Chronological Study on Forested Watershed Changes due to sediment movement by forest age analysis

基于森林年龄分析的泥沙运动引起的森林流域变化的年代学研究

• 批准号: 08456072
• 负责人: ARAYA Tohru
• 金额: $ 3.07万
• 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: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08456072/
• 关键词: Riparian forest; Forset stand; Forest age distribution; Tree rings; Adventitious roots; Volcanic ash; Volcanic mudflow; Sedimentary deposit

Chronological analysis of geomorphic surfaces using forest ages, radiocarbon dates or tephra dates is an effective method for investigating geomorphic history of watersheds, and even for understanding spatial and temporal characteristics of sediment movement processes within the watersheds. Summarized results of this study are as follows : 1) We examined sediment routing in the Saru River basin. Tephrochronological analysis of hil1slopes showed long-term rates of sediment production caused by landslides. Volume of reservoir sedimentation and age distribution of forests established on sediment in the reservoirs were analyzed, indicating sediment yields from upstream basins. 2) Regeneration dynamics of riparian forests were examined along the Tokachi River. Analysis of species composition and tree age structure of the riparian forests revealed that the magnitude of sediment movement associated with flood events controlled the extent of disturbance and regeneration of riparian forests, creating a mosaic distributional pattern of forest patches in the riparian zone. 3) Debris flow history was researched at the alluvial fan head on Rishiri Island. Tree-ring chronology obtained from living trees was used to cross-date the establishment and death of the trees which were buried by debris flows of indeterminate ages. Results indicated two clusters of the debris-flow dates in the 1870s and the early l950s. 4) Radiocarbon dates and stratigraphic analysis of volcanic mudflow deposits provided new findings of mudflow occurrences in Mount Tokachi Volcano and Mount Meakan Volcano.

利用森林年龄、放射性碳年代或火山灰年代对地貌面进行年代学分析是研究流域地貌历史乃至了解流域内泥沙运动过程时空特征的有效方法。主要研究成果如下：1）研究了萨鲁河流域泥沙运移规律。对hil1slopes的年代学分析表明，滑坡造成的沉积物产生的长期速率。分析了水库淤积量和水库沉积物上建立的森林年龄分布，表明上游流域的产沙量。2)对沿着十胜川河岸林的更新动态进行了研究。河岸林的物种组成和树龄结构的分析表明，与洪水事件相关联的泥沙运动的大小控制了河岸林的干扰和更新的程度，创造了一个镶嵌分布格局的森林斑块在河岸带。3)对利尻岛冲积扇头泥石流历史进行了研究。从存活树木获得的树木年轮年表被用来交叉日期的建立和死亡的树木被掩埋的泥石流不确定年龄。结果表明，两个集群的泥石流日期在19世纪70年代和50年代初。4)火山泥流沉积物的放射性碳测年和地层分析提供了十胜火山和密坎火山泥流发生的新发现。

项目成果

新谷 融: "十勝岳火山泥流災害" 土木学会誌. 81・8. 65-69 (1996)

新谷彻：《十胜岳火山泥浆灾害》日本土木工程学会杂志 81・8（1996）。

Futoshi Nakamura: "Influences of channelization on discharge of suspended sediment and wetland vegetation in Kushiro Marsh,northern Japan." Geomorphology. 18. 279-289 (1997)

Futoshi Nakamura：“渠道化对日本北部钏路沼泽悬浮泥沙排放和湿地植被的影响”。

Aruga, M., Nakamura, F,Kikuchi, S.and Yajima, T.: "Characteristics of floodplain forests and their site conditions in comparis on to toeslope forests in the Tokachi River." J.Jpn For.Soc. 78(4). 354-362 (1996)

Aruga, M.、Nakamura, F、Kikuchi, S. 和 Yajima, T.：“冲积平原森林的特征及其立地条件与十胜河滨坡森林的比较。”

Nakamura, F.: "Present and future problems in conserving Kushiro Mire from watershed perspectives." Wildlife Forum. 2(4). 101-111 (1997)

Nakamura, F.：“从分水岭的角度来看，保护钏路泥沼当前和未来的问题。”

Yoshida K., Kikuchi S., Nakamura F.and Noda M.: "Dendrochronological analysis of debris flow disturbance on Rishiri island." Geomorphology. 20. 135-145 (1996)

Yoshida K.、Kikuchi S.、Nakamura F.和 Noda M.：“利尻岛泥石流扰动的树木年代学分析”。