Ecological effects of waterway regulation buildings in upper reaches of the Yangtze River under different discharges
Waterway regulation structures exist widely in the upper reaches of the Yangtze River,which can change the hydrodynamic,physical and chemical characteristics of water body,and also have an important impact on the planktonic communities.In this study,on-site monitoring of hydrodynamics,water quality and plankton biomass is carried out in the longitudinal and spur dike at the flow rate of 11 000 m3/s at Cuntan station.Furthermore,the change trend of hydrodynamic,water quality and biomass upstream and downstream of the two dikes under various discharges is simulated using MIKE21 software.The monitoring results show that compared with the upstream of the two dikes,the flow velocity in the downstream of two dikes decreases,and the dissolves oxygen concentration,phytoplankton density and biomass increase.The phytoplankton densities of the longitudinal and spur dike increase by 69.39%and 62.18%respectively,and the biomasses increase by 77.42%and 56.41%respectively.Based on the field monitoring data,the model is established.The differences in hydrodynamics,water quality,and biomass gradually decrease at 4 500,11 000 and 39 200 m3/s flow,and the ecological effect of renovation buildings is the best at 4 500 m3/s flow.The research results can provide a theoretical basis for the protection of organisms and the construction of ecological waterways in waterway regulation project area.
万方数据
维普
