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.