Incorporation of Models
for Integrated River Basin Management and Decision Making

Emil Bournaski

Institute of Water Problems, Bulgarian Academy of Science, Bulgaria
e-mail: bournaski@netscape.net
 

Abstract

The creation of an operational and integrated comprehensive Decision Support System (DSS) for optimal watershed management especially of transboundary catchments is the main outcome of the European TRANSCAT project. The implementation of different models and developed decision-oriented applications applied and tested under different conditions gives rise to a contemporary tool for the creation of new transboundary management options.

Integrated River Basin management needs to incorporate all the relevant sectors that interact within water management. TRANSCAT DSS comprises five major subsystems that are concerned with data management, modelling, mapping and spatial analysis (geoprocessing), DSS functionality and module for user management:

• The mapping subsystem deals with the manipulation and visualisation of geographic information.
• The spatial analysis subsystem implements a series of geographic analysis functions for the geographic operations. Proximity and overlay analysis as well as functions for data conversion are basic geographic operations.
• The modelling subsystem encapsulates various hydrologic and hydraulic models as CASC2D for surface water flow, QUAL2K for surface water quality, HEC-HMS for rainfall-runoff process, ModFlow for ground water flow and particle tracking, ECOSWIM, GRASS, etc. The individual models should be linked through an unified interface to be able to call different models.
• The data management subsystem concentrates on editing and management of data needed in other subsystems. Data access should be fast, secure and reliable. The data management subsystem should be able to handle large volumes of data of various formats and structures.
• The role of the DSS subsystem is to find decision alternatives and choose between them. The alternatives are analysed and ultimately ranked according to a number of criteria by which they can be compared. These criteria are checked against the objectives and constraints, involving possible trade-offs between conflicting objectives.

The five subsystems cover the essential functionalities that should be offered to the user.

The infrastructure of the TRANSCAT DSS is created as distributed, consisting from decision analytic and auxiliary applications, modelling subsystems, and core servers is based on the principle of web services.

The operation of the TRANSCAT DSS is illustrated  on the Bulgarian-Greek Mesta/Nestos transboundary river.
The HEC-HMS is applied for continuous hydrologic simulation of the catchment. The basic elements of the model and incorporated methods of analysis are shortly presented. A realization of water management approach of the Mesta river catchment in Bulgarian territory is demonstrated. A set of alternative actions for sustainable improving of water quality are presented. They are evaluated according to a number of eleven ecological and economic objectives. The formulated Multiple Criteria Decision problem is solved with the help of MULINO software. 

The multiple modeling tools provide the user with the possibility of selection according to the needs of the area and the data available. The connection between strategic decision tools and modeling support through the core system is a way to meet the need of integration of different tools in water management. Hence, based on modeling tools predictions (rainfall-runoff modeling, ground water flow, water quality models) and indicators stored in an integrated data base the user can apply a range of decision support tools (MULINO, Mediator etc) that will assist with evaluation of different scenarios/choices and the design of decision making procedures.

The co-existence of such different tools and functions is a major achievement in the sector of water management. The manager/user can store data, run hydrologic models and evaluate possible scenarios and even apply group-decision making techniques if required, while visualizing geographic information through the mapping sub-system. This approach has provided a complete scientific tool to support integrated water management, whose elements can be used in a variety of configurations.