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Study on Flow, Sediment and Nutrients, Primary Production in Gravel rivers for Restoration of Ecosystem

砾石河流量、泥沙、养分、初级生产力研究以恢复生态系统

基本信息

批准号：
14205070
负责人：
IKEDA Synsuke
金额：
$ 36.44万
依托单位：
TOKYO INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14205070/
关键词：
Gravel rivers Nutrients transport Primary production Periphyton Sediment transport pollution load in watershed Plants on flood plain 土砂流出流れ栄養塩有機物洪水粒度分布一次生産

项目摘要

1.Laboratory experiments were performed to know the characteristics of growth, detachment and interspecific competition of filamentous and non-filamentous periphyton, in which the primary production rates, the respiration rates and the detachment rates of each kind of periphyton were measured by using various methods. The results of the experiments show that there are no significant differences of the primary production rates and the respiration rates between filamentous and non-filamentous periphyton. The detachment rate of periphyton is found to increase with friction velocity, and the detachment rate of filamentous periphyton takes smaller value than that of non-filamentous periphyton.2.The field observations were performed to understand the characteristics of growth and nutrient uptake of Phragmites japonica on flood plain in a gravel river, in which the temporal variation of plant biomass, the content of nutrients of vegetation and the concentrations of nutrients in the groundwater were measured. The result of the field observations show that the growth of the vegetation was restricted by the groundwater level in the present observation site. The hydroponics experiment of the riparian vegetation was conducted to understand the nutrition uptake due to photosynthesis. The results of the experiment show that the nitrogen uptake of the vegetation was closely associated with the amount of respiration of the roots of the vegetation.3.Field observation on the supply of sediment and nutrients from Nagura river basin, Ishigaki Island, was studied. They were estimated by measuring water velocity, depth, turbidity, concentrations of carbon, nitrogen and phosphrous. It was found that heavy rains yield nutrients mainly in particulate type. However, sugar cane field yields dissolved nutrients gradually after the rain. The timing of flood and tide is an important factor to control the discharge of sediment and nutrients to the tidal area such as lagoon and river mouth.

1.为了解丝状和非丝状附着生物的生长、分离和种间竞争特性，采用不同方法测定了不同种类附着生物的初级生产率、呼吸率和分离率。实验结果表明，丝状和非丝状附着生物的初级生产率和呼吸率没有显著差异。附着生物的脱落速率随摩擦速度的增大而增大，丝状附着生物的脱落速率小于非丝状附着生物。2.通过野外观测，研究了砾石河流河漫滩上芦苇的生长和养分吸收特征。测定了植被的养分含量和地下水的养分浓度。野外观测结果表明，植被的生长受到地下水位的制约。通过水培法研究了河岸带植物光合作用对养分的吸收。实验结果表明，植物根系呼吸量与植物氮素吸收量密切相关。3.对石垣岛纳仓河流域沉积物和营养盐的供给进行了野外观测。通过测量流速、水深、浊度、碳、氮和磷的浓度来估算它们。结果表明，暴雨产生的养分主要是颗粒态。然而，甘蔗田产量溶解养分后逐渐下雨。洪潮时机是控制泥沙和营养盐向泻湖、河口等感潮区输移的重要因素。