Fine-scale characteristics of groundwater flow in a peatland

Abstract

Abstract:Fine-scale dynamics of groundwater¯ow were studied in a 1 . 5 ha peatland in central New York. Measurements of the hydraulic head throughout a detailed network of piezometer clusters revealed spatial and temporal variability in the direction of groundwater¯ow at a very ®ne (within a few metres) scale of analysis. Within the small wetland, there were areas of groundwater recharge, discharge and lateral¯ow. Such patterns of groundwater¯ow frequently reversed or changed due to¯uctuations of only a few centimetres in hydraulic head. Speci®c conductance, deuterium signatures and calcium concentrations of groundwater corroborated the groundwater¯ow patterns determined with hydraulic head measurements and illustrated the in¯uence of source water chemistry and evaporation on dierent layers in the peat column. The control of peat chemistry by such ®ne-scale groundwater¯ow may have important implications for plant community composition and diversity in groundwater-fed peatlands.

Hydro-ecology of groundwater-dependent ecosystems: applying basic science to groundwater management

“…Plant species distributions in fens are a function of various physical gradients in groundwater depths and fluxes and chemistry (Bridgham et al 1996, Hajkova et al 2004, Wheeler et al 2004, and these gradients can be used to set thresholds to groundwater alteration based on hydroecological relationships. Numerous studies report that fen species respond to the maximum depth of the water (Amon et al 2002), calcareous mires in Colorado, USA (Johnson and Steingraeber 2003), spring fens in the Czech Republic (Hajkova et al 2004), peatlands in central Alberta, Canada (Karlin and Bliss 1984) and kettle hole fens in New York (Drexler et al 1999, Godwin et al 2002.…”

“…However, fen plants may respond to gradients or variation defined at a greater level of detail, which are evident only from a more extensive data set. Examples include the duration of initial growing season saturation Waddington 2011, Duval et al 2012), seasonal water table fluctuations (Drexler et al 1999, Ilomets et al 2010) and gradients in hydraulic head (Schutten et al 2011). What is common to all of these cases is that the plants are responding to cues associated with saturation in the rooting zone.…”

Hydrogeological controls on spatial patterns of groundwater discharge in peatlands

“…Groundwater discharge to surface water is one of the most important physical controls on peatlands stability (Siegel et al, 1995;Watters and Stanley, 2007); yet the underlying physical hydrogeologic framework governing the development of surface seepage distribution in these systems is not well understood. Preferential flow paths, hydraulic conductivity (K) anisotropy, and geologic heterogeneities likely influence the surface expression of discharge zones (Chason and Siegel, 1986;Drexler et al, 1999;Smart et al, 2012). However, these variables have been difficult to constrain due to the spatial resolution of traditional localized groundwater wetland methods (wells, boreholes, surface point measurements, etc.)…”

The impact of postglacial palaeoenvironmental changes on the properties of sediments in the kettle hole at the site of Jurki (NE Poland)

“…The func tion ing of these land forms may be strongly linked to re gional or lo cal set tings and there fore large-scale changes asso ci ated with cli mate and hy dro log i cal con di tions may af fect their eco log i cal in teg rity (Drexler et al, 1999;Fra ser et al, 2001). The most im por tant ef fects of such changes may in clude changes in the de po si tion/sedentation of sed i ments, fluc tu ations in wa ter lev els and in creased peat de com po si tion (Gorham and Rochefort, 2003;Lamentowicz et al, 2008;Karasiewicz et al, 2014b;Forysiak, 2015).…”