Daily Discharge Forecasting Using Least Square Support Vector Regression and Regression Tree


1 Civil and Environmental Engineering Department, School of Engineering, Shiraz University, Shiraz, Iran

2 School of Civil Engineering, College of Engineering, Tehran University, Tehran, Iran

3 Civil Engineering Department, Director of Research and Technology Affairs, Jundi-Shapur University of Technology, Dezful, Iran

4 Civil and Environmental Engineering Department, Environmental Research and Sustainable Development Center, Shiraz University, Shiraz, Iran

5 Civil and Environmental Engineering Department, Portland State University, Portland, OR., USA


Prediction of river flow is one of the main issues in the field of water resources management. Because of the complexity of the rainfall-runoff process, data-driven methods have gained increased importance. In the current study, two newly developed models called Least Square Support Vector Regression (LSSVR) and Regression Tree (RT) are used. The LSSVR model is based on the constrained optimization method and applies structural risk minimization in order to yield a general optimized result. Also in the RT, data movement is based on laws discovered in the tree. Both models have been applied to the data in the Kashkan watershed. Variables include (a) recorded precipitation values in the Kashkan watershed stations, and (b) outlet discharge values of one and two previous days. Present discharge is considered as output of the two models. Following that, a sensitivity analysis has been carried out on the input features and less important features has been diminished so that both models have provided better prediction on the data. The final results of both models have been compared. It was found that the LSSVR model has better performance. Finally, the results present these models as a suitable models in river flow forecasting.