How to Use GIS Successfully: A Case Study
Although the field of Geographic Information Systems (GIS) has been around for many years, it is a technology being used more often to inform prevention activities.  Data mapping has numerous advantages, yet it is not always readily apparent which initiatives will benefit most from its application.  

Over the past several years, the staff at EVALCORP has increasingly applied GIS technology to our work helping clients to inform and measure the impact of environmental prevention initiatives in counties across Southern California.  For instance, we have created maps for clients depicting alcohol-related billboards and documenting oversaturation in predominantly Spanish-speaking communities.  Other maps we created identified 'head shops' (places known to sell drug paraphernalia) including their distances from schools and parks.  Others highlighted where DUI arrests and/or alcohol-involved collisions cluster.  

In 2006, we began developing maps stemming from data collected through Ventura County Behavioral Health Department (VCBH) Alcohol and Drug Programs' Place of Last Drink Survey.  These maps were built to assist the County and their community partners know which retail establishments contributed to the greatest proportion of DUI arrests, as well as the impact impaired driving has on surrounding communities.*  

Simply put, GIS is a tool for analyzing and presenting data visually in the form of maps.  This visual representation of your data makes it quickly digestible for all with whom you need to communicate - your staff, partners, and community alike.

So how do you use it successfully?  Our work with VCBH Alcohol and Drug Programs - Prevention Services is one case example of the power of GIS.

First, we developed a master database comprised of thousands of the County's Place of Last Drink (POLD) Survey.  This survey is completed by people arrested for impaired driving and enrolled in Ventura County's DUI Program.  The POLD Survey allows ADP and their community partners to identify the places, settings and circumstances associated with impaired-driving arrests.  

We then developed a map representing the bars, clubs, and restaurants mentioned most frequently as the last place an impaired driver consumed alcohol prior to arrest (see below).  Colored dots of varying size were used to denote retail alcohol establishments.  Dotted lines were used to indicate how far people drove, on average, before getting pulled over.  This information allowed people to see the impact impaired driving can have on surrounding neighborhoods and communities.

New Building

The map helped highlight the gravity of the problem in a way a table of numbers never would have done.  As a result, it helped VCBH share with law enforcement and the community at large information useful for prevention planning and strategy development. 

VCBH and their partners are currently engaged in multiple effective initiatives designed to reduce impaired driving, decrease collisions, and save lives.

Whereas graphs, tables and charts are effective tools for communicating information, maps paint a picture and often tell a story, which can be even more powerful depending on your needs or objectives.

So how do you decide when to use GIS mapping?  Here are a few starter questions to ask:
  1. Is your service or intervention influenced by where your target population is located?
  2. Can mapping help you answer an assessment/evaluation question better than traditional presentation methods?
  3. Can you collect your data to include some level of identifying geographic location (such as exact address, zip code, or city name)?
  4. Do you have access to other publicly available data that can be mapped to help you answer the question?
  5. Who is your audience and how responsive are they to visual presentation?
Please contact us if you'd like to know more about GIS mapping or find out how it could help inform your initiatives.

* Worth noting is that although EVALCORP began developing data maps for VCBH several years ago, others before us effectively applied the use of GIS for crime mapping, zoning, policy development and other prevention efforts. For example, see County of Ventura GIS, and the work of Dr. Fried Wittman.