Questions GIS can Answer
Location --- Where is it?
•The first of these questions seeks to find out what exists at a particular location. A location can be described in many ways using, for example, place name, post or zip code, or geographic references such as latitude and longitude.
Condition --- What is it?
•The second question is the converse of the first and requires spatial analysis to answer. Instead of identifying what exists at a given location, you want to find a location where certain conditions are satisfied (e.g., an unforested section of land at least 2000 square meters in size, within 100 meters of a road, and with soils suitable for supporting buildings).
Trends --- What has changed since.....?
•The third question might involve both of the first two, and seeks to find the differences within an area over time.
Patterns --- What spatial patterns exist?
•This question is more sophisticated. You might ask this question to determine whether cancer is a major cause of death among residents near a nuclear power station. Just as important, you might want to know how many anomalies there are that don't fit the pattern, and where they are located.
Modelling --- What if.....?
•"What if...." questions are posed to determine what happens, for example, if a new road is added to a network, or if a toxic substance seeps into the local ground water supply. Answering this type of question requires both geographic and other information (and possibly even scientific laws).