Effective unsteady flow calculation method by the Preissmann Scheme for looped channel network

Many Asian deltas located downstream of big rivers have been developed as paddy fields area, but they appear to be suffered from floods and also serious drainage problems. In these areas, tributary rivers, branch rivers and drainage channels often form networks, and flow direction in such waterways is usually affected by tide and is not consistent. In order to design flood control facilities or to improve drainage systems, such a technique is required as can exactly estimate and calculate water levels in rivers or channels. Usual runoff analysis which is carried out by water balance equation and simplified movement equation cannot deal with such complex phenomena and the unsteady flow analysis method should be utilized for such problems.