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Soil Erosion as Affected by Freeze‐Thaw Regime and Initial Soil Moisture Content
Author(s) -
Liu Hongyuan,
Yang Yang,
Zhang Keli,
Sun Chuanlong
Publication year - 2017
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2016.08.0271
Subject(s) - rill , water content , flume , soil science , infiltration (hvac) , moisture , hydrology (agriculture) , environmental science , soil water , geotechnical engineering , chemistry , geology , flow (mathematics) , materials science , mathematics , composite material , geometry , organic chemistry
Core Ideas Freeze‐thaw generally increased detachment capacity by an average of 36.5%. The impact of freeze‐thaw on soil erosion was affected by initial moisture content. Detachment capacity and rill erodibility was increased at 30 and 45% moisture. Soil erosion was reduced at 20% moisture content after 5 or 10 freeze‐thaw cycles. The effect of freeze‐thaw exponentially increased with the freeze‐thaw cycles. To quantify the effects of freeze‐thaw (F‐T) on rill erosion, scouring test using a tilting flume (5 m length, 0.4 m width) was conducted. Typical black soil in Northeast China was tested. Five F‐T cycles (FTCs; 0, 1, 3, 5 and 10), four gravimetric moisture contents (θ g ; 10, 20, 30 and 45%), and seven flow shear stresses (τ; evenly spaced from 1.90 to 14.59 Pa) were examined. The soil samples subjected to 0 FTC were termed as the unfrozen control group. The results showed that the F‐T processes increased soil detachment capacity (Dc) by an average of 36.5% across all experimental conditions together. The effects of F‐T on Dc varied with initial θ g . To eliminate the consolidation impact induced by water spraying, the Dc ratio (RDc) between each F‐T group and the corresponding unfrozen control group was calculated. This ratio was found to exponentially increase with FTCs, with an R 2 of 0.94. The rill erodibility (Kr) increased with FTCs only at initial θ g of 30 and 45%. Soil critical shear stress (τ c ) of the experimental group was significantly higher relative to the unfrozen control group and reached its maximum after 10 FTCs at the initial θ g of 20%. These findings help to understand the effects of FTCs on soil erosion and thereby to improve soil erosion models, e.g. modifying rill erodibility parameters.