Separate simulation models (e.g., agent-based models) may depend on spatial data associated with geographic locations. Use of autonomous interaction models allows independent models to be composed into an aggregate model without alteration of the composed models. The Geographic Knowledge Interchange Broker (GeoKIB) is proposed as a mediator of spatial-temporal models. The GeoKIB regulates unidirectional interactions between composed models of the same type or not. Different input and output data types are supported depending on whether data transmission is passive or active. Synchronization of time-tagged input and output values is made possible via connections to shared simulation clocks. A spatial conversion algorithm transforms any two-dimensional geographic data map for another region of different map cell sizes and boundaries. A composition of a cellular automaton and an agent-based model is developed to demonstrate the proposed approach for spatially-based heterogeneous model composition with the GeoKIB.