Effects of frozen soil and snow cover on cold‐season soil water dynamics in Tokachi, Japan
Effects of frozen soil and snow cover on cold‐season soil water dynamics in Tokachi, Japan
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DOI：
10.1002/hyp.7621
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发表时间：
2010-06
影响因子：
3.2
通讯作者：
Y. Iwata;T. Hirota;M. Hayashi;S. Suzuki;S. Hasegawa
中科院分区：
文献类型：
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作者：
Y. Iwata;T. Hirota;M. Hayashi;S. Suzuki;S. Hasegawa
尽管冬季土壤水分运动在寒冷地区有潜在影响，但相对较少的实地研究调查了春季融雪入渗开始之前发生的冷季水文过程。通过5年多的田间观测，评价了冬季土壤水分通量对日本北海道东京一块农田年水量平衡的贡献。在其中两个冬季，土壤霜冻的最大深度为0.2米(“冻结”冬季)，而在其余三个冬季(“非冻结”冬季)，土壤霜冻基本不存在。冬季融雪水显著渗入，深度超过1.0m，在冰冻和非冰冻冬季都有。土壤入渗量为126~255 mm，占年土壤水分通量的28~51%。在寒冷的冬季，当冻结时，大量的水(约40毫米)从更深的层被吸收到0-0.2米的表土层。在此条件下，冻锋的推进和退缩受积雪厚度的调节，控制着冻层以下的土壤水分通量。在未冻的冬季，13-62毫米的水渗入到0.2米深的地方，直到春季积雪融化。这些结果表明，正确评价寒区冬季土壤水分运动具有重要意义。版权所有©2010 John Wiley&Sons，Ltd.
Despite the potential impact of winter soil water movements in cold regions, relatively few field studies have investigated cold‐season hydrological processes that occur before spring‐onset of snowmelt infiltration. The contribution of soil water fluxes in winter to the annual water balance was evaluated over 5 years of field observations at an agricultural field in Tokachi, Hokkaido, Japan. In two of the winters, soil frost reached a maximum depth of 0·2 m (‘frozen’ winters), whereas soil frost was mostly absent during the remaining three winters (‘unfrozen’ winters). Significant infiltration of winter snowmelt water, to a depth exceeding 1·0 m, occurred during both frozen and unfrozen winters. Such infiltration ranged between 126 and 255 mm, representing 28–51% of total annual soil water fluxes. During frozen winters, a substantial quantity of water (ca 40 mm) was drawn from deeper layers into the 0–0·2 m topsoil layer when this froze. Under such conditions, the progression and regression of the freezing front, regulated by the thickness of snow cover, controlled the quantity of soil water flux below the frozen layer. During unfrozen winters, 13–62 mm of water infiltrated to a depth of 0·2 m, before the spring snowmelt. These results indicate the importance of correctly evaluating winter soil water movement in cold regions. Copyright © 2010 John Wiley & Sons, Ltd.