social justice and equity among the different groups of interests demand public participation. ... implemented to reach a good ecological state of the rivers within a basin after a given deadline. ..... The German Federal Ministry of. Education and ...
6th International Conference on Hydroinformatics - Liong, Phoon & Babovic (eds) © 2004 World Scientific Publishing Company, ISBN 981-238-787-0
AN INTERACTIVE SPATIAL DECISION SUPPORT SYSTEM FOR INTEGRATED RIVER BASIN MANAGEMENT JOERG DIETRICH ANDREAS H. SCHUMANN Institute for Hydrology and Water Management Ruhr-University Bochum, Universitätsstr. 150 D-44780 Bochum, Germany Integrated river basin management is a process, in which hydrological, ecological and socio-economic conditions have to be considered. Stakeholder participation belongs into the key elements of planning and decision making. Acceptance of planned measures, social justice and equity among the different groups of interests demand public participation. This paper is focused on a Spatial Decision Support System (SDSS) which can be used interactively with a posterior specification of reasonable goals as part of the mediation process. Based on an assessment of the ecological and socio-economic changes, measures and management strategies have to be defined, which should be implemented to reach a good ecological state of the rivers within a basin after a given deadline. Within a joint research project with ecologists, engineers, IT-specialists and hydrologists a SDSS is designed by the Ruhr-University to develop management schemes for the implementation of the European Water Framework Directive. It is based on a comprehensive analysis of the efficiency and feasibility of water management strategies. Use cases and workflows of river basin managers are specified using the Unified Modeling Language (UML). Workflow oriented tools to manage, evaluate and communicate data and decisions are developed. A structured system design ensures the placing of data within a dynamic context of driving forces, pressures, status, impacts and responses. Special emphasis has to be given to the spatial distribution and the different temporal and spatial scales of socio-economic, ecological and hydrological data and information. The result will be an interactive, learning-based spatial decision support system, which allows multi-criteria trade-off in participatory group decision situations. INTRODUCTION The European Water Framework Directive The Water Framework Directive (WFD) [4] specifies the guidelines for a coherent water policy and water management within all member states of the European Union. A principle environmental objective of the WFD is the protection of surface waters and groundwater in order to achieve a good ecological and chemical status. River basin management schemes including programmes of measures have to be set up for European rivers until 2009. Within these schemes a detailed description how the ecological objectives should be reached by 2015 has to be given. However, prolongation of
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2 deadlines and modifications of the objectives are possible, e.g. if the total costs of the measures are disproportionate. One objective of river basin management planning consists in balancing the interests of various groups. Socio-economic conditions have to be considered within the planning process. Public participation becomes a key element of the WFD. The planning cycle of the implementation is based on the general scheme of Driving forces, Pressure, State, Impact and Responses (DPSIR) adopted by EEA [3]. It emphasizes the interaction between society (human activities in the river basin) and environment in integrated river basin management. Integrated Management for the Werra River Basin An exemplary research and development project is being carried out under guidance of the Ruhr-University Bochum in the Werra river basin, a sub-basin of the Weser basin. The complexity of integrated river basin management demands cooperation of ecologists, hydrologists, water managers, computer scientists and socio-economists (Fig. 1). Local measures and regional management strategies have to be developed in cooperation with local authorities and stakeholders. Under consideration of their different spatial scales of interest the possible ecological consequences of measures are simulated by models and ecological assessment tools. Costs, benefits, conflicts and equity considerations are estimated by socio-economic methods under different baseline scenarios. A multi-criteria analysis has to be applied in order to find the most cost-efficient, feasible combinations of measures according to the preferences of decision makers. All information can be accessed and evaluated via an internet-based spatial information and decision support system. efficient and feasible strategies
Decision Support System
Hydrology
definition of the decision space
Socio Economy
management strategies predict influence of human activity on the ecological quality of the river basin River Water Quality Modelling
ecological and economic assessment
Ecology
GIS-based Information System
Figure 1. Relationship between the different disciplines in integrated river basin management for the Werra pilot basin. The IT-disciplines (column in the center) provide services for planners and decision makers.
3 DECISION SUPPORT FOR INTEGRATED RIVER BASIN MANAGEMENT Requirements for Supporting Decision Makers during the planning stage In the planning stage decision makers need information about the possible consequences of management options at different functional scales. Reductions of the targets, e. g. by prolongation of deadlines or less stringent environmental objectives are counted among the management options. At the river basin scale the most cost-efficient, ecologically effective management strategy (combination of measures) has to be selected. River basin managers have to consider the social and economic effects of cost recovery of water uses. This results in a classical multi-criteria decision problem. The WFD asks the EU member states to encourage active involvement of all interested parties. Public participation can be supported at different levels: information, consultation or active involvement. One option to support the mediation process is an interactive collaborative exploration of the decision space by administration and stakeholders (“explore, what is possible”), e.g. during a focus group meeting. Here the preferences of decision makers cannot be defined a priori (Fig. 2, changed from a figure in Malczewski [8]). The manageability of collaborative decision making processes in complex decision situations is an important issue (Jankowski and Nyerges [6]). The use of complex physical models and interdisciplinary assessment tools is not practicable in such situations. Instead of modelling in real time, a database of measures and strategies has to be prepared during the previous planning phase (Fig. 2), spanning a discrete space of decision vectors. Water bodies with potential modifications of the objectives or deadlines should be identified and marked by the planners. Prognoses for the consequences of modifications have to be provided to support decision makers in their final choice during the decision phase.
intelligence phase design phase
objectives evaluation criteria
constraints
decision matrix
measures strategies
collaborative exploration of the decision space choice phase
preferences of decision makers
public participation
multi-criteria analysis sensitivity analysis recommendation
action phase
river basin management plan
enact programme of measures
monitoring
Figure 2. Phases of participatory decision making in integrated river basin management.
4 Design of an Interactive Spatial Decision Support System The concept of the SDSS is based on the workflow of river basin managers and decision makers in water resources management implementing the WFD. These following main tasks are supported: • display and analysis of spatial representations of the consequences of measures using an internet enabled Geographic Information System, • support for organization and documentation of the different steps of decision making via an internet based user interface, • exploration of the decision space based on a decision matrix which is dynamically calculated from a selected subset of measures. Use cases, activities and object models are specified using UML (unified modeling language, Booch et al. [1]) to define the flow of information between actors and the workflow of river basin managers at different levels (Fig. 3). In this way workflow oriented tools to manage, evaluate and communicate data can be developed and iteratively adapted to new management methods. A structured design of the information system following an industrial standard ensures the placing of data within a dynamic context of driving forces, pressures, impacts and responses. The software development process follows an iterative approach close to a subset of the unified process. In difference to a completely new business situation, the WFD redefines water management. So the development of the SDSS was started with a revision of existing spatial data models (static view). The required system interaction demanded a completely new development of user interfaces (dynamic view). are the total costs of the proposed management strategy disproportionate?
[no]
confirm the proposed management strategy
[yes] propose derogations from environmental objectives for economic reasons [for each potentially affected water body] [extended deadline not sufficient]
water body objectives [confirmed]
define extended deadline
define less stringent environmental objectives
water body objectives [proposed derogation: extended deadline]
water body objectives [proposed derogation: less stringent objectives]
river basin management strategy [confirmed] redefine management strategy
select management strategy for further analysis
Figure 3: UML activity diagram showing an exemplary workflow for the socio-economic assessment of the total costs of the program of measures.
5 SOFTWARE COMPONENTS OF THE SDSS Spatially Enabled Information System A wide range of different, mostly spatial information has to be collected to set up interdisciplinary water management schemes as required by the WFD. For research and planning purposes an information platform that ensures distribution of data among all the involved institutions is needed. In its practical application this platform has to provide aggregated information to decision makers and stakeholders in order to support public participation. The development of a common, interdisciplinary spatial object model was carried out extending the model presented in the European “Guidance Document on Implementing the GIS Elements of the WFD” [2]. Special emphasis is put on the spatial characteristics and the different scales of socio-economic, ecological and hydrological data. Water bodies are modelled as linear events of segments of the topological river network using linear referencing features of the ESRI ArcGIS software (Zeiler [10]). Socio-economic data are often related with administrative units. For water management purposes, many of these data have to be related to water bodies. Here overlay techniques are used to estimate the spatial distribution of socio-economic data on a smaller scale depending on land use. For the analysis of the cost-efficiency of the planned measures the classes which store attributes of measures are important parts of the object model. Relationships between the natural objects and the management objects ensure the dynamic placing of data into the context of the DPSIR approach (Fig. 4). The “strategy” class stores the criteria attributes for the possible consequences of a proposed program of measures, which itself is an aggregation of many single measures. The “measure” class stores single measures with information about local and regional components of criteria attributes. Object behaviour of the strategy class is used to recalculate the overall assessment of a strategy dynamically, whenever management options for a single water body are changed and notified via the relationships. strategy is assumed under baseline scenario 1..* 1 1
DPSIchain
BaselineScenario
-driverOID -pressureOID -stateOID -impactOID
-name
ManagementStrategy -total costs -total benefit +recalculateTotalBenefit()
1
* strategy is related to water bodies SpatialObject
Measure
* measure is related to spatial object 1..*
*
* measure is related to DPSI cause-effect chain
strategy contains measures
*
-costs -local benefit -regional benefit -local ecological effectivity -regional ecological effectivity
EcologicalClassification
river water body has predicted freshwater ecological classification
RiverWaterBody
1
0..*
management strategy is related to predicted freshwater ecological classification *
Figure 4. Simplified extract from the UML object model.
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-overall ecological status -phytoplankton -macrophyto -benthic invertebrates -fish -hydrological regime -river continuity -morphological conditions
6 User Interface The user interface provides access to information, workflow assistants and a documentation of the decision process in a tree structure (fig. 6, upper right corner). The documentation tool is used to record all steps of the collaborative decision analysis immediately, to bring transparency and durability in the feedback process of the participating stakeholders and water managers. The internet user interface for the SDSS is developed based on the UML model from the analysis of requirements. A challenging task is the parallel recording of all temporary selections from the database of measures in order to calculate the decision matrix. Possible selections include the setting of restrictions, baseline scenarios and modifications of deadlines or objectives. Interactive Multi-criteria Analysis Method From the database of measures a decision matrix is calculated as the starting point for the application of a method of multi-attribute decision making (MADM) in a discrete decision space. In this project the Reasonable Goals Method with Interactive Decision Map technology (RGM/IDM, Gusev & Lotov [5], Lotov et al. [7]) was chosen. It focuses on the interactive visual exploration of the decision space and the multi-criteria trade-off in a collaborative decision situation. With this methodology a collaborative learning approach of the mediation process can be supported, which is an important feature of interactive methods (Vincke [9]). The RGM/IDM assists decision makers in the identification of a reasonable goal (Fig. 5). A set of many decision alternatives can be reduced to several Pareto-efficient alternatives, which are close to the reasonable goal. The performance of the RGM/IDM is suitable for the exploration of a very large decision space due to the examination of the Convex Edgewoth-Pareto Hull (CEPH) instead of all alternatives. For a detailed description of RGM/IDM see Lotov et al. [7]. Variety of alternatives
CEPH IDM
Several efficient alternatives
Reasonable Goal
Figure 5. General workflow of the RGM/IDM method (left, Lotov et al. [7]), interactive decision map with a reasonable goal (black cross, right). System Architecture The architecture of the spatial decision support system is designed as a 4-tier architecture with database server, application server, web server and internet clients. The RGM/IDM software is started from the user interface with a parameterized request, which is dynamically constructed from the geodatabase classes. The ESRI ArcIMS service is used for spatial analysis and display of the alternatives (Fig. 6).
7 «ODBC»
«HTTP»
Application Server
Client: Browser
RGDB-Server
Database Server
DSS Client
Web Server Servlet-Engine
Geodatabase
http-Server
«Java-Applet» RGDB-Client
ArcIMS ArcIMS Client
ArcSDE
Figure 6. Software components of the interactive spatial decision support system. CONCLUSIONS The implementation of the WFD in the EU is a new task of policy for many water authorities, even conflicting or coinciding with spatial planning. Multi-criteria methods allow water resources managers to search for efficient measures, which take into account ecological and socio-economic criteria and have to correspond with their preferences. The modelling of decision makers’ preferences is a very important task. Should this be done a priori? Are the decision makers able to express weights and preferences on all relevant criteria? Interactive methods provide a suitable solution for collaborative participatory decision making in a dynamic decision environment like the implementation of a new directive. Learning based methods could improve the active involvement of the public. Complex simulation models and tools for environmental assessment can not be integrated in the SDSS due to performance issues. This might be a limitation of the SDSS, because the decision space is limited by the prepared database of measures and cannot be extended during the decision phase. Thus the generation of measures and strategies is one of the most critical problems of the project. On the other hand, planners often don’t want to apply complicated simulation models which needs a lot of expertise. Further research should be done in the development of scenario generators, which could produce a large amount of alternatives in a semiautomatic process, and metamodels, which could be integrated in an SDSS without the performance issues of numerical models. An iterative software development process is a suitable way to cope with rapidly changing requirements of river basin managers during the implementation of the WFD. UML models of workflow and objects allow a detailed discussion between water management experts and system analysts. They can further be used as a formal standard for the description of river managers’ business processes. From a technological point of
8 view, new software capabilities like GIS object servers could significantly improve the development of complex, workflow oriented decision support tools. ACKNOWLEDGEMENTS We thank all participants of the Werra River Basin Management project for their input, especially the cooperating partners Federal State of Hesse, Free State of Thuringia and Flussgebietsgemeinschaft Weser, who provided a huge amount of data and knowledge about business processes of the responsible authorities. The German Federal Ministry of Education and Research (BMBF) is acknowledged for financial support of the project. REFERENCES [1] Booch G., Rumbaugh J., Jacobson I., “Unified Modeling Language User Guide”, Addison Wesley (1997). [2] CIS Common Implementation Strategy Working Group 3.1 GIS, “Guidance document on implementing the GIS elements of the WFD”, 04-12-2002. [3] European Environment Agency (EEA), “Environmental indicators: Typology and overview”, Technical Report No. 25, EEA (1999). [4] European Union, “Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy”, 22-12-2000, L 327/1 Official Journal of the European Communities EN. [5] Gusev D. and Lotov A., “Methods for Decision Support in Finite Choice Problems”, in: Operations Research: Models, Systems, Decisions, edited by Ju.Ivanilov, Computing Center of RAS (in Russian) (1994), pp 15-43. [6] Jankowski P. and Nyerges T., “Geographic Information Systems for Group Decision Making”, Taylor & Francis (2001). [7] Lotov A.V., Bushenkov V.A., Chernov A.V., Gusev D.V. & Kamenev G.K., “Internet, GIS and Interactive Decision Maps”. Journal of Geographic Information and Decision Analysis, Vol. 1, No. 2, (1997), pp 118-149. [8] Malczewski J., “GIS and Multicriteria Decision Analysis”, J. Wiley & Sons (2001). [9] Vincke P., “Multicriteria Decision-Aid”, J. Wiley & Sons (1992). [10] Zeiler M., “Modeling Our World. The ESRI Guide to Geodatabase Design”, ESRI Press (1999).
