Examining Hydrogeological Processes in Freezing Soils using Remote Geophysical and Numerical Techniques

• Main Author: Glass, Brittney
• Format: Master Thesis
• Language: English
• Published: University of Waterloo 2019
• Subjects: Groundwater; Icings; Freezing soils; Remote sensing; Hydrogeology; GW-SW Interactions; Differential stress; Northwest Territories; Morse; Mackenzie Valley; Bogg Creek; morse
• Online Access: http://hdl.handle.net/10012/14466

The work presented in this thesis aimed to demonstrate the use of remote geophysical methods and numerical modelling to address questions related to hydrogeological processes in freezing soils. Two different study areas and research questions were investigated: In chapter 1, Landsat 4-5 TM and RapidEye-3 datasets were used to identify groundwater discharge zones in the Central Mackenzie Valley of the Northwest Territories. Given that this area is undergoing active shale oil exploration, identification of groundwater discharge zones is of great importance. Discharge zones represent groundwater-surface water interaction points that are potential pathways for contaminants associated with hydraulic fracturing to move. Following the works of Morse and Wolfe (2015), a series of image algorithms were applied to imagery for the entire Central Mackenzie Valley, and for the Bogg Creek Watershed (a sub watershed of the CMV) for selected years between 2004 and 2017. The algorithm series extracted ‘icings’ from the images. Icings (also called aufeis) are surface ice lenses where groundwater discharges in the winter months, then freezes. Icings were statistically examined for all of the selected years to determine whether a significant difference in their occurrence and size existed. It was concluded that there was a significant difference in the spatial distribution of icings from year to year, but that there were several places where icings were recurring. During a field visit in August of 2018, high resolution thermal imagery was captured for several of these locations and it was found that groundwater was also discharging in the summer. This provides strong evidence to suggest that the recurring icings represent springs from which groundwater discharges year-round. These springs represent ideal locations to monitor the quality of discharging groundwater following the establishment of fracking operations. Furthermore, identifying these monitoring points remotely is expected to have drastically reduced the field efforts ...