Simulação do movimento de água no solo e sua variabilidade, considerando o efeito da evapotranspiração

Abstract

The simulation of the movement of water in the soil constitute an useful tool in the studies of control and available water to the plants. However, the characteristics of the soil that involve the principal parameters of the models, exhibit a great variability along the area and depth. The present work analyse the diferent aspects that involve the movernent of water in the soil-water-plant system, the mathematical equalization of the flux problems, the principals analytical and numerical solutions for to solve the sirmlation. The variability of the parameters, in general form is rejected, however constitute imprtant factor of extensive use of simulation in great areas, where this variability reach great values. A simplified model based in numerical solution was introduced and utilized with literature data, bringing out good results. In this model was introduced the "probability uncertainty concepts" in determination of the input data, which permite, for simplifications, the obtention of uncertainty also in the results of simulation, expressed through simulated standard deviations. In the uncertainty of knowledge of the characteristic parameters of the soil, the optimization of this parameters constitute acceptable solution. For the experimental data obtained, the simulation of the standard deviation was reasonable, only in the superficial conditions, due the adopted solution for the obtention of this values.