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Implementing Universal GIS Functionality under a Virtual GIS Interface 
Jochen Albrecht, Stefan Jung and Manfred Ehlers 
'TslPf ISPA [jalbrecht, sjung, mehlers]@ispa.um-vechta.de 
University ofVechta, P.O. Box 1553 
D-49364 Vechta, Germany 
KEY WORDS: GIS, Tasks, User, Integration, Experience, Systems, Theory 
ABSTRACT 
The ever increasing functionality of GIS makes these systems more and more complex. Goal of the Virtual 
GIS (VGIS*) graphical user interface is to facilitate the work with GIS and to allow its use for non-GIS 
experts as well. The user interface consists of a flow-charting environment where operation icons can be freely 
combined and moved around. The operations are independent of the underlying GIS data structure. All format 
conversions are performed transparently (although the user may enforce explicit consent). No intermediate 
results must be stored, only the final results are visualized. First experiences with prototype applications in 
environmental modeling show that the results seem to be worth the efforts. Limitations of the current 
implementation are the restriction to analytical GIS operations, leaving the chores of data input, management 
and more sophisticated (cartographic) output to the user. This constraint, however, does not affect the general 
proof of concept. First applications of the VGIS front-end are introductory GIS courses for students of a post 
graduate program in environmental momtonng and its use as a modeling environment for erosion hazard 
research. 
1 INTRODUCTION 
The handling of geographical information systems (GIS) becomes increasingly difficult for the user. The 
complexity and sheer amount of operations offered is growing faster than the quality of user interfaces which 
are by far less comfortable than those of other software packages such as word processors or spreadsheets. An 
additional problem is the combination of raster and vector data. Many users are overwhelmed by the need to 
understand the principles underlying transformations between different data models. 
Funding from the German Science Foimdation.(DFG) is gratefully acknowledged. 
Since 1992, the terms Virtual GIS and VGIS have been coined and used in numerous presentations at international conferences 
to describe the project pursued at the University of Vechta. There is no connection to the Virtual GIS™ marketed by Erdas 
Corporation, Inc. (Atlanta, GA) since 1995