Taiwan island is the product of an oblique collision between the
Luzon arc, the Philippine Sea Plate and the Eurasian continental
margin. The orogen yields an uplift rate which averages 5–7 mm/yr
(Li, 1976; Willett et al., 2003), but the integration of frequent typhoon
attacks, 4 per year on average, with earthquake activities results in an
average sediment discharge of 384 Mt per year to the ocean and a
rapid erosion rate of 3–7 mm/yr (Dadson et al., 2003). Dadson et al.
(2004) and Lin et al. (2008a) report that after the 1999 Chi-Chi
earthquake, the concentration of suspended sediment increased 2–4
fold in central Taiwan, the epicenter area of Chi-Chi earthquake. The
residual sediment in upstream channel or on hillslope was delivered