高地下水位条件下盐渍土区潜水蒸发特性及计算方法

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

为了了解盐渍土区潜水蒸发特性,通过室内模拟实验,研究了不同大气蒸发能力条件下,盐渍土中盐分对潜水蒸发强度以及模型中参数的影响。结果表明:由于土表盐壳形成后对水分蒸发的抑制,不同大气蒸发能力条件下地下水埋深为50 cm时,随蒸发历时的延长,潜水蒸发由稳定变为非稳定状态。雷志栋公式在计算盐渍土的潜水稳定蒸发强度时的误差明显小于阿维里扬诺夫公式,但其参数η并非为常数,且参数β和潜水极限蒸发强度均明显减小。最后,建立了非稳定潜水蒸发强度的计算模型。该研究将为重新认识盐渍土区土壤的蒸发特性以及对其进行进一步深入研究提供重要依据。

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.