Identification and characterisation of subsurface flows in the Apex River, Iqaluit, Nunavut

Recent research suggests that climate warming could be impacting the hydrology of Arctic river systems. Long term discharge records in some Arctic catchments indicate a significant reduction in the ratio of maximum to minimum annual discharge, suggesting an increased importance of subsurface flows and groundwater discharge (Burn and al., 2008). In most catchments, the local scale spatial distribution of groundwater fluxes to surface waters, remain poorly known. The distribution and dynamics of local groundwater fluxes to surface waters remain difficult to predict due to uncertainties about the various nested physical controls that modulate subsurface flow and discharge patterns to surface waters (Hinton, 2014). There is a strong need to improve our understanding of the dynamics of subsurface flow processes to better anticipate the impact of climate change on northern freshwater ecosystems. This need extends to the management of northern water resources, where for example the City of Iqaluit has recently proposed drawing water from the Apex River to meet its future needs for freshwater. Here we present a dataset developed in the aim to advance our understanding of the spatial distribution and physical controls on local-scale groundwater inputs to northern surface waters. The data have been developed to address the following specific research objectives; (i) Identification of spatio-temporal patterns of subsurface discharge to the Apex River, (ii) Analysis of the observed spatio-temporal patterns in local subsurface discharge in relation to detailed knowledge of local surficial deposit and topography, (iii) Characterization of the temporal dynamics of subsurface flownets in a selection of hillslope-riparian stream sequences with distinct surficial deposits. The results will be presented simultaneously for the first two objectives, while distinct results will be developed for the third objective.