Evaluation of the Efficiency of Different Artificial Intelligence and Statistical Methods in Estimating the Amount of Runoff (Case Study: Shahid Noori Watershed of Kakhk, Gonabad)

Rainfall-runoff models are used in the field of hydrology and runoff estimation for many years, but despite existing numerous models, the regular release of new models shows that there is still not a model that can provide sophisticated estimations with high accuracy and performance. In order to achieve the best results, modeling and identification of factors affecting the output of the model is necessary. In this regard, in present study, it has been tried to identify the factors and estimating the amount of runoff using a variety of methods of artificial intelligence and multiple regression. Then, to evaluate the efficiency of the implemented models and choose the best model, some performance criteria including the correlation coefficient (R), Nash-Sutcliffe coefficient (NSE), the root mean square error (RMSE) and the mean absolute error (MAE) were used . The data used in this study were 9 rainfall events data measured in time period of 2011- 2015 taken from the Khakh watershed of Gonabad. Artificial intelligence models used in this study were: normal feedforward neural networks, feedforward Cascade neural networks, feedbackward Elman neural networks, Adaptive Neuro Fuzzy Inference System (ANFIS) and regression decision tree model (Regerssion Tree) that were implemented in MATLAB software environment and also step multiple regression as statistical methods which was implemented in Minitab software. The results of this study showed that the used statistical and artificial intelligence methods are considered acceptable with almost similar performance and with relatively appropriate accuracy and low error they are able to estimate the amount of runoff. In the meantime, Cascade and normal feedforward neural models with 5 input parameters, presented better performance comparing to the other models, as the performance criteria of R, RMSE, NSE and MAE in these models were the similar values of 0.88 , 0.76, 2 and 1.5, respectively. Overall, the findings indicate better estimations of the artificial intelligence models comparing to the regression model.