抄録
The Tenryu River Upper Reaches River Office has carried out many investigations to reveal hydrological process and sediment discharge of Tenryu river upper reaches actually. We have placed the sediment transport observation facility in Yotagiri River that is a sediment discharge measurement device by the method to gather sediment discharge directly. It became clear that the tendency that quantity of sediment discharge increases after outbreak of debris flow temporarily and tapers after that, and sediment which flowed down at Bouzudaira consisted of about 50% silt, about 40% sand, and about 10% pebbles. It is necessary for us establishing of the ruled about repairing to slit type, and management of deposit of sabo dam based on the knowledge about sediment movement properties in the Yotagiri River.
