NWT RESEARCH DATABASE

Tags: vegetation, hydrology, aquatic plants, ice, ground ice, snow depth, weather, wetlands

Objective(s): To determine and record lakes where ice has frozen to the bottom and areas where floating ice is present for the winter survey; and to observe broad wetland types and the extent and presence of submerged aquatic vegetation for the summer survey. Collectively, this information will be used to calibrate satellite observations and validate the derived map products.

Project Description: The objective of the winter field survey is to determine and record lakes where ice has frozen to the bottom and areas where floating ice is present. Along with obtaining this information, snow depth, ice thickness, ice type, photos, and local weather conditions will be recorded. The objective of the summer field work is to observe broad wetland types and the extent and presence of submerged aquatic vegetation. Collectively, this information will be used to calibrate satellite observations and validate the derived map products. Winter fieldwork will involve collecting lake ice information using equipment such as Ground Penetrating Radar (GPR). These units are very portable and can be dragged on their own skid-plate and record ice thickness information and also detect areas of grounded ice. To enhance the data collected by the GPR, at each selected site, a hole will be drilled into the ice using an ice auger and the following measurements will also be taken: •Snow Depth – a metre stick is used to measure snow depth from the top of the ice surface to the top of the snow layer. A qualitative assessment of whether the snow is wet or dry is also recorded. •Ice Thickness – a metre stick attached to a perpendicular bracket and hooked under the ice is used to measure the distance from the bottom of the ice to the water surface. •Ice Type – A description of the type of ice is recorded at 10 cm intervals in the drilled hole. •Description of the snow/ice interface is recorded to document whether it was smooth, rough or if there was water present. •Photo Documentation – Photos will be taken at each sampling location to document general ice characteristics. •Supporting Information – weather conditions, wind direction, and UTM coordinates will be recorded at each sampling location. Summer fieldwork will involve visual observations and documenting broad wetlands types and the presence and extent of submerged aquatic vegetation. This will be accomplished using a series of low altitude aerial surveys by fixed wing aircraft or helicopter. Surveys will use visual observation to assess the percent area of aquatic vegetation. High quality geo-referenced photos will also be acquired. Location information will be recorded using onboard GPS as well as handheld GPS devices for additional tracking. For select lakes, a ground-based survey will be implemented in the vicinity of operating mines in the region. Ground fieldwork will employ standard vegetation survey approaches to obtain information along linear transects covering major wetlands types. The project is looking at possible additional sources of funding to engage residents. Hatfield would welcome the opportunity to work with First Nations and communities in field observations and “ground truthing” wetlands, ice and water body related data, and understanding the use of ice roads, importance of ice type and classification for northern users (ice fishing, ice roads, landing of planes, ungulate crossings, other relevant information). It is possible that further scope of work or funding would include the participation of First Nations and information gathering from land users. The Hatfield team will be in Yellowknife during the Geoscience Forum and will attempt to meet with as many groups as possible, including First Nations. An information brochure has been finalized very recently and will be distributed, mailed or emailed in the next weeks. The fieldwork for this study will be conducted from March 10, 2014 to August 31, 2014.