Field observations and assessment of riverine geomorphologicalenvironments in view of integrated floodplain management

洪泛区综合管理下的河流地貌环境实地观测与评估

• 批准号: 22681026
• 负责人: AZUMA Ryoukei
• 金额: $ 5.82万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Young Scientists (A)
• 财政年份: 2011
• 资助国家: 日本
• 起止时间: 2011 至 2012
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-22681026/
• 关键词: 河岸侵食; 河川地形環境; 氾濫原マネジメント; 堆積環境; 宇治川; 河道地形変化; 水害地形環境; 侵食崖

This study focuses on the unconfined groundwater table fluctuations in a floodplain of river channel that occur in response to water level changes of the low channel. The array of observation wells normal to the low channel bank was set up at the floodplain near the 43.0km station of Uji River. The observed performance of a rapid rise and slow fall in the groundwater table clearly captured the response to a flood stage associated with a typhoon and heavy rainfall. Careful time-series analyses identified lateral infiltration during the rising period and vertical infiltration during the falling period. The apparent coefficients of permeability in floodplain soil during the rising and falling period were calculated as equal to 1.6×10-2~1.32 cm/s and 1.9~3.4×10-4 cm/s, respectively. The residual groundwater table during the falling period closely related to a process of bank erosion. A discussion is made to identifying practical implications for future river management.

这项研究的重点是在河道的洪泛区中无限制的地下水位波动，这是针对低通道的水位变化而发生的。在乌吉河（Uji River）43.0公里处的洪泛区建立了一系列与低通道库的观察井。观察到的地下水桌快速上升和缓慢下降的表现清楚地捕获了对与台风和大雨相关的洪水阶段的反应。仔细的时间序列分析确定了在上升期间的横向渗透和跌倒期间的垂直渗透。在上升期和下降期间，洪泛区土壤中渗透性的明显系数分别等于1.6×10-2〜1.32 cm/s和1.9〜3.4×10-4 cm/s。下降期间的残留地下水表与银行侵蚀过程密切相关。进行了讨论，以确定对未来河流管理的实际意义。