Modelling upland and instream erosion, sediment and phosphorus transport in a large catchment

This overview presents background information to place the subsequent paper s by Beavis et al., Dietrich et al. and Green et al, in the context of a un ified approach. The modelling framework described here consists of two majo r components: an upland catchment model and an instream sediment transport model. The upland model simulates stream flow (Q), suspended sediment (SS) and associated phosphorus (P) using rainfall data, and is calibrated to dai ly stream flow time-series under historical conditions. The instream model routes SS and attached P from the outlet of upland catchments to gauging po ints downstream. The instream transport model can infer sources (resuspensi on and bank erosion) and sinks (deposition) within a reach. Aerial photogra phs are used to assess the on-site effects of climate and land cover/use on erosion and the drainage network. Changes in land cover/use and the effect s on the drainage network are related to the parameters in the rainfall-run off model so that associated effects on Q (and hence SS and P) can be asses sed. This modelling framework is prototyped on the Namoi Basin in northern New South Wales, Australia, and is described briefly herein. Copyright (C) 1999 John Wiley & Sons, Ltd.