Geographical Information Systems

Before computers, information systems for geographers were limited to paper maps, tables, lists and atlases, and showed information about human and physical geography. The information they supplied could be years out of date by the time you were using it, which limited their usefulness apart from classroom use to teach students the techniques needed to analyze and interpret the geographical data. It was very time consuming.

A modern geographical information system links hardware (computers), software (computer programs) and data, and enables geographers to capture, analyze and display virtually any form of geographic information in helpful ways. It can produce maps and map overlays (for example like showing the parish boundaries of villages or areas of cell phone coverage as well as reports, graphs and charts to display the data in an easy-to-understand form to answer questions about different locations. Data capture by professional geographers can be used to update the data so that you have the very latest information.

In a GIS, lots of different information about places is stored in a database or on a spreadsheet. You can use a variety of tools to display the information on a map. The software adds layers representing different geographical features such as roads or buildings, and data sets such as census data, crime statistics or even pet ownership. You end up with a 'stack' of layers, each of which can be turned on or off and analyzed to understand the relationships between them. As well as answering the question 'where' it can help to answer others like 'what if ...', 'why' and 'how does ...'. This makes it a powerful tool for businesses too as they can add customer data and improve their marketing and sales.