How can data from headwater catchments be used to improve runoff and nutrient predictions at larger scales?

Abstract

Intuitively there should be a difference in the runoff and nutrient generation from catchment areas of varying sizes. The total runoff and constituent load can be modelled using one of the many hydrological models. However, how well a model performs can depend on the size of the catchment that it is applied to. In this study the modelling system Source Catchments is examined, to see if it can be improved when applied to different sized subcatchments to generate the total runoff and constituent concentrations. Within Source Catchments the AWBM model for predicting runoff on a daily timestep, is coupled with the EMC/DWC constituent generation model to predict sediment and nutrient concentratio..