In the vicinity of rivers, flooding of available lowlands can be considered as a possibility for temporal storage of river water during high water events. Thus, the risk of flooding inhabited areas can be reduced. This approach to deal with excessive water quantities fits in the concept of "Integral Water Management" and the implementation of EU Water Framework Directive 2000/60/EC. Creation of wetlands or controlled flooding areas also contributes to increasing valuable ecosystem area from an ecological and biodiversity viewpoint. As such it also fits within the concepts of e.g. the RAMSAR Convention, NATURA 2000 and the implementation of the 6th Environment Action Programme of the European Community 2001-2010.
As metals can accumulate, created wetlands can only be sustained if processes affecting metal mobility are thoroughly understood and metal fate can be predicted. However, they can be designed based on different flooding regimes, such as periodic inundations or permanent flooding, which has an impact on mobility, bioavailability and toxicity of heavy metals. The possible development scenarios when applying different flooding regimes are often inquired by governmental organisations, especially concerning polluted areas. Therefore, a thorough understanding of processes affecting metal mobility is needed to quantitatively predict the consequences of different management regimes on metal bioavailability, toxicity and ecosystem development.
This study aims at contributing to management-oriented models to deal with questions arising from the creation of wetlands or controlled flooding areas. Such models should make it possible to predict trace metal behaviour and ecosystem development in controlled flooding areas. They should allow to evaluate whether and under which conditions ecosystem development may still be acceptable in terms of environmental quality and public health when choosing different wetland creation options.
Factorial experimental trials at the greenhouse scale will be set up to study biogeochemical processes as affected by different flooding scenarios. The influence of vegetation on soil biogeochemistry and, reverse, the impact of pollution on plant metal uptake, growth and development will be assessed by incorporating plant growth as a separate factor in the experimental set-up. Contaminant effects under the different management scenarios will be assessed using appropriate biomarkers and toxicity tests. Models constructed from these trials will be validated in a pilot-scale experiment in Kruibeke.
Interaction between the different partners
All of the partners co-operate in the design and implementation of the experimental trials and in processing the data. The project management, sampling and analyses co-ordination for the experimental trials is performed by the Laboratory of Analytical Chemistry and Applied Ecochemistry (UGent - Prof. F. Tack). The Research Group Ecosystem Management (UA - Prof. P. Meire) co-ordinates sampling of the pilot-scale experiment in Kruibeke. Metal biogeochemistry and bioavailability are studied by the Laboratory of Analytical Chemistry and Applied Ecochemistry (UGent - Prof. F. Tack). Contaminant effects on reed plants and invertebrates are studied by the Research Group Ecosystem Management (UA - Prof. P. Meire) and the Laboratory of Environmental Toxicology and Aquatic Ecology (UGent - Prof. C. Janssen).
Link with international programmes
This integrated study can join other national European research projects (such as the Dutch RIZA-project "Biochem") that aim to develop management-oriented models for dealing with questions that arise from the creation of wetlands or controlled flooding areas.
Expected results and/or products
The study aims at contributing to management-oriented models for dealing with questions arising from the creation of wetlands or controlled flooding areas. Criteria will be developed to appraise the risks associated with the creation of wetlands in polluted areas. The main application of the results obtained in this project is situated in the regulatory, governmental policy-making and policy-supporting arena.
All results will be published in international, peer-reviewed journals. The data, constructed models and criteria will be brought together in a book and on CD-rom. The results will be disseminated to the various national and international research institutes and governmental bodies and a workshop will be organised to discuss the issue with national and international representatives of environmental departments.
Metal biogeochemistry and bioavailability are studied at the Laboratory of Analytical Chemistry and Applied Ecochemistry (UGent - Prof. F. Tack). Reed growth and development are studied at the Research Group Ecosystem Management (UA - Prof. P. Meire). Contaminant effects on invertebrates are studied at the Laboratory of Environmental Toxicology and Aquatic Ecology (UGent - Prof. C. Janssen).