Geographic Information Systems

Geographic information systems (GIS) are a specialized category of information systems, in which data and information have an explicit spatial component given by location. A GIS comprises data, software, hardware, people, and operational procedures. GIS does not exist in a vacuum, it is always a part of a larger information infrastructure, where it fulfills specific functions aimed at responding to users’ information needs. The users of geographic information involve public organizations, such as local, regional, and national governments; private companies; and individual members of the public. Since much of the information generated by GIS is used to support decision making, GIS have been sometimes referred to as spatial decision support systems. GIS share a core set of functions enabling spatial data input, storage, editing and management, data analysis, visualization, and report generation. Traditionally, GIS have been centralized and operated by GIS professionals, responding to the information needs of end users. With the proliferation and advancement of networking and Web-based technologies, a parallel (to the centralized) model of GIS has emerged, in which software engineers and GIS professionals develop geographic information (GI) Web-based services and GI-savvy users access the services using proliferating points of network access.

Application domains of GIS are numerous and include diverse areas such as disaster and hazard management, retailing, homeland security, crime prevention and community policing, environmental management, city planning, regional development, transportation programming, logistics, construction management, public health and epidemiology, and natural resource development.