盐渍土壤孔隙结构及分形特征研究

发布时间：2018-09-12 10:56

【摘要】：为了探明盐分对土壤孔隙特征及分形特征的影响,采用CT(computed tomography)扫描技术获取了6个盐分处理(ECe:S1=8.52 d S/m,S2=21.89 d S/m,S3=24.78 d S/m,S4=25.71 d S/m,S5=26.36 d S/m,S6=33.26 d S/m)的土壤分层剖面图像,并结合Image J软件提取分析了土壤孔隙数目、孔隙面积等参数在土壤剖面上的分布特征,同时,采用杨培岭模型计算了土壤分形维数。结果表明:盐分影响土壤孔隙结构的形成和分布,具体而言,从S1到S6,随着盐分的增加,土壤孔隙度先减小后增加,S1盐分处理(ECe=8.52 d S/m)的孔隙度明显大于其他盐分处理,并且,S1盐分处理的孔隙度波动也大于其余5个盐分处理,S4(ECe=25.71 d S/m)盐分处理的孔隙度最小;此外,土壤孔隙数也表现为先减少后增加的趋势,S4(ECe=25.71 d S/m)总孔隙数最少(481)。在本次土样深度分析范围(6.3~44.1 mm)内,土壤孔隙结构随深度并无明显的关系。土壤分形维数计算结果表明,盐分影响土壤的分形维数,随着盐分的增加,分形维数先减小后增大,S4最小(2.58),同盐分对土壤孔隙的影响规律一致,进一步说明盐分影响土壤的物理性质,同时壤土(S1和S6)的分形维数大于粉质壤土(S2~S5),说明土壤质地变细,分形维数有增大的趋势。同时,和其他获取土壤孔隙结构特征的方法相比,CT结合Image J的方法可以快速准确地获取土壤孔隙的大小、数目等几何参数,处理过程方便快捷,操作简单,更能批量处理。
[Abstract]:In order to find out the effect of salinity on soil pore and fractal characteristics, the soil stratification profiles of 6 salt treatments (ECe:S1=8.52 d S / m ~ (2) S ~ (2 +) (ECe:S1=8.52 d S / m ~ (2) S ~ (2) 21.89 d S / m ~ (3) S ~ (3) = 24.78 d S / m ~ (4) S ~ (4) ~ 25.71 d S / m ~ (5) ~ (26.36) S ~ (r) S ~ (633.26) d S / m) were obtained by CT (computed tomography) scanning technique. The distribution characteristics of soil pore number and pore area in soil profile were analyzed by Image J software. At the same time, the fractal dimension of soil was calculated by using Yang Peiling model. The results showed that salinity affected the formation and distribution of soil pore structure. Specifically, from S1 to S6, the porosity of soil porosity decreased first and then increased with the increase of salt content. The porosity of ECe=8.52 d S / m was significantly higher than that of other salt treatments. Moreover, the porosity fluctuation of S _ 1 salt treatment was higher than that of the other five salt treatments, and the soil porosity was the smallest in the salt treatment (ECe=25.71 d / m), and the soil porosity number was the lowest (ECe=25.71 d S / m), which decreased first and then increased (481). In the range of soil sample depth analysis (6.3N 44.1 mm), there is no obvious relationship between soil pore structure and soil depth. The results of soil fractal dimension calculation show that salt affects the fractal dimension of soil. With the increase of salt, the fractal dimension decreases first and then increases to the minimum (2.58), which is consistent with the effect of salt on soil porosity. It is further explained that salt affects the physical properties of soil, and the fractal dimension of loam (S1 and S6) is larger than that of silty loam (S2~S5), indicating that the soil texture becomes thinner and the fractal dimension increases. At the same time, compared with other methods to obtain soil pore structure characteristics, CT combined with Image J method can quickly and accurately obtain the geometric parameters of soil pore size and number, the processing process is convenient, the operation is simple, and the batch processing is more convenient.
【作者单位】：武汉大学水资源与水电工程科学国家重点实验室;长江水利委员会长江勘测规划设计研究院;江苏省盐城市第三人民医院;
【基金】：国家自然科学基金项目“考虑补偿效应的盐渍农田作物水氮吸收规律研究与模拟”(51609157);“基于作物生长模拟的盐渍农田水肥生产函数研究”(51379151)
【分类号】：S156.4

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