Prediction of flow discharge in compound open channel using group method of data handling

Prediction of flow through the compound open channel is one of the main problems in the field of hydraulic engineering. One of the main parameter related to the flow properties in the compound open channel is Shear Stress. The shear stress is because of difference of velocities between the main channel and floodplains. The Shear Stress causes of turbulence and vortex creation on the border of main channel and floodplains. The difference between the roughness of main channel and floodplains intensities the shear stress in the border zone and also decreases total discharge. In this paper, the discharge of flow in compound open channels was predicted using group method of data handling technique. To this end, related dataset were collected from literature. Involved parameters in modeling are relative hydraulic depth ( ), relative hydraulic radius ( ), and relative roughness ( ) and relative area ( ). To compare the performance of GMDH with other types of soft computing methods, the MLPNN as most well-known soft computing technique is developed as well. Results indicate that the GMDH model with coefficient of determination 0.91 and root means square error 0.057 is more accurate than the MLPNN. Reviewing the structure of developed GMDH model shows that and are the most effective parameters on prediction of discharge in compound open channels.