Fluvial Effects on Coastal Flooding in the U.S. Pacific Northwest
Tidal and fluvial forces can create compound flooding hazards in the U.S. Pacific Northwest because Pacific storms often result in large rainfalls. The total water level (TWL) of astronomical tides
Tidal and fluvial forces can create compound flooding hazards in the U.S. Pacific Northwest because Pacific storms often result in large rainfalls. The total water level (TWL) of astronomical tides and fluvial-induced water levels is used to calculate long-term frequency and duration of inundation in the fluvial system. Our analysis indicates that there is a linear relationship between detided water level elevation and river discharge when river discharge is above a certain stage. By applying 70-year (1940 – 2010) discharge values to the linear relationship, the 70-year time series of TWL is constructed and analyzed. Long term sea-level trends, increased frequency and intensity of storms, variations in rainfall and decadal variations in sea level due to the El Nino Southern Oscillation (ENSO) can also be incorporated in the total water level to predict coastal inundation in similar geomorphologic settings in the Pacific Northwest.
