Affiliation:
1. College of Resources and Environment, Southwest University, Tiansheng Road, Beibei District, Chongqing 400715, China
Abstract
The independent effects of hedgerow or grass ditches on the migration of runoff, sediment and nutrients are well known; however, the effects of combined hedgerow–grass ditch systems have rarely been assessed. Vegetation stem diameter (VSD) is an essential variable that changes the effectiveness of a hedgerow–grass ditch system in reducing runoff and sediment yield on sloping lands. A hedgerow–grass ditch system was simulated to interpret the effects of varied VSDs [i.e., 0 (control), 0.1, 0.2, 0.4 and 0.8 cm] in hedgerow on runoff and sediment yield by laboratory rainfall simulation. Compared to the control, the time to runoff initiation presented a 43.3% delay in 0.8 cm VSD (p < 0.05), and the runoff rate was significantly reduced by 16.6% in the 0.2 cm VSD and by 17.0% in the 0.8 cm VSD, respectively (p < 0.05). The sediment yield rate decreased by 74.2% and 85.8% relative to that of the control, respectively (p < 0.05). The reduction was 5.3–17.0% for the runoff rate and 3.5–85.8% for the sediment yield rate with varied VSDs relative to the control. The sediment yield rate decreased remarkably as an exponential function with increased stem diameter (p < 0.05). Our results have great significance for creating strategies for soil and water conservation on sloping lands.
Funder
National Natural Science Foundation of China
Technology Innovation and Application Development Project of Chongqing, China
Major Science and Technology Project of the Ministry of Water Resources, China
Graduate Student Research and Innovation Program of Chongqing, China
Innovation and Entrepreneurship Training Program for College Students