The sediment yield caused by rill erosion is the main source of sediment yield in the water-wind erosion crisscross region of the Loess Plateau. It is of great scientific significance and practical value to make clear the characteristics of rill erosion process and its influencing factors in this region

so as to effectively prevent and control sediment entering the Yellow River and effectively maintain the safety of the watershed. In this study

the typical aeolian sandy soil on the underlying surface in the water-wind erosion crisscross region was selected as test soil

and the indoor flume scouring experiments with different flow discharges (3

5

7

9

11 L/min) and different slope gradients (9°

12°

15°

18°

21°) were carried out

so as to establish equations

which could quantitatively reveal the response of rill detachment capacity to slope gradient

flow discharge and flow velocity. The results showed that: (1) The responses of detachment capacity to slope gradient and to flow discharge were both linearly and positively correlated

and the correlation were significant. The influence of flow discharge on detachment capacity was greater than that of slope gradient. In addition

detachment capacity was also affected by the superposition effect of slope gradient and flow discharge. The order of the influences on detachment capacity were: flow discharge

superposition effect of slope gradient and flow discharge

slope gradient. The relationships between detachment capacity and above three factors could also be well expressed by linearly positive correlations. (2) Flow velocity could be used as a key factor to reflect the superposition effect between slope gradient and flow discharge. There was a significant positively linear correlation between rill detachment capacity and flow velocity. Under the experimental conditions

the critical velocity was 0.607 m/s. (3) The four detachment capacity equations under the combination of slope gradient and flow discharge

under the combination of slope gradient

flow discharge and the superimposed effect of slope gradient and flow discharge

under the single flow velocity factor

and under the combination of slope gradient

flow discharge and flow velocity factor could predict and simulate the detachment capacity of aeolian sandy soil well

among which the equation considering the combination of slope gradient

flow discharge and the superimposed effect of slope gradient and flow discharge was the best. The results provide a theoretical basis for perfecting the rill erosion process model in water-wind erosion crisscross area.