“…Nowadays, with advances in soft computing techniques in most areas of engineering, specifically in water engineering, researchers have attempted to apply them to increase the accuracy of modelling. In this regard, modelling the scouring phenomena (Najafzadeh and Azamathulla, ; Najafzadeh et al ., , , b; Najafzadeh and Tafarojnoruz, ), hydraulic and hydrologic indices (Noori et al ., , , , ) and water quality parameters can be stated (Azamathulla and Ghani, ; Azamathulla and Wu, ; Parsaie and Haghiabi, ). In this study, to predict the discharge coefficient of triangular labyrinth weirs, artificial neural network (ANN), adaptive neuro fuzzy inference system (ANFIS), support vector machine (SVM), group method of data handling (GMDH) and multivariate adaptive regression splines (MARS) techniques are developed and their performance is compared.…”