Digital Mapping and GIS Explained

So what is a GIS and what is it used for?

A Geographic Information System (GIS) is a computer system for storing, manipulating, and displaying geographic information, and depicting the spatial relationships of mapped objects. Before computers, transparent maps were placed on top of each other to view different types of geographical information. These maps have now been computerised and can be used together with all the related information in a much faster environment that helps you see the relationships between all the layers of spatial information. One of the most basic descriptions of a GIS is that it is a database in map form. Imagine each point or object on a map related to an entry in a database.

While a map may represent a road as a line, a GIS will also recognise it as a border between a wetland and an urban development. The road could have its name stored in the database as well as who uses the road, how often they use it, where it leads, what the surface is made of, or even the probability of an accident occurring on it. This gives GIS fantastic scope for spatial interpretation of data for many different situations potentially using hundreds of different variables.

A GIS can convert existing digital information, which may not yet be in map form, into forms it can recognise and use. For example, digital satellite images can be analysed to produce a map like layer of digital information about vegetative covers.

A GIS makes it possible to link/integrate information that is otherwise difficult to associate through other means. A GIS can use combinations of mapped variables to build and analyse new variables. For example you could find out what sort of geological unit gold mines occur on by combining two different geology layers and their data. You could even use predictive modelling to determine what the probability is of a potential gold mine occurring in a particular area!   

It is estimated that ~80% of all data can be analysed spatially. This means that much of the information you use everyday in your business could be used in a GIS to enhance the way you do business. You could target new customers for your fertiliser business by working out who owns land were there are mineral deficiencies, you could find all the customers within easy walking distance of your restaurant, or even workout the best place to locate a school based on the latest census results!

Data restructuring can be performed by a GIS to convert data formats. For example, a GIS can be used to analyse land use information in conjunction with property ownership information. It is this flexibility that allow difference data to be compared modelled and shared with other GIS users. You can even display your data on the internet using a live and interactive Web map.

Some ways GIS's are used:

• Emergency services – fire and police
• Environmental – monitoring and modelling
• Business – site location, delivery systems
• Industry – transportation, communication, mining, pipelines, healthcare
• Government – local, central, military
• Education – research, teaching, administration