GeoSurveillance: GIS-based Exploratory Spatial Analysis Tools for Monitoring Spatial Patterns and Clusters

Abstract

Spatial clusters are often formed by underlying non-random geographic processes generated from various factors (for example, a disease outbreak around a pollutant source). Spatial randomness is a theoretical baseline in comparison of which spatial clustering is assessed in statistical frameworks dealing with spatial uncertainty. Spatial statistical methods for investigating spatial clustering have been developed to reveal the locations of probable sources (for example, environmental factors) that may cause unusual concentrations of geographic events. Clustering tests assess the overall tendency for geographic events to concentrate in space, as well as measure the associated statistical significance, while clusters point to where geographic events are densely located in close proximity (Waller and Gotway 2004).