计算北回归线附近蒸发量的经验公式

Calculation on empirical formula for evaporation in nearby tropic of cancer

利用四会新气象观测站2009～2011年小型蒸发皿蒸发量的资料,选取30个气象样本资料,建立日照、相对湿度、水汽压、风速与蒸发量之间对应的多元线性关系式[1],采用潮州气象站已有的样本资料回代蒸发经验公式,得出潮州日平均蒸发估算值是实际蒸发值的1.2倍,说明此经验公式配上适当的修正系数,适用于岭南北回归线内陆和沿海附近地区蒸发量的理论估算值计算,其值可作为判断因降水引起蒸发误差是否偏大的主要依据,同时为科研机构研究近地面蒸发量提供参考数据。

By means of evaporation data from mini evaporator of new Sihui meteorological station in 2009-2011, this paper selects 30 meteorological samples in order to build up a corresponding plural linear equation among sunlight, relative humidity, vapor pressure, wind speed and evaporation. According to back substitution of the known samples in Chaozhou meteorological station to empirical formula of evaporation,the estimated value of daily average evaporation in Chaozhou city is 1.2 times than the actual values. Therefore, this empirical formula with a relevant correction coefficient is compatibly applied to calculate the theoretical value of evaporative capacity in Lingnan in-land tropic of cancer and nearby regions along the coast. This theoretical value could be used as the base to judge whether there is a big difference in the evaporation caused by the rainfall, meanwhile it gives the reference data to the study on evaporative capacity of the earth surface.