CGRG Bibliography of Canadian Geomorphology
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Author : Devito, K.J.; Fraser, C.J.D.; and Creed, I.F.
Date : 2001.
Title : Runoff characteristics from a glaciated headwater catchment on the boreal plain, Alberta.
Publication : Annual Scientific Meeting of the Canadian Geophysical Union. May 14-17, 2001, University of Ottawa, Ottawa.
Issue :
Page(s) :
Abstract
Surface and subsurface runoff was monitored in a 55 ha aspen dominated headwater catchment located near Lac La Biche (55.1 o N, 113.8 o W), Alberta, from 1997-2000. During most years runoff coefficients within and from the catchment were small, ranging from < 0.1 to 3.3%, but varied with differences in stratigraphy and depth to confining layer. Rainfall-runoff hysteresis plots suggest that runoff generation is complex and dependant on the variability in soil storage and antecedent moisture conditions. In most years precipitation (P) was less than potential evaporation (PET) and soils and trees are often at a deficit. Surface runoff prorated over saturated area of valley wetlands and draws yielded runoff coefficients that ranged from 0-55%. Thus, runoff is largely a function of saturated area extent in valley bottoms because the antecedent moisture conditions required to exceed valley bottom and hillslope subsurface storage, although small, are rarely met. Although the probability of summer rainfall exceeding hillslope storage is small, once hillslope storage is exceeded, runoff can be very high. Long term regional rainfall -runoff analyses indicate that the annual P exceeds PET by more than 50 mm 1-2 times in every 10 years. With soil storage filled, runoff from both hillslopes and valley bottoms occur and continues the following year regardless of the P- PET deficit. These findings have important implications for adaptive landuse planning in the boreal plains.
Bibliography of Canadian Geomorphology