Numerical Modeling of Unsaturated Ground-Water Flow Including Effects of Evapotranspiration.

摘要

A mathematical model describing two-phase flow in porous media has been developed. The model,which consists of describing differential equations and an algorithm for their numerical solution,is applicable to the problem of one dimensional,vertical ground water movement in unsaturated soils,considering evaporation and transpiration losses (evapotranspiration). The model is a major extension of one presented earlier by the authors which describes unsaturated flow in the absence of evapotranspiration. The second order,non linear,partial differential equations describing water-air flow through porous media have been extended to include water losses due to unsteady-state evapotranspiration. The basis of the extension is an analogy to Ohm's law. The water transport in the soil atmosphere or the soil plant-atmosphere system has been considered to take place due to the existence of successively decreasing driving-force potentials from the soil to the atmosphere. (Author)