A conceptual model of sediment transport: application to the Avon River Basin in Western Australia

Abstract

Abstract:This paper deals with the coupling of a sediment modelling algorithm to an existing conceptual model of water and salt¯uxes (LASCAM). In the model, sediment generation is based on a modi®ed version of the universal soil loss equation. The sediment transport processes of channel deposition and re-entrainment, and bed degradation are coupled with the existing stream-routing algorithm of LASCAM. The model is applied to the Avon River Basin, a large, dry catchment in Western Australia. The paper highlights some of the scienti®c issues involved in quantifying the sediment discharge processes in this catchment and presents validation results comparing model predictions with observations of sediment transport at dierent locations in the catchment. The results indicate that despite the strongly non-linear relationship between stream¯ow and sediment load, both are predicted well by the model. The model also highlights that in the Avon River Basin, disproportionately more stream sediment is generated in the wheat belt region than in the lower catchment.

Modelling catchment processes in the Swan–Avon river basin

“…This problem is addressed in the first part of the Results section. Viney and Sivapalan (1999) also presented coincidental water and sediment flux calibration results for many other streams in the Avon River basin. They showed that LASCAM is capable of providing excellent predictions across a wide range of climate and land-use regimes in what is a large, heterogeneous catchment.…”

Evaluation of Human Impact on Sediment Dynamics in an Intensively Managed Agricultural Watershed Using Distributed Modeling

“…The modeling framework adopted for this study combines a network hydrology model based on the representative elementary watershed (REW) theory (Reggiani et al 2001) with a network sediment-transport model (Viney and Sivapalan 1999) within the context of a large scale catchment model (LASCAM) (Sivapalan et al 2004). Only key processes are described here for the sake of brevity.…”

“…Modeling of deposition and entrainment in channels follows the conceptual model of water and sediment fluxes developed from the LASCAM model (Viney and Sivapalan 1999). Sediment entrainment in the channel is a function of stream carrying capacity and critical shear stress.…”

“…Sediment is generated on hillslopes and transported into river channels by surface runoff. The sediment erosion rate on hillslopes is a generalized formulation of the Universal Soil Loss Equation (USLE) (Viney and Sivapalan 1999). This generalized formulation allows hillslope sediment delivery to channels to be calibrated to data on stream sediment loads by varying the value of the cover management factor ( C ) while accounting for the effects of modeled in‐channel fluxes of sediment.…”

Soil Loss Assessment Using the Revised Universal Soil Loss Equation (RUSLE) Model

“…Here, underlying transfer mechanisms that involve generation of sediment and runoff are incorporated in the model where flow paths within the catchment are represented as storages in a series form where the dynamic behavior of each requires some characterization [39]. Some good examples of conceptual models include Chemical Runoff and Erosion from the Agricultural Management Systems (CREAMS) model [61] and Large Scale Catchment Model (LASCAM) [62].…”