GIS means "geographic information systems" – a mix of specialized software and data that allows linking locations on a map with information about those locations.

Most organizations work on issues that are geographic – neighborhoods, cities, counties, regions, states, ecosystems, etc. Using Geographic Information Systems (GIS) can help groups be more effective in carrying out their programs. For those who don't yet have much background with GIS, this page answers these common questions:

• What Is GIS?
• How can I start using it in my own organization?

A more extensive tutorial can be found on the LandTrust GIS web site, created by GreenInfo Network - while this site is focused on land trusts, its GIS information is broadly applicable.

What Is GIS?

Imagine you have a paper map of census tracts or land ownership boundaries that you want to know more about. By itself, the map only shows the geography of the tracts or parcels it depicts. But if you had a table of information about each of the tracts or ownerships that could be "attached" to those boundaries on the map, you could show important information – for example, where do people live who have below average incomes? Or, where do people live who have below average incomes and a high percentage of single parent households?

GIS is computer software that knows how to attach geography (e.g., census tracts, ownerships, roads, school sites) to data that describes that geography (e.g., number of people, capacity of roads, quality of schools). GIS uses lines, shading or symbols to show this information on computer-generated maps.

By creating a "layer" for each type of mapped information GIS also lets you link layers – you can say to a GIS program, "find me all census tracts (layer number 1) where most households have one car and that are within a mile of a public park (layer number 2)".

GIS Desktop Software Choices: There are advanced, mid-range and basic GIS software. The leading mid-range products (about $1,200 each) are:

• ArcGIS – ArcView GIS from ESRI
• MapInfo Professional – From MapInfo Corporation

Most groups associated with GreenInfo Network use the ArcGIS software which also has many "extensions" (supplemental program tools) that add extensive new functionality (working with digital elevation models, 3D information, business information, etc.).

Advanced GIS software like ESRI’s ARC/INFO and specialized extensions to ArcView are usually appropriate only for groups with large budgets and strong needs for intensive GIS. 

Basic GIS software is also available ($100-400) and includes:

• ESRI's Business Map
• MapInfo's MapInfo Desktop
• Caliper Corporation's Maptitude
• Microsoft's MapPoint

Simple GIS "viewing" software is also available. See the ESRI software site for instructions on how to download and use their free ArcExplorer program. 

Online GIS via World Wide Web: For some groups, serving maps over the Internet may be an appropriate strategy. This can be done simply, by taking one or more static images of a GIS map and posting it on a web site, or it can be done interactively.

Interactive GIS web mapping allows users to choose data variables and have a custom map redrawn in front of them. A good example of a basic demographic mapping engine is the U.S. Census Bureau 's American Factfinder site, which allows users to pick and choose data and places to map online.

Web-based geobrowsers also offer useful online mapping options: Google Earth, Microsoft Local Live and Yahoo Maps are all useful tools. In addition, NASA's WorldWind project is very effective.

A very useful guide to Internet-based map strategies and data is the Geography Network.

How Can I Start Using GIS In My Own Organization?

The key factor in using GIS isn't software, data or computers – it's people. It takes a fairly skilled person who can work regularly with it to have an effect with GIS (someone with a geography or city planning degree). And, it normally takes one to two days a week of active use of GIS to keep up skills – if you don't have budget or personnel for this, it may be better to look for outside services. 

If you do want to create an in-house GIS, GreenInfo Network recommends this strategy:

1. First, get a very simple or free mapping program and give it a try – it will help you understand what GIS is;
2. Second, define a useful but modest sized GIS project and contract with a consulting group (GreenInfo Network or another) to undertake it so that you can evaluate the usefulness of GIS for your work;
3. Third, if you want to use GIS in-house, consider establishing an agreement with GreenInfo Network or another consulant to assist you in setting up your in-house system. Doing it this way gives you practical experience before you make a big commitment.

If you are going to use GIS internally, focus on how long the key person who will use it will be with you. Many groups start with GIS through an enthusiastic staffer or volunteer, but run into problems when that person leaves and someone else tries to understand the system they were building.

You can also ask a consulting group to create basic projects and templates for you, which you can then use on a day-to-day basis.

Adventurous organizations or those with people who already have extensive computer and mapping know-how can take the plunge on their own. It's very exciting to create GIS products for your own organization. Just keep an eye on the long term!

Basic GIS software screen view

(images from ESRI)

Using GIS for analysis (fire hazards)