基于遥感的珠江三角洲城镇等级规模研究

从 TM卫星影象提取出城镇实际建筑覆盖专题信息 ,以城镇建筑覆盖面积代替人口统计数据 ,对 2 0世纪末珠江三角洲城镇体系等级规模变动特点进行分析。重点分析了城镇等级规模总体时空格局、各等级城镇数量与规模变动特征、各行政等级城镇规模变动特征、城镇等级规模总体变动态势。结果表明 ,1 988至 1 998年珠江三角洲城镇的内外圈层空间格局较为稳定 ,核心城镇的地位有所下降 ,各等级规模的城镇均衡化趋势较为明显 ,按行政等级划分的城镇中镇级城镇增长速度最快。

Studies on Urban Grade-size Change in the Pearl River Delta Based on Remote Sensing

Metadata is one of the valid technique for data sharing. Current Metadata management models and management systems focus on the Metadata, the management of Dataset is independent, and there is no direct connection between Metadata and Dataset, it leads to the inconsistency of Metadata and Dataset. Due to the direct relationship of Metadata and Dataset, the management model based on Metadata and Dataset is given, it consists of three level including integrating management level, service level, application level and solve the independent management of Metadata and Dataset. Integrating management level exchanges services flow with service level. Service level manages the distributing Metadata servers and Dataset servers, and it exchanges Metadata information flow and Dataset information flow with application level. Application level consists of customer machines. In addition, the application flow of this model is explained in three parts. The first part is the construction of Dataset object. it includes the filling and registering Metadata, submitting the Dataset to Dataset server. The second part is Dataset object querying and getting. it includes searching the Dataset based on the Metadata searching engine, and downloading the Dataset from Dataset server. The third part is Dataset object revising. it includes the Metadata revising in Metadata Server and Dataset revising in Dataset server consistently. In the end, with IIMS which is based on the integrating application model, typical application research is done in Xiamen Environment Bureau's Metadata management system.