Geographic Information Systems Geographic information systems is a multidisciplinary field that draws from the areas of geography, computer science, mathematics, and cartography to name just a few. Many other disciplines, ranging from social sciences to defense, have benefited from the existence of this technology. Indeed, the US Army Corps of Engineers, Omaha District has found it indispensable in several applications. A geographic information system, or GIS, is composed of people, computer hardware and software, and data. The first three are used to acquire, store, maintain, analyze, and display the last. When extracted, the data within the GIS can be used to form spatially referenced information. The most familiar example would be a map. However, GIS is far more than just a mapping tool. Another prevalent use is to analyze patterns in space on and near the surface of the earth. Many more applications exist.