地形图图形输出系统GOSTM的设计与实现

本文在分析现有数字地形图图形输出的前提下,提出了地形图图形输出系统GOSTM(Graphic Output System for Topographic Maps)的设计原理,并详细介绍了其系统结构,各种模块的基本功能及其数据接口。本系统与地形图数字化系统DSTM(Digtial System for Topographic Maps)联接已成功地实现了地形图图形输出。     

基于自组织神经网络算法的华北区域夏季天气气候学特征

对华北区域的天气气候学研究,有助于理解该区域大气环流场与地面要素场之间的相互联系。利用自组织神经网络算法(SOMs),基于1958—2002年夏季ERA-40日平均海平面气压距平场(MSLPA),对华北区域的海平面气压场进行分型,研究其天气气候特征。36种典型地面环流形势被识别出来,包括强北高南低、强西高东低槽、强西北低东南高和强东部高压西伸4种极端类型,以及它们之间的过渡型。天气型的空间特征分析表明二维自组织图上天气型的对称性体现了华北区域天气气候的一般性特征,而非对称性则体现其独特性。天气型演变特征分析表明高、低压系统越强,或以高压系统活动为主时,华北地区的天气形势相对稳定,反之则转变较快。年际变化分析指示出其中6种天气型出现较明显的年际线性变化趋势。最后,分析天气型相应的降水分布特征,表明区域内不同地区的降水来自不同天气型的影响,地面环流场的细小差别将会造成地面强降水中心位置的较大不同,且地形的影响将进一步放大该差别。上述分析结果采用更完整和更高时间分辨率的资料,定量化地研究华北区域夏季的天气分型特征,拓展其天气气候学研究。研究成果可用于发展客观化的数值模式典型天气过程识别技术,以及作为区域气候情景分析的基础。     

Map Use by Adults with Visual Impairments

In this paper we summarize five experiments that were designed to investigate how tactile maps contribute to the cognitive maps of people with visual impairments. In two experiments we demonstrated that tactile maps can contribute to peoples' ability to learn a route through an unfamiliar area. From the results of two further studies, we argue that compared to people with sight, people with visual impairments have greater difficulty encoding information from a map. We considered this directly in a fifth experiment by investigating how people with visual impairments search and learn a map. We found that they used less efficient strategies than people with sight. We conclude that tactile maps are an important source of geographical information when people need to learn about new environments, but we also point out that to benefit most from tactile maps people need to encode the map information as effectively as possible. As people with visual impairments do not always use the most appropriate encoding strategies we suggest that tactile map users might benefit from greater experience and training in map encoding strategies.     

数字正射影像图的质量控制与评价方法

总结应用VirtuoZo NT、JX4C DPW全数字摄影测量系统(DPS)制作数字高程模型(DEM)和数字正射影像图(DOM)的经验,论述DEM和DOM生产过程主体技术线路及存在的主要技术问题,分析如何提高DEM和DOM的精度方法,阐述DEM和DOM的质量控制环节,探讨特性划分评价方法。     

基于GIS数据的快速地图制图技术探讨

本文通过对基于GIS数据的地图制图工艺流程的分析梳理和有关软件的功能分析,给出了一套基于GIS数据的快速、高效的地图制图方法。     

网络地图的研究现状与发展趋势

随着信息技术、网络技术和多媒体技术在数字地图学领域的不断渗透,网络地图已经成为地图产品的重要组成部分。通过分析研究现有的网络地图产品,总结了网络地图的特点和存在的问题,分析了其发展趋势,并提出了相应的一些设想。     

Satellite-based damage mapping following the 2006 Indonesia earthquake—How accurate was it?

The Yogyakarta area in Indonesia suffered a devastating earthquake on 27 May 2006. There was an immediate international response, and the International Charter “Space and Major Disasters” was activated, leading to a rapid production of image-based damage maps and other assistance. Most of the acquired images were processed by UNOSAT and DLR-ZKI, while substantial damage mapping also occurred on the ground. This paper assesses the accuracy and completeness of the damage maps produced based on Charter data, using ground damage information collected during an extensive survey by Yogyakarta's Gadjah Mada University in the weeks following the earthquake and that has recently become available. More than 54,000 buildings or their remains were surveyed, resulting in an exceptional validation database. The UNOSAT damage maps outlining clusters of severe damage are very accurate, while earlier, more detailed results underestimated damage and missed larger areas. Damage maps produced by DLR-ZKI, using a damage-grid approach, were found to underestimate the extent and severity of the devastation. Both mapping results also suffer from limited image coverage and extensive cloud contamination. The ground mapping gives a more accurate picture of the extent of the damage, but also illustrates the challenge of mapping a vast area. The paper concludes with a discussion on ways to improve Charter-based damage maps by integration of local knowledge, and to create a wider impact through generation of customised mapping products using web map services.     

Visualization of geochemical data on maps at the Geological Survey of Finland

Software for presentation of geochemical data on maps has been integrated into a user-friendly package, ALKEMIA, at the Geological Survey of Finland (GSF). ALKEMIA contains procedures for generating dot maps, colour surface maps, shaded relief maps, and vector images, and for interpolating and smoothing irregularly gridded data. Combining dots and colour surfaces provides a means of visually integrating up to three variables on a map, revealing the spatial relationships between them. The methods employed are described in detail, particularly the moving weighted median, which has been widely used at the GSF for interpolating and smoothing geochemical and other numerical data. Several geochemical and oncological atlases and series of maps have been produced with these methods.     

奥维互动地图在城市地质调查勘测中的应用

在开展城市活动断层探测工作时,奥维地图可有效提高地质地貌调查、地球物理勘探、钻探等野外工作及数据管理的效率。在地质地貌调查中可对地质调查点进行记录描述、查看宏观地貌特征、定位及导航等;地球物理勘探中可借助卫星影像进行测线设计、测线信息记录等;钻探中可用于钻孔编录信息的保存。奥维提供了备注模版功能,用户可自定义备注格式及内容用于记录各种信息。可将地质调查点、物探测线、钻孔等叠加于Google卫星图之上进行展示,分类管理城市活动断层探测野外调查数据。     

Determining safe yield and mapping water level zoning in groundwater resources of the Neishabour Plain

Groundwater is a crucial sources of water supply, especially in arid and semi-arid areas around the world. With uncontrolled withdrawals and limited availability of these resources, it is essential to determine the safe yield of these valuable resources. The Hill method approach was used in this study to determine the safe yield the Neishabour aquifer in Khorasan Razvi province in Iran. The results showed that the safe yield in the Neishabour aquifer is 60% lower than the current pumping amounts...