title: Combining a finite mixture distribution model with indicator kriging to delineate and map the spatial patterns of soil heavy metal pollution in Chunghua County, central Taiwan.
abstract: This study identifies the natural background, anthropogenic background and distribution of contamination caused by heavy metal pollutants in soil in Chunghua County of central Taiwan by using a finite mixture distribution model (FMDM). The probabilities of contaminated area distribution are mapped using single-variable indicator kriging and multiple-variable indicator kriging (MVIK) with the FMDM cut-off values and regulation thresholds for heavy metals. FMDM results indicate that Cr, Cu, Ni and Zn can be individually fitted by a mixture model representing the background and contamination distributions of the four metals in soil. The FMDM cut-off values for contamination caused by the metals are close to the regulation thresholds, except for the cut-off value of Zn. The receiver operating characteristic (ROC) curve validates that indicator kriging and MVIK with FMDM cut-off values can reliably delineate heavy metals contamination, particularly for areas lacking background information and high heavy metal concentrations in soil.
authors: Department of Bioenvironmental Systems Engineering, National Taiwan University, 1, Section 4, Roosevelt Road, Da-an District, Taipei City 106, Taiwan, ROC. yplin@ntu.edu.tw
authors: Yu-Pin
authors: YP
authors: Lin
authors: Bai-You
authors: BY
authors: Cheng
authors: Guey-Shin
authors: GS
authors: Shyu
authors: Tsun-Kuo
authors: TK
authors: Chang
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D040362:Geographic Information Systems; D019216:Metals, Heavy / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D013624:Taiwan
chemical_list: D019216:Metals, Heavy; D012989:Soil Pollutants