Study On Numerical Simulation Of Suspended Solids Space-time Distribution Of Yuqiao Reservoir

With the rapid economic development and urbanization, eutrophication andsedimentation phenomenon of lakes or reservoirs has aroused widespread concern ofthe public. Eutrophication and sedimentation of water sources was great harmful toboth the water source environment and its normal function exercise. Therefore, moreand more experts and scholars conduct in-depth research on the movement, migrationregularity and sediment movement law of suspended solids. They have made certainachievements at present.This paper took Yuqiao Reservoir which is the source water for the water supplyof Tianjin City as the research object. The development of industry and agriculturalsurrounding the reservoir area brought huge ecological harm. So this paperestablished numerical simulation model to analysis the planktonic algae and sedimentchanges for providing scientific management ways that are the safe operation aboutthe reservoir. The studying method: first, using two-dimensional shallow waterequation established reservoir hydrodynamic model for simulating the movement ofwater. Then introducing the comprehensive coefficient K characterized the algaegrowth based on the results of the growth model. The comprehensive coefficient, asthe variables, was integrated into the convection-diffusion equation and solved withthe hydrodynamic model. The algae growth and migration model has been completed.In the same way, the sedimentation model was established by introducing sedimentdeposition equation, bed deformation equation and suspend diffusion equation. Theobserved data was used to calibrate the model and the accuracy of predication wasacceptable. It indicates that the model can be used for predicting the spatial andtemporal distribution of algae and sand. According to the prediction results whichwere based on setting different working conditions of numerical simulation, it canachieve the following conclusions:(1) In the mid and end of September, theconcentration of algae was high and broke out the algae bloom easily.(2) The highvalue concentration areas were formed by the large circulation which transferring andenriching the algae. The three regions were mainly in the western north area ofreservoir, center of the reservoir, and the southern area of Fengshan, that breaking out algae bloom easily.(3) The sediment and erosion were mainly distributed in thechannel and the conflux of Li River and Lin River before constructing the reservoir. Itwould not affect the safe operation of the reservoir at the existing level.