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.

使用森林年龄、放射性碳年代或火山灰年代对地貌表面进行年代分析是研究流域地貌历史、甚至了解流域内沉积物运动过程的时空特征的有效方法。本研究的总结结果如下： 1）我们研究了萨鲁河流域的沉积物路径。对山坡的年代学分析显示了山体滑坡造成的沉积物产生的长期速率。分析了水库沉积量和在水库沉积物上建立的森林的年龄分布，表明上游流域的沉积物产量。 2）研究了十胜川沿岸河岸森林的更新动态。对河岸森林的物种组成和树龄结构的分析表明，与洪水事件相关的沉积物运动的幅度控制着河岸森林的扰动和更新程度，形成了河岸带森林斑块的马赛克分布格局。 3）对利尻岛冲积扇头泥石流历史进行了研究。从活树上获得的树轮年表被用来交叉确定被不确定年龄的泥石流掩埋的树木的建立和死亡日期。结果表明，泥石流的两个时期分别发生在 1870 年代和 20 世纪 50 年代初。 4）火山泥流沉积物的放射性碳测年和地层分析为十胜山和雌阿寒火山的泥流发生提供了新的发现。

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: "Some methodological developments in the analysis of sediment transport processes using age distribution of flood plain deposits" Geomorphology. 16. 139-145 (1996)

Futoshi Nakamura：“利用洪泛平原沉积物的年龄分布来分析沉积物输送过程的一些方法学进展”地貌学。

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”。

有賀 誠: "十勝岳上流域における河畔林の林分構造および立地環境-隣接斜面との比較から" 日本林学会誌. 78・4. 354-362 (1996)

有贺诚：“十胜岳上游河岸森林的林分结构和位置环境 - 与邻近斜坡的比较”日本林业学会杂志 78・4（1996）。

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

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