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FEDERATING HETEROGENEOUS DATABASES IN A MULTI-LEVEL DECISION
SUPPORT SYSTEM FOR WATERSHED MANAGEMENT - A CLIENT/SERVER APPROACH
Mustafa Radwan., Yaser Bishr, Edison Espinoza., and Tankiso Mabote.
Department of Geoinformatics
International Institute for Aerospace Survey And Earth Sciences, ITC
P.O.Box 6, 7500 AA Enschede, The Netherlands
Commission IV, Working Group 6
KEY WORDS: Decision Support System, Information sharing, Watershed management, Multi-level Decision making
ABSTRACT
Environmental decision making in general and watershed management in particular involve three main components: ecological,
economic and social. These components are highly correlated and interdependent. Ideally we should consider the impact of changing
one component on the other in the decision making process. The assessment of the impact of a proposed program should consider
two main aspects: the interrelationship between the components of the underlying watershed (ecological, economic and social) and
the hierarchical level of decision making (local, regional and global). The latter strictly affects the relation between the environmental
variables.
In this paper a proposal for developing a multi-level decision support system for watershed management is presented. The system
provides a link between the three levels of decision making. The emphasis is on the aspects related to linking the component
databases which support the three levels. These databases play an important role in the multi-level analysis of watersheds. The link
must allow information and decision transfer and resolve databases heterogeneity. Problems as well as their solutions, which are
pertaining to linking these spatial databases, are explained.
Figure 1 shows the interaction and relationship between the
three levels. They are characterized by an extensive flow of
1. MUTLI-LEVEL WATERSHED MANAGEMENT information and decision between the three levels. This can be
In order to eventually propose the proper components and
architecture, the first phase in developing multi-level decision
support system for watershed management, MLDSS, is to
analyze the functional relationship between the three levels of
interest, i.e., national, regional, and local. The MLDSS should
be able to support three main activities in watershed
E
Analysis
zoning and aggregation rules
Y Y
Output Output Y
degraded zones aggregated impact of MP's
Basin water
quality analysis
New scenario
[CI National scale
Regional Scale
523 Local Scale
Figure 1 Interrelations between the three scales
management: 1- monitoring of watersheds and basin status in
order to keep records of the type and rate of degradation; 2-
analysis of watersheds in order to investigate the causes of their
degradation and propose plans for sustainable management; 3-
management of watersheds, where the actual execution of the
plans is executed.
summarized as follows:
+ At the national level, decisions concerning the guidelines and
constraints for initiating an environmental sustaining project
are defined for the whole country..Decisions are taken based
on the information provided by the regional level. The
information is used to analyze the underlying watershed in
order to locate and identify degraded areas. The areas are
then ranked according to the rate and degree of degradation,
and their social and economic impact. At this level, political
factors are likely to be considered and even sometimes can
overrule other considerations. Information on the impact of
the new management practices on each watershed, at the
regional level, is used for further analysis at the national level
in order to improve decision making.
¢ At the regional level, decisions are mostly dealing with
identifying the proper combination of management scenarios.
Usually the objective at this level is to have maximum
positive environmental impact on the whole watershed. This
combination and their corresponding impacts are aggregated
and quantified at the national level for approval as mentioned
above. Subcatchments are also analyzed and ranked at the
regional level. The ranking is used to prioritize sites for
further analysis and protection [Bishr et al., 1995]. Scenarios
with highest ranks are implemented at the local scale.
¢ At the local level, scenarios with the highest priority are
implemented. Their results and impacts are used to provide a
feedback to the regional scale for modifying and improving
the scenarios.
Despite all developments in computer based tools, many
mangers are not benefiting from these competent tools. The
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International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996
