Evaporation from Mackenzie Delta Lakes, N.W.T., Canada

Abstract

Evaporation is an important component of the water balance of lakes in the Mackenzie Delta, but the amount of summer evaporation in this area is not well known. A microclimatologic and water balance study conducted over a 5-yr period demonstrated that lake evaporation ranged from 200 to 387 mm per summer. Evaporation was always greater than summer precipitation and in some cases greater than annual precipitation. Measured evaporation varied significantly from lake to lake and was considerably different from that given in standard maps of evaporation over northern Canada. Since these delta lakes receive little runoff from the surrounding basin, lakes which are not flooded by the Mackenzie River experience gradually decreasing water levels. Given sufficient time between flooding events, these lakes will completely dry up. This has important implications to the effect of flow regulation on the hydrology of lakes in the Mackenzie Delta.