Muskingum and lag method river routing parameters for Klang river at Kuala Lumpur city centre derived using recorded hydrographs

Abstract

In this Study, the Muskingum and Lag river routing models were used to estimate the routing coefficients of Klang river using flood records of gauging stations at Leboh Pasar and Sulaiman Bridge, for a river reach of 900m between the two gauging stations. Recorded inflow hydrographs at Leboh Pasar and outflow hydrographs at Suilaman Bridge were used to calibrate and validate the Muskingum and Lag routing models. Best fit routing parameters for the models were derived using the optimization module of HEC-HMS, and the average parameters obtained were used to validate the routing models using different sets of flood events. The outflow hydrographs at Sulaiman Bridge derived from routing models were used to compare with the observed hydrographs by plotting the hydrographs for visual inspections. The ability to produce the observed flow at the Sulaiman Bridge by the routing models were also assessed statistically by calculating the goodness of fit indices from the routed and observed hydrographs. Graphical inspections of routed and observed hydrographs show that the Muskingum and lag models give congruent results in estimating the outflow at Sulaiman Bridge. The results obtained are also in good agreement with the observed flows. However, the goodness of fit indices show that the Muskingum model overall gives a better fit than the Lag method.