WONGSA Sanit and i SHIMIZU Yasuyuki Graduate School of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo, JAPAN, Division of Environment and Resources Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo, JAPAN.
The potential for flood and sediment material is strongly affected by river meandering and changes in land use. Therefore the modelling of pre-channelization and land use change is important with respect to prediction of flood, sediment yield and its on-site consequences. However, the impact of sediment yield in difference environments and how this affects sediment materials delivery to downstream area are incompletely understood. Therefore, modelling of the effects on pre-channelization and land use change could help us to better understanding the alluvial river systems. The proposed model obtained from this study was used to simulate possible past As such, pre-channelization and land use change in six rivers of Hokkaido region were analyzed by comparing two scenarios. Performance of the proposed numerical model was applied to simulate flood events in 1975, 1992 and 1998 to test the hypothesis that pre-c change would also be an important component of reducing/increasing flood and sediment yield in Hokkaido region. The results indicate that pre-channelization has a significant impact on flood peak, but no significant effect on sediment yield. In contrast, land use change has significant effect on eroded soil from hillslope, but no significant effect on flood for a large scale river