松嫩平原盐碱土水分扩散率研究

Study on Saline-alkali Soil Moisture Diffusivity in Songnen Plain

对盐碱地土壤水盐运动的定量描述是控制区域土壤次生盐碱化的基础，其中的土壤水分扩散率是研究土壤水盐运动的重要参数之一。文章通过非稳定流水平土柱法对实验区扰动的盐碱地土壤水分扩散率进行了测定，并将实验结果拟合为经验公式，然后将测定的土壤水分扩散率应用于水平入渗方程，用数值计算软件Mathcad6.0对土柱水分水平入渗进行了数值模拟，将实测结果和方程模拟的土壤水分分布状况进行了对比。结果表明本研究得出的土壤水分扩散率的经验方程误差较小。最后讨论了影响土壤水分扩散的土壤质地因素及土壤水分扩散率和含水率之间的单值函数关系。

The quantificational study on water and salt motion in saline-alkali soil is the foundation to control the soil secondary saline-alkalization in region, and moisture diffusivity of saline-alkali soil is one of the essential parameters to study quantificationally water and salt motion in saline-alkali soil. In this paper, the method of unsteady flow horizontal soil pillar is applied to determine soil moisture diffusivity of disturbed saline-alkali soil, and the experiment results are modeled into experience formulae which are applied to calculate the saline-alkali soil moisture diffusivity by the soil water content. Furthermore, the determined saline-alkali soil moisture diffusivity is applied by the horizontally infiltration equation, and the relationship between distance of water moisture horizontal movement and water content and time in saline soil is simulated with Philip's interactive method. The study results show that the experience formulae which is obtained can be used in the water flow simulation in unsaturated soil water movement and get relatively accuracy results.