NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region

Tags: physical sciences, remote sensing, plants, soil chemistry, forest ecosystem

Objective(s): To determine the spatial extent, distribution, and timing of winter icing events in streams along the Inuvik to Tuktoyaktuk Highway through ground-based and aerial reconnaissance of stream crossings.

Project Description: The specific objectives of the project are: 1) determine the spatial extent, distribution, and timing of winter icing events in streams along the ITH through ground-based and aerial reconnaissance of stream crossings; 2) identify relations between physical watershed characteristics and icing dynamics through field observations and analyses of watercourse and catchment morphological parameters in Geographic Information System (GIS); 3) monitor the thermal regime of ground and water in riparian systems (both ephemeral and continuously flowing), geochemical water characteristics, soil characteristics and moisture, and water level in watersheds producing icings using existing and new instrumentation; 4) to install ground temperature monitoring instrumentation and use ground penetrating radar, electric resistivity tomography and elevation surveys of ground and ice surfaces; 5) analyze multidisciplinary datasets obtained from monitoring to understand the processes that may trigger icing development including air temperature changes, thresholds in snow accumulation and ice thickness, active layer freeze-back, groundwater dynamics and lake storage and/or water level changes; and, 6) engage local community members and organizations in the research. Ground Penetrating Radar (GPR) uses radar technology to measure conditions below the ground surface. A GPR survey involves pulling a small antenna along the ground surface, as shown in Figure 1. GPR is especially suitable for showing the shape of the boundary between frozen ground and unfrozen ground, which might occur beneath streams. Electrical Resistivity Tomography (ERT) is an approach that passes a mild electric current through the ground to measure the electrical resistance of the ground. The resistance is dependent on the amount of unfrozen moisture in the ground. An ERT survey can therefore be used to measure the shape of unfrozen materials beneath the ground surface, similar to GPR, but is generally more sensitive. Elevation Surveys of Ground and Ice Surfaces would be completed using a high-precision GPS, with a handheld rod and a base station on a tripod, to measure the height of stream icings above the stream bed in late April. The height of the stream bed would be measured later in the year, so that the height difference between the stream bed and icing surface could be calculated. This would help determine the size and volume of stream icings, which are expected to help estimate how much water flows in small streams in winter. This project is a partnership between the Northwest Territories Department of Transportation (DOT), the Northwest Territories Geological Survey (NTGS), and Wilfrid Laurier University (WLU). Long-term research activities in the fields of meteorology, hydrology and permafrost science by NTGS and WLU in the study region, especially Trail Valley Creek, will help provide context and direction for the investigation of icing dynamics. Supplementary geotechnical data and observations from highway construction and maintenance will be available from DOT. It is expected that equipment will be installed at up to nine streams near the Inuvik to Tuktoyaktuk Highway to measure ground temperature, water temperature, and soil moisture. This equipment will remain in place for about four years, and will be regularly monitored. This research project could engage community organizations and individuals that have long-term knowledge of mid-winter stream conditions between Inuvik and Tuktoyaktuk, gained through travel and land use. It is hoped that this project will improve the understanding of winter flow in large streams and smaller riparian systems. This could lead to educational opportunities, and further research opportunities, relating to fish habitat. Research results will be provided through presentations to interested parties in Tuktoyaktuk, Inuvik, and Yellowknife following sufficient data collection and analysis. Research papers, plain-language summary reports, and a PhD thesis will be provided to interested individuals and communities. Results will also be available within the government and university research communities, and will be provided to the Northwest Territories Department of Transportation. The fieldwork for this study will be conducted from April 1, 208 to October 1, 2018.