Regional analysis of the impact of river basin modifications on neighboring coasts

流域改造对邻近海岸影响的区域分析

• 批准号: 17560455
• 负责人: YUHI Masatoshi
• 金额: $ 1.79万
• 依托单位: Kanazawa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17560455/
• 关键词: Coastal Erosion; Regional Analysis; Sediment Budget; Sediment Discharge; Longshore Bar; 土木環境システム; 水工水理学; 環境変動; 水圏現象; 国土保全

Long-term and large-scale morphological changes in the integrated watershed from the Tedori River basin to the Ishikawa Coast, Japan have been examined based on survey records across a broad time scale spanning over 40 years. Contemporary data for coastal and riverbed evolution was compiled and compared in order to assess implications of anthropogenic modifications of the river basin. Focus is placed on the influence of sand extraction and dam constructions on the sedimentary deficit resulting in accelerated coastal erosion. The morphological response near the river mouth indicates that the reduced sand discharge from the river has profound implications on the morphodynamic behavior under various time scales, including periodical sand bar migration. The collation between existing records of the integrated watershed shows that the persistent sand mining, flood control operation, and retention of sediment in terrestrial reservoirs has led to a serious imbalance of the coastal sediment budget : this has resulted in the decrease of coastal sediment volume at approximately 5×105 m3/year in the study area of 21.5 km2 when the erosion was most accelerated.Furthermjore, an effective method is proposed in order to quantify the co-existing morphological changes of various time scales. The proposed method is based on the EOF (Empirical Orthogonal Function) technique combined with a preconditioning operation using temporal moving-average. The method has been applied to the long-term variations of the cross-shore seabed profile near Tedori River mouth, Japan. The results show that suitable moving-average operation prior to EOF analysis enables effective mode decomposition. Both the long-term transition of eroding regimes and the periodic features of bar migration are clearly captured.

长期和大规模的形态变化的综合流域，从铁取河流域的石川海岸，日本已被检查的基础上跨越了40多年的广泛的时间尺度的调查记录。为了评估流域人为改变的影响，对沿海和河床演变的当代数据进行了汇编和比较。重点放在采砂和水坝建设对沉积赤字的影响，导致加速海岸侵蚀。河口附近的地貌响应表明，减少的输沙量对各种时间尺度下的地貌动力学行为，包括周期性的沙洲迁移有着深刻的影响。综合流域现有记录之间的整理表明，持续的采砂、防洪和陆地水库的泥沙滞留导致了海岸泥沙收支的严重失衡：这导致在侵蚀最加速的21.5km2研究区域内，海岸沉积物体积以约5×105 m3/年的速度减少。提出了一种有效的方法，以量化各种时间尺度的共存形态变化。该方法是基于经验正交函数（Empirical Orthogonal Function）技术结合使用时间移动平均的预处理操作。该方法已被应用于日本Tedori河口附近的跨岸海底剖面的长期变化。结果表明，在EOF分析之前进行适当的移动平均运算可以实现有效的模态分解。侵蚀制度的长期过渡和酒吧迁移的周期性特征都被清楚地捕捉到。

项目成果

手取川河口周辺における海底地形の長期変動に対する河川土砂管理の影響

河流泥沙管理对手取河口周围海底地形长期变化的影响

• 发表时间: 2005
• 期刊: 海岸工学論文集 52
• 作者: 由比政年;石田 啓;山田文彦
• 通讯作者: 山田文彦

Intertidal Multiple Sand Bars on Meso-Tidal Beach Proceedings of the 30th International Conference on

中潮汐海滩潮间多沙洲第 30 届国际会议论文集

• 发表时间: 2007
• 期刊: Coastal Engineering, ASCE (in press)
• 作者: F.Yamada;N.Kobayashi
• 通讯作者: N.Kobayashi

石川海岸美川地区における沿岸砂州の変動

石川海岸三河地区沿岸沙洲的变化

• 发表时间: 2007
• 期刊: 金沢大学日本海域研究 38
• 作者: 早川和宏;由比政年
• 通讯作者: 由比政年

Two-way Feedbackによる波浪-海浜流解析に関する研究

双向反馈波岸流分析研究

• 发表时间: 2006
• 期刊: 海岸工学論文集 53
• 作者: 山田文彦;土田将己;鄭金海;間瀬肇
• 通讯作者: 間瀬肇

A Field Study on the Long-Term Migration of Sand Bars in Mattou Coast, Japan

日本麻藤海岸沙洲长期迁移的实地研究

• 发表时间: 2006
• 期刊: Annual Journal of Coastal Engineering, JSCE 53
• 作者: 小林健一郎;立川康人;佐山敬洋;宝馨;Fumihiko Yamada;Masatoshi Yuhi
• 通讯作者: Masatoshi Yuhi