Location modelling and GIS

Webster’s Dictionary defines location as (1) position in space, and (2) an area marked off for a specific purpose. Hence, a location problem would involve identifying a specific position or place for a specific function or activity. There are several common types of location problem associated with GIS. The most common involves the measurement of where something exists. Given adequate time, it is possible to measure the location of virtually anything on the Earth. This type of problem can be called a location measurement problem. The second type involves the search for an appropriate location for an activity. This problem can be called the locational search problem. It is common to refer to the locational search problem as a facility location problem. This type of problem can involve the placement of one activity (e.g. a retail store) or the placement of a set of interrelated facilities (e.g. fire stations to serve an urban area). Such problems are called single and multi-facility location problems. Other chapters in this book provide examples in the contexts of business and service planning (Birkin et al, Chapter 51), transportation (Waters, Chapter 59), and electoral districting (Horn, Chapter 67). 2 EARLY HISTORY AND DEVELOPMENT