Initially, SPHY development focussed on soil erosion and sediment transport. The empirical Modified Universal Soil Loss Equation (MUSLE) was already implemented by previous developers. However, we had the feelint that this model did not agree well with the process-based nature of the SPHY model. Hence, we implemented the process-based Morgan-Morgan-Finney soil erosion model into SPHY. This model requires more input than MUSLE, but most model parameters are measurable which makes the application relatively easy. At the same time we also implemented a sediment transport module, to determine sediment yield at the catchment outlet or reservoirs. Soil erosion mostly occurs during extreme rainfall events when the rainfall intensity is often higher than the infiltration rate. Therefore, we also implemented a daily derivation of the Green-Ampt infiltration capacity equation to account for infiltration excess surface runoff.