Gauthier, M. J.; Camporese, M.; Rivard, C.; Paniconi, C. et Larocque, M.
(2009).
« A modeling study of heterogeneity and surface water-groundwater interactions in the Thomas Brook catchment, Annapolis Valley (Nova Scotia, Canada) ».
Hydrology and Earth System Sciences, 13(9), pp. 1583-1596.
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Résumé
A modelling study of the impacts of subsurface
heterogeneity on the hydrologic response of a small catchment
is reported. The study is focused in particular on the
hydraulic connection and interactions between surface water
and groundwater. A coupled (1-D surface/3-D subsurface)
numerical model is used to investigate, for a range of scenarios,
the spatio-temporal patterns of response variables such
as return flow, recharge, groundwater levels, surface saturation,
and streamflow. Eight scenarios of increasing geological
complexity are simulated for an 8 km2 catchment in
the Annapolis Valley (eastern Canada), introducing at each
step more realistic representations of the geological strata
and corresponding hydraulic properties. In a ninth scenario
the effects of snow accumulation and snowmelt are also considered.
The results show that response variables and significant
features of the catchment (e.g. springs) can be adequately
reproduced using a representation of the geology and
model parameter values that are based on targeted fieldwork
and existing databases, and that reflect to a sufficient degree
the geological and hydrological complexity of the study area.
The hydraulic conductivity values of the thin surficial sediment
cover (especially till) and of the basalts in the upstream
reaches emerge as key elements of the basin’s heterogeneity
for properly capturing the overall catchment response.