Soil physical and hydraulic properties in the Donato stream basin, RS, Brazil. Part 1: Spatial variability

Abstract

The processes of water flow and water storage in the soil are directly associated with its hydraulic properties, which may vary significantly in space. Therefore, this study aimed to perform a spatial analysis of saturated hydraulic conductivity and the parameters of the soil water retention curve in the Donato basin, located in the municipality of Pejuçara, in the northwest region of the state of Rio Grande do Sul, Brazil, with geographic coordinates between 28º 25’ 34” S and 53º 40’ 30” W, and 28º 24’ 50” S and 53º 41’ 30” W, 590 m of altitude. Undisturbed soil samples (total of 55) were collected from August to November of 2012. The results have demonstrated larger variability for hydraulic conductivity and for the parameter α of the retention curve, and allowed identifying that the high spatial heterogeneity of the studied variables could be associated with factors such as climate, land use and land cover, sampling errors, sampling grid density and also the level of soil compaction.

Soil physical and hydraulic properties in the Donato stream basin, RS, Brazil. Part 2: Geostatistical simulation

“…As the first validation criterion of the simulations performed, it is assumed that the generated fields ( Figure 1) are in agreement with the sampled values and their locations [see Figure 3, Part 1 (Siqueira et al, 2019)]. In this case, it is noted that the high and low values were well represented by the simulation.…”

“…These samples were used to determine the soil water retention curve, and its parameters as given by Genuchten (1980), and the saturated hydraulic conductivity. For more information about the study area and soil sampling, see Part 1 (Siqueira et al, 2019) of this research.…”

“…The analysis of the spatial variability of the saturated hydraulic conductivity and the soil water retention curve presented in Part 1 (Siqueira et al 2019) was done by means of geostatistical simulation using the sequential Gaussian simulation (SGS) method.…”

“…Based on the foregoing, this study aimed to perform a stochastic analysis of the saturated hydraulic conductivity (K sat ) and the parameters of the soil water retention curve (RC) in the Donato stream basin, RS, Brazil, presented and discussed in Part 1 (Siqueira et al 2019).…”

Variability and spatial distribution of hydrodynamic properties in soil with preserved Caatinga

“…The hydrodynamic properties have various spatial variability sources (Šípek et al, 2019;Siqueira et al, 2019;Bagarello et al, 2019). The variability sources might be linked with soil's textural and structural characteristics.…”