What is GIS?
Geographical Information Systems (GIS) is a computer system for capturing, storing, checking, integrating, manipulating, analyzing and displaying data related to positions on the Earth's surface. GIS uses layers, called "themes," to overlay different types of information, much as some static maps use mylar overlays to add tiers of information to a geographic background. Each theme represents a category of information, such as drinking water and wastewater treatment plants, floodplains or impaired streams. As with the old mylar maps, the layers that are underneath remain visible while additional themes are placed above.
How does GIS work?
It is estimated that approximately 80 percent of all information has a "spatial" or geographic component. In other words, most information is tied to a place by coordinates or an address. GIS can help us relate elements on the basis of common geography, illuminating hidden patterns, relationships and trends that are not readily apparent in spreadsheets or statistical packages, often revealing information from existing data resources. So when making decisions about citing facilities, creating water supply plans, protecting wetlands or coordinating drought relief plans, geography plays a significant role.
This “geographic approach” represents a new way of thinking and problem solving that integrates geographic information into how we understand and manage our water resources. It can improve the way we do our work by facilitating better decision making; saving money, time and resources; and allowing us to more effectively communicate through geospatial visualization. GIS can be a powerful tool for developing solutions for water resources problems, such as assessing water quality, determining water availability, preventing flooding, understanding the natural environment and managing water resources on a local or regional scale.
For more information on GIS resources within the Division of Water, see the Quick Links on the right side of this page.