丰满水库一址双坝模式下热状态响应的模拟分析OA

The thermal regime of reservoirs plays a crucial role in aquatic ecosystems.As a special mode of defective dam reconstruction,the influence mechanism of the"one-site two-dam"configuration on reservoir thermal regime alteration remains unclear.Taking the"one-site two-dam"(new dam+old dam as an anterior retaining wall)at Feng-man Reservoir as the research object,this study established a vertical two-dimensional hydrodynamic-water temperature-ice regime coupled model to comparatively analyze the variation patterns of water temperature,ice condi-tions in the reservoir area,and released water temperature.The results show that the"one-site two-dam"configura-tion significantly elevates the thermocline in the reservoir area while significantly strengthening the stable stratifica-tion of the water body.In August,the vertical buoyancy frequency in front of the dam increases from 0.67 s-1 to 0.80 s-1,indicating a long-term regulatory capacity on water temperature stratification.During winter,the icing period is slightly prolonged,with the maximum ice thickness increasing by approximately 16 cm.The two-dam system exhibits a retention effect on low-temperature bottom water.Due to the anterior retaining wall effect of the old dam,the released water temperature increases by 0.2-3.3 ℃ during the spawning period,while decreasing by an average of 0.9 ℃ in autumn and winter.The old dam as a retaining wall reduces the bottom flow velocity below Eleva-tion 240 m by 30％-50％.During the stratification period,the central elevation of the main flow zone rises by an aver-age of 18.0 m.The elevation increase of the main flow zone shows a positive correlation with both the amplitude of improvement in released water temperature and the water temperature difference at the reservoir bottom between the new and old dams,with explanation degrees reaching 77％and 82％,respectively.The research results provide a sci-entific basis for the operation and ecological protection of the Fengman Reservoir,as well as a scientific reference for assessing thermal regime change in similar defective dam rehabilitation projects.