Spatial Variability of Metal Elements
in Soils of a Waste Disposal Site
in Khulna: A Geostatistical Study
H. Nath and I. M. Rafizul
1 Introduction
Today, thousands of processes are constantly contaminating soils on a daily basis.
Accumulation of heavy metals and metalloids due to pollution from rapidly devel-
oping industrial areas, mine littering, disposal of high metal wastes, excess of lead
in gasoline and paints, application of compost to grounds, animal compost, sewage
sludge, pesticides, wastewater irrigation, leftovers from coal combustion, petrochem-
icals spilling and atmospheric deposition, etc., can be some of the major examples
[1]. Heavy metals comprise some ill-defined groups of inorganic chemical hazards
in the contaminated sites. The most hazardous and toxic heavy metals found in these
groups are lead (Pb), chromium (Cr), arsenic (As), zinc (Zn), cadmium (Cd), copper
(Cu), mercury (Hg), nickel (Ni), etc. In the soil, the concentration of these metals
holds for a very long time and puts on a substantial threat to human health and the
ecological system. Soil samples are taken from various points of the site to determine
the concentration of heavy metals in a contaminated site, and several geostatistical
approaches can provide precise predictions at the unsampled locations.
Spatial prediction, usually referred to as spatial interpolation, is a widely used
analytical technique for estimating an unknown spatial value using known values
observed at a range of sample locations [2]. The techniques of interpolation are based
on the principles of spatial autocorrelation, which assumes that the points closer to
each other are more similar than the farther ones [3]. There are several space inter-
polation methods, each according to different estimation criteria that are considered
to produce a good prediction. This research focuses on four of the most commonly
used methods for spatial interpolation: inverse distance weighting (IDW), ordinary
kriging (OK), universal kriging (UK), and empirical Bayesian kriging (EBK). Such
methods approximate values at unsampled locations with certain allocated weights
H. Nath (B ) · I. M. Rafizul
Department of Civil Engineering, Khulna University of Engineering and Technology, Khulna,
Bangladesh
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022
S. Arthur et al. (eds.), Advances in Civil Engineering, Lecture Notes
in Civil Engineering 184, https://doi.org/10.1007/978-981-16-5547-0_3
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