对常用潜水蒸发经验模型中 E0值的探讨

摘要

The evaporation rate of water surface (expressed with E0 ) is contained in the common empirical models of groundwater evaporation ,which can be replaced by the evaporation rate of soil surface at groundwater depth of zero . Measured data of groundwater evaporation rate ,evaporation rate of soil surface at groundwater depth of zero and evapora-tion rate of water surface were used to made a discussion on the selection of E0 value in Averiyanov equation ,Ye equation and Lei equation ,so as to improve the accuracy of calculation .Meanwhile ,the groundwater evaporation rate was com-pared under the two conditions in which E0 was the evaporation rate of water surface and the evaporation rate of soil sur-face at groundwater depth of zero ,respectively .The results turned to be that ,in the light of clay loam in Xinjiang ,some calculation error would be caused if the evaporation rate of soil surface at groundwater depth of zero were used instead of the evaporation rate of water surface as for the above three equations .So it was suggested that the evaporation rate of wa-ter surface be used as E0 ,and an exponential function relationship between ηand groundwater table was obtained .The study results may provide references for the selection of E0 in the empirical models of phreatic evaporation ,and offer a new method for calculating the parameter ηin Lei equation .%　　为提高潜水蒸发计算精度，利用潜水蒸发强度、埋深为零时的土面蒸发强度和水面蒸发强度的实测资料对阿维里扬诺夫公式、叶水庭公式和雷志栋公式中 E0值的选取进行了探讨，同时对比分析了 E0分别为水面蒸发强度和埋深为零时土面蒸发强度两种情况下的潜水蒸发强度。结果表明，针对新疆地区粘壤土类型，对于上述三种公式，若用埋深为零的土面蒸发强度代替水面蒸发强度，计算结果会产生误差，精度偏低，应选用 E0为水面蒸发强度进行计算，获得了η与地下水埋深的指数函数关系。该研究为潜水蒸发经验模型中 E0值的选取提供参考，同时为求解雷志栋公式中参数η提供一种新方法。