2. MATERIALS AND METHODS
2.1 Study Site
The study site is located at the southern tip of the Romaine-2
hydropower reservoir, 80 km north of the city of Havre-Saint-Pierre, on
the north shore of the Gulf of St. Lawrence, Quebec, Canada (50.68°N,
63.25°W; Fig. 1a). The Romaine-2 reservoir is a dimictic water body that
is ice-free from May to December. The regional climate has a mean annual
air temperature and precipitation of 1°C and 852 mm (52% as rain),
respectively (Hydro-Québec, 2007). This is typical of the subarctic
(Dfc) Köppen-Geiger climate classification type (Beck et al., 2018). The
reservoir, which flooded in 2014, drains a 14,351-km2area that is mostly covered with a spruce-moss forest. At its southern
end, the reservoir is about 1 km-wide, and sits at an elevation of 244 m
above mean sea level. When full, it has a surface area of 85.6
km2 and a maximum depth of 101 m (mean depth of 44 m).
It has an elongated north-south shape that channels the near-surface
winds. Hydropower production imposes large water level fluctuations, up
to 17 m in winter and 2 m in summer and fall (Fig. 2a), resulting in a
smaller surface area during these seasons when the water is shallow.
Turbine flow rates also fluctuate yearly, with maximum values in winter
when the demand for energy is at its maximum (Fig. 2b) and during
freshet to avoid spillage. The study period extended from 27 June 2018
to 12 June 2022.