FEUWAnet: a multi-box water level and lateral exchange model for riparian wetlands

Abstract Riparian wetlands as typical aquatic-terrestrial interfaces control, in a very specific way, nonpoint water and related chemical fluxes exchanging between catchment areas to their respective water systems (streams, lakes). The existing groundwater and soilwater flow models reveal gaps in dealing with the complex behaviour of processes and the considerable spatial and temporal heterogeneity of riparian wetlands. Based on long-term experience gained through field observations and the interpretation of model produced data, a multi-box aggregation of processes which determines lateral as well as vertical flows and, as a whole, water balance, is used to discretise a generic riparian wetland transect situated between an upland aquifer and a receiving water body. The resulting mathematical model, FEUWAnet, endowed also with an original methodology to adapt parameters, has been applied to a riparian alder wetland adjacent to Lake Belau (northern Germany). Results of simulations illustrate a good fit between calculated water levels and observed values and an accordance of calculated water balance to previous independent evaluations. This confirms that the sound simplifications of real situations performed by the FEUWAnet mathematical model are a promising way to deal with hydrological complexity of riparian zones. Moreover, FEUWAnet permits, to a certain extent, one to unravel the spatial heterogeneity and temporal variation of lateral (from catchment area to water systems) and vertical (from canopy to groundwater zone) water fluxes typical of riparian ecosystems: this is the necessary step to undertake when developing integrated models capable of assessing the effectiveness of riparian systems in controlling the fluxes of nonpoint pollution discharging in the open water bodies.

[1]  Ludger Kappen,et al.  Water use in neighbouring stands of beech (Fagus sylvatica L.) and black alder (Alnus glutinosa (L.) Gaertn.) , 1999 .

[2]  Kenneth H. Reckhow,et al.  Engineering approaches for lake management , 1983 .

[3]  William J. Mitsch,et al.  Productivity-Hydrology-Nutrient Models of Forested Wetlands , 1988 .

[4]  Vesientutkimuslaitos.  Publications of the Water and Environment Research Institute , 1988 .

[5]  J. Schouwenaars,et al.  A simple procedure to model water level fluctuations in partially inundated wetlands , 1997 .

[6]  D. Boeye,et al.  The hydrological balance of a groundwater discharge fen , 1992 .

[7]  Louis F. Cohn,et al.  Computing in Civil and Building Engineering , 1993 .

[8]  P. Durand,et al.  Solute transfer in agricultural catchments: the interest and limits of mixing models , 1996 .

[9]  Development and application of an analytical model of stream/aquifer interaction , 1997 .

[10]  U. Wendling,et al.  Bereitstellung von täglichen Informationen zum Wasserhaushalt des Bodens für die Zwecke der agrarmeteorologischen Beratung , 1991 .

[11]  W. Kluge,et al.  Einfluß von Talniederungen auf die diffusen Stoffeinträge in Kleingewässer über den Grundwasserpfad , 2000 .

[12]  N. Haycock.  Buffer zones : their processes and potential in water protection : the proceedings of the International Conference on Buffer Zones, September 1996 , 1997 .

[13]  Jürgen Schmidt,et al.  Soil erosion : application of physically based models , 2000 .

[14]  Jayantha Obeysekera,et al.  A Wetland Simulation Module for the MODFLOW Ground Water Model , 1998 .

[15]  J. Bear,et al.  Modeling groundwater flow and pollution , 1987 .

[16]  V. Vaněk.  Groundwater/Surface Water Ecotones: Biological and Hydrological Interactions and Management Options: Heterogeneity of groundwater-surface water ecotones , 1997 .

[17]  Jos T. A. Verhoeven,et al.  A model of carbon, nitrogen and phosphorus dynamics and their interactions in river marginal wetlands , 1999 .

[18]  G. Miehlich,et al.  Stoffhaushalt von Auenökosystemen , 2000 .

[19]  L. Kappen,et al.  The ratio of transpiration versus evaporation in a reed belt as influenced by weather conditions , 1999 .

[20]  V. Vaněk.  Riparian zone as a source of phosphorus for a groundwater-dominated lake , 1991 .

[21]  Parameter acquisition for modelling exchange processes between terrestrial and aquatic ecosystems , 1994 .

[22]  J. Mathieu,et al.  Groundwater/surface water ecotones : biological and hydrological interactions and management options , 1997 .