Soft-rock erosion in the lower reaches of the Renyitan weir in the Pachang River is a problem, particularly in the riverbed between cross-sections 94 and 9732 (Xinshang Bridge). Anti-scouring check dams had been built,but exposed rock plates in some river sections remain problematic. Erosion of the rock riverbed could deepen after the next flood and subsequent period of weathering. To simulate this situation, this study used two types of rock bed scouring function in the NETSTARS (Network of Sediment Transport Model for Alluvial River Simulation) model.This special erosion–deposition simulation was executed with 15 years of hydrological data and riverbed sections of the Pachang River. The simulation results of both functions were better fitted to the riverbed variation of field data than were the general erosion–deposition simulation results. In this study, an error evaluation parameter was used to evaluate the accuracy of both functions, and the simulation that considered the suspension composition in the formula produced better results.
Key Words: Rock bed scouring, NETSTARS, check dam, erosion–deposition simulation