【摘要】 从连续介质力学出发,应用Whitaker提出的局部体积平均法,建立了一个描述植物生长的土壤中热、湿、气及溶质耦合迁移的多场数学模型,以揭示非饱和土壤内复杂的传输机理.此模型中考虑了植物根系对水分、热量、气体和溶质的吸收或排放,同时在边界条件中反映了植物冠层对土壤表面遮阳的影响.因此,该模型相对于已有的其他模型来说,所包含的物理机制更加完备,并且它还具有可解性.更多还原

【Abstract】 Starting from the continuous medium mechanics, a mathematical model for investigating simultaneous transfer of heat, moisture, gas and solute in unsaturated soil with plants growing was built on the basis of local-volume-averaging method. In this model, absorption or discharge functions of the plant root system, such as water extraction, respiration, heat demand and solute absorption are all taken into account. Meanwhile, the shading effect on soil surface exerted by plant canopy is also demonstrated in the boundary condition. Thus, more physical mechanisms are involved in the present model in comparison with those having hitherto appeared in literature. Moreover, this model consists of ten equations with ten independent variables and it can therefore be solved numerically.更多还原