Decision support for integrated wetland management*

Wetlands perform functions that support the generation of ecologically, socially and economically important values. European legislation has increasingly recognised the importance of preserving wetland ecosystems. The Water Framework Directive (WFD) embodies many of the existing directives that have implications for wetlands. The EU funded EVALUWET project (European valuation and assessment tool supporting wetland ecosystem legislation) aims to develop and implement an operational wetland evaluation decision support system to support European policy objectives. A multidisciplinary approach is adopted combining expertise from natural and social scientists. The region of Noord-Hollands Midden is selected as the Dutch case study within EVALUWET. This region north of Amsterdam is a typical Dutch landscape with drained peat meadows in polders below sea level. Important stakeholders are: agricultural organisations, recreation, nature conservation organisations, and provincial/regional authorities. Water levels are controlled in the area. Changes in water regimes are proposed (National Policies, WFD) which will have an impact on the performance of functions such as agriculture, nature and residential and recreation opportunities. In this case study, three alternatives will be compared: (1) modern peat pasture (current), (2) historical peat pasture and (3) dynamic mire. Impacts of these alternatives on a number of criteria relevant to EU policy are assessed. Spatial evaluation techniques in combination with multicriteria methods are used to support evaluation. This provides a better insight into the consequences of alternative water regimes on the performance of the wetland functions and is used to support stakeholders participating in the decision process. The system is based on the following software components: impact assessment is performed by a rule-based knowledge base implemented in NetWeaver. Spatial evaluation and map presentation are handled in ArcView and ArcMap. Multicriteria analysis is performed using the software package DEFINITE.