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Design Of Federated Databases For Multi-Level Decision 
Making In watershed Management* 
Yaser A. Bishr and M.M. Radwan 
Department of Geoinformatics 
International Institute for Aerospace Survey and Earth Sciences, ITC 
P.O. Box 6, 7500 AA Enschede, The Netherlands 
Email: yaser@itc.nl 
Email: radwan@itc.nl 
Abstract 
Environmental decision making usually requires spatial and thematic data from different disciplines. 
Geographic information systems are capable of handling both types of data in an integrated environment. 
Incorporating GIS in a decision support system will increase its functional capabilities and will allow 
decision makers to analyze the impact of their decisions on the environment, and provide more thorough 
understanding of the problem domain which will eventually lead to more environmentally and 
economically sound decisions. 
In the framework of developing a multi-level spatial decision support system (MLSDSS) for watershed 
management a proposal for federating heterogeneous autonomous GISs is presented. Most of the national 
environmental projects involve three levels of decisions making (local, regional, and national). The local 
level has the catchments as its Universe of Discourse, UoD. The objective at the local level is to effectively 
promote management practices that will eventually provide maximum sustainable production of the area. 
UoD of the regional level is the whole basin which is formed by many catchments. The objective at this 
level is usually to monitor the collective impact of management practices, which was applied on the 
different catchments, on the whole basin. At the national level regions that require immediate action 
according to the environmental, socio-economic and political factors defined in the national plan, are 
prioritized. In practice the three main decision levels are managed and handled by three different interest 
groups. This would imply that each group has its own databases. The heterogeneity at the different groups 
can be in hardware, GIS software, data model and its supporting schema, data structure (vector raster), 
spatial level, and requirements by analytical models. 
The focus of this paper is on the heterogeneity in the data models. In this context a framework for schema 
integration is presented. Furthermore, prototype that shows what data and information are needed to be 
exchanged amongst the involved levels of decision making is explained. 
1. Levels Of Decision Making And SDSS 
Environmental decision making, EDM, is a multi-disciplinary and multi-level process. In relation to the 
earlier it involves three main components: ecological, economic, and social. These components are highly 
correlated [Loehr, D.A., et al. 1978]. Ideally decision makers should consider the impact of changing one 
component on the other [Philips P.D., et al., 1993]. For example, changing land cover and land use might 
Presented at the International Society for Photogrammetry and Remote Sensing “Workshop on New Development in 
Geographic Information Systems, Milan, Italy, 6-8 March 1996.