해수범람에 따른 호안 배후 해안대수층의 수직 해수침투 및 담수 회복에 관한 실험적 분석

초록

Rising sea levels and extreme coastal hazards increase the likelihood of seawater flooding, thereby exacerbating the risk of seawater intrusion into coastal aquifers. This study experimentally investigated the vertical seawater intrusion and freshwater recovery processes occurring in a coastal aquifer behind an impermeable seawall under seawater flooding conditions. To this end, sand tank experiments were conducted under varying inundation heights and inundation distances. In addition, a computer vision-based image analysis method was applied to track the spatiotemporal evolution of the seawater region and to quantify its expansion and recovery characteristics. The results showed that seawater introduced from the land surface propagated downward and interacted with the pre-existing seawater region. As inundation height increased, the spatial extent of the seawater region changed, whereas the maximum seawater-region area exhibited a nonlinear response. In contrast, as the inundation distance increased, both the amount of seawater entering the aquifer and the spatial extent of the seawater region increased markedly, resulting in a substantial increase in the time required to reach the recovery criterion. Furthermore, the time required to reach the recovery criterion was more sensitive to inundation distance than to inundation height, indicating that inundation distance is a key factor governing the persistence and recovery of the seawater region in coastal aquifers.

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