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桂西北喀斯特地区土壤中常常含有土石隔层,分析其对土壤水分入渗过程的影响有助于深入研究该区水循环机理和促进植被恢复重建进程。通过室内模拟土柱试验,研究了不同土石隔层碎石粒径(5～20,20～40 mm)及土石隔层(土石质量比为1:1)位置(上层(0～20 cm),中层(10～30 cm),下层(20～40 cm))对土壤水分入渗过程的影响。结果表明,碎石粒径为5～20 mm时,土石隔层位于中层时土壤累积入渗量最大。碎石粒径为20～40 mm时,土石隔层位于下层时土壤累积入渗量最大。当土石隔层位置一定时,碎石粒径较小有利于土壤水分入渗;粒径为5～20 mm的土石隔层土壤稳定入渗速率最大,且达到稳定入渗的时间最短,但土层隔层位于下层时均质土壤及不同粒径土壤的稳定入渗速率无显著差异。土石隔层位置和隔层碎石粒径对初始入渗速率没有显著影响;土石隔层位于上层时,土石隔层的存在缩短了水分入渗运移过隔层的时间。土石隔层位于中层时,隔层碎石粒径为20～40 mm时水分入渗到达隔层及运移过隔层的时间最长。土石隔层位于下层时,隔层碎石的存在缩短了水分入渗到达隔层及运移过隔层的时间。Kostiakov入渗模型与Philip方程都可以较好地描述含土石隔层土壤的入渗过程,但Kostiakov入渗模型模拟效果更好。
The soil compartment in the karst area of northwestern Guangxi often contain soil-stone intercalations, and its influence on soil water infiltration process is helpful to further study the water cycle mechanism and promote the process of vegetation restoration and reconstruction. The indoor soil column simulation was used to study the location of the gravel (5 ~ 20,20 ~ 40 mm) and the earth-rock layer (1: 1 mass ratio) (10 ~ 30 cm) and lower layer (20 ~ 40 cm) on soil water infiltration process. The results show that when the diameter of gravel is 5 ~ 20 mm, the cumulative infiltration of soil into the middle layer is the largest. When the gravel diameter is 20 ~ 40 mm, the cumulative infiltration of soil is the largest when the soil layer is located in the lower layer. When the position of soil-stone interlayers is fixed, the smaller gravel diameter is conducive to soil water infiltration. The soil infiltration rate of soil-stone interbed with particle size of 5-20 mm is the largest and the infiltration time reaches the minimum, There was no significant difference in the steady infiltration rate between homogeneous soil and different size soils when the interlayer was located in the lower layer. The location of the earth-rock barrier and the size of the gravel did not significantly affect the initial infiltration rate. The presence of the earth-stone barrier shortened the time for water infiltration to move through the barrier when the earth-stone barrier was located in the upper layer. When the earth-rock layer is located in the middle layer, the infiltration of water infiltrates into the layer and migrates through the layer for the longest time when the particle size of the layer is 20-40 mm. The presence of barrier gravel shortens the time it takes for water infiltration to reach and move through the barrier when the barrier is in the lower level. Both the Kostiakov infiltration model and the Philip equation can well describe the infiltration process of the soil with the soil compartment, but the Kostiakov infiltration model is more effective.