Spatiotemporal data model and query language for tracking land use change

Abstract

Management of spatiotemporal information requires a more generic and consolidated data model to facilitate applications such as tracking land use parcel changes. This paper presents such a spatiotemporal data model in the context of object databases by extending the Object Data Management Group (ODMG) standard and examines its feasibility in a land use application. This model extends the ODMG object model with a parameterized type, TimeSeries〈T〉 , which allows the shifting of spatial types into spatiotemporal types to support the representation of a series of states (i.e., the history) of an object. An object query language (OQL), spatiotemporal OQL (STOQL), which adds spatial and temporal dimensions to ODMG's OQL, is also designed. A case study demonstrates that STOQL supports the formulation of various spatiotemporal queries pertaining to historical states of spatial objects as well as spatial changes, including spatial type substitution. The model and query language have been implemented by using an object-oriented language in a geographic information system environment.