Characteristic Spatiotemporal Scales of Runoff and Sediment at the Plot Scale: Implications to Sediment Transport Modeling

Changing climate and topography gradients are factors that collectively account for the variability in water and sediment fluxes in large agricultural systems. This variability hinders the effective management and monitoring of water quality and nutrient cycling, and emanates from the characteristic spatiotemporal scales of runoff and sediment processes for both the smaller and larger systems. The aim of this study is to describe these characteristic spatiotemporal scales at the plot scale by accounting for the interplay between relevant erosion processes and the forcing characteristics. Two experimental cases with uniform slope are considered, rainfall simulators are used to generate rainfall, and runoff and sediment are continuously measured at a downstream weir. Our results show how the coevolution of the aforementioned processes affect the characteristic spatiotemporal scales of runoff and sediment transport. A qualitative assessment of the coevolution of the dominant processes and their impact on the hydrologic response and landscape evolution at the plot scale, combined with the observed spatial features of the plot throughout the rainfall event provide insight into the interplay between these processes. This study is a step towards understanding patterns of runoff and sediment and the associated propagation across scale, as well as informing sediment transport modeling.