Numerical simulation of flow in a fishway of Karkheh-Hamidieh diversion dam and environmental considerations to investigate possibility of fishway use in Mazandaran Province

Abstract

Pool and weir is a type of fishway that provides a route for fish to migrate to dam<br />upstream. The effective parameters for fish swimming include velocity, water depth and<br />turbulence. Several rubber dams have been under construction in Mazandaran Province, but<br />the necessary structures have not been built around them yet. When constructing these rubber<br />dams, numerical models can be used to evaluate flow velocity and currently in Iran there is<br />also the possibility of comparing the results with field measurements at Karkhe-Hamidieh<br />dam of Khuzestan Province. In this paper, the three-dimensional equations governing shallow<br />water in the weir and orifice fishway were solved using the suitable models of turbulence, and<br />the flow pattern and turbulence were calculated. The results of flow simulation and field<br />measurements using Micromollineh were also compared. The final result showed that the<br />velocity lines in submerged and non-submerged modes with constant velocity were similar to<br />those estimated by Micromollineh - about 0.469 mps. We suggest it is not necessary to reduce<br />the flow rate in a submerged state using devices such as baffles. The small Cyprinidae fishes<br />are able to cross the fishway due to the slow flow of non-submerged state. In case of nonsubmerged<br />state, there is a need to reduce the flow rate.