Influence of land-use development on suspended sediment and wetland vegetation in Kushiro Marsh

土地利用开发对钏路湿地悬浮泥沙和湿地植被的影响

• 批准号: 07456065
• 负责人: NAKAMURA Futoshi
• 金额: $ 2.88万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07456065/
• 关键词: Wetland; Kushiro Marsh; Land-use; Wash-load; Suspended sediment; Cs-137; Wetland vegetation; River regulation; ヤチダモ; ウォッシュロード; ハンノキ; 濁度; 流域保全

Wetlands' effects on hydrology, water quality, and wildlife habitat are internationally recognized. We examined the influences of channelization on discharge of suspended sediment and wetland vegetation in Hokkaido, northern Japan. The impact of river channelization was confirmed not only by the sediment gudgets but also by river aggradation or degradation lafter the channelization and by the resultant vegetational changes. The budgets of suspended sediment demonstrated that wash load was the predominant component accounting for 95% of the total suspended load delivered into the wetland. This suspended sediment was primarily transported into the wetland by floding associated with the heavy rainfall. 25% of the wash load and 75% of the suspended bed material load were deposited in the channelized reach, which produced aggradation of about 2 m at the end of the reach. A shorting of the length of the channel, due to channelization of a meandering river, steepened the slope and enhanced the stream power to transport sediment. This steepening shifted the depositional zones of fine sediment 5km downstream and aggraded the riverbed. The aggradation reduced the carrying capacity of the channel and caused sediment ladened water to flood over the wetlands. the fine sediment accumulated on the wetlands gradually altered the edaphic conditions and wetland bvegetation. Salix spp.and Artemisis princeps dominate the sites representing a high water-level fluctuation and high total nitrogen, and low redox potential of wetlands' ground water. These sites are more evidence indicating taht the present condition is far different from normal. Orifinal vegetation such as sedges and Alunus japonica sere disappearing from the adjacent areas of the river channel and were being replaced by willow trees.

湿地对水文、水质和野生动物栖息地的影响是国际公认的。本文研究了日本北方北海道河道化对悬浮泥沙排放和湿地植被的影响。河流渠化的影响，不仅证实了沉积物gugets，但也通过河流加积或退化后，渠化和由此产生的植被变化。悬浮泥沙的收支表明，冲刷负荷是最主要的组成部分，占总悬浮泥沙输入湿地的95%。这些悬浮泥沙主要是通过与强降雨相关的漂浮作用进入湿地的。25%的冲刷负荷和75%的悬浮床沙负荷沉积在渠化河段，在河段末端产生约2m的淤积。由于曲流河的渠化，河道长度缩短，使坡度变陡，水流动力增强，从而增加了输沙能力。这种变陡使细泥沙的沉积带向下游移动了5公里，并使河床加积。淤积降低了河道的承载能力，并导致泥沙携带的水淹没湿地。细颗粒泥沙在湿地上的堆积逐渐改变了土壤条件和湿地植被。湿地地下水水位波动大，总氮含量高，氧化还原电位低，主要为沙柳和卤虫。这些遗址更多地表明，目前的情况与正常情况大不相同。莎草和日本Alunus japonica等原生植被从河道附近地区消失，取而代之的是杨柳。

项目成果

栗山浩一: "釧路湿原における湿原景観の環境価値の計測" 林業経済研究. 129. 45-50 (1996)

Koichi Kuriyama：“测量钏路湿地景观的环境价值”林业经济研究 129. 45-50 (1996)。

Nakamura, F., Sudo, T., Kameyama, S.and Jitsu, M.: "Influences of channelization on dis charge of suspended sediment and wetland vegetation in Kushiro Marsh, northern Japan." Geomorphology. 18. 279-289 (1997)

Nakamura, F.、Sudo, T.、Kameyama, S. 和 Jitsu, M.：“渠道化对日本北部钏路湿地悬浮沉积物和湿地植被排放的影响”。

Nakamura, F.: "Forest, river and people" Forest Science. 19. 69-73 (1997)

Nakamura, F.：“森林、河流和人类”森林科学。

中村 太士: "森と川と人" 森林科学. 19. 69-73 (1997)

Taishi Nakamura：“森林、河流和人类”森林科学 19. 69-73 (1997)。

Nakamura, F.: "The influences of land-use developments on river environment-Restorationh of structure and function of riparian zone-" World River Conference Proc. II-34-II-41. (1997)

Nakamura, F.：“土地利用开发对河流环境的影响——河岸带结构和功能的恢复——”世界河流会议论文集。