Applicability of Unsteady Flow Computational Method to Runoff Analysis in a Tidal Low-Flat Basin

Abstract

An analysis is dealt with here about the applicability of an unsteady flow computational method to a tidal low flatland's water balance.The model is based on the Preissmann implicit scheme.The subjected basin was disassembled to such components as channels, hydraulic structures and fields.They were modeled to computational units and were treated as ‘key’ elements, of which the whole area's model was composed. ‘Ooe’river's basin in the ‘Takasu’ polder, which is situated between the ‘Nagara’ and ‘Ibi’ rivers, was the subjected region.
The results obtained by simulating the winter period in 1992 were:
1.The unsteady flow calculation, considered not appropriate in the case of long?-period simulation, became possible nowadays through the development of hardware, software and calculation methods.
2.Present method showed a high potential for analysing runoff process in which mechanical forces play main roles.
3.Because of a physical model, a large number of data were required and the expected results were dependent directly on the quality of data.