Soil infiltration characteristics and pore distribution under freezing–thawing conditions

Autor: R. Jiang, T. Li, D. Liu, Q. Fu, R. Hou, Q. Li, S. Cui, M. Li
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: The Cryosphere, Vol 15, Pp 2133-2146 (2021)
Druh dokumentu: article
ISSN: 1994-0416
1994-0424
DOI: 10.5194/tc-15-2133-2021
Popis: Frozen soil infiltration widely occurs in hydrological processes such as seasonal soil freezing and thawing, snowmelt infiltration, and runoff. Accurate measurement and simulation of parameters related to frozen soil infiltration processes are highly important for agricultural water management, environmental issues, and engineering problems in cold regions. Temperature changes cause soil pore size distribution variations and consequently dynamic infiltration capacity changes during different freeze–thaw periods. To better understand these complex processes and to reveal the freeze–thaw action effects on soil pore distribution and infiltration capacity, black soils, meadow soils, and chernozem were selected as test subjects. These soil types account for the largest arable land area in Heilongjiang Province, China. Laboratory tests of soils at different temperatures were conducted using a tension infiltrometer and ethylene glycol aqueous solution. The stable infiltration rate and hydraulic conductivity were measured, and the soil pore distribution was calculated. The results indicated that for the different soil types, macropores, which constituted approximately 0.1 % to 0.2 % of the soil volume under unfrozen conditions, contributed approximately 50 % of the saturated flow, and after soil freezing, the soil macropore proportion decreased to 0.05 % to 0.1 %, while the saturated flow proportion decreased to approximately 30 %. Soil moisture froze into ice crystals inside relatively large pores, resulting in numerous smaller-sized pores, which reduced the number of macropores but increased the number of smaller-sized mesopores, so that the frozen soil infiltration capacity was no longer solely dependent on the macropores. After the ice crystals had melted, more pores were formed within the soil, enhancing the soil permeability.
Databáze: Directory of Open Access Journals
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