National 1:250,000 public version fundamental geographic data covers China's terrestrial territory and major islands including Taiwan Island, Hainan Island, Diaoyu Islands, South China Sea Islands, and their adjacent waters, totaling 816 map sheets. The geospatial reference adopts the China Geodetic Coordinate System 2000 (CGCS2000), the 1985 National Height Datum, and geographic coordinates (longitude and latitude). The complete dataset has undergone confidentiality processing for spatial positional accuracy and attribute content through cartographic security technology, complying with the Several Provisions on the Representation of Content in Public Maps, Supplementary Provisions on the Representation of Content in Public Maps, and Provisions on the Open Representation of Fundamental Geographic Information Content.
While ensuring national security, this initiative actively promotes the societal application of fundamental surveying and mapping achievements to meet the growing public demand for fundamental geographic data. Approved by the Ministry of Natural Resources, the "National Geographic Information Resources Catalog Service System" now provides free partial 1:250,000 data downloads with continuous version updates. Currently, downloadable data is organized by standard 1:250,000 map sheets, with an overall timeliness of 2015. The layer content includes 9 feature categories: Hydrography (Points, Lines, Polygons), Highways, Railways (Lines), Residential Areas (Points, Polygons), Residential Toponyms (Annotation Points), Natural Toponyms (Annotation Points), etc.
Since the downloadable data consists of original vector formats rather than finalized maps, its visual representation differs from symbolized maps. Therefore, users creating maps from this geographic information data must strictly adhere to the relevant provisions of the Regulations on Map Management. Maps intended for public release must undergo mandatory map review procedures as required by law.
CnOpenData has obtained authorization from the National Geomatics Center of China to include 1:250,000 National Fundamental Geographic Data in its public data section, facilitating access for researchers. For data downloads, please visit the National Geographic Information Resources Catalog Service System.
This page content is sourced from the National Geographic Information Resources Catalog Service System at www.webmap.cn.
Product Specifications
- Map Sheet Division and Numbering
The 1:250,000 public version fundamental geographic dataset comprises 816 map sheets, organized according to GB/T 13989-2012 Division and Numbering of National Fundamental Scale Topographic Maps. Spatial storage unit: 15′ (longitude difference) × 10′ (latitude difference).
- Geospatial Reference
- Plane Coordinate System: China Geodetic Coordinate System 2000 (CGCS2000).
- Elevation Datum: 1985 National Height Datum.
- Map Projection: Geographic coordinates (in degrees) are used for map-sheet data.
- Geometric Accuracy
The root mean square error (RMSE) of updated feature points relative to nearby field control points in planimetric position and elevation meets the requirements specified in the table below, with twice the RMSE set as the maximum permissible error.
Data Organization
The downloadable 1:250,000 public version fundamental geographic data currently comprises 4 datasets and 9 data layers.
Data layers are named using four characters: the first indicates data classification, the second and third represent abbreviations of data content, and the fourth denotes geometric type.