Drawing a map with QGIS
Note - this description is based on my limited experience with QGIS. The version I used was 1.7.4 for Windows.
- Download and install QGIS. Versions are available for Windows, Linux and Mac OSX.
- Download/enable three Python plug-ins -- SimpleSVG, Shaded Relief and GdalTools.
GIS software works by reading data encoded with geographic information (e.g, longitude, latitude, elevation) and renders it as a map. Common file types that QGIS can read are:
- DEM (Digital Elevation Model) - contains geo-referenced elevation data
- GeoTIFF - contains geo-referenced elevation data (note - not all TIF files are geo-referenced)
- KML - a mark-up language kind of like XML that stores vectors, is commonly used by Google Earth
- SHP (Shapefile) - stores geo-referenced vectors, can be a very powerful format as SHP files are linked to database files with additional information on each vector (shape)
1. Obtain Elevaton / Bathymetry data (if desired)
Elevation data is usually found in DEM format, although it can be as a GeoTIFF in some cases. Good sites for elevation and bathymetry data are:
- ETOPO1 - Elevation and bathymetry data good for maps covering large areas. GeoTIFF format. The image is downloadable as one (very large) tile so it can be difficult to manipulate.
- SRTM - Elevation info only that covers 50 deg S to 60 deg N. There are a number resolutions:
- SRTM1 - the finest resolution, only available for the US
- SRTM3 - data files are 1 deg latitude by 1 deg longitude and available for the entire world
- SRTM30 - DEM files that cover large parts of the world. A good substitute if the ETOPO1 file is too big.
Add colour to elevations
Create shaded relief
Remove scale bar, north arrow and copyright
Export as SVG
Clean-up in Inkscape