坡面生物调控措施对土壤水分入渗的影响

为了研究不同生物调控措施的植被覆盖度、降雨强度和坡度以及各因素间交互作用对土壤水分入渗的影响，本文通过室外人工模拟降雨试验，对不同生物调控措施坡面的土壤水分入渗规律进行了探索。结果表明：1）有生物调控措施坡面的土壤稳定入渗率较裸坡偏大，且差异极显著，但生物调控措施坡面之间的差异并不明显。2）降雨强度、坡度与土壤稳定入渗率间不是线性单值函数，均存在使土壤稳定入渗率最大的临界雨强与临界坡度。稳定入渗率随植被覆盖度增加的速率是非恒定的，存在着增速变化的临界植被覆盖度。临界植被覆盖度前，稳定入渗率的增加速率很快，之后，迅速降低并趋于稳定。3）坡面径流调控度随雨强增大而减小；相同雨强下不同措施坡面径流调控度排序为：黑麦草＞春小麦＞苜蓿＞裸坡。4）采用SPSS软件通过逐步回归分析法提取了影响土壤稳定入渗率最显著的单因子交互作用项，建立了包含降雨强度、坡度和植被覆盖度在内的多因素非线性入渗模型，通过实测数据对其进行验证发现该模型精度较高。

Impact of slope biological regulated measures on soil water infiltration

In order to research the impact of rainfall intensity, slope, vegetation coverage and the interaction between multiple factors on the soil infiltration, the soil infiltration law was researched under different biological regulated measures through the artificial simulated rainfall. The results indicated that the stable infiltration rate of hillslope with biological regulated measures was larger than those of hillslope without biological regulated measures, and the difference was extremely significant, however, the differences were not obvious among those hillslope with biological regulated measures. It was not a simple linear single-valued function between rainfall intensity, slope and the soil stable infiltration rate. There were critical rainfall intensity and critical slope to make the soil stable infiltration rate reach a maximum. The increasing speed of the stable infiltration rate with the increasing of vegetable coverage was not constantly, there was a critical vegetable coverage. Before the critical vegetation coverage, the increasing speed of the stable infiltration rate was very fast, while after that, the increasing speed of the stable infiltration rate reduced quickly and tended to stabilization. Runoff regulating degree decreased with the increasing of rainfall intensity. The sequencing of runoff regulating degree under different control measures in the same rainfall intensity was as follow: ryegrass> wheat> alfalfa> Bare. On that basis, by the stepwise regression analysis, the impacts of each factor and the interaction between the various factors on the stable infiltration were analyzed by using the t test to eliminate the item of independent variable insignificant, and a multiple non-linear model including rainfall intensity, slope and vegetation coverage was established. Finally, the measured data were used to prove this model fitness and feasibility.