Journal of the Japan Society of Erosion Control Engineering, Vol.59,No.5,2007
Development of 2D numerical model of mudflows for estimation of sediment
deposition in volcanic basins
Naoki MIYAZAWA Kengo SUNADA Satoru OISHI
Abstract
2D numerical model of mudflows has been developed considering the estimation of
sediment deposition in volcanic basins. Equations of erosion/deposition rate of
suspended sediment were used in the 2D numerical mudflow model developed by Miyazawa
et al. (2002). The previous mudflow model is improved in the present study by
using the equations of erosion/deposition rate applicable to mudflow, which were
determined empirically by laboratory tests from Hirano et al. (1997), Egashira
et al. (1993) and Winterwerp et al. (1990). The erosion/deposition rates are related
with the hindered settling velocity. The revised model was applied to compute
the bed elevation variations inside Mega]Dike system in the lower Pasig]Potorero
River basin near the Mt. Pinatubo, Philippines. It is found that the simulated
bed variations are in reasonable agreement with the measurements. Using the model,
the deposition areas of sediment to the several scale flood determined virtually
are calculated numerically and estimated in the Pasig]Potrero River basin.
Key words:mudflow, 2D numerical model, volcanic basin, Pasig]Potrero River basin,
hindered settling
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