农田土壤水分二区模型的研究

本文考虑作物根系吸水的特性，把农田土壤水分变化层分为包含根系的根区和无根系的储水区，以土壤-植物-大气连续体物质能量运动原理和土壤水动力学理论为依据，构建了农田土壤水分二区模型。对该模型的简化，即可得到了两个现在常用的描述土壤水分变化的概念性模型，表明本文提出的土壤水分二区模型是一通用式。对其中考虑下界面水分通量的概念性模型与二区模型进行了比较，结果表明，二区模型拟合精度较高，其复相关系数达到0.91以上，由二区模型计算的蒸发蒸腾量和根区下界面水分通量与实测值有更好的一致性。

Two zone model for simulating field soil moisture

The soil moisture in field along the depth can be divided into two zones, including the root zone and moisture storage zone. Based on the theory of soil plant atmosphere continum (SPAC) and soil water dynamics a two zone model for describing the variation of soil moisture is established. The further study on this model shows that the current used conceptual models for describing the variation of moisture in soil can be deduced by simplifying this two zone model. It demonstrates that the proposed two zone model is a universal equation. The comparison of the simulation result of an example for the conceptual model considering the moisture flux at the lower boundary with the result of two zone model shows that the correlation coefficient of the latter model is higher than that of former and reaches about 0.91. The evapotranspiration calculated by two zone model well agree with observation data.