土壤-植物-大气系统水热传输的研究

近代对水分循环的研究，倾向于将土壤-植物-大气视为物理上的连续体，称之为SPAC系统。本文应用土壤水动力学、微气象学和能量平衡原理，建立了作物生育期SPAC系统的水热迁移和转化模型，并采用全隐式有限差分法进行离散，通过自动调节计算步长和反复迭代等方法设计了数值模拟程序，对冬小麦返青至成熟期的水热状况进行了模拟，结果表明，模型真实地反映了作物生长过程中土壤的水热状况和蒸散发动态过程，可用于田间墒情预报，并制定适宜的灌溉定额。

Research on water and heat transfer in soil-plant-atmosphere system

Soil-plant- atmosphere system tends to be regarded as continuum in the physics of water circulation in the field, and is called SPAC. Based on the theory of soil water dynamics, micrometeorology and energy balance principle, a model of water and heat transfer in SPAC is established. The numerical simulation is realized by using implicit finite difference scheme and iteration method with automatically changing time steps. Water and heat condition during winter wheat growing period from greening to mature is analyzed and discussed. It shows that this model can simulate the process of water and heat transfer in the soil and evapotranspiration, and is very important for soil moisture prediction and good irrigation norm.