Six vector maps are selected as experimental data. These maps are referred to as the coastline map, river map, building map, green land map, road map and waterway map, as shown in Fig. 9. The coastline map and river map, both in the China Geodetic Coordinate System 2000 (CGCS2000), can be downloaded from the website of the National Catalogue Service for Geographic Information of China (https://www.webmap.cn).