Abstract

Experimental studies provide a basis for understanding the mechanisms of rill erosion and can provide estimates for parameter values in physical models simulating the erosion process. In this study, we investigated sediment delivery during rill erosion in purple soil. We used the volume-replacement method to measure the volume of eroded soil and hence estimate the mass of eroded soil. A 12 m artificial rill was divided into the following sections: 0–0.5 m, 0.5–1 m, 1–2 m, 2–3 m, 3–4 m, 4–5 m, 5–6 m, 6–7 m, 7–8 m, 8–10 m, and 10–12 m. Erosion trials were conducted with three flow rates (2 L/min, 4 L/min, and 8 L/min) and five slope gradients (5°, 10°, 15°, 20°, and 25°). The eroded rill sections were refilled with water to measure the eroded volume in each section and subsequently calculate the eroded sediment mass. The cumulative sediment mass was used to compute the sediment concentration along the length of the rill. The results show that purple soil sediment concentration increases with rill length before eventually reaching a maximal value; that is, the rate of increase in sediment concentration is greatest at the rill inlet and then gradually slows. Steeper slopes and higher flow rates result in sediment concentration increasing more rapidly along the rill length and the maximum sediment concentration being reached at an earlier location in the rill. Slope gradient and flow rate both result in an increase in maximal sediment concentration and accumulated eroded amount. However, slope gradient has a greater influence on rill erosion than flow rate. The results and experimental method in this study may provide a reference for future rill-erosion experiments.

Highlights

  • Soil erosion is a serious problem in China

  • The experimental data fits to the model in Eq (3) are plotted in Fig. 2, and demonstrate how purple-soil sediment concentration varies along the rill length, for the different slopes and flow rates

  • Under conditions of known slope gradient and flow rate, the data followed the model closely: sediment concentration increased along the length of the rill but at a decreasing rate until the sediment concentration tended towards a stable value, and the rate of increase tended to zero

Read more

Summary

Introduction

Researching the soil erosion process and controlling soil and water loss important to improving human survival in the environment. It is important for the sustainable development of poor areas in China especially (Lei, How to cite this article Huang et al (2015), An experimental study of rill sediment delivery in purple soil, using the volume-replacement method. In regions with purple soil, rill erosion is an important mechanism of erosion on hillslopes, and is the main source of sediment particles in the watershed. Research into rill erosion in regions with purple soil remains limited

Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call