论文部分内容阅读
季节性冻融是干旱区土壤盐碱化形成的主要驱动因子,但冻融过程中土壤水盐耦合关系及热量调控机理仍不清楚。通过分析2009年11月~2010年5月新疆玛纳斯河流域典型盐荒地季节性冻融过程中土壤剖面160 cm以内的水分、盐分和温度动态变化,探讨了不同土层冻融过程中水热盐的耦合关系。结果表明:土壤最大冻结深度为150 cm左右,表土层(0~40 cm)温度与气温关系密切;土壤剖面水分呈现“C”型垂直分布,表土层和底土层(100~160 cm)含水量较大,而心土层(40~100 cm)含水量不足10%,土层平均含水率在冻融前期增加了12.91%,而在初蒸期减少了10.01%;土壤剖面盐分在冻结期和初蒸期表聚作用明显,心土层和底土层含盐量稳定,土壤剖面含盐量表现为“积盐-脱盐-再积盐”的变化过程。水热盐之间具有高度协同性,心土层和底土层表现为水盐相随、而表土层为水去盐留的耦合特征,热量传输是调控水盐运移的关键因素。
Seasonal freezing and thawing are the main driving factors for the formation of soil salinization in arid regions. However, the coupling of soil water and salinity and the mechanism of heat regulation are still unclear. Through the analysis of the dynamic changes of water, salinity and temperature within 160 cm of the soil profile during the seasonal freeze-thaw process in the salt deserts of the Manas River Basin in Xinjiang from November 2009 to May 2010, the effects of water Thermal salt coupling. The results show that the maximum freezing depth of soil is about 150 cm, and the temperature of top soil layer (0 ~ 40 cm) is closely related to temperature. The vertical distribution of soil water content is “C”, and the topsoil and subsoil (100 ~ 160 cm) The moisture content in the soil layer (40 ~ 100 cm) is less than 10%, the average water content in the soil layer increased by 12.91% in the early period of freezing and thawing, and decreased by 10.01% in the initial steaming period; The synergistic effects of period and initial steam table are obvious, the salt content in the heart and soil layers and the subsoil are stable, and the salt content in the soil profile appears as the process of “salt-desalination-re-salt accumulation”. The hydrothermal salt has a high degree of synergy, the soil layer and the subsoil behave as the water-salt phase, and the top soil layer is the coupling feature of the water-to-salt retention. The heat transfer is the key factor to regulate water and salt transport.