扇状地の無堤河川の築堤後の河道平面の変化に関する考察

抄録

This paper presents the morphological change of newly improved alluvial fan rivers by earth dike during the flood events in 2008 in the Philippines. Using satellite images before and after the construction works, the river conditions such as thalweg and channel width were illustrated to discuss the effect of man-made impacts such as dike confinement and sediment control dam in the upstream. So-called conversion and diversion in terms of thalweg positions were recognized to be reproductive even after the confinement by dike. Some sections of those rivers showed the tendency to enlarge the channel width due to large boulder bar. These phenomenons should be accumulated to guide us to design new dike alignment in natural braided rivers.