Use of ordinary cokriging with magnetic susceptibility for mapping lead concentrations in soils of an urban contaminated site

• Published in: Journal of soils and sediments 2020-03, Vol.20 (3), p.1357-1370
• Main Authors: Golden, Nessa, Zhang, Chaosheng, Potito, Aaron, Gibson, Paul J., Bargary, Norma, Morrison, Liam
• Format: Article
• Language: English
• Subjects: Allotments; Brownfields; Contamination; Correlation analysis; Cost analysis; Density; Earth and Environmental Science; Environ Risk Assess; Environment; Environmental Physics; Field study; Fieldwork; Green infrastructure; Interpolation; Intervals; Kriging interpolation; Landfills; Lead; Magnetic permeability; Magnetic susceptibility; Open spaces; Performance evaluation; Procedures; Roadsides; Root-mean-square errors; Sec 2 • Global Change; Soil; Soil analysis; Soil contamination; Soil mapping; Soil pollution; Soil Science & Conservation; Soils; Spatial analysis; Statistical methods; Sustainable Land Use • Research Article; Urban planning; Waste disposal sites
• ISSN: 1439-0108; 1614-7480
• DOI: 10.1007/s11368-019-02537-7

Purpose Lead contamination is a prevalent issue affecting cities worldwide. Traditional fieldwork and laboratory analysis techniques can be time-consuming and costly. The purpose of this study was to evaluate the performance of ordinary cokriging (CK) when volume magnetic susceptibility ( κ ) is used as a co-variable for spatial interpolation of Pb in contaminated urban soils. Materials and methods The study was conducted in contaminated urban soils of a former unregulated landfill site. A total of 76 surface samples (0–10 cm) were collected using a systematic sampling grid separated by 20-m intervals. Magnetic susceptibility measurements were taken at a higher density of 10-m intervals with 288 measurements. Thus, it was used as an auxiliary variable to predict Pb concentrations by the CK procedure with an aim to improve spatial interpolation of Pb. To determine the effectiveness of CK over the ordinary kriging (OK) procedure, the spatial density of samples was reduced prior to interpolation. A total of ~ 15%, 25%, 35%, and 50% of the Pb samples were randomly selected and reserved for validation. Omnidirectional semivariograms and covariograms were fitted using log-transformed data prior to interpolation. Results and discussion Measurements of κ shared a significant relationship with Pb concentrations by the Spearman’s Rho correlation analysis ( r s  = 0.676, p