太湖底泥营养要素动态释放模拟和模型计算

采用太湖湖区底泥,根据环型水槽实验总结了各种扰动强度下太湖底泥的起动、悬浮和营养盐释放规律.环型水槽内水体流速均匀且能够通过控制水槽的转速精确控制水槽的水体流速.通过考察水槽中水体TN、TP浓度的变化,建立起了底泥TN、TP释放率(y)与水体流速大小(x)的定量化关系.根据实验确定的各种参数,采用ECOMSED模型计算模拟,并和太湖实测资料进行了对比,结果较为合理.由于目前太湖的野外监测资料存在较明显的时空不一致性,模型参数率定的精度受到了较大影响,通过室内实验模拟底泥的内源释放对太湖的富营养化治理具有重要意义.

Simulation and Model Computation on Dynamic Release of Nutrition Factors of Bottom Mud in Taihu Lake

The dynamic release of bottom mud in Taihu Lake was simulated indoors in an annular tank. The rules of starting principle, resuspension and release rate of bottom mud were analyzed under different kinds of disturbing intensity. The velocity of flow was basically uniform in the annual tank. Both the rotation rate of the tank and the velocity of flow can be controlled precisely. The relational expression between the release rate of TN,TP(y) and flow velocity (x) was calculated on the basis of the relationship between them. The calculated result from the model of ECOMSED conforms to the observation data in Taihu Lake very well. Because the conflict of field observation data in time and space greatly influences the accuracy of model parameters, simulating the dynamic release of bottom mud indoors is very important to the cure of eutrophication in Taihu Lake.