Columbus 1:100000 Quad Hydrography DLGs

Digital line graph (DLG) data are digital representations of cartographic information. DLG's of map features are converted to digital form from maps and related...数字线图（Digital Line Graph，DLG）数据是制图信息的数字化表达形式。各类地图要素对应的DLG数据均由纸质地图及相关资料转换为数字形式。