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| Titel |
Multidisciplinary approach to identify aquifer-peatland connectivity |
| VerfasserIn |
Marie Larocque, Stéphanie Pellerin, Vincent Cloutier, Miryane Ferlatte, Julie Munger, Anne Quillet, Claudio Paniconi |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250107907
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| Publikation (Nr.) |
 EGU/EGU2015-7629.pdf |
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| Zusammenfassung |
| In southern Quebec (Canada), wetlands sustain increasing pressures from agriculture, urban
development, and peat exploitation. To protect both groundwater and ecosystems, it is
important to be able to identify how, where, and to what extent shallow aquifers and wetlands
are connected. This study focuses on peatlands which are especially abundant in Quebec. The
objective of this research was to better understand aquifer-peatland connectivity
and to identify easily measured indicators of this connectivity. Geomorphology,
hydrogeochemistry, and vegetation were selected as key indicators of connectivity. Twelve
peatland transects were instrumented and monitored in the Abitibi (slope peatlands
associated with eskers) and Centre-du-Quebec (depression peatlands) regions of Quebec
(Canada). Geomorphology, geology, water levels, water chemistry, and vegetation
species were identified/measured on all transects. Flow conditions were simulated
numerically on two typical transects. Results show that a majority of peatland transects
receives groundwater from a shallow aquifer. In slope peatlands, groundwater flows
through the organic deposits towards the peatland center. In depression peatlands,
groundwater flows only 100-200Âm within the peatland before being redirected
through surface routes towards the outlet. Flow modeling and sensitivity analysis have
identified that the thickness and hydraulic conductivity of permeable deposits close to
the peatland and beneath the organic deposits influence flow directions within the
peatland. Geochemical data have confirmed the usefulness of total dissolved solids
(TDS) exceeding 14Âmg/L as an indicator of the presence of groundwater within
the peatland. Vegetation surveys have allowed the identification of species and
groups of species that occur mostly when groundwater is present, for instance Carex
limosa and Sphagnum russowii. Geomorphological conditions (slope or depression
peatland), TDS, and vegetation can be measured/observed with limited effort in
the field. Results from this study have the potential to help water managers and
decision makers better understand and characterize aquifer-peatland interactions. |
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