The total sediment yield from the 1999 Chichi earthquake to Typhoon Morakot in 2009 in the Chenyoulan River watershed is around 158.1×106 m3. The excess sediment yield has resulted
in serious sediment deposition, widening river width and river meandering in the Chenyoulan River. By comparison of DEMs from 2004 and 2010, sediment deposits are obvious at the convergences of the tributaries and the in main river. Especially apparent are the deposited depth of 2.9 m at
the convergence of the Junkeng River and the main river and the deposited depth of 2.6 m at the convergence of the Shibachong River and the main river. The serious sediment deposition has also resulted in river meandering and serious scouring upstream from the convergence of the Shibachong
River and the main river, and widening river width and scouring in the main channel downstream from the convergence of the Shibachong River and the main river.
Key Words : Excess sediment yield, sediment deposition, river morphology, Chenyoulan River.