“…Firstly, conventional methods (CMs) such as Auto Regression (AG), Moving Average (MA) and Auto Regression Moving Average (ARMA) have been examined for several case studies and show potential for accurate forecasting for medium stream-flow classes (Billings, 2013;Chen and Dyke, 2007;Clark et al, 2008;Husain, 1985;Kalman and others, 1960;Moradkhani et al, 2005;Noureldin et al, 2007;Schreider et al, 2001;Valipour et al, 2012;Veiga et al, 2014). However, it has been reported that 15 there are several drawbacks in developing these models (Clark et al, 2008;El-Shafie et al, 2012;Husain, 1985;Ju et al, 2009;Maier et al, 2004;Noureldin et al, 2007Noureldin et al, , 2011Schreider et al, 2001). The main meagreness that associated to the application of CMs methods for developing the forecasting model for stream-flow is the stipulation to integrate it with a pre-formulation of the trustful stochastic model to ascertain the source of uncertainty for the model input and output.…”