Important Topics

Geographic Information Systems (GIS): Effective Tool for Prevention

Geographic information systems (GIS) have been used for many years in a variety of setting to help organize and present important data. Currently, more data and more analysis tools have become available to help community agencies and organizations use GIS in decision-making and outreach.† Following are frequently asked questions about GIS and its use.

What is a Geographic Information System (GIS)?

A geographic information system (GIS) lets us visualize, question, analyze, and interpret data to understand relationships, patterns, and trends. GIS is becoming essential to understanding what is happening and what will happen in geographic space. Once we understand, we can prescribe action.

One of the earliest examples of using geographic methodology to address a health problem was in 1854 when John Snow determined the source of a cholera outbreak in London by marking points on a map depicting where the cholera victims lived, and connecting the cluster that he found with a nearby water source. [See the figure below.]

Now we have much more readily available data and sophisticated electronic tools that enable us to address a host of public health and safety problems.

Who uses GIS?

The field is growing constantly. Examples include:

  1. Public Health
  2. Law enforcement
  3. Firefighters
  4. City Planning Commissions

How can we use GIS for alcohol problem prevention?

A primary use of GIS in the alcohol field is to determine the relationship between alcohol outlets and alcohol related incidents. An example from PIRE/PRC below shows alcohol outlets with a record of selling alcohol to minors. The full presentation can be accessed:

Similar maps can be used to show the incidents of alcohol related crimes and violence or impaired driving arrests and crashes. This kind of information can be very useful to city planners, licensing authorities, and law enforcement to determine where problems are arising and how they may be addressed.

Maps can also show change over time. As shown below, sales to minors decreased between 1999 and 2001.

Another example helps identify those areas of British Columbia that experienced more alcohol related deaths. More information can be found at the University of Victoria’s Centre for Addictions:

The example shown below indicates the relationship between alcohol outlets and incidents of violence in Sydney, Australia. The complete article can be accessed here:

This example for Bay Points/Pittsburg, California, shows the locations of alcohol outlets and how close they are to schools. This map was part of a successful campaign to ban alcopops in the community. The map below was made by Dr. LisaMarie Miramontes with the Prevention Research Center. Data on the map is available for the entire state of California, and the data set includes other layers such as population data.

Why is GIS mapping effective?

Maps such as those in the examples above are very powerful tools because:

  1. They can put complex information into a visually clear form to enable policy makers and practitioners to identify issues and trends and thus make better decisions about how to allocate resources and address alcohol problems.
  2. They can provide compelling pictures and thus are effective tools in persuading decision makers and the general public that particular actions are needed.

What other resources are available to help develop GIS? Here are a few:

  1. Users can set up a free trial with online access to ArcGIS at:
  2. Many GIS tutorial books come with a 6-month trial for full ArcGIS access. Many can be found on Websites such as Amazon, and will state if they come with a temporary license. An example can be found at the link below:
  3. Search community college courses for credit or non-credit courses. Many courses are offered online and in-person. Credit courses are often offered through the Computer or Geography department.
  4. Many Websites often free downloads of data that can be used in Excel and GIS. For example, Census data can be found at:
    California traffic crash data can be accessed: