Um novo método para estudos dinâmicos, in situ, da infiltração da água na região não-saturada do solo. / A new method for dynamic studies, in situ, of water infiltration in the unsaturated zone of soil.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

Agriculture is the human activity that most affects the environment. Huge amounts of chemicals are applied on the soil. Pesticides percolation and runoff degrades water resources. Thus, soil hydraulic properties must be known due to their influence on solute transport. The measurement of these properties and the modelling of related parameters are often difficult, if not impossible, due to the involved time, money, instrumentation, and scale. Traditional methodologies infer hydraulic properties in samples that are in equilibrium, through invasive techniques and under some special constraints. This thesis contributes with environmental science, via soil science, as it proposes a new method to study the infiltration in the unsaturated zone of soil, by means of CT. The scanner was developed and constructed in this work. The proposed methodology uses profiling CT to measure the water content (theta) during the water flow, and by means of numerical solution of Richards equation and Rossi-Nimmo model water retention, sorptivity, hydraulic conductivity k(theta), and diffusivity D(theta) are obtained. Qualitative results, as 2D and 3D images, are presented and the quantitative results of water retention show good correlation of the proposed method with the conventional tensiometers method. Structured soil column samples are analyzed in the field and in laboratory.

ASSUNTO(S)

tomografia conservation tillage infiltration plantio direto tomography meio-ambiente solo agriculture infiltração agricultura soil environment

ACESSO AO ARTIGO

Documentos Relacionados