中文摘要：

为了揭示季节性冻土区积雪覆盖条件下土壤垂直剖面各层次液态含水率序列的复杂性变化过程,基于(2013年11月-2014年4月)实测的田间数据,分析了裸地、自然降雪、积雪压实和积雪加厚覆盖处理条件下5、10、15、20、40、60、100、140、180 cm土层土壤液态含水率的变化过程,采用变异系数、方差等指标评价其时间序列的离散程度,同时利用小波变换信息量系数(wavelet transform information cost function,WT-ICF)值对含水率序列的复杂性进行识别验证。结果表明:冻融期,积雪覆盖阻碍了土壤与环境之间的水汽传输与能量交换过程,裸地处理条件下土壤含水率变幅最大的层面出现在20 cm土层处,其含水率变幅为18.31%,自然降雪、积雪压实和积雪加厚条件下其最大变幅层面分别为15、15、10 cm,层面逐渐上升;裸地处理条件下20 cm土层处的离散程度最大,随着积雪覆盖厚度的增加和密度的增大,序列离散程度最大的层面逐渐上移,其变异系数依次为6.0189%、6.1367%和6.8546%,波动性增强;小波变换信息量系数能够精确的测算各土层土壤含水率的复杂度,裸地、自然降雪、积雪压实和积雪加厚处理条件下其复杂性活跃层依次为21、18、14和10 cm,积雪的存在导致了环境因子对于土壤的影响区域减小,复杂性活跃层向地表移动。该研究揭示了北方寒区冻融期土壤水分迁移的复杂性特征,对于合理预测春播期土壤墒情,精准、高效的利用土壤水资源具有指导意义。

英文摘要：

In order to reveal the complex changing process of the liquid moisture content sequence at all depth levels of soil vertical section in seasonal frozen region covered with thick snow, based on the field experimental data measured during the winter from November 2013 to April 2014, we analyzed the variation characteristics of liquid moisture content of soil layer in the different depth levels of 5, 10, 15, 20, 40, 60, 100, 140 and 180 cm under the following treating conditions: bare land area (no snow cover), nature snow cover area, compressed snow cover area and thickened snow cover area. And the dispersion degree of time series was evaluated with some indices like coefficient of variation and variance. Then the preliminary identification of spatial distribution regularities on soil liquid moisture content complexity was made under different snow cover treating conditions, and at the same time, we identified and checked out the complexity of the sequence of soil moisture content by the method of wavelet transform information cost function. During the seasonal freezing and thawing period, the snow cover blocked the water vapor transmission and energy exchange process between soil and external environment, owing to its high albedo and low thermal conductivity, the infiltration of snowmelt water played a role in the migration of soil liquid moisture and the soil temperature at the parallel time. The biggest variation amplitude of soil liquid moisture content was 18.31%, which appeared at the depth of 20 cm soil layer under the condition of bare land treatment, while it appeared at the depth of 15 cm soil layer under the condition of nature snow cover area, at the depth of 15 cm under the condition of compressed snow cover area and at the depth of 10 cm under the condition of thickened snow cover area, which showed a trend of gradually rising in 4 different levels. The largest discrete degree appeared at the depth of 20 cm under the treatment condition of bare land; with the increase in snow cover thickness and the e