辽西低山丘陵区坡地砾石含量及粒径对土壤入渗性能的影响

基于室内土柱模拟试验对比分析辽西低山丘陵区坡地不同粒径及砾石含量的土壤入渗规律,并采用4种模型分析了含砾石土壤对传统土壤入渗模型的适用性。结果表明:粒径一定时,随砾石含量的增加土壤累积入渗量减少,随累积入渗量的增加土柱湿润锋变化速率由小变大;砾石含量小于20%时,湿润锋前进到一定深度下,土壤累积入渗量随粒径的增加而增大;当砾石含量增大到一定值时,砾石含量相同直径不同的土壤累积入渗量与湿润锋随时间的变化基本无差异。累积入渗量与湿润锋推进距离呈良好的线性关系。利用Green-Ampt模型、通用模型、Horton模型和Kostiakov模型对入渗率与入渗历时的关系进行拟合,其中砾石含量为5%时,Horton模型拟合效果最好,砾石含量为10%~30%时通用模型适用性更强,Horton模型拟合效果最差,其他模型拟合效果因砾石含量及粒径等因素的不同而异。

Effect of Gravel Content and Particle Size on Soil Infiltration in Low Mountainous Uplan[1]d Region of Western Liaoning Province

The study based on laboratory soil-column experiments to research the effects of different gravel content and particle size on soil infiltration process and the applicability of the traditional soil infiltration model by four models.The results showed that the cumulative infiltration of soil decreased with the increase of gravel content,and the change of the wetting front in soil column was reduced and gradually tend to be level off with the increase of cumulative infiltration.When the gravel content was less than 20％,the cumulative infiltration rate increased with the increase of the particle size,and there was no difference betwee n the cumulative infiltration and wetting front with time when the gravel content increases to a certain value (20％～ 30％).There was a good linear relationship between the amount of cumulative infiltration and wetting front distance.Green-Ampt model,General model,Horton model and Kostiakov model were used to fit the relationship between infiltration rate and infiltration duration.Horton model showed best fitting effect when the gravel content was 5％,but worst in 10％～30％,while general model was more applicable,the fitting effect of other models varied with gravel content and particle size.