Performance of the model Hydrus – 1D using different forms of hydrodynamic characterization

Abstract

The use of mathematical modeling to simulate hydrological events is important for land use and soil conservationplanning for agriculture and livestock, in meteorology, in water resources management as it becomes a convenient tool to evaluate environmental impacts due to human activities. The agricultural use of certain types of soil (like the Neossolo Flúvico) depends on its drainage conditions and wheter corrections of this factor are necessary or not. These conditions can be characterized by computational models as the Hydrus – 1D. So, this paper intended to evaluate the performance of the four forms of hydrodynamic characterization of the soil offered by the software Hydrus 1-D by means of the water retention curves and the hydraulic conductivity. The hydraulic parameters of the soil, as well as the hydraulic conductivity were determined in laboratory tests, and statistic parameters were used  to analyze the performance of the models . The model that presented the best performance during the simulations used information about the soil granulometric composition as input data and the model ofworst performance used the soil granulometric composition and the density of the studied material, unlike the expectations, due to the high relative sensibility, in the model Hydrus-1D, when calculating the hydrodynamic parameters “n” and “ 0s"> ”.