Variabilities of coastal system characterized by spatial and temporal reversal in dominant directions of longshore sediment transport

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06505
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Hydraulic engineering
• Research Institution: Kanazawa University
• Principal Investigator: YUHI MASATOSHI 金沢大学, 地球社会基盤学系, 教授 (20262553)
• Co-Investigator(Kenkyū-buntansha): 楳田 真也 金沢大学, 地球社会基盤学系, 准教授 (30313688) ; 斎藤 武久 金沢大学, 地球社会基盤学系, 教授 (40242531)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 広域漂砂 / 海浜動態 / 海浜システム / 地形変化 / 汀線変動

Outline of Final Research Achievements

This study investigated the middle to long-term variabilities of a coastal system characterized by spatial and temporal reversal of dominant directions in longshore coastal currents and sediment transport. The study area selected for this study is the northern Kaetsu Coast, Ishikawa Prefecture, Japan, that is located on the middle north coast of Japan. On the basis of long-term field survey records, the characteristics of large-scale behavior of the coastal system including systematic sandbar migration and shoreline change were investigated in detail and modeled empirically. The characteristics of complicated coastal current system and related longshore sediment transport were analyzed based on the long-term hindcasting as well as observation records of incoming waves. In addition, an efficient local remote sensing system utilizing a small Unmanned Aerial Vehicle was developed to monitor the multi-scale morphological variations of sandy beaches.

Free Research Field

海岸工学

Academic Significance and Societal Importance of the Research Achievements

本研究は，海浜の季節変動で通常考慮される岸沖漂砂方向の変動に加え，沿岸漂砂方向が季節的（時間的）および岸沖領域により（空間的）反転する漂砂系に着目した点に特色がある．多様な時間スケールの現象が重畳し，海浜動態について未解明な点が多いこの種の海岸に対して，地形変動・漂砂移動の特性解明や長期的波向き変動の影響推定が進められたことで，海岸保全対策の検討に資する基礎的な海岸工学的知見を獲得することができた．また，小型無人機（ドローン）による低空空撮画像を活用し，海底地形を推定する画像解析システムなど，海浜地形学分野でのモニタリングの高度化に有効な基盤技術を構築することができた．