River rejuvenation on a fluvial fan induced by typhoons and earthquakes
摘要
This study investigates decadal-scale river rejuvenation and migration in Taiwan’s Mu-Gua River watershed, influenced by typhoons and earthquakes. Typhoon Ofelia (1990) caused rapid sediment aggradation and channel instability, leading to severe damage and the relocation of Tung-Men Village. Analysis of historical hydrological and topographic data reveals that such extreme events accelerate riverbed incision and channel migration, disrupting fluvial equilibrium. Post-earthquake observations indicate heightened sediment transport during high-flow events within three years of seismic activity, while low-flow conditions show negligible differences. These findings underscore the profound influence of compound natural hazards on river morphology and community safety, highlighting the necessity of integrating geomorphic insights into disaster risk reduction and land-use planning.