Current numerical models for debris flow simulation usually use one�]dimensional models in gullies and two�]dimensional models in alluvial fans. However, using different models gives inaccurate results in the boundary areas between gullies and alluvial fans. In this study, we aimed to improve results in the boundary areas by constructing an integrated model. We used one�]dimensional models in gullies and two�]dimensional models in alluvial fans for each timestep, but the procedure considered the mutual influence between these models at the boundary areas. Using our integrated model, we simulated debris flow on a virtual watershed that had different slope angles between a gully and an alluvial fan. The results demonstrated that our integrated model provided a more rational description of debris flow in the boundary areas. This led to more accurate results in the alluvial fans. Therefore, our integrated model is more effective at numerically simulating debris flow than current models.


Key words�Fdebris flow, numerical simulation, 1�] and 2�]dimensional integration model