Phreatic evaporation characteristics and calculation methods with the shallow water table in the saline soil region

In order to understand the phreatic evaporation characteristics of the saline soil, the effects of saline soil salt on phreatic evaporation rate and parameters under different air evaporations through the indoor simulation experiment were studied. The results show that the steady state phreatic evaporation changes into non-steady state with the increase of evaporation time at 50 cm depth of groundwater table owing to the effect of salt crust on the water movement. The steady phreatic evaporation rate calculated by Averiyanov equation has a less error than that calculated by Lei equation, but the parameter η is not a constant, and the coefficient β and evaporation rate become smaller for saline soil. In addition, the model of the non-steady state phreatic evaporation rate was developed. This new research achievement on the evaporation for the saline soil provides useful information for the further research.