Field Simulated Experiment on Erosion Processes of Different Farm Roads under a Heavy Rain in Red Soil Region

Zheng Haijin1,2 Yang Jie2 Zhang Hongjiang1 Wang Bangwen2 Xiao Shengsheng2 Duan Jian2(1.College of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China 2.Jiangxi Institute of Soil and Water Conservation,Nanchang 330029,China)

Farm roads,Red soil region of southern China,Erosion process,Sediment reduction rate

Totally 4 farm roads,i.e.the bare unpaved road,the stone covered road,the stone and grass covered road and the grass covered road,were selected on the representative area named Jiangxi Eco-science Park of Soil and Water Conservation.Twelve rainfall simulation experiments with an intensity of 3.0 mm/min were carried out on the selected roads.The results indicated that runoff from the farm roads was recorded less than 2 min.The runoff rate increased quickly and reached steady level in the first 2~6 min.The runoff coefficient was above 65%.The erosion rate was high at the beginning of the rainfall and then decreased due to the loss of fine soil surface particles and porosity changes.At later period,the erosion rate of the bare unpaved road increased to some extent due to the appearance of rill and micro-gully.Compared with the bare unpaved road,the stone covered road,the stone and grass covered road and the grass covered road can all change the runoff hydraulic characteristics,so to protect the farm roads and decrease sediment yield.The lowest benefit of sediment reduction was up to about 40% among them,and the grassed road had the best benefit of soil and water conservation.