عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Flow routing is a mathematical procedure for predicting volume change, speed, and shape of a flood
wave in a channel as a function of time which is of great importance in river engineering, flood
control and hazard reduction, river conservation, and modeling of flow in weirs and reservoirs. The
solution of flood routing can be carried out using hydrologic or hydraulic procedure depending on
conditions and existing information. In this research, hydraulic routing was carried out using
4-point finite difference Muskingum method based on St Venant dynamic wave equations.
Furthermore, Muskingum linear and nonlinear hydrological approaches were applied for the
purpose of comparing results of the methods and the parameters of Muskingum models were
estimated using least square errors procedure. Along the reach of Mehranrood between Lighvan and
Hervi hydrometer stations using upstream input hydrographs (Lighvan station) and downstream
output hydrographs (Hervi station) 3 flood events were selected for flood routing. In hydraulic
routing procedure, output hydrograph was obtained using input hydrograph and hydraulic
characteristics of the reach. Hydraulic characteristics used in this method were longitudinal slope,
side slope, bottom width and length of reach. In hydrologic routing procedure, one of the input
flood hydrographs associated with the related output one were used for estimation of linear and
nonlinear Muskingum models parameters. The resulted parameters then were used to evaluate the
goodness of fit of the models by application of the two other input and output flood hydrographs.
Results showed that hydraulic flood routing using dynamic wave method (4-point finite difference
Muskingum method) was more compatible with the observed output hydrograph than Muskingum
hydrological methods. Weak efficiency of the linear Muskingum model was also observed in
comparison with the nonlinear one.