title: Identification of soil heavy metal sources and improvement in spatial mapping based on soil spectral information: A case study in northwest China.
abstract: In a sewage irrigation area of northwest China, 52 topsoil samples were collected to measure the contents of arsenic (As), chromium (Cr), copper (Cu), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn). To identify their sources, multivariate statistics and geostatistics were applied to separate pedogenic elements (As and Mn) from anthropogenic elements (Cr, Cu, Hg, Ni, Pb and Zn). The accumulation of soil Hg was mainly attributed to long-term sewage irrigation, whereas Cr, Ni and Zn were mainly from industrial activities and dust deposition. In addition to the impacts of industry and dust, traffic-related factors were the main sources of Pb and Cu contamination. Based on the relationships of heavy metals with various soil properties and reflectance spectra, co-kriging (CK) was used to improve the interpolation of heavy metals. Comparatively, soil spectra were more suitable as covariates due to their ease and low-cost of collecting as features.
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Shaanxi, Yangling 712100, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Shaanxi, Yangling 712100, China.
authors.forename: Qingrui
authors.initials: Q
authors.lastname: Chang
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Shaanxi, Yangling 712100, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.affiliation: Laboratory of Geo-Information Science and Remote Sensing, Wageningen University, Droevendaalsesteeg 3, 6708 PB Wageningen, The Netherlands.
authors.forename: J G P W
authors.initials: JGPW
authors.lastname: Clevers
authors.affiliation: Laboratory of Geo-Information Science and Remote Sensing, Wageningen University, Droevendaalsesteeg 3, 6708 PB Wageningen, The Netherlands.
authors.forename: L
authors.initials: L
authors.lastname: Kooistra
mesh_terms: D057914:Agricultural Irrigation / Q000379:methods; D002681:China; D004784:Environmental Monitoring / Q000379:methods; D005843:Geography; D007220:Industrial Waste / Q000032:analysis*; D019216:Metals, Heavy / Q000032:analysis*; D012722:Sewage / Q000032:analysis*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D007220:Industrial Waste; D019216:Metals, Heavy; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants
keywords: Co-kriging; Reflectance spectra; Soil heavy metals; Source identification; Spatial distribution