Author(s): Koichiro Ohgushi; Jeffry Sumarauw; Takenori Hino
Linked Author(s): Koichiro Ohgushi
Keywords: Overflow embankment; Geotechnical sampling; Numerical simulation; Retarding basin; Flood control; Catchment basin operation
Abstract: In 17th century in Japan, full-scale countermeasures against flood disasters were carried out. The Saga Plain includes such flood damage prevention facilities everywhere. At present, several facilities of the flood control are left and can be seen as historic remains. It is significantly useful to find out and restore these remains and clarify their functions to consider a future flood control including catchment basin operations. In this study, overflow embankments and open levees of the Jobaru River are focused on the investigated field for estimating a controlled water flow spreading the retarding basin with sediment transports. We adopted a geotechnical sampling method to obtain a plate-like sample that can be easily analyzed for estimating water flow velocity, flow direction and a process of sediment settling. An additional investigation of numerical simulation is implemented to estimate water flow on the retarding basin from the overflow embankment. One dimensional flow analysis of Jobaru River gave a boundary condition for two dimensional simulation of flood flow on the retarding basin. The results of geotechnical investigation and hydraulic approach show the controlled water flow in the retarding basin in the residential area. This result gives a quantitative consideration about the flood control including catchment basin operations.
Year: 2012