Geographic Information Systems (GIS)
What is GIS?
First, to understand GIS, you must understand GEOGRAPHY, as it is the fundamental principle that drives a GIS.
Geography: “a science that deals with the description, distribution, and interaction of the diverse physical, biological and cultural features of the earth’s surface.” (Merriam-Webster Dictionary)
GIS enables us to layer and compare many different sources of geographic informationGeographic Information Systems (GIS) is a new frontier in geography and refers to a system of computers, software and databases that enable users to collect, manage, analyse, visualize and distribute geographic information.
- Collect: The exact location of objects and events can be collected with Global Positioning Systems (GPS), a series of satellites orbiting around the Earth which send signals of their location to base stations on Earth’s surface. Read more about GPS....
- Manage: GIS software, such as ESRI’s ArcView, helps you organize your various databases of geographic information so they are easy to find.
- Analyse: Algorithms within GIS software allow users to query and interpolate the geographic data they have collected. This is known as Spatial Analysis.
- Visualize: A GIS can create easy to understand displays of spatial data, usually in the form of maps but also as diagrams and charts. Better informed decisions can be made using these visualizations.
- Distribute: The sharing of spatial data across networks and the internet has revolutionized GIS. Organizations are more efficient and effective when they have access to up-to-date data and redundancy is significantly reduced when everyone is working with the same, centralized collection of data.
Why is it important?
Knowledge of location enables us to make more informed decisions and GIS puts that knowledge at our fingertips.
The decision can be as simple as turning left instead of right or much more complicated, such as determining the source of a deadly disease, as was the case for the 18th century physician John Snow.
London was in the midst of a deadly cholera outbreak and it was not known exactly how this disease spread, therefore effective decisions about how to contain it could not be made. By talking to residents and creating a spot map to illustrate the location of cholera cases, Snow was able to identify a clustering of cases around a public water pump. With this evidence Snow had the pump closed and the incidence of cholera diminished. (More about John Snow)
