GIS or Geographic Information System is a computer program that can analyse, calculate, editing, integrating, displaying and sharing geographically referenced data. Users of this system can make searches, analyse and edit this information and then present the results.
Information from a normal map is digitised using special programs like Computer Aided Drafting (CAD). Images from satellite and other aerial pictures are being used more and more to make GIS aerial maps. Geographic data is then traced on directly on the image. This is to say that a satellite image of vegetation can be turned into a GIS map.
Any spatial data can be fed into a GIS; it can contain an infinite number of data variables; for example postal codes and longitude and altitude. These variables can then be layered to know how they work together. A good example of the versatility of the GIS system is the mix of data that can be put in; one can have aerial photos, images from space satellites, data in table form (e.g. postal codes and street names) and information from digital maps all into one GIS database producing new information or a GIS map.
An important feature of GIS is the ability to present results of data analysis in graphics on a computer or on paper. These could be in the form of wall maps, interactive maps allowing decision-makers to arrive at informed solutions.
Producing GIS maps is costly and time consuming and requires the cooperation among different data collectors helps to bring the cost down. Organisations like the University Consortium for Geographic Information Science) and the Federal Geographic Data Committee are involved in efforts to standardize data collection methods so that information that can be used to produce GIS maps can be easily shared among organizations.
Like most maps, GIS maps are useful in almost all the areas of our modern existence. GIS aerial maps can be used for logistics planning, resource management, map making, urban planning, sales and marketing and even in Environmental Impact Assessment studies.
For example an export company can use GIS to determine new areas where they need to cover if a search on a GIS system shows non-existent distributors in the area. Postal and courier companies like DHL and UPS find GIS useful for associating parcels to street addresses or to find the shortest route for shipment.
To study the effect of oil exploration and mining on wildlife populations scientists in Canada and Alaska mapped the migration of caribou and polar bears using collar transmitters and satellite receivers. This information was then transferred into a GIS system and represented by different colours for each month. It was in turn transferred onto a map of oil development plans to see the potential risk of the plans to the animals.