GIS – Geographic Information Systems – is a massive field; we’re just scratching the surface here.
But it’s possible to actually create real maps that no one has made before pretty easily by drawing together elements from various map layers online.
- Map Data formats
- Raster: image files: points with colors but without semantics
- Vector: files of lines; not as pretty but capable of handling data.
The industry standard is ArcGIS, made by the company ESRI. It’s expensive! That’s about the only downside. If you take a GIS class, they usually use Arc.
QGIS is free, and not all that bad. We’re using it so you get used to something you’ll be able to keep using without a site license.
Finding Map Layers
- Large scale
- Smaller Scale: Examples
Working with layers
Right click on a layer to examine it. The two most important options are:
- Attribute table, which lets you see and sometimes edit the data about each item in a vector layer, and
- Properties, which lets you change the appearance of a layer: map cities by population density, for instance.
Georectification is the process of warping a map so that it can be used
Some examples of various sorts:
The process of matching places to points on the map.