The 24th IAHR-APD Congress (24th IAHR-APD Congress)

259 / 2024-02-28 19:10:44

The nonlinear relationship between tidal surge and runoff under the influence of typhoons

Typhoons,tide-surge-river interaction,FVCOM

Abstract: Typhoons can cause extreme natural disasters，such as storm surges , extreme precipitation, and coastal flooding, seriously affecting the safety of human 's life and property. In estuaries, strong nonlinear interactions are reported exist between surges, tides and the river discharge. This interaction may elevate the surge levels and exacerbate the coastal flooding harzard. Previous studies have shown high-frequency tids are strengthened by typhoons in coastal areas (>4 cycles/day). Quantitative evaluation of their importance on surges in estuaries (which we consider tidal river interactions) is needed but not well documented in literatures. This study establied a high-resolution numerical model for the Pearl River Estuary based on the FVCOM model, and applied in quantifing the nonlinear tide-surge-river interaction on the surges and extreme water levels during Typhoon Koinu. The results show that the tide-surge-river interaction can induce higher surges in most area of the estuary . The nonlinear effect is mainly generated by the convection term.