Estimating evaporation using stable isotopes: quantitative results and sensitivity analysis for two catchments in northern Canada

Abstract

Areally weighted evaporative discharge from an 850 km2 tundra catchment in south-central District of Keewatin is estimated to be about 7% of total water discharge (~16 mm/yr), compared to about 19% (~65 mm/yr) from a 300 km2 forested watershed in the Upper Mackenzie Valley. Lakes in both watersheds exhibit broad ranges of evaporation/inflow ratios related to local water balance. The potential errors in the estimates are evaluated through consideration of possible variations in basin storage, humidity, and the isotopic composition of atmospheric vapour. -from Authors