| Title | Field and laboratory estimates of pore size properties and hydraulic characteristics for subarctic organic soils |
| Author | Carey, S.K.; Quinton, W.L.; Goeller, N.T. |
| Author Affil | Carey, S.K., Carleton University, Department of Geography and Environmental Studies, Ottawa, ON, Canada. Other: Trent University, Canada; Wilfrid Laurier University, Canada; Simon Fraser University, Canada |
| Source | Hydrological Processes, 21(19), p.2560- 2571, ; 32nd annual meeting of the Canadian Geophysical Union, Banff, AB, Canada, May 14- 17, 2006, edited by L. Martz and J. Buttle. Publisher: John Wiley & Sons, New York, NY, United States. ISSN: 0885- 6087 |
| Publication Date | Sept. 15, 2007 |
| Notes | In English. 57 refs. GeoRef Acc. No: 282498 |
| Index Terms | experimentation; moisture; peat; permafrost; porosity; sediments; soils; soil tests; subpolar regions; thin sections; Canada--Yukon Territory; Canada; cores; experimental studies; field studies; Granger Basin; hydraulic conductivity; hydraulic head; hydraulic pressure; image analysis; infiltration; laboratory studies; rates; spatial distribution; statistical distribution; subarctic regions; Western Canada; Wolf Creek research basin; Yukon Territory |
| Abstract | Characterizing active and water- conducting porosity in organic soils in both saturated and unsaturated zones is required for models of water and solute transport. There is a limitation, largely due to lack of data, on the hydraulic properties of unsaturated organic soils in permafrost regions, and in particular, the relationship between hydraulic conductivity and pressure head. Additionally, there is uncertainty as to what fraction of the matrix and what pores conduct water at different pressure heads, as closed and dead-end pores are common features in organic soil. The objectives of this study were to determine the water-conducting porosity of organic soils for different pore radii ranges using the method proposed by Bodhinayake et al. (2004) [Soil Sci. Soc. Am. J. 68:760-769] and compare these values to active pore size distributions from resin- impregnated laboratory thin sections and pressure plate analysis. Field experiments and soil samples were completed in the Wolf Creek Research Basin, Yukon. Water infiltration rates were measured 16 times using a tension infiltrometer (TI) at 5 different pressure heads from -150 to 0 mm. This data was combined with Gardiner's (1958) exponential unsaturated hydraulic conductivity function to provide water- conducting porosity for different pore-size ranges. Total water-conducting porosity was 1.1×10-4, which accounted for only 0.01% of the total soil volume. Active pore areas obtained from 2-D image analysis ranged from 0.45 to 0.60, declining with depth. Macropores accounted for approximately 65% of the water flux at saturation, yet all methods suggest macropores account for only a small fraction of the total porosity. Results among the methods are highly equivocal, and more research is required to reconcile field and laboratory methods of pore and hydraulic characteristics. However, this information is of significant value as organic soils in permafrost regions are poorly characterized in the literature. Abstract Copyright (2007), Wiley Periodicals, Inc. |
| URL | http://hdl.handle.net/10.1002/hyp.6795 |
| Publication Type | conference paper or compendium article |
| Record ID | 62002941 |