Dynamics of Fine Particle Organic Matter at forested watershed - Challenging of New Management of River Environment -

颗粒有机物为细菌和水生昆虫提供食物，是水环境保护和修复的重要特征。细粒底栖生物有机质(FBOM)，是在洪水条件下大量输出的细颗粒有机物的沉积形式。但对FBOM的冲刷和沉积机理的研究还不是很清楚。本研究的目的是对洪涝灾害中FBOM丰度的影响因素进行分析。结果表明：1)FBOM丰度的波动不同于FBOM的粒度分布；2)FBOM丰度在汛期涨水期有所下降，但多数在汛期降水期有所增加。

Particle organic matters is an important feature of the conservation and renovation of an aquatic environment, because of providing the food for bacterias and aquatic insects. Fine Benthic Organic Matters (FBOM), which is sedimented forms of fine particle organic matters exported largely in a flood condition. But the examination of the mechanism of FBOM flushing and sedimentating is not known well. The purpouse of this study is the analysis of the affected factors on the abundance of FBOM on the flood event. The results at upstream of the weir of hydraulic plant show that 1)the fluctuation of the abundance of FBOM were different from FBOM size distribution, 2)the abundance of FBOM were decreased during the water level increasing period, but mostly the abundance of FBOM were increased during the water level decreasing period at the flood event.