Predicting sediment rating curves with a cellular landscape model

Sediment rating curves are used frequently to estimate suspended sediment concentration for the subsequent calculation of sediment fluxes and to establish sediment budgets. This paper discusses a cellular model (Cascade 6) of erosion and sediment transport in a drainage basin that is used to derive sediment rating curves. In Cascade 6, water and sediment are routed from each cell to its lowest neighbour, and ultimately, to the drainage basin outlet. The sediment flux from one cell to the next is a nonlinear function of discharge and slope. The Cascade 6 model was applied to the 45-ha Catsop basin, a loess-covered agricultural basin with a gently to moderately sloping topography located in South-Limburg, The Netherlands. The Cascade 6 (a partly empirical model) results compare favourably with those generated by LISEM (a fully physically-based model). However, Cascade 6 is far less demanding in terms of input data, which gives it a distinct advantage as the interpretation of the modelling results is much more straightforward.