不同泥沙级配浑水灌溉入渗量及减渗作用分析

Analysis on Infiltration Capacity and Infiltration Reduction Effect of Muddy Water with Different Sediment Gradation under the Conditions of Irrigation

浑水灌溉是黄河流域普遍存在的现象,浑水中泥沙级配和浓度的大小对土壤入渗过程有很大的影响,不同泥沙级配和浓度的浑水入渗结果有显著差异。通过分析不同泥沙级配浑水灌溉入渗试验数据,并与清水灌溉入渗试验对照得出:不同泥沙级配浑水灌溉累计入渗量与时间的关系和清水相同,均为指数为正的幂函数曲线。相同含沙量、同一入渗历时,泥沙较粗的浑水始终比泥沙较细的浑水累计入渗量大。泥沙颗粒越细的浑水,其相应的累计入渗量越小,减渗量和减渗率越大;而相同累计入渗量条件下,泥沙颗粒越细,相应入渗历时越长。不同泥沙级配浑水相对于清水的时段减渗量和减渗率随时间均先增大后减小,最大值均发生在前50 min,泥沙组成颗粒越细,最大值出现的时间越早,同时刻浑水的减渗作用越强。

Muddy water irrigation is a widespread phenomenon of the Yellow River basin. Sediment gradation and concentration of muddy water has a great effect on soil infiltration process. The muddy water that has different sediment gradation and different sediment concentration＇s infiltration results has significant differences. Through analyzing the data from muddy water irrigation infiltration test with different sediment gradation and the clear water irrigation infiltration tests,we get the following conclusions： the relationship between accumulative infiltration capacity of muddy water with different sediment and time are consistent with clear water,both are power function relationship that＇s index is positive. At the same infiltration time in the condition of the same sediment concentration,the accumulative infiltration capacity of muddy water with coarse sediment gradation is always more than the muddy water with fine sediment gradation. The sediment particles of muddy water is finer,the corresponding cumulative infiltration capacity is smaller,the volume of reduction infiltration and rate of reduction infiltration is bigger; and in the condition of same cumulative infiltration capacity,muddy water＇s sediment particles is finer,the corresponding infiltration duration is longer. The volume of reduction infiltration and rate of reduction infiltration of different muddy water compared with fresh water are first increased and then decreased with time,and the maximum values all occur in the first 50 minutes,and the sediment particles in muddy water are finer,the maximum values appear earlier,the effect of corresponding muddy water reduction infiltration are stronger at the same time.