1:45 PM - 3:15 PM
[O07-P14] The Change of Microtopography of Samejima Coast Caused by the Storm Surge Brought by Hagibis
Keywords:Samejima coast, Hagibis, level surveying, grain size analysis, trench surveys
The Enshu Sea Samejima coast, where our school conducts regular surveying, showed significant coastal erosion on October 17, 2019, with the shoreline receding and the boardwalk destroyed. A study was conducted to elucidate the extent and cause of this damage.
We conducted meteorological observations, aerial photography, level surveying, mineral analysis, grain size analysis, and trench surveys to determine the cause of coastal erosion.
As a result, it was found that the topographic cross-sectional area decreased significantly after the passage of Hagibis, the average grain size of the sand became finer as it moved away from the coast, and the sediments showed a tendency toward upward finer grainedness and a structure that appeared to be a hummocky diagonal stratification. This indicates that the seaward side of Samejima Beach was eroded by the storm surge of Hagibis, and that storm surge sediments were deposited behind the landward side of the beach.
We conducted meteorological observations, aerial photography, level surveying, mineral analysis, grain size analysis, and trench surveys to determine the cause of coastal erosion.
As a result, it was found that the topographic cross-sectional area decreased significantly after the passage of Hagibis, the average grain size of the sand became finer as it moved away from the coast, and the sediments showed a tendency toward upward finer grainedness and a structure that appeared to be a hummocky diagonal stratification. This indicates that the seaward side of Samejima Beach was eroded by the storm surge of Hagibis, and that storm surge sediments were deposited behind the landward side of the beach.