TITLE:
Determining the Soil Erodibility for an Experimental Basin in the Semi-Arid Region Using Geoprocessing
AUTHORS:
Erich Celestino Braga Pereira, Fernando Bezerra Lopes, Francisco Emanoel Firmino Gomes, Aldênia Mendes Masceno de Almeida, Ana Caroline Messias de Magalhães, Eunice Maia de Andrade
KEYWORDS:
Erosion, Universal Soil Loss Equation, Geostatistics
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.12,
November
28,
2017
ABSTRACT: Erosion is the natural process
which has the greatest environmental impact, and is the principal trigger for desertification
around the globe. The main model used to estimate soil loss by erosion is the Universal
Soil Loss Equation (USLE), which unites the major factors that influence erosion
into one equation. The soil erodibility factor (K) is the component of this equation
that represents soil physics, and is defined as the inherent capacity of the soil
to withstand disintegration of its particles and their subsequent transport. The
use of geostatistics is seen as an alternative in spatializing this variable from
sampled to non-sampled points. The aim of this study therefore, was to determine
the soil erodibility factor for an experimental basin in the semi-arid region of
Brazil, in addition to generating the soil erodibility map using geostatistics.
Disturbed and undisturbed soil samples were collected from 35 points, and laboratory
samples were processed to determine the granulometry, permeability and organic matter
of the soil, data which are used to determine the K-factor. Kriging was performed
to spatialize the study variable, when spherical, exponential and Gaussian semivariograms
were tested for generation of the soil erodibility map, these being evaluated by
their respective deviations resulting from cross-validation. The mean value of K
for the Haplic Luvisol was 0.0328 ton·ha·h/ha·MJ·mm; for the eutrophic Red-Yellow Argisol it was 0.0258 ton·ha·h/ha·MJ·mm; and
for the Fluvic Neosol, it was 0.0424 ton·ha·h/ha·MJ·mm. The experimental
basin is classified as highly erodible. The semivariogram that presented the best
fit for generating the soil erodibility map of the study area was Gaussian.