摘要：在分析国内外研究现状的基础上,探讨了基于GIS的系统总体设计的目标、原则、结构和系统的功能实现。以河南省镇平县的饮水安全评价与预测为研究对象,依据调查数据,选取预测因子和评价标准,以综合指数评价模型为例,详细阐述了饮水安全评价与预测系统所实现的图文双向查询、空间分析、水质评价与模拟等一系列功能,以实现饮水安全工程规划的空间信息管理和辅助决策支持。

摘要：为了解决公安视频监控网络中视频实时动态显示、查询与播放问题,以Visual ***、Ar-cEngine和Access为平台,在构建视频网络框架的基础上,对网络拓扑算法和网络最短路径算法进行了设计,通过构建空间数据库和网络数据集,实现了网络分析和视频实时查询和播放,提高了视频监控的空间化和可视化程度.

摘要：为了满足对点状实体进行扇形缓冲区分析的需要,在Visual ***和ArcObjects平台上,开发了点要素扇形缓冲区分析模块。首先,新建一个Polygon图层,迭代读取图层属性表字段值;其次,计算扇形圆弧两端点坐标和弦长,判断绘制圆弧方式,并把圆弧和扇形的两条边分别加入ISegmentCollection实例;最后,绘制出扇形缓冲区并进行多边形叠置处理。为了便于使用该功能,并能进行多种方法和参数选择,开发了扇形缓冲区向导。用两个实例证明了扇形缓冲区使用的方便性、动态性和有效性及其广阔的应用前景。扇形缓冲区是圆形缓冲区的一种扩充,包含了更多的信息和规律,便于分析和得出更可靠的结论,从而为管理者提供更准确的决策支持,同时丰富了空间分析中缓冲区的理论和方法。

摘要：Building a cloud geodatabase for a sponge city is crucial to integrate the geospatial information dispersed in various departments for multi-user high concurrent access and retrieval,high scalability and availability,efficient storage and *** this study,Hadoop distributed computing framework,including Hadoop distributed file system and MapReduce(mapper and reducer),is firstly designed with a parallel computing framework to process massive spatial ***,access control with a series of standard application programming interfaces for different functions is designed,including spatial data storage layer,cloud geodatabase access layer,spatial data access layer and spatial data analysis ***,a retrieval model is designed,including direct addressing via file name,three-level concurrent retrieval and block data retrieval *** functions are realised,including real-time concurrent access,high-performance computing,communication,massive data storage,efficient retrieval and scheduling decisions on the multi-scale,multi-source and massive spatial ***,the performance of Hadoop cloud geodatabases is validated and compared with that of the Oracle *** cloud geodatabase for the sponge city can avoid redundant configuration of personnel,hardware and software,support the data transfer,model debugging and application development,and provide accurate,real-time,virtual,intelligent,reliable,elastically scalable,dynamic and on-demand cloud services of the basic and thematic geographic information for the construction and management of the sponge city.