一种常用水库水温计算经验公式的改进研究

东勘院法是在总结新安江、新丰江等水库水温分布规律基础上,经统计分析得出的常用于计算水库垂向月均水温的经验公式。该方法用于计算其他区域不同类型水库水温时,存在一定的偏差:一是1~3月垂向水温存在不合理的温跃层;二是对于水深大于40 m的水库,总是出现一个滞温层,温跃层和滞温层的交界面基本分布在水深40 m左右。为减小计算偏差,本研究通过分析东勘院法主要参数n、x取值对计算结果的影响,对参数n、x的取值进行了优化改进。通过国内多个水库水温资料验证,表明:改进后的东勘院法可明显提高水温预测精度。

Study on improvement of a common empirical calculation formula of reservoir water temperature

A common empirical formula for calculating the monthly mean vertical water temperature of reservoir is proposed by China Water Northeastern Investigation Design Research Co.，Ltd. is obtained from the relevant statistical analysis on the basis of summarizing the water temperature distribution laws of Xinanjiang Reservoir，Xinfengjiang Reservoir，etc. When the method is applied to calculate the water temperatures of different types of reservoirs in the other regions，a certain deviation is there from it，i.e.（1） an unreasonable thermocline is there for the vertical water temperature from January to March；（2） a hypolimnion is always there for the reservoir with the water depth over 40 m，while the interface between both the thermocline and the hypolimnion is basically distributed in the water depth about 40 m. In order to reduce the calculation deviation，the influences of the taken values of the main parameters n and x in this method are analyzed，and then both of them are optimized and improved. Through the verifications made on the water temperature data from several reservoirs in China，it is indicated that the improved method can obviously enhance the prediction accuracy of the water temperature.