Modeling of Sediment Transport Capacity by Overland Flow Using Multifactorial Analysis: Flume Experiment

Department of Civil Engineering, Faculty of Engineering, Universiti Pertahanan Nasional Malaysia, Malaysia

^* Corresponding author: zuliziana@upnm.edu.my

Abstract

Sediment transport capacity (STC) is critical in predicting soil erosion under overland flow, especially on sloped and vegetated terrains. This study aims to assess the influence of hydraulic parameters (flow velocity, depth, shear stress, unit stream power) and root mass density on STC and to develop an empirical model through controlled flume experiments. Experiments were conducted under bare and vegetated surface conditions with varying slopes. STC was calculated from sediment mass collected at the flume outlet. Flow properties were derived using standard hydraulic equations, while root mass density was obtained from soil volume and dried root mass. Multiple linear regression was used to analyze variable contributions to STC. Unit stream power showed the strongest positive influence on STC (β = 0.689), while root mass density had a negative effect (β = –0.235), suggesting a stabilizing role. However, none of the predictors were statistically significant (p > 0.05). Visual trends indicated lower sediment transport in vegetated conditions, especially at higher velocities and slopes. The findings support integrating both hydraulic energy and vegetation factors into erosion prediction models and offer a base for improving land management in erosion-prone areas.