紫色丘陵区不同弃土弃渣下垫面入渗特征及影响因素

Infiltration characteristics and its influencing factors of different underlying surfaces from disturbed soils in purple hilly area

采用环刀法研究了紫色丘陵区不同碎石含量弃土弃渣下垫面的入渗特征及影响因素.结果表明,不同弃土弃渣下垫面入渗性能随碎石含量的增加而差异显著,其中,碎石含量为40%的弃土弃渣下垫面初始入渗率、稳定入渗率及平均入渗率分别是土质弃渣下垫面的1.30、1.13和1.54倍.不同下垫面初始入渗率和稳定入渗率与弃渣初始含水率、容重呈显著负相关,与下垫面总孔隙度、非毛管孔隙度呈显著正相关.其中,初始入渗率与初始含水率相关系数在-0.689^-0.912之间,稳定入渗率与容重相关系数为-0.745^-0.999,且稳定入渗率随非毛管孔隙度增加而显著提高.Horton模型对不同弃土弃渣下垫面入渗率与时间拟合的可决系数在0.899以上,且Horton模型计算入渗率与实测入渗率的相对误差在0.07%~6.60%之间,是紫色丘陵区分析不同弃土弃渣下垫面入渗过程的适宜性模型.研究结果可为紫色丘陵区弃土弃渣水土流失量预测和评价提供技术参数.

Infiltration characteristics of underlying surfaces from disturbed soils with different contents of rock fragments were studied by using ring sampler method in purple hilly area. These results indicated that： ①All underlying surfaces were significantly different in infiltration capability with increasing rock fragment content. The initial infiltration rate,stable infiltration rate and mean infiltration rate of the underlying surface with 40% rock fragment content were 1. 30,1. 13 and 1. 54 times greater than that of terrene underlying surface,respectively. ②The initial infiltration rate and stable infiltration rate of all underlying surfaces had significantly negative correlation with initial water content and bulk gravity,and had significantly positive correlation with total porosity and non-capillary porosity. The correlation coefficients between initial infiltration rate and initial water content varied from-0. 689 to-0. 912 and from-0. 745 to-0. 999 between stable infiltration rate and bulk gravity. Furthermore,the stable infiltration rate increased significantly with increasing non-capillary porosity. ③Determination coefficients for fitting infiltration rate and infiltration time by Horton model were over 0. 899,and its relative error between calculated infiltration rate by Horton and measured infiltration rate ranged between 0. 07% and 6. 60%. Hence,Horton model was suitable for analyzing the infiltration process of underlying surfaces in purple hilly area. These study results could provide some important parameters for predicting and evaluating soil and water loss from disturbed soils in purple hilly area.