Matsuba, Y., Matsunaga, Y., Mizuno, T., Nishi, H., Kotoura, T., Nishihata, T. & Tajima, Y. (2026). Development of a lidar-based real-time monitoring system for wave runup and overtopping. Coastal Engineering Journal, 1–21.
台風や冬季風浪等による高潮・高波の到来時に正確な避難指示情報を出すためには、時々刻々と変化する波浪うちあげ高をリアルタイムに観測するシステムの構築が必要不可欠です。本研究では、3D LiDARスキャナを用いた波浪うちあげ高のリアルタイム観測システムを構築し、2023年12月から2025年2月までの期間にわたり、石川県の2海岸にて現地実証試験を行いました。結果、本システムの安定した観測精度と高いノイズ耐性が示されました。本研究は国土交通省河川砂防技術開発の中で行われ、本技術の現地実装が始まっています。
Wave runup and overtopping pose significant risk to coastal areas and need continuous monitoring to support disaster mitigation. We propose a real-time coastal monitoring system employing Light Detection and Ranging (lidar) technology. The system was tested at two beaches facing the Sea of Japan over two winter seasons. Both sites experienced heavy snow, rain, and steam fog, and the presence of coastal structures further complicated the accurate shoreline detection. The lidar-based measurements were validated by shoreline positions derived from videos taken by surveillance cameras synchronized with the lidar scanners. While the lidar-based shoreline positions tended to be slightly seaward, the runup height measurements showed strong agreement with the camera-based data. Root mean squared difference (RMSD) values of the runup heights were approximately 0.35 m at the gravel beach, where the wave runup heights reached 5 m several times. At the composite beach of sand and gravel, the RMSD values were below 0.2 m, with maximum runup heights reaching 2.5 m. The system also demonstrated the capability to detect wave overtopping at a seawall under severe storm conditions. The findings demonstrate that the proposed system can provide quantitative data on wave runup and overtopping, offering valuable support for coastal management.