Evaluation of entropy based chiu's method for prediction of the velocity distribution and discharge in rivers

Determination of the appropriate velocity distribution and accurate estimation of river discharge is important to water resource management, water supply and safe design of hydraulic structure. Common methods in measurement of flow rate are on the basis of direct measurement of flow velocity. These methods are time consuming; costly and impracticable during flood in wide rivers. Therefore, use of methods that, while having sufficient accuracy, and the time required is also cost effective, In this research, using the principle of maximum entropy and Chiu’s velocity distribution, velocity distribution and flow in several cross sections of the Pasikhan river in Guilan province were estimated and the results were compared with measured data collected during 1389-1390. It’s found that there is a good agreement between predicted velocities and discharges based on Chiu’s method and the measured values with R2= 0.996 and RMSE= 3.9. So, it can be used as a quick and easy way to be replaced with conventional methods for estimating flow velocity distribution in rivers, especially in times of floods.