-

Occurrence of frequent high peak floods in arid and semiarid regions with weak plant coverage causes density current containing fine sediment materials. Such current when meets a reservoir plunges under the still water due to high density relative to still water. Sedimentation in the plunge point of river-reservoir system elevates river bottom line, increases flood plain and swamp area, and decreases useful volume of reservoir.
In this study, by using dimensional analysis, plunge depth equation was determined. And by adapting a physical hydraulic model for slopes of one to eight percent, plunge depth were measured. A constant coefficient in the equation for all slopes was determined. The range of the constant coefficient varies from 0.6 to 2.01, such for the step slope less than one, for mild slope more than one and for critical slope almost equal to one. The equation along, with related constant coefficient can be used to compute plunge depth for different slopes.