基于底泥再悬浮试验的太湖水质模拟

为探索浅水湖泊水动力扰动作用对底泥再悬浮影响的规律,在室内矩形水槽内模拟了各种水动力条件下太湖底泥的起动规律,得到了太湖底泥在3种不同起动标准下的起动流速,通过考察上覆水中悬浮物浓度的变化,建立了底泥沉积物再悬浮通量与水体流速的定量化关系。结果表明:太湖底泥在个别动、少量动、普遍动3种标准下的起动流速分别为15、30和40 cm/s,且底泥沉积物再悬浮通量与流速呈现线性正相关关系,再悬浮通量随流速增大而增大,且相关性较好。将该试验结果应用于太湖的水量水质数学模型中,并和太湖实测资料进行了对比,取得了比较满意的效果。该模拟装置能够在室内可控条件下较好地反映太湖沉积物再悬浮特征,对太湖的富营养化治理具有重要意义。

SIMULATION STUDY ON WATER QUALITY BASED ON SEDIMENT RESUSPENDED EXPERIMENT IN LAKE TAIHU

The starting principles of sediment under hydrodynamic conditions in Lake Taihu were simulated in the laboratory in a rectangle tank to study sediment resuspension in shallow lakes.The three different stages of sediment movement were analyzed and the quantitative correlations between resuspended flux of sediment and flow velocity were achieved on the basis of the relationship between them.It was showed that the starting velocities of sediment in Lake Taihu at three different incipient standards(individual movement,ounce movement,universal movement) gained from the experiments were 15,30 and 40 cm/s,respectively.The resuspended fluxs of sediment were increased with the increasing of flow velocity,and they demonstrated good linear relationship.The experiment result was applied in the numerical model of water flow and water quality in Lake Taihu,and a satisfactory result was obtained.It portrays well the characteristic of sediment resuspension,which demonstrates the applicability of using the rectangle tank to studying the dynamic of sediment release in the laboratory,and is very important to the cure of eutrophication in Lake Taihu.Sediment release under different flow velocities of Lake Taihu was simulating in a rectangle flume