GIS Design

Geographic information system (GIS) design refers to a process of developing a spatially explicit computer information system to provide a simplified representation of geographical entities and phenomena and support relevant spatial analyses. Since its formative years in the 1960s, GIS has experienced rapid progress in its capacity to handle spatial information, and it has become a powerful research tool for various study fields inside and beyond the discipline of geography. For example, GIS has been widely used in agriculture and land use planning, natural resource management, transportation, geology, municipal applications, and business, among others. These application domains have quite different requirements in spatial modeling and analysis. A GIS design process aims at helping system developers identify unique data needs and develop an effective model to support data analyses.

A GIS comprises five key components: data, people, hardware, software, and procedures. Geographic data, which include both spatial information and nonspatial attributes of geographic entities, are considered as the most important component of GIS. They are often stored and maintained in a database management system (DBMS) and provide the basis for data query and spatial analysis. The people component covers a wide variety of individuals who are related to a GIS application at different levels. They can be GIS professionals who design, develop, and manage the system; general GIS users who use the system to complete their everyday work; or geographic data viewers who simply browse a GIS database occasionally for information. The hardware component consists of equipment that supports the operation of a GIS application and other devices that facilitate the input/output of geographic data (e.g., global positioning system [GPS] data loggers, digitizing tablets, scanners, and plotters). The software component refers to computer programs and user interfaces that provide for the spatial data handling capabilities of the system. Finally, procedures define the specific steps of manipulating and analyzing the geographic data to solve domain-specific application problems. All five components interact with one another to form a functioning system. Therefore, an effective integration of these components is paramount to creating a successful GIS application. A GIS design process can help ensure the effective integration of the components in a specific application domain by identifying the domain-specific requirements and incorporating the components to meet the application data-processing needs. Similar to the development of other information systems, a GIS design process follows standard steps. In general, these steps include identifying and analyzing user information needs, defining the system scope, making choices about data and database models, determining the system requirements, and, finally, implementing the system.

User needs analysis, which is the first step in developing a GIS application, presents an important task to help system developers understand the purpose of a proposed system. As each GIS application is created to support spatial decision making in a particular problem domain, there are specific requirements to integrate the five GIS components. System developers need to examine the following questions: Who are the end users of the system? Do they all share the same needs? If not, how many different user groups are there, and what are the major functions demanded by each user group? What are the final information products of the system? Detailed answers to these questions can provide proper guidance for the application development.

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