Quantifying the changes of soil surface microroughness due to rainfall impact on a smooth surface
Date
2017Type
ArticleAuthor
K. B. Abban, Benjamin
Papanicolaou, A. N. (Thanos)
P. Giannopoulos, Christos
C. Dermisis, Dimitrios
M. Wacha, Kenneth
G. Wilson, Christopher
Elhakeem, Mohamed
Metadata
Show full item recordAbstract
This study examines the rainfall-induced change
in soil microroughness of a bare smooth soil surface in an
agricultural field. The majority of soil microroughness studies
have focused on surface roughness on the order of ∼ 5–
50 mm and have reported a decay of soil surface roughness
with rainfall. However, there is quantitative evidence from
a few studies suggesting that surfaces with microroughness
less than 5 mm may undergo an increase in roughness when
subject to rainfall action. The focus herein is on initial microroughness
length scales on the order of 2 mm, a low roughness
condition observed seasonally in some landscapes under
bare conditions and chosen to systematically examine the
increasing roughness phenomenon. Three rainfall intensities
of 30, 60, and 75 mm h−1
are applied to a smoothened bed
surface in a field plot via a rainfall simulator. Soil surface
microroughness is recorded via a surface-profile laser scanner.
Several indices are utilized to quantify the soil surface
microroughness, namely the random roughness (RR) index,
the crossover length, the variance scale from the Markov–
Gaussian model, and the limiting difference. Findings show
a consistent increase in roughness under the action of rainfall,
with an overall agreement between all indices in terms
of trend and magnitude. Although this study is limited to a
narrow range of rainfall and soil conditions, the results suggest
that the outcome of the interaction between rainfall and
a soil surface can be different for smooth and rough surfaces
and thus warrant the need for a better understanding of this
interaction.