A GIS-based approach for supporting groundwater protection in eskers: Application to sand and gravel extraction activities in Abitibi-Témiscamingue, Quebec, Canada

摘要

Highlights ? Depending on the prevailing conditions, eskers can host significant aquifers. ? Eskers constitute a significant source of exploitable sand and gravel. ? Such glaciofluvial formations are often implied in land use conflicts. ? A GIS-based approach was developed for supporting groundwater protection. ? The outputs of the approach are used to guide land management strategies. Abstract Study region Part of Abitibi-Témiscamingue in northwestern Quebec (25,750 km 2 ), within the Quebec/Ontario Clay Belt, Canada. Study focus The focus is set on the unconfined granular aquifers found in eskers, the latter containing significant groundwater resources, both in terms of water quality and quantity. Yet, these glaciofluvial deposits also constitute the main source of exploitable sand and gravel and are therefore frequently at the roots of land use conflicts. New hydrological insights Methods and indices based on the use of geographic information systems (GIS) were developed in support of land management strategies oriented towards the protection of groundwater resources in eskers of northwestern Quebec. A groundwater resource sensitivity index was defined for each 10 × 10 m parcel of esker on the basis of (1) an evaluation of the aquifer potential based on three geomorphological parameters observable on well-known granular aquifers and (2) estimates of the parameters included in the DRASTIC method. The pressure induced by sand and gravel extraction on the groundwater resources was subsequently evaluated on the basis of (1) the resource sensitivity index, and (2) the spatial density of sand and gravel extraction sites and groundwater wells. These calculations are used to suggest solutions for supporting the sustainable management of sand and gravel extraction activities at the regional scale and for highlighting sectors where field data acquisition is most needed.