Hydrology of a Patterned Bog-Fen Complex in Southeastern Labrador, Canada

A 0.05 km 2 patterned bog and a 0.29 km 2 ribbed fen were compared to determine the influence of their morphometry on runoff and evapotranspiration. The bog hydrology was dominated by irregularly located and poorly linked pools ≤1.0 m deep, separated by prominent ridges containing local water-table maxima. This small basin had an appreciable lag-to-peak time ( e.g . 6 h), and a low runoff ratio (0.1 to 0.2), because of the large depression storage of the pools, and a long detention storage caused by the weak pool-to-pool linkage. The ribbed fen was dominated by a 1.3 km water track, which consisted of shallow pools (≤0.25 m deep), separated by low ridges that did not produce local water table maxima. The pools were well linked, but their sequential arrangement resulted in a very large detention storage which trimmed the runoff ratio to only 0.003 to 0.07. The lag-to-peak time was relatively short (approx. 3 h), because of sheet flow in the lower water track, just above the weir. The large depression and detention storage of both systems enhanced evapotranspiration losses. Between July 5 and August 14, 1990, evapotranspiration from the bog was 97 mm, compared to 126 mm from the fen, while runoff was only 12 and 28 mm for the bog and fen, respectively. Evapotranspiration from ridges was 67 and 84% of pool evaporation, in the bog and fen respectively.

[1]  J. D. Smith,et al.  The Effect of Weather Variability on the Energy Balance of a Lake in the Hudson Bay Lowlands, Canada , 1990, Arctic and Alpine Research.

[2]  J. Mccaughey.  ENERGY EXCHANGE FOR A FOREST SITE and A CLEAR-CUT SITE AT CHALK RIVER, ONTARIO , 1989 .

[3]  M. Woo,et al.  Wetland and Lake Evaporation in the Low Arctic , 1986, Arctic and Alpine Research.

[4]  N. Malmer.  Vegetational gradients in relation to environmental conditions in northwestern European mires , 1986 .

[5]  Virginia Carter,et al.  An overview of the hydrologic concerns related to wetlands in the United States , 1986 .

[6]  Masakatsu Hiraoka,et al.  Water movement in mirelands: K. E. Ivanov Academic Press, London, 1981, £24.60 , 1982 .

[7]  J. Monteith,et al.  Boundary Layer Climates. , 1979 .

[8]  H. Ingram.  SOIL LAYERS IN MIRES: FUNCTION AND TERMINOLOGY , 1978 .

[9]  A. C. Grant.  Seismic Reconnaissance of Lake Melville, Labrador , 1975 .

[10]  C. Priestley,et al.  On the Assessment of Surface Heat Flux and Evaporation Using Large-Scale Parameters , 1972 .

[11]  R. R. Bay.  RUNOFF FROM SMALL PEATLAND WATERSHEDS , 1969 .

[12]  D. Boelter.  HYDRAULIC CONDUCTIVITY OF PEATS , 1965 .

[13]  M. J. Hvorslev.  Time lag and soil permeability in ground-water observations , 1951 .

[14]  G. V. Winters,et al.  Late Quaternary marine geology of Lake Melville, Labrador , 1987 .

[15]  J. Price.  The Influence of Wetland and Mineral Terrain Types on Snowmelt Runoff in the Subarctic , 1987 .

[16]  Donald I. Siegel,et al.  Groundwater flow in a bog- fen complex, Lost River peatland, northern Minnesota. , 1987 .

[17]  D. S. Munro,et al.  On Forested Wetlands as Evaporators , 1986 .

[18]  D. Foster,et al.  THE RAISED BOGS OF SOUTH-EASTERN LABRADOR, CANADA: CLASSIFICATION, DISTRIBUTION, VEGETATION AND RECENT DYNAMICS , 1986 .

[19]  J. O. Wilkes,et al.  HE HYDROLOGY OF OVERLAND FLOW IN WETLANDS , 1981 .

[20]  D. Hodgson,et al.  Wisconsin glacial retreat, southern Labrador , 1979 .

[21]  Peter Ackers,et al.  Weirs and flumes for flow measurement , 1978 .