C O N T E N T S - Physical Land Resources - Vrije Universiteit Brussel

the ‘Temperature stick’ and seepage meters lead to a better perception of the diversephysical and biological processes and their temporal and spatial distribution on a localscale. Several of these processes like physical transport and chemical reactions of solutesoccur simultaneously, thus the investigations should finally lead to the calculation ofmass balances of the exchange terms between the different parts of the system. During2007 the project focused less on field data sampling and more on the integration ofdifferent models developed by the project partners as well as on different simulations.The field work performed by the VUB focused on gathering continuous data sets ofsurface water and groundwater temperatures and heads. Similar measurements have beenperformed at the Poederlee site of the Aa River in Flanders and then in June and autumnalso around Rogozynek in the upper basin of the Biebrza River in Poland. The Biebrza waschosen to serve a as second study case to validate the models and results. Thecontinuous survey of this data can give overview over the magnitude and the variation ofvertical groundwater flow in the hyporheic zone of the rivers. For the modeling thecoupling of the different ecological, ground- and surface water processes which havedifferent spatial and temporal dimensions, is the main challenge. GIS is used for datamanagement, while FEMME (Soetaert et al., 2002) became a platform for the integration ofthe different models. This platform allows a 1D-transient state simulation of several ofthe mentioned processes in the river simultaneously. Beside the validation of the modelswith datasets from the Biebrza, the coupling of the surface water model with groundwaterflow formulations is a further research point for the coming year.C. Anibas participated in the General Assembly of the European Geosciences Union inVienna, Austria, from 15.04.2007- 20.04.2007 and at the conference of the InternationalUnion of Geodesy and Geophysics in Perugia, Italy from 02.07.2007- 13.07.2007.C. Anibas, O. Batelaan and F. De SmedtBiebrza Wetland ResearchThe Biebrza River is located within the Biebrza National Park and is according to theRAMSAR Convention list one of the most important wetlands even on a worldwide scale.Situated in the north-eastern part of Poland, around 200 km from Warsaw, the parkcovers about 60.000 ha including the 156km long stretch of the Biebrza River. Thecatchment of the Biebrza River is divided into three geomorphologic units (Okruszko et al.1990): the Upper Biebrza, the Middle and the Lower Biebrza basin. The unique ecologicalvalue of the wetlands abundant in the Biebrza national park is, especially for Europeancircumstances, the result of the extensive usage of the area in the last decades comparedto other areas with similar character. Large peat deposits and several yearly flood events- 57 -