Using Geographic Information Systems (GIS)
Read this article. When you read the section on Centroid (geometric and population-weighted), think about the location of your local supermarket. Where is it in relation to customers, suppliers, or other partners?
Background
The role of the built environment in explaining the spatial patterning of obesity has recently received considerable attention in the public health and epidemiology literature. The built environment comprises of urban design, land use, and transportation systems. Research in this field has shown that features of the built environment exert an influence on physical and mental health as well as health behaviours, independently of the socio-demographic characteristics of the people living in these places. For instance, researchers have evaluated whether aspects of the food environment including access to supermarkets, convenience stores, and fast food outlets are associated with body mass index (BMI). Similarly, other features of the built environment that influence obesity through the promotion of physical activity include street connectivity, transport infrastructure, and the location and quality of community resources (e.g. parks and schools). Built environments that encourage unhealthy eating or are not conducive to physical activity are often termed obesogenic..
Public health researchers with an interest in the built environment have benefited from the emergence of Geographic Information Systems (GIS) technology. GIS offers the opportunity to integrate spatial information from a range of disparate sources into a single framework, and to use these data to develop precise measures of the built environment. The tools available within a GIS also enable precise spatial measures to be derived such as the road distance from a household location to the nearest supermarket or calculations of the amount of neighbourhood greenspace.
This glossary introduces unfamiliar users to key terminology and some of the ways in which GIS can be utilised to measure and represent features of the built environment that may relate to obesity as well as highlighting some basic methodological issues. The terms covered are restricted to those where GIS has, or has the potential to assist in developing more precise measures of the built environment. Text in italics refers terms defined elsewhere in the glossary. Terms are divided into three key categories: 1) data collection; 2) concepts; and 3) measurement.