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Spatial distribution of soil heavy metals in different land uses of an industrial area of Tehran (Iran)
Mahmoudabadi, E.; Sarmadian, F. & Nazary Moghaddam, R.
Abstract
Vegetation and different land uses may affect
the spatial distribution of heavy metals in soils. The objective
of the current article was to study the impact of
industrial activities and land use type on the distribution of
heavy metals in soils of Chitgar Forrest Park, located in
industrial zone in the west of Tehran City. The soil samples
were taken from 116 sites in a regular sampling grid
(250 × 250 m) at a depth of 0–20 cm, including three
different land uses, needle leaf forests, broadleaf forests
and rangeland. Nitric acid-extractable form of seven metals,
Cu, Cd, Fe, Mn, Ni, Pb and Zn, and DTPA-extractable
form of Cu, Fe, Mn and Zn were measured. Soil texture,
pH, organic carbon, carbon-to-nitrogen ratio, percentage of
calcium carbonate and electrical conductivity (EC) were
also determined. According to the maps and background
amounts, heavy metals were affected by industrial activities
and road traffic. Proximity to heavy traffic highway
of Tehran–Karaj and large autoindustry plants can be
considered for increasing metal concentrations. Results of
statistical methods (coefficient variation and cluster analysis),
besides geostatistical analysis (variogram and map),
showed that total concentrations of heavy metals are controlled
by intrinsic and extrinsic factors in the studied area.
Although land use type did not affect the alteration in the
distribution of total concentrations of heavy metals, it
changed the distribution of DTPA form of heavy metals in
the soils through affecting the soil organic matter.
Keywords
Chitgar; Kriging; Soil properties; Soil pollution; Industrial activity
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