黄土丘陵区不同撂荒年限土壤入渗及抗冲性研究

为了评价植被恢复对撂荒地土壤性状的影响,采用时空互代法,以黄土丘陵区不同年限撂荒地为研究对象,利用"环刀法"和原状土冲刷试验结合室内理化分析对其渗透性能和抗冲性进行了研究。结果表明:同一撂荒阶段,土壤初始入渗速率、稳定入渗速率、平均入渗速率和抗冲系数均随土壤深度的增加而下降;随着撂荒阶段延长,表层土壤初始入渗速率、稳定入渗速率、平均入渗速率和抗冲系数均为撂荒前期显著增大,后逐步趋于稳定,撂荒阶段间的差异显著大于土层深度的差异。在黄土丘陵区,利用Kostiakov模型回归参数a可有效表征初始入渗速率,相关系数为0.999 1,用方正三模型回归参数f_1和K可同时表征初始入渗速率和稳定入渗速率,相关系数分别为0.869 4和0.998 1,其初始入渗速率相关性较模型Kostiakov差,结合使用两者可更好的表征土壤入渗过程。

Research on Soil Infiltration Capacity and Soil Anti-scouribility on Different Abandoned Land in the Loess Hilly Region

In order to evaluate the influence of vegetation restoration on soil properties of the abandoned land,in the paper we adopt the spatio-temporal substitution method,and took the abandoned land at different stages in the Loess Hilly Region as the research object.By combining with laboratory experiments and physiochemical analysis,soil infiltration and anti-scouribility were studied through the point-source infiltration method and undisturbed soil erosion experiment.The results indicated that.:at the same abandoned stage,initial infiltration rates (IIRs),stable infiltration rates (SIRs),average infiltration rates (AIRs),and anti-scouribility (AS) decreased with the increasing soil depth.As the abandoned stage extended,initial infiltration rates (IIRs),stable infiltration rates (SIRs),average infiltration rates (AIRs),and anti-scouribility (AS) in the surface layer increased significantly after the first pre abandonment,then gradually stabilized.The differences in abandonment phase was significantly greater than that between the soil layer.In the Loess Hilly Region,the Kostiakov model could effectively characterize the initial infiltration rate,and the correlation coefficient was 0.999 1.The Fang Zhengsan model parameters 1 and K could simultaneously characterize the initial infiltration rate and stable infiltration rate,the correlation coefficients was 0.869 4 and 0.998 1,respectively.Its initial infiltration rate was not as good as that of the correlation of the Kostiakov model.The process of soil infiltration could be well described by combining Kostiakov model and Fang Zhengsan model.