Location and Physical Characteristics
- Located at roughly 68°45'N, 133°30'W, Trail Valley Creek is 50 km north-northeast of Innuvik, NWT, and 80 km south of the Beaufort Sea, Arctic Ocean;
- The basin is 63 km2 in area and is dominated by gently rolling hills and some deeply incised river valleys;
- Elevations range 50 m to 180 m above seal level and the terrain has a mean slope of 3° (maximum slope 30°);
- Located at the northern edge of the boreal forest - tundra ecotone, vegetation of dominant upland tundra areas consists mostly of grasses, lichens, and mosses. Moister hillslopes and valley bottoms support shrub tundra with vegetation ranging from 0.5 m to 3 m in height. There are sparse pockets of black spruce forest throughout the basin;
- Climate is characterized by short summers and long cold winters, with an 8-month snow-cover period. Mean annual air temperature is about -10 °C and annual precipitation is about 266 mm (66% of which is snow);
- Trail Valley Creek is in the continuous permafrost zone and active layer thickness ranges from 0.3 m to 0.8 m.
History
- Trail Valley Creek has been a focal hydrological research basin since 1992, where the National Water Research Institute (NWRI) has operated a meteorological station since that time;
- The Water Survey of Canada (WSC) has operated a gauging station at the outlet of the basin since 1979;
- Trail Valley Creek represented an important research basin contributing to the objectives of the Mackenzie GEWEX Study (MAGS) and the IP3 Network.
Current Science Focus and Instrumentation
- Long-term hydrological research in the Sub-Arctic to Arctic transition region (Taiga to Tundra ecoregions);
- Research is currently focused on the integrated dynamics and variability of vegetation, snow, energy balance, active layer depth, thermokarst, soil water storage, and runoff;
- Important insights are being developed on the expansion of shrub Tundra and its associated effects;
- Instrumentation consists of:
- Meteorological stations in 3 main Tundra and tall shrub sites measuring soil temperature, soil moisture, air temperature, wind speed and direction, incoming/outgoing short- and long-wave radiation, precipitation, and eddy covariance flux measurement for key periods;
- WSC streamflow measurement at the outlet of Trail Valley Creek;
- Other more recent stations set up (e.g. flux station near lake in upper part of basin, WMO SPICE (Solid Precipitation Intercomparison Experiment) site in lower part of basin);
- Field observations including:
- Distributed end-of-winter snow surveys, detailed snowpack monitoring (GEONOR snowfall measurement, snow pillow, Cosmic ray SWE measurement), ground-based and remote sensing (Lidar, Radar) methods for spatial variability of soil moisture, soil temperature, and SWE;
- All meteorological towers to be upgraded for flux observations of water, energy, carbon, and to include 15 m deep well casings to allow installation of thermistors for monitoring of permafrost conditions.
