Abstract:

By using a method of overflowing in a slope plot, a final infiltration rate on hillslopes under 4 typical vegetation forms and the influencing factors were investigated in the small watershed of Diediegou. The result showed that the final infiltration rate of different vegetation types were: natural grassland＞shrub of Ostryyopsis davidiana＞ shrub of Hippophae rhamnoides＞ plantation of Larix principis-rupprechtii. The final soil infiltration rate on different slope aspects showed shady slope ＞ semi-shady slope ＞ semi-sunny slope. The final soil infiltration rate under different slope position exhibited midst slope position ＞ lower slope position ＞ upper slope position. The final soil infiltration rate under different slope gradient showed middle slope gradient ＞steep slope ＞gentle slope. The final infiltration rate increased with rising slope gradient as the slope gradient is smaller than 25°, and decreases with slope gradient as it is higher than 25°. Based on the data, the dominant influencing factors were discovered, and the relations between infiltration rate and influencing factors were obtained by step-wise regressing analyses for the cases below or above the slope gradient to 25°.

Key words: soil infiltration, final infiltration rate, influencing factors, Liupan Mountains