Abstract: Based on experimental data on phreatic evaporation from the bare soil at the Wudaogou hydrology test station in Anhui Province, the representations of different empirical formulas have been compared for calculations of groundwater evaporation of fluvo-aquic soil and lime concretion black soil with the shallow groundwater table. The evaporation capacity calculated by Penman-Monteith formula is suggested to replace the water surface evaporation observed for an improved regression. It shows that A-Verianov formula, the hyperbola type formula, the exponential type formula and the power type formula are better fitting the phreatic evaporation of fluvo-aquic soil, while A-Verianov formula, the hyperbola type formula, the exponential type formula and the inverse-logistic formula are better fitting the phreatic evaporation of lime concretion black soil. The Tsinghua formula is not suitable for the calculation of the phreatic evaporation in the Huaibei plain. The coefficients of each empirical formula are also listed.

Key words: phreatic evaporation, fluvo-aquic soil, lime concretion black soil, comparison of the formulas