Print ISSN: 1813-0526

Online ISSN: 2220-1270

Keywords : Thomas

Lowflowmodeling for Greater Zab and Lesser Zab riversin Northern Iraq

Dr.Taymoor A. Awchi; Mr. Ihsan F. Hasan

Al-Rafidain Engineering Journal (AREJ), 2014, Volume 22, Issue 3, Pages 108-120
DOI: 10.33899/rengj.2014.88206

This research analyzes the minimum daily flows of each month for 52 years from Eskikalak and Dokan gauge stations onGreaterZabriverand Lesser Zab river respectivelyto predict their lowflowsusingtwo Stochastic Models;(ARIMA)model (Autoregressive Integrated Moving Average) and (Thomas-Fiering)model.A comparison is conducted for the results of both methodsutilizing theMean Average Error(MAE) and Root Mean Square Error (RMSE)ofpredicteddatafrom bothmodelsto verify theirperformanceandreliability. The results showed that the ARIMA model has given more appropriate forecasts and harmonic direction comparing to the same historical time series than those given by (Thomas-Fiering)model. Minitab version 14package is utilizedto assess the statistical side of the research.
Key word: Lowflow, GreaterZab, Lesser Zab, ARIMA, Thomas-Fiering

Evaluate the Performance of stochastic models in Generating Monthly Discharges for the Rivers in North of Iraq

Gada Younis Abdullah AL-ubaidy; Dr. Khalid Mahmood Khidir

Al-Rafidain Engineering Journal (AREJ), 2012, Volume 20, Issue 3, Pages 7-22
DOI: 10.33899/rengj.2012.50467

The data of monthly discharge which are available for most of the rivers in the north of Iraq have a short recorded period ,which has a great influence in the design and planning of water resources systems , where this short recorded not contain a critical and extreme flows sample of the low flow sequences.
Two stochastic models , bivariate "Thomas & Fiering" model and multi-side "matalas" model were used for generating time series for(100) years for the lower Zab and Diyala river at upstream of Dokan Dam and Derbendekhan Dam using the available recorded data for the period (1962-1997) .
From application of different statistical tests (Kolmogrov–Smirnov), Chi-Square (X2), Root Mean Square Error (RMSE), Mean Absolute Error (MAE, Z), found that "Matalas" model is more performance than the bivariate model, "Thomas & Fiering" generate time series for both rivers, so it can be concluded that the "Matalas" model can be proposed to be used for generating the flow series for the different rivers in the northern Iraq.
Key Words: Time Serious for monthly discharge, Stochastic Models , bivariate "Thomas & Fiering" model, "Matalas" model, Statistical Tests