Abstract:

By setting up standard runoff plots to carry on long-term positioning monitoring, the authors explored the effect of different land use on slope runoff and sediment production under natural rainfall condition, aiming to provide a theoretical basis for watershed land use plan, comprehensive management of soil erosion, and improvement of ecological environment. Based on 8 runoff plots with 2 slopes and 6 different land use types, natural rainfall and runoff observation were conducted. The results showed that (1) the rainfall in the experiment period was higher than that of the average rainfall in the same period of many years, which was a high glow year, and the rainfall distribution of the year was larger than that of the average rainfall in many years; (2) the amount of runoff was significantly different under different land use patterns, the amount of runoff under different land use was the highest in bare slope land when the slope was 15°, followed by slope cropland and grassland; the amount of runoff under 18° was followed the order of bare slope land >grassland > forest plot (Pinus tabuliformis Carrière) > shrub plot (Rosa xanthina Lindl); (3) the land use patterns influenced clearly the amount of sediment, the amount of sediment under 15° slope followed the order of bare slope land > flax > potato > grassland; while as to 18° slope, the amount of sediment from the shrub plot and forest plot was the least, which was 0.30 t/hm², and the amount of sediment from the bare slope was the highest, which was 92.08 times of that of forest plot; the effect of reducing runoff and sediment in forest and grass was obvious. The study could provide reference for ecological reconstruction, and land use plan for small watersheds in the upper reaches of Fenhe River.

Key words: Loess Hilly Region, High Flow Year, Land Use, Fenhe River, Water and Soil Erosion, Characteristics