A GIS-based method for predicting groundwater discharge areas in esker aquifers in the Boreal region

In the Boreal region, anticline eskers aquifers are recharged in upland hillslopes and water discharges in the surrounding lowlands. Organic peat soils often confine the aquifer discharge area and drainage of these confining peat layers can decrease the flow resistance in the peat soil, which may cause unintentional groundwater level drawdown. This poses a risk to groundwater bodies and their good water status in the Boreal region. To increase awareness of the risk areas and to assess potential areas for drainage restoration, a model based on geographical information systems (GIS) was developed to predict the locations of high groundwater discharge. The output of the model is a map highlighting the potential areas where groundwater is more likely to discharge. The model output was validated with stream flow data collected from two eskers located in Finland. The developed GIS model is recommended as a tool to delineate groundwater protection areas where drainage of the peat soil should not be allowed and for assessing areas where such drainage networks could be restored to protect vulnerable groundwater systems.