CGRG Bibliography of Canadian Geomorphology
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Author : Asare, S.N.; Rudra, R.P.; Dickinson, W.T.; and Wall, G.J.
Date : 1997
Title : Frequency of freeze-thaw cycles, bulk density and saturation effects on soil surface shear and aggregate stability in resisting water erosion
Publication : Canadian Agricultural Engineering
Issue : 39(4):
Page(s) :
Abstract
Soil erodibility is the soil's inherent resistance to detachment and transportation by raindrops and runoff energy and is reflected in relative indices. Some of the factors from which these indices are calculated are surface shear strength and aggregate stability. These two soil properties were measured on remolded soil cores after subjecting them through a number of freeze-thaw cycles, a phenomenon which has been observed to aggravate stream sediment events in late winter and early spring periods. The three Southern Ontario soil textures chosen for the experiments were a Conestogo silt loam, a Brookston clay, and a Fox loamy sand. The surface shear strength and aggregate stability test was conducted to determine the influence of repeated freeze-thaw cycles on these properties and to incorporate the interactive effect of textural class, bulk density, and saturation on these variables. The mean weight diameter (MWD) method was use as an index to quantify aggregate stability. Surface shear strength was measured with a fall cone apparatus fitted with permanent magnetic suspension. Results of factorial analysis of variance indicate that the means of surface shear strength and aggregate stability proved to be significantly different among soil textural classes and bulk density. Also, the mean surface shear strength also indicated significant differences among the number of freeze-thaw cycles and saturation levels. Keywords: erodibility, erosion, freeze-thaw, bulk density, saturation ratio.
Bibliography of Canadian Geomorphology