E-mail address: chengyihuang@sicau.edu.cn (C. Huang).
Abstract: For the purpose of heavy metals’ spatial-temporal
trends and source allocation in arable soil with the rapid urbanization
in Western China, samples were collected in two stages (2008 and 2017)
in Chengdu city which was chosen for the case study. Positive Matrix
Factorization (PMF) receptor models and Multivariate statistical
analysis were used to understand the heavy metals’ spatial-temporal
variability. The results showed that Cd, Cr, and As in arable soil were
presented with an increasing trend during the 10-year period.
Semi-variation analysis showed that the block basis ratios of the five
heavy metals (Pb, As, Cr, Hg, and Cd) showed an increasing trend, which
suggests that the spatial distribution of heavy metals in arable soil is
more influenced by human disturbances. The source analysis shows that
the enrichment of As is closely related to agricultural activities in
both phases (2008 and 2017). Further source analysis showed that source
of As did not change, but the contribution increased significantly. The
main sources of Hg pollution changed from agricultural activities to
medical equipment manufacturing, Cd changed from soil parent material
sources to chemical industry waste emissions, and the sources of Pb and
Cr expanded from single transportation sources to multiple sources such
as road traffic and human construction. In this study, the examining of
the temporal and spatial patterns of heavy metal contamination in
farmland of typical rapidly developing cities in China can also provide
a basis for the conservation and management of arable soil in similar
areas in the context of rapid urbanization in China.
Keywords: arable soil; heavy metals; spatial and temporal
variability; source analysis