Seasonal to decadal morphodynamics in an integrated watershed composed of a steep river and barred coasts

• Project/Area Number: 15K06229
• 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: Umeda Shinya 金沢大学, 環境デザイン学系, 准教授 (30313688)
• Research Collaborator: YUHI Masatoshi ; KARUNARATHNA Harshinie
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000); Fiscal Year 2017: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2016: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2015: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: 海岸 / 河口 / 河川 / 底質輸送 / 汀線 / 砂州 / 海岸工学 / 海浜変形 / 河床変動 / 流域 / 砂浜 / 流砂 / 漂砂 / 季節変化 / 波浪 / データ解析 / 数値解析

Outline of Final Research Achievements

Seasonal to decadal variability of shoreline position at a long multi-barred beach with gentle slopes was investigated using a dataset of biannual shoreline surveys of 23 years. EOF and spectral analysis were conducted to describe characteristic patterns of shoreline variation at multiple scales in time and space. A alongshore uniform shoreline migration toward offshore in summer and onshore in winter was dominant in the first EOF mode which secondarily exhibited a long-term trend of shoreline recession. The shoreline pattern reconstructed on a longer time scale represented a large scale shoreline undulation whose scale and migration speed were comparable to shoreline sand waves observed in various coasts. The shoreline pattern reconstructed on a shorter time scale represented alongshore uniform shoreline migration toward onshore and offshore in about five-year cycles, which corresponded to the average cycle of net offshore sandbar migration observed at the site.

Research Products

• [Int'l Joint Research] Swansea University(英国)
• [Int'l Joint Research] Swansea University(英国)
• [Int'l Joint Research] Swansea University(英国)
• [Journal Article] MIDDLE- AND LONG-TERM VARIATIONS OF SHORELINE CHANGE AT CHIRIHAMA BEACH, ISHIKAWA PREFECTURE, JAPAN (2017)
  • Author(s): 楳田 真也、福井 貴大、由比 政年
  • Journal Title: Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering) Volume: 73 Issue: 2 Pages: I_769-I_774
  • DOI: 10.2208/kaigan.73.I_769
  • NAID: 130006171938
  • ISSN: 1883-8944, 1884-2399
  • Peer Reviewed / Open Access
• [Journal Article] THEREE-DIMENSIONAL PARAMETRIC MODEL FOR SANDBAR MIGRATION ON THE CHIRIHAMA AND TAKAMATSU COAST, ISHIKAWA, JAPAN (2017)
  • Author(s): 由比 政年、山腰 司、楳田 真也
  • Journal Title: Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering) Volume: 73 Issue: 2 Pages: I_763-I_768
  • DOI: 10.2208/kaigan.73.I_763
  • NAID: 130006171918
  • ISSN: 1883-8944, 1884-2399
  • Peer Reviewed / Open Access
• [Journal Article] A PARAMETRIC MODEL FOR SYSTEMATIC MIGRATION OF SANDBARS ON THE CHIRIHAMA AND TAKAMATSU COAST, ISHIKAWA, JAPAN (2016)
  • Author(s): 由比政年，楳田真也，山腰 司，岡部祐子
  • Journal Title: Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering) Volume: 72 Issue: 2 Pages: I_673-I_678
  • DOI: 10.2208/kaigan.72.I_673
  • NAID: 130005282467
  • ISSN: 1883-8944, 1884-2399
  • Peer Reviewed
• [Presentation] 石川県千里浜海岸における沿岸砂州の波と流れに及ぼす影響に関する研究 (2018)
  • Author(s): 楳田真也，山本拓之，由比政年
  • Organizer: 平成29年度土木学会中部支部研究発表会前日シンポジウム
• [Presentation] 石川県千里浜海岸における沿岸砂州による波・流れの変化特性 (2018)
  • Author(s): 山本拓之，楳田真也，由比政年
  • Organizer: 平成29年度土木学会中部支部研究発表会
• [Presentation] 石川海岸と手取川下流部における地形の中・長期的変化 (2018)
  • Author(s): 森田拓磨，根岸和憲，楳田真也，由比政年
  • Organizer: 平成29年度土木学会中部支部研究発表会
• [Presentation] 千里浜海岸周辺における汀線の中・長期的変動特性 (2017)
  • Author(s): 楳田真也，福井貴大、由比政年
  • Organizer: 第64回海岸工学講演会
• [Presentation] 千里浜海岸周辺の多段砂州システムの組織的移動に伴う3次元地形の時空間変動に対する経験モデルの構築 (2017)
  • Author(s): 由比政年，山腰司，楳田真也
  • Organizer: 第64回海岸工学講演会
• [Presentation] 庄川の河床変動と土砂量に関する基礎的研究 (2017)
  • Author(s): 前島浩平，楳田真也
  • Organizer: 平成28年度土木学会中部支部研究発表会
  • Place of Presentation: 金沢大学（石川県・金沢市）
• [Presentation] 石川県押水・羽咋海岸の汀線変動特性に関する研究 (2017)
  • Author(s): 福井貴大，楳田真也，由比政年
  • Organizer: 平成28年度土木学会中部支部研究発表会
  • Place of Presentation: 金沢大学（石川県・金沢市）
• [Presentation] 河口テラスの形成と消滅に関する数値解析 (2017)
  • Author(s): 根岸和憲，楳田真也，由比政年
  • Organizer: 平成28年度土木学会中部支部研究発表会
  • Place of Presentation: 金沢大学（石川県・金沢市）
• [Presentation] Morphodynamic characteristics of high-energy micro-tidal beaches in North Kaetsu Coast, Japan (2016)
  • Author(s): Shinya Umeda, Harshinie Karunarathna and Masatoshi Yuhi
  • Organizer: The 12th Young Coastal Scientists and Engineers Conference (YCSEC2016)
  • Place of Presentation: Swansea University, Swansea, United Kingdom
  • Year and Date: 2016-03-22
  • Int'l Joint Research