Prediction method of dissolved gas concentration downstream of high dams

摘要

The eco-environmental effects of great hydropower engineering have been long on concern at home and abroad. The dissolved gas concentration will be supersaturated downstream of spillways and cause fish gas bubble disease, eventually mortality. So it is very important to search an accurate and quick method to predict the dissolved gas concentration. The dissolved gas transfer efficiencies are calculated according to the measured data of spillway. The results shows that the transfer efficiency is a constant value for a given flow conditions, independently of the upstream concentration and the tailwater depth. So, this paper develops a method to predict the downstream dissolved gas concentration downstream of spillway for any given conditions based on the transfer efficiency, the upstream dissolved gas concentration and the tailwater depth. The results show that the present method is easy to be applied and suitable for different projects.