ABSTRACT
The progressive development from spatially lumped models to distributed hydrological models seems to be reasonable only if based on geographic information systems (GIS) technology. According to the objectives and complexity of hydrological modelling, the need for basic data and GIS functions, the availability of interfaces and compatibility of data models, the hardware environment, the system architecture of GIS and modelling software and so on, the method and intensity of integration should be different. T. L. Nyerges has developed a conceptual framework for the coupling of spatial analytical models with GIS. The Munster study group is developing a GIS toolbox called Tools for Hydrological Information and Modelling (T4HIM) for the integration of spatial hydrological GIS tools with the GIS platform. The GIS workshops have shown the necessity of developing such a flexible toolbox with an ergonomic graphical user interface. T4HIM runs on different UNIX systems with X-Windows based user interfaces.
