Effects of check dam construction on sediment production and topographic changes in a gully in the Loess Plateau: A rainfall simulation experiment

To maintain a reasonable sediment regulation system in the Loess Plateau, it is critical to determine the effects of check dam construction on sediment production and topographic changes. An indoor simulation experiment was conducted to investigate sediment production at the outlet section of the gully and micro-topographic changes within the channel before and after dam construction. The results showed that check dam significantly affected the run-off and sediment transport processes in the watershed. Specifically, the cross-sectional morphology index (η) and the width-depth ratio increased by 10.23% and 40.44%, respectively, while sediment content and particle size decreased by 39.29% and 18.58%, respectively. Additionally, the relative importance of section parameters and micro-topographic parameters that affect sediment production rate and particle size was ranked using the random forest algorithm. The roughness after check dam construction was identified as a relatively important topographic factor affecting sediment production and particle selection by erosion. These findings provide valuable information for future check dam construction and development in the Loess Plateau region.