EGU21-9918, updated on 29 Apr 2021
https://doi.org/10.5194/egusphere-egu21-9918
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

The quantification of water storage capacity of peatlands across different hydroclimatic settings using a simple rainfall event to water-table response ratio method

Marc-André Bourgault1, Michel Bechtold2, Joseph Holden3, Antony Blundell3, Ullrich Dettman4, Michelle Garneau5, Tim Howson3, Sylvain Jutras6, Bjørn Kløve7,8, Marie Larocque9, Hannu Marttila7,8, Kathryn McKendrick-Smith3, Meseret Menberu7,8, Anna-Kaisa Ronkanen7,8, Nigel Roulet10, and Bärbel Tiemeyer4
Marc-André Bourgault et al.
  • 1Département de géographie, Université Laval, Québec, Canada
  • 2Department of Earth and Environmental Sciences, KU Leuven, Belgium
  • 3water@leeds, School of Geography, University of Leeds, Leeds, UK
  • 4Institute of Climate-Smart Agriculture , Thünen institute, Braunschweig, Germany
  • 5Département de géographie, Université du Québec à Montréal, Montréal, Canada
  • 6Département des sciences du bois et de la forêt, Université Laval, Québec, Canada
  • 7Freshwater Centre, Finnish Environment Institute (SYKE), Oulu, Finland
  • 8Water, Energy and Environmental Engineering Research Unit, University of Oulu, Oulu, Finland
  • 9Département des sciences de la Terre et de l’atmosphère, Université du Québec à Montréal, Montréal, Canada
  • 10Department of Geography, McGill University, Montréal, Canada

In wetlands, the water budget is traditionally quantified by measuring the hydrologic components including precipitation, evapotranspiration and surface water-groundwater inflows and outflows. However, the reliability of measurements is often questioned due to the difficulty of rigorously monitoring all components of the water budget. Quantifying the rainfall event to water table response ratio is an alternative approach with minimal need for data commonly collected in peatland studies. However, the method has been used only in a limited number of biophysical settings including different microforms, hydroclimatic and hydrogeological settings. The objectives of this study are to quantify the reactivity of the water table to precipitation for different pristine peatlands located in different hydroclimatic conditions and to provide quantitative assessments of water storage of as many peatlands as possible. To do so, site-specific hourly water table and precipitation measurements was collected from northern peatlands worldwide. In total, data from more than 30 sites were retrieved from 8 research groups. For all peatlands, water-table depths varied between 80 cm below the peat surface and 10 cm above the peat surface. The results highlight that the hydrology of all peatlands is characterized by a shift from an environment that can store water to an environment that contributes to rapid outflow, and this is a uniform feature across sites. However, for peatlands with the lowest water storage capacities, this shift occurs during relatively moderate rainfall events (40 mm) or successive small rainfall events. Blanket peat bog best embodied this type of hydrological response. For peatlands with the highest water storage capacity, this shift occurs following multiple moderate to large precipitation events (40 mm – 80 mm) and it is strongly enhanced by the shift from high to low evaporative periods. The peatlands with the highest storage capacity are raised bogs with deep water-table. These conditions are best observed in peatlands located in geographical settings with high evaporation rates. Among all the peatlands, maximum water storage capacity for given rainfall events was equal to ≈150 mm. These analyses also confirm that the water table rise caused by precipitation events contain sufficient information to constrain water storage variations around monitored wells peatlands for a wide array of biophysical settings.

How to cite: Bourgault, M.-A., Bechtold, M., Holden, J., Blundell, A., Dettman, U., Garneau, M., Howson, T., Jutras, S., Kløve, B., Larocque, M., Marttila, H., McKendrick-Smith, K., Menberu, M., Ronkanen, A.-K., Roulet, N., and Tiemeyer, B.: The quantification of water storage capacity of peatlands across different hydroclimatic settings using a simple rainfall event to water-table response ratio method, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9918, https://doi.org/10.5194/egusphere-egu21-9918, 2021.

Corresponding presentation materials formerly uploaded have been withdrawn.