Natural Earth - Mapping - 2020

Hydrogeology, Geology, & Environmental Issues / Field Methods & Procedures

The  Natural Earth website was developed as a convenient resource for making custom maps. Unlike other map data intended for scientific analysis or military mapping, Natural Earth is designed to meet the needs of production cartographers using a variety of software applications. Maximum flexibility is a goal.

Natural Earth Vector comes in ESRI shapefile format, the de facto standard for vector geodata. Character encoding is UTF-8.

Natural Earth Raster comes in TIFF format with a TFW world file.

All Natural Earth data use the Geographic coordinate system (projection), WGS84 datum

Intelligent data: The attributes assigned to Natural Earth vectors make for more efficient mapmaking. Most lines and areas contain embedded feature names, which are ranked by relative importance. Up to eight rankings per data theme allow easy custom map “mashups” to emphasize your map’s subject while de-emphasizing reference features. Other attributes focus on map design. For example, width attributes assigned to rivers allow you to create tapered drainages. Assigning different colors to contiguous country polygons is another task made easier thanks to data attribution.

Character encoding: Natural Earth uses UTF-8 character encoding to support internationalization with a full range of language scripts (and even emojis: 🌎 🌍 🌏). Initial versions of Natural Earth were in the Windows-1252 encoding limited to Latin-based scripts. Applications like QGIS and OpenOffice handle UTF-8 well. ArcGIS supports UTF-8 since version 10.2.1, and their technical article has details on configuring earlier versions to work with UTF-8. GDAL/OGR and Postgres/PostGIS also support UTF-8. Natural Earth shapefile character encoding is specified in the code page flag in the shapefile’s DBF file and for additional compatibility is also specified in the CPG file. Version 3 of Natural Earth switched to UTF-8 and version 4 fixed encoding conversion errors and omissions.

Projection: Natural Earth’s WGS84 projection is specified in shapefile’s PRJ file. It can also be described as a PROJ4 code EPSG:4326 string “+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs”.

Other key features:

• Vector features include name attributes and bounding box extent. Know that the Rocky Mountains are larger than the Ozarks.
• Large polygons are split for more efficient data handling–such as bathymetric layers.
• Projection friendly—vectors precisely match at 180 degrees longitude. Lines contain enough data points for smooth bending in conic projections, but not so many that computer processing speed suffers.
• Raster data includes grayscale-shaded relief and cross-blended hypsometric tints derived from the latest NASA SRTM Plus elevation data and tailored to register with Natural Earth Vector.
• Optimized for use in web mapping applications, such as Google or Yahoo, with built-in scale attributes to direct features to be shown at different zoom levels.