In this paper, the first objective is to study the capabilities of spreadsheets for performing Muskingum flood routing in complex hydraulic systems considering computation and optimization facilities available in spreadsheets. This is achieved by using Microsoft Excel spreadsheet to perform multiple-reach Muskingum flood routing in a river for which the observed inflow and outflow hydrographs are available and its storage-discharge relationship is highly non-linear. The second objective is to study the effect of multiple-reach routing and piecewise linearization of the hydraulic system on the accuracy of flood routing computations by selecting different number of reaches. It is shown that a significant change in sum of the square of the deviations between observed and computed outflows (SSQ) is observed while the number of reaches changes from one to two. Then, SSQ changes gradually with increasing the number of reaches. In general, it is concluded that multiple-reach Muskingum flood routing can be recommended as an alternative for non-linear Muskingum models, considering its simple calibration and computation procedure, which can be easily performed in tabular form in spreadsheets.

Keywords