EROSION CHARACTERISTICS OF SEA CLIFF ON THE FUKUSHIMA COAST

摘要

The Fukushima Coast composed of a series of soft rock cliffs had suffered from severe erosion due to two factors: high wave attacks and weak rocks. This study attempts to quantify these factors, respectively, by the onshore component of wave energy flux at the breaking point, F, through the refraction analysis, and by Young's modulus, E, through the measurement of the elastic wave. The dimensional consideration yields a dimensionless parameter Πc ≡ qEL/F where q is the recession rate, L is the cliff height. On this coast, the value of ΠC = 0.082 obtained from the best fit of the present data-set gives the recession characteristic q = 0.082F/EL.