Abstract:

The paper aims to provide a theoretical basis for the vegetation protection of gully. We observed the characteristics of producing runoff and sediment of 7 vegetation configurations on 1:1.5 and 1:1.2 ratio slopes, through the field experiment of the runoff plots. The results showed that: the runoff mainly changed with rainfall, which was affected greater than that of vegetation; the sediment was mainly concentrated in the early heavy rainfall, and the 15 mm rainfall was the threshold; the sediment increased significantly with rainfall above 15 mm; and little sediment was produced during the late growth period; the superior vegetation configurations of reducing runoff and sediment were not the same in different time periods; the effect of reducing runoff and sediment of Medicago sativa L. was good in the early stage, and Bromus inermis Leyss. and Poa annua L. were excellent with reducing runoff and sediment in the late stage; as the slope became steeper, the sediment was gradually increased with the growth of vegetation from the similar amount, and the amount of sediment was significantly increased only under heavy rainfall. In order to improve the ability to withstand heavy rainfall in the early stage, the mixed sowing proportion of Medicago sativa L. needs to be higher in the protection of gully.

Key words: Slope, Rainfall, Runoff, Sediment, Vegetation Configuration