Development of hierarchical model of river ecosystem for its conservation and restoration-analyses on interrelations amongst sediment dynamism, channel geomorphology and ecological functions.

河流生态系统的层次结构：综述了河流系统各层次的地貌特征。基于河流地貌和河岸植被模式对木津河进行了分段分类。研究了京都市卡莫川桑迪拦门沙中潜流带的物理化学结构，并给出了桑迪拦门沙中水质和水温的变化规律。为评价淀川流域大坝运行对洪水衰减的影响，开发了分布式径流预测系统。泥沙动力学与河流形态的相互关系：以奈良县吉野川为例，研究了河道淤积量与地貌和微生境结构的关系。以黑部川和高原川为例，研究了大坝冲沙对河流SS浓度和河流地貌的影响。土壤侵蚀过程监测系统 关于我们 在黑部大坝，在冲洗工作期间，水库河床中的沉积物被开发出来。等级结构与生境功能的关系：研究了鱼类和水生昆虫产卵场分布的决定因素，阐明了产卵场分布的尺度特征是由一系列物理因素如水力梯度、弗劳德数、层次结构与物质循环函数的关系：研究了宇治川和木津川在不同水流条件下SPOM的粒径和来源组成的纵向变化，结果表明，桑迪结构既是漂浮SPOM的过滤器，又是SPOM的提供者。SPOM来源于河岸植被对河流生态系统的影响。对17条河流表层沉积物的生物测定结果表明，表层沉积物的产生更多地取决于有机质、流速和水温的供给，而不是营养盐的供给。对不同含沙量河流的底栖动物群落进行了比较，发现中等含沙量河流的物种多样性最高。在阿武熊川和久津龙川研究了利用水库大坝冲水流进行人工输沙的效果，结果是恢复了泥沙运动，促进了石面上表生体的更新。少

Hierarchical structure of river ecosystems : Geomorphological features of each hierarchy in the river systems were reviewed. Segment classification was conducted for the Kizu River based on stream geomorphology and riparian vegetation patterns. Physico-chemical structure of hyporheic zones in the sandy bar was studied in the Kamo River in Kyoto City and changing patterns of water quality and water temperature in the sandy bars were presented. A distributed rainfall-runoff prediction system was developed for assessing flood attenuation under the dam operation in the Yodo River system.Interrelations between sediment dynamism and river morphology : Sediment amount accumulated in the channel was investigated in relation to the geomorphology and microhabitat structure in the Yoshino River in Nara Prefecture. Effects of sediment flushing from dams on the SS concentration and stream geomorphology were studied in the Kurobe River and the Takahara River. Monitoring system for erosion process of … More sediment in the reservoir bed during the flushing work was developed in the Kurobe Dam.Relations of hierarchical structure to habitat function : Determinant factor for distribution of oviposition sites in fish and aquatic insects were investigated was elucidated to be a feature of reach scale which is caused by oxygen supply through a set or physical factors such as hydraulic gradient, Froude number, and permeability of the streambed.Relations of hierarchical structure to material cycling function : Longitudinal changes in size and source composition of SPOM were investigated in Uji River and Kizu River under different flow conditions and the results indicate that sandy bar structure functions as both fifterer of drifting SPOM and provider of SPOM derived from riparian vegetation to the river ecosystem. Results of a series of field experiments on bioassay of epilithon in seventeen rivers indicated that production of the epilithon depends more on supply of organic matter, current velocity and water temperature than on nutrient supply.Amount of sediment supply required for restoration of ecological function in the river ecosystems : Benthos community was compared among rivers different in sediment load and found that the species diversity was the highest in the rivers with intermediate sediment supply. Effects of artificial sediment supply with flushing flow from the reservoir dams were studied in the Abukuma River and the Kuzuryu River, resulted in recovery of sediment moving which promoted a renewal of epilithon on the stone surface. Less