Geospatial Data  Tags: gis geospatial maps  

This is intended to be a brief guide to working with data in Quantum GIS. If you require further help with Quantum GIS, or GIS in general, please make an appointment to see Troy Mutton, Faculty Liaison Librarian at the SciTech Library.

Please note that I am not an expert user of ArcGIS, MapInfo, or any of the commercial GIS products. I will try to help, but may not be able to help you to the standard you require.

Why should you use Quantum GIS?

There are dozens of applications available for using GIS data, some of it good, some of it not so good. Quantum GIS is one that I have found to be easy to use, free, open source, and full featured. For users who are using GIS datasets irregularly and don't want to pay for ESRI or MapInfo products, this is program should meet your needs.

There are several types of formats that GIS data can be downloaded in - Quantum GIS can open the following files that are commonly found:

• ESRI Shapefiles (.shp) - commonly opened by ArcGIS
• MapInfo (.mif, .tab) - commonly opened by MapInfo
• Spatial Data Transfer Standard (*catd.ddf)
• Geography Markup Language (.gml)
• and many other raster file types.

Shape and MapInfo files are quite common. Quantum GIS cannot open .e00 types - you will need to convert these to shape files.

After downloading the dataset you want to look at, unarchive the file contents of the file, retaining the directory structure.

You are now ready to start up Quantum GIS and begin working with your data.

For this demonstration, I will use the Sydney Special Topographic Themeset available for download from Geoscience Australia.

The first step is to add a layer to the software - to do this click the Add Vector Layer button and then in the subsequent window, browse to where you have unarchived the dataset.

The open dialogue box should default to Shapefile as the file type - if you have MapInfo data, you will need to change the Files of Type box to the appropriate setting.

Select the appropriate shapefile - in this example, I have chosen the frameworkboundaries shapefile from the Framework directory.

It will look like this within Quantum GIS.

To add further information to the map, select Add New Vector Layer, and then choose different datasets. In the following example, i have added (from bottom to top) Builtup Areas, Recreation Areas, Cultivated Areas, Native Vegetation Areas, and Roads.

By zooming in on the area around the University of Sydneys Camperdown Campus, we can see more detail, as shown below.

You can layer data from different sets into your project, building a rich picture of information. You are only restricted by the types of data that you can find.

I hope this brief introduction has been useful, and helped you to get started using Geospatial information with Quantum GIS.