温度势梯度下土壤水平一维水盐运动特征的实验研究
One-Dimensional Water and Salt Transport Induced by Temperature Gradient
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摘要: 为了分析温度势梯度作用下的土壤水平一维水盐运动特征,该文对土柱中存在温度势梯度时不同初始含水率下水盐运动的实验结果进行了分析。通过对瞬态温度变化过程和稳态温度形成特征的探讨,研究了温度势梯度存在时水平一维土柱中水盐运动的特点。在温度势梯度影响下土壤水分总体上从暖端向冷端迁移,而土壤盐分则以某位置为临界点在暖端累积,在该临界位置前后土壤含盐量与初始含盐量相比,由高于该值到低于该值,并在接近冷端处与初始值相同Abstract: The experimental results of the soil moisture and salt content with temperature gradient at different initial soil moisture levels were analyzed in this paper in order to illustrate water and salt transport characteristics with temperature gradients. The features of transient and steady temperature were considered in detail, and the characteristics of soil moisture and salt transport were studied. Under the influence of the temperature, water moves in both liquid and gas form; and moisture is transported from the heated end to the cool one, while salt accumulates at the heated end before critical position. Near the critical position soil salt goes from being larger to smaller than the initial value, while near the cool end it is close to the initial value.