Influence of shallow groundwater–surface water interactions on the hydrological connectivity and water budget of a wetland complex

Abstract

Linkages between the controls on surface storage and catchment streamflow response were examined in a wetland‐dominated basin in the Canadian Prairie Pothole region. Snowmelt, surface storage, water table elevation, atmospheric fluxes, and streamflow were monitored during spring snowmelt and summer in a 1 km2 sub‐catchment containing a semi‐permanent pond complex connected via an intermittent stream. Snow accumulation in the basin in the spring of the 2013 study year was the largest in the 24‐year record. Rainfall totals in 2013 were close to the long term average, although June was an anomalously wet month. The water budget of the pond complex indicates that there was a significant subsurface contribution to surface storage. Activation of an effective transmission zone occurred between uplands and the stream network where the water table was located near the ground surface, which allowed significant lateral movement of subsurface water into the stream network. This was also important for maintaining and re‐establishing surface connectivity and streamflow during rainfall events. The observed period of surface‐water connectivity was one of the longest on record in the catchment due to unusually wet conditions; nevertheless, the results of this study have implications for how contributing area and runoff should be considered in monitoring and modelling studies in the region, as inclusion of more frequent and varied runoff processes will be essential to understanding changing streamflow regimes. © 2015 Her Majesty the Queen in Right of Canada. Hydrological Processes. © 2015 John Wiley & Sons, Ltd.

On the relationship between flood and contributing area

“…Surface–subsurface hydrological linkages are known to be important for maintaining surface stream connections and contributing areas (Brannen, Spence, & Ireson, ) in this landscape. Golden et al () recommend that they be represented in models applied to this landscape.…”

“…Surface-subsurface hydrological linkages are known to be important for maintaining surface stream connections and contributing areas (Brannen, Spence, & Ireson, 2015) of comparable frequency to be available, so this approach was not be feasible. This could be addressed in the future with remote sensing products from satellite platforms as these have been proven useful in estimating saturated and inundated areas at the required resolutions and spatial scales (Phillips et al, 2011;.…”

Testing the ability of a semidistributed hydrological model to simulate contributing area

“…The results of Brannen et al . [] reveal that in this landscape, different storage thresholds, and predominant runoff generation mechanisms can be expected during a typical period of intermittent streamflow. With a diversity of surface stores and a shallow subsurface store of which access to is threshold mediated [ van der Kamp and Hayashi , ], the storage‐streamflow relationship in this catchment could be very complex.…”

Groundwater–surface water interactions in Canada

“…Although it is very difficult to quantify available groundwater resources, it is estimated that there is more groundwater in Canadian aquifers than surface water in rivers and lakes, similar to what is observed elsewhere (Rivera 2014). In the generally humid and cold Canadian climate, groundwater-surface water interactions are omnipresent (Devito et al 1996;Langston et al 2013;Brannen et al 2015;Foster and Allen 2015), but remain relatively seldom studied. The Canadian Council of Academies (CCA 2009, 185) expert panel on groundwater concluded that a sustainable use of groundwater resources requires that "groundwater and surface water be characterised and managed as an integrated system within the context of the hydrological cycle in a watershed or groundwatershed."…”