In order to explore the difference of loess and red soil erosion affected by rainfall intensity and slope and its relationship with soil properties

various physical and chemical properties of loess and red soil were measured and analyzed

and four rainfall events were carried out on the two soils under two slope gradients (15°

20°) and two rainfall intensity (60

90 mm/h). The results showed that: (1) Compared with red soil

soil particles of loess were finer

and the differences in capillary porosity

saturated water content and field water holding capacity between loess and red soil were within 3% to 6%. There was no significant difference in the aggregates of each size of dry sieving

but the difference between the aggregates of the two was large after the destruction of wet sieving. The relative mechanical fragmentation index (RMI) of red soil was lower than that of loess. The organic matter content

cation exchange capacity and complex oxide content of loess were all higher than that of red soil

while amorphous oxide and free oxide were lower than that of red soil. (2) Under the same rainfall intensity and slope conditions

the runoff generation time of loess was shorter than red soil

after the start of runoff

red soil reached a stable runoff rate before loess. Under different rain intensity and slope conditions

the stable runoff rate of red soil ranged from 30 to 120 mL/s

while that of loess was between 100 to 220 mL/s. And within this range of slope and rain intensity

the runoff rate of red soil varied in distinct layers

while that of loess was staggered and complex. (3) The sediment yield and runoff sand content rate of red soil were both low

and the maximum sediment yield rate usually occurred within a few minutes of runoff. The sand yield rate of loess was similar to the runoff rate

it increased rapidly in the early stage of runoff

and then began to fluctuate after 10 minutes. When it entered the stage of relatively stable sediment yield

the sand yield rate and runoff sediment rate changed complicated with rainfall intensity and slope. (4) Different physical and chemical properties of soil were the internal factors affecting slope erosion. Compared with loess

red soil had better infiltration capacity and stronger resistance to runoff shear and denudation. The erosion degree of red soil under the same rainfall intensity and slope condition was much lower than that of loess

and the regularity was more obvious.