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

河流生态系统的等级结构：回顾了河流系统中各等级的地貌特征。根据河流地貌和河岸植被格局对克孜河进行了河段划分。对京都卡莫河沙洲潜流带的物理化学结构进行了研究，给出了沙洲水质和水温的变化规律。开发了一个分布式降雨径流预报系统，用于评价吉野河流域在大坝运行情况下的洪水衰减情况。泥沙动力与河流形态的相互关系：研究了奈良县吉野河的河床泥沙量与地貌和微生境结构的关系。研究了大坝冲沙对黑边河和高原河泥沙浓度和河流地貌的影响。…烧蚀过程监测系统研究了影响鱼类和水生昆虫产卵点分布的决定因素，阐明了河段尺度的特征是通过一定的水力坡度、弗劳德数、层次结构与物质循环功能的关系：研究了不同水流条件下乌吉河和克孜河SPOM的大小和来源组成的纵向变化，结果表明，沙洲结构既是漂流SPOM的第五级，也是河岸植被SPOM向河流生态系统的供给者。17条河流附生生物测定的野外试验结果表明，附生生物的产生更多地依赖于有机质的供应、流速和水温，而不是营养物质的供应。恢复河流生态系统功能所需的底泥补给量：对不同含沙量的河流底栖生物群落进行了比较，发现中等含沙量的河流物种多样性最高。在阿布库马河和库祖尔尤河研究了水库坝冲流人工补沙的效果，恢复了泥沙运动，促进了石面上的泥沙更新。较少

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