地理信息系统的特点，分析了基于GIS的数字地图的优势及主要作用，总结了目前数字地图的使用情况和应用效果，探讨了提高数字地图使用效益的有效途经。认为，保证数字地图信息的位置精度和现势性，实现数字地图信息资源共享，扩大地图应用领域和提高地图利用率，增强使用数字地图的先进手段，构造数字地图设计制作与应用的互动平台，开展互联网地图使用情况的调查研究是今后地图应用学研究的重点。     

构建"数字湖北"的建议

讨论了如何构建“数字湖北”。针对湖北省情，建议以湖北的江湖水系作为切入点，有步骤、分阶段地建成数字湖北。并对建立数字湖北江湖水系，提出了实施相关地理数据采集的具体建议。     

基于四象限光电池的激光准直仪

介绍了一种用激光光线作为基础，用四象限光电池作为探测器的激光准直仪，该仪器结构简单、稳定性好且成本低廉，其分辨力为０.01mm，作用距离可达40m。     

基于普通数码相机的核线相关方法

用普通数码相机获取数字影像具有一定的优势，但由于普通数码相机是一种非量测相机，其数据处理需要特殊方法，介绍了一种适合普通数码相机进行核线相关的方法，实验数据表明该方法是可行的。     

利用DJC数字测绘软件制作数字地形图

DJC数字测绘软件是综合性的测绘软件 ,在制作地图方面有很高的利用价值 ,能方便的进行地图数据的矢量化 ,减少劳动强度 ,同时也能方便的进行数据格式的转换 ,在地形图的生产中有着重要意义     

在数字城市构建中GPS测量技术方案的选择

选择完善的GPS测量技术方案对提高数字城市构建的效率 ,保证城市控制框架的高质量 ;有效地拓展数字城市技术发展空间将奠定很好的基础。笔者根据数字城市建设工作的实践提出了比较规范、优化的GPS测量技术方案     

建立数字城市、数字矿区和地理信息系统

阐述城市数字化 ,矿区数字化 ,地理信息系统以及它们之间的关系 ,讨论了建设数字矿区重要子集之一———数字矿山的必要性及其战略意义