Resumo

CHAVEZ, Carlos; MOTA, Carlos; FUENTES, Carlos  e  QUEVEDO, Antonio. TWO-DIMENSIONAL MODELING OF WATER INFILTRATION IN FURROWS APPLYING THE CONJUGATE GRADIENT. Tecnol. cienc. agua [online]. 2018, vol.9, n.1, pp.89-100.  Epub 24-Nov-2020. ISSN 2007-2422.  https://doi.org/10.24850/j-tyca-2018-01-06.

Knowledge of the bulb moisture distribution during an irrigation event helps to understand the depth of wet soil better. The flow of water in soil is modeled with Richards’ equation, however, most solutions require a lot of computational time or the solution is bounded to a specific domain. In this study, the two-dimensional Richards’ equation is solved using two schemes: one implicit in the entire depth and a mixed scheme: explicit in the unsaturated zone and implicit in the saturated zone. The implicit scheme was solved with the conjugate gradient for non-linear problems using a sinusoidal function on the surface. The comparison was performed between the two schemes and the results of wetting profiles and infiltrated depth were similar, given an error criterion. The infiltration process was simulated in a furrow irrigation event through a constant depth in the three furrows, and in a second event they were imposed a different depth to each one. The moisture distribution profiles obtained during the simulated time can help us to give recommendations for the disadvantages of establishing a different depth in the furrows during an irrigation event.

Palavras-chave : Richards; two dimensional; finite differences; furrow irrigation.