Advanced Search
Spatial heterogeneity of heavy metals and influencing factors in the surface cultivated soil of the loess hillygully region, China
Received:June 16, 2019  
View Full Text  View/Add Comment  Download reader
KeyWord:soil heavy metals;spatial distribution;geographic detector;loess hilly-gully region
Author NameAffiliationE-mail
ZHANG Min College of Urban and Environmental Science, Northwest University, Xi'an 710127, China  
CHEN Hai College of Urban and Environmental Science, Northwest University, Xi'an 710127, China chw@nwu.edu.cn 
SHI Qin-qin College of Urban and Environmental Science, Northwest University, Xi'an 710127, China  
ZHANG Hang College of Urban and Environmental Science, Northwest University, Xi'an 710127, China  
LIU Di College of Urban and Environmental Science, Northwest University, Xi'an 710127, China  
ZHAO Yan College of Urban and Environmental Science, Northwest University, Xi'an 710127, China  
Hits: 1755
Download times: 1616
Abstract:
      The spatial differentiation and influencing factors of heavy metals in the soil layer of the loess hilly and gully region of China were evaluated in Gaoqu Township, Mizhi County, Shaanxi Province. Using a geostatistical method, the spatial differentiation of the heavy metals Pb, As, Cu, Cr, Ni, and Zn were analyzed on the surface layer of cultivated soil. Geo-detector and statistical methods were combined to analyze the factors influencing the spatial heterogeneity of heavy metals. The content of As, Cu, Ni, and Cr was 23%, 100%, 100%, and 100% higher than the background value of the loess soil, respectively. The variability of As and Cu contents was moderate, and that of Pb, Cr, Ni, and Zn was weak. The nugget coefficient of Ni was the largest(0.59) and that of Pb was the smallest(0.12). Pb and Zn levels showed a strong spatial correlation, mainly based on structural variation. As, Cu, Cr, and Ni showed moderate spatial correlations, which were affected by structural factors and were also greatly affected by random factors. From the perspective of spatial distribution patterns, spatial agglomeration was observed with local high-value areas and low-value areas. The spatial differentiation of heavy metals was affected by the combination of topography and planting methods. The influence of topography on the distribution of heavy metals was greater than that of planting. The interaction between slope direction and planting type had the greatest influence on the distribution of heavy metals. Previous studies hade demonstrated that the content of Ni in the soil layer of Gaoqu Township was generally high, which may pose a potential threat to the soil environment and the safety of agricultural production. Moreover, different heavy metals were affected by the interaction of complex terrain and planting methods, and the spatial difference was evident. These findings provide a scientific basis for the spatial differentiation of heavy metals in cultivated soils, and for evaluation of soil environmental quality and ecological environment management.