Dare- Gap River in the north of Booshehr province of Iran, in the reach of study, has a meandering pattern.
Most of the arcs are left wise in the reach of study that caused to increase water level during flood
events through the city. To solve this problem, it was supposed, if the arcs are omitted by making three
cutoffs in designed path, river slope, flow velocity and also river erosion potential will increase. Then the
average of annual erosion, aggradation and also the maximum depth of erosion and aggradation for
designed flood were studied for two paths existing path and artificial path, by using MIKE 11 model.
Results showed that the maximum erosion for annual flows occured in two reaches with bridges in them.
The amount of erosion in Kamarbandi Bridge was more than Main Bridge. And also deeper erosion was
observed in the designed path than existing path. In the Dare- Gap River in the kamarbadni Bridge, results
of the maximum depth of erosion and aggradation in the case of designed flood (100- years Flood) showed
that the maximum erosion in the designed path and for former path, was 0.65 and 0.78 meters, respectively.