Abstract
The water volume of 1.15million m3 of Typhoon 22 flood in 2004 was stored in the Tsurumigawa river retarding basin. The assessment of effects of the Tsurumigawa river retarding basin is an important subject for the flood control plan.
The objective of the papar is to demonstrate control effects of the retarding basin against the Typhoon 22 flood in 2004 and to present a quantitative method estimating flood-control effects of the retarding basin.
Detailed measurements of water levels in the Tsurumigawa river and the retarding basin were carried out for the Typhoon 22 flood.
The 2-D unsteady flow analysis whose solutions are measured water surface profiles made a numerical estimation possible for a water volume stored in the retarding basin during the flood and the decrease in the water level in the downstream reach.
