Author(s)

Wei Zheng¹, Hui Zhang¹, Yun Jiang², Xin Zhang¹, Yawen Tong¹, Qingfeng Zhang^1*

¹College of Natural Resources and Environment at Northwest A & F University, Yangling, China.
²Department of Foreign Languages at Northwest A & F University, Yangling, China.

Slope gradient is one of the critically important factors which drive the erosional response of microtopographic surfaces. This study investigates the effect of slope gradient on the evolution of erosion under accumulative rainfall in laboratory experiments and calculates critical slope values that help evaluate land suitability for farming and similar purposes. Dynamics of accumulative runoff, accumulated sediment and their rates in each erosion stage are studied when the slope gradient varies. The critical slope value for the microtopographic surface was calculated according to the relationship between the sediment yield and slope gradient. The amount of eroded soil downhill in each erosion stage was calculated using DEM data of point cloud. Results show that 1) a steeper slope would increase cumulative runoff; 2) cumulative sediment increases rapidly initially and then stabilizes with the increase of slope; 3) the critical slope value for the whole erosion is determined as 10°. The findings of the dynamics of interrill erosion and sediment characteristics are useful information for future research of erosion prediction and conservation of soil and water in the Chinese Loess Plateau.

Critical Slope Values, Cumulative Runoff, Cumulative Sediment, Interrill Erosion, Rate of Erosion

Zheng, W. , Zhang, H. , Jiang, Y. , Zhang, X. , Tong, Y. and Zhang, Q. (2019) Effect of Slope Gradient on Erosion Evolution Process at Microtopographic Tillage Soil Surfaces. Journal of Geographic Information System, 11, 481-492. doi: 10.4236/jgis.2019.115029.