地图出版系统中公路类符号绘制的解决方法

在地图符号中公路类符号的绘制具有其特殊性，必须进行特殊处理才能正确显示。文中首先介绍了常见的两种处理方法，并分析了其存在的问题；然后针对地图出皈的要求，在全数字地图出版系统中，利用STL标准模板库技术，对公路要素进行批处理绘制，很好地解决了公路类符号的绘制问题。     

网络地图人性化界面设计

目前网络地图发展迅猛,但界面设计缺少理论指导,仍存在着许多问题.文中首先研究了网络地图的特点和界面内容,对目前网络地图界面设计中存在的突出问题进行归纳.接着提出了基于认知心理学理论的一般性网络地图界面设计原则.最后,对网络地图的用户层次进行分类,举例说明上述设计原则在人性化网络地图界面设计中的应用.     

Subsidence hazard avoidance based on geomorphological mapping in the Ebro River valley mantled evaporite karst terrain (NE Spain)

In the valley of the Ebro River to the southeast of the city of Zaragoza (NE Spain), the dissolution of evaporite sediments (gypsum, halite and Na-sulphates) which underlie alluvial deposits gives rise to numerous sinkholes. These sinkholes are a potential hazard to human safety, particularly where they develop in a catastrophic way. Even slow-developing sinkholes are problematic, as they damage urban and agricultural infrastructure, necessitating costly repairs and vigilant maintenance. To assist in developing avoidance strategies for these hazards, the factors controlling sinkhole occurrence have been assessed using geomorphological maps produced from aerial photographs for 1956 and 1981. Important controls on sinkhole development are found to include underlying geological structure (manifest in preferred orientations of sinkholes on the azimuths N130-150E and N30-40E), and the presence of glauberite in the groundwater flow path, which apparently promotes accelerated gypsum dissolution. Perhaps surprisingly, alluvium thickness does not appear to significantly correlate with the density of sinkholes on the floodplain in this area. The maps for 1956 and 1981 reveal that both human activity and natural processes can serve to obscure the true density of sinkhole development. For instance, a large number of sinkholes which were conspicuous in 1956 have since been back-filled by farmers. In the most fluvially active zone of the Ebro valley (the meander belt), the relatively low density of sinkholes compared with adjoining zones suggests that subsidence is being masked by morpho-sedimentary dynamic processes (aggradation and erosion). Careful geomorphological mapping for different time periods yields a much more accurate impression of the frequency of sinkhole development than would be gained from surveying currently visible sinkholes in the area of interest.     

城市多媒体电子地图系统探讨

为及时反映城市信息的多媒体电子地图融合了数字制图技术、GIS技术、多媒体技术等多种高科技手段,为政府部门、公司企业、社会公众构建了一套便捷的、可视化的空间信息服务平台。介绍了多媒体电子地图的一些特点和重要性,并对多媒体电子地图的制作方法和设计理念等方面进行了探讨。     

网络上分级统计地图制图软件的设计与开发

分析了网络环境中分级统计图表达信息的特点,阐述了交互式分级统计图的设计方法和思路,运用JavaApplet设计并实现了网络上分级统计地图制图子系统。     

基于ArcGIS Engine的地图符号制作工具的设计实现

分析了ArcGIS Engine符号体系特点,设计了一套基于ArcGIS Engine的符号制作工具,采用C#语言开发实现。     

网络环境下分区统计地图制图子系统的设计与实现

分析了网络环境下分区统计地图表达信息的特点,根据其可视化地理统计信息的需要,运用Java Ap-plet技术,设计和开发了网络环境下交互式分区统计地图制图子系统。     

矩阵运算的几种算法实现探讨

以求解正形变换10参数为例,讨论了分别采用True BASIC语言、Mathematica软件、MATLAB软件和C Builder语言的矩阵运算的算法实现方法,分析了4种算法的计算结果,说明了其相互之间精度相差很小、各有所长。     

三维地图符号视觉参量研究

在常规地图符号参量体系上,通过引入动态特征、交互式操作等方面的参量,提出了三维地图符号的视觉参量,它由状态、动态变化和操作三个方面的参量组成,并采用认知实验研究了这些符号参量在质量特征、数量特征、关系特征以及动态特征等信息表达上的应用及功效.