1 IntroductionIt is scientifically proved that stream-flow is characterized by high nonlinearity distribution and dynamic pattern [1–6]. Over the past several decades, stream-flow forecasting has been an important and challenging issue [7–9]. In practical management, stream-flow forecast is tremendously significant for water resources planning and operation. Real-time forecasting that can be addressed as shortterm stream-flow can yield an important and reliable operation for flood control and mitigation protection, whereas long-term forecasting is essential for several water resources applications involving river sediment operation, reservoir and water demand sustainability, hydro power production, and several others uses [10, 11]. Since the early of 1970, the classical approaches based on mathematical and statistical models had been undertaken to solve this issue; for instance, multiple linear regression (MLR) model and autoregressive integrated moving average (ARIMA) [12–16]. The main drawback of the classical models is that they are limited with linear regression solution that is not really applicable in capturing the highly stochasticity of stream-flow pattern. Recently, a noticeable use of artificial intelligence (AI) techniques to