While there has been considerable research (Peuquet,1994, 2002, Langran, 1992, Worboys, 1998,

Usery, 2000) dedicated to developing a complete theory and data model for spatiotemporal data, few

of these initiatives have addressed the problem of persisting this data model. It has been

repeatedly shown that the relational database model is insufficient for representing spatial and

temporal data and is certainly insufficient for representing both types of data simultaneously.

Extended relational data models for these types of data suffer from defects and particularly from

the loss of clarity expressed in the data model. Object-oriented database systems are better able

to capture the semantics of the spatiotemporal model, but have not gained widespread acceptance or

use. The eXtensible Markup Language (XML) has achieved near ubiquity and efforts to incorporate its

use for persisting semi-structured data in XML database systems have proceeded apace. This research

examines the use of XML for persistence of spatiotemporal data, develops a prototype GIS

application with XML persistence and compares it qualitatively to development of a GIS application

with relational persistence. The development process in this work shows that implementing the

spatiotemporal data model in XML is technically no more difficult than implementing it in a

relational model and that software performance for this limited application is comparable.

However, the XML data model is semantically much clearer than the analogous relational

model and allows for better comprehension when viewed without the use of specialized

software.