document: In representing wetland-river interactions involving GIWs, many models assume that the wetland can discharge into a river but cannot receive overbank flows from it. In such models, the volume of water (or water level elevation) in a wetland and its corresponding threshold value (predominantly controlled by outlet elevation) are the prime determinants of wetland outflow (Feng et al., 2012; Hammer and Kadlec, 1986; Johnson et al., 2010; Kadlec and Wallace, 2009; Powell et al., 2008; Voldseth et al., 2007; Wen et al., 2013; Zhang and Mitsch, 2005). However, in regions characterised by widespread riparian wetlands that are hydraulically connected with adjacent rivers, wetland-river interaction is likely to be bidirectional. Such interactions should be quantified according to hydraulic principles involving relative river and wetland water level elevations as well as the properties of the connection between the two (Kouwen, 2013; Liu et al., 2008; Min et al., 2010; Nyarko, 2007; Restrepo et al., 1998). In the WATFLOOD model, for instance, riparian wetland-river interaction is modelled using the principle of Dupuit-Forchheimer lateral/radial groundwater flow (Kouwen, 2013). Since exchange between riparian wetlands and rivers can occur over the surface and/or through the subsurface, Restrepo et al. (1998) incorporated an equivalent transmissivity expression, obtained for wetland vegetation and the subsurface soil, into the Darcy flow equation of the MODFLOW model.
extractive_keyphrases: darcy flow equation equivalent transmissivity expression interactions should be quantified according to hydraulic principles modflow outlet elevation properties of the connection between the two relative river and wetland water level elevations subsurface soil watflood wetland vegetation
abstractive_keyphrases: principle of dupuit-forchheimer lateral/radial groundwater flow representing wetland-river interactions involving giws riparian wetland-river interaction is modelled