Modified ideal point method for estimating minimum environmental flow of rivers

This research aims to compare the results of different hydraulic methods and choose the appropriate discharge for the environmental flow of the Beshar River. At some periods between 2013 and 2018, the Beshar River practically turned into a dry river in the areas near Yasouj city during the summer time, and only a small subsurface stream trickled down from it. For the preparation of hydraulic sections and calculations of hydraulic methods of the wetted perimeter, 15 cross sections between Dehno and Pataveh stations were selected and their cross sections were mapped and digitized. The present study showed that an accurate wetted perimeter method, including both slope method (SM) and ideal point method (IPM), will produce acceptable results. The final result indicates that the newly presented method called Modified Ideal Point Method (MIPM) is an accurate and conservative hydraulic method for calculating environmental flow.