湖泊三维水动力——水温耦合模型及其应用研究

Studies on three-dimensional hydrodynamic force and water temperature coupling model of lakes and its application

水温是湖库科学研究中的重要环境因子之一,是认识水体各种理化生现象和动力过程的基础。水温很大程度由太阳辐射决定,最新研究成果表明水体与床体的热交换收支对浅水湖泊垂向水温分布也有很大影响。研究湖泊热循环规律,选择合适的水气热交换计算方法,通过联立CE-QUAL-W2底部热交换模型方程和一种改进的床体热平衡方程求得水体-床体热通量。基于σ坐标变换和相关定解条件建立三维水动力学-水温耦合模型,采用有限差分法对模型方程进行求解。以武汉市东湖为研究对象,根据东湖1978年7月的定点观测资料进行水温模拟,探究东湖水温月变化、日变化过程。

Water temperature is one of the key environment factors in scientific studies of lake reservoirs and also the basis for understanding various types of physical phenomenon and dynamic processes of water bodies.Water temperature mostly depends on solar radiation and the recent study results demonstrate that heat exchange balance of water and bed bodies has great impact on vertical distribution of water temperature of shallow lakes.Through examination of heat cycle of lakes,a suitable method for calculating water-air-heat exchange was adopted,which using the bottom heat exchange equation model of CE-QUAL-W2 and an improved bed body thermal equilibrium equation to derive the heat flux of water and bed bodies.Based on transformation of coordinate ofσand relevant definite conditions,a three-dimensional hydrodynamic force and water temperature coupling model was created,and finite difference method was applied to obtain the equation model.By chosing the Donghu Lake in Wuhan City as an study objective,the monthly and daily variation of the lake have been observed,on the basis of water temperature simulation data at the observation point of the Donghu Lake in July 1978.