Design and implementation of a prototype temporal geospatial information system (TGIS)

New users of geospatial information systems (GIS) are often surprised to discover that their software has great difficulty in responding to requests such as, ‘Display the land parcel changes between 2002/10/05 and 2002/10/15’. In our world any feature has three basic components including time, space and attribute. Therefore, geospatial data should be described by spatial, temporal and attribute components. Missing temporal component means that GIS analyses of past events and future trends are difficult or impossible. The primary objective of this paper is to design and develop a prototype temporal geospatial information system (TGIS) based upon an existing static GIS. The prototype is able to create, store and update TGIS data sets and perform display and analysis operations. Ideally, the working system would have a menu-driven user interface for a set of temporal data management, editing and query functions. The TGIS data model would be selected and designed to minimize the volume of data required to retain the necessary information for temporal analysis. The spatial data sets used in this paper are a digital cadastral map of Qom city in Iran, and the prototype TGIS functions include feature split, feature merge, topology queries, etc. The prototype TGIS was developed based on existing ArcView GIS software. Some macro programs were written with Avenue language to provide menu-driven temporal data management, editing and display as well as query functions. The prototype TGIS can trace, display and query versions of features using an extensive set of criteria such as ‘Where was feature X at time T?’, Snapshots of trends can be created and played to show changes over time.