Spatial distribution of lead (Pb) in soil: a case study in a contaminated area of the Czech Republic

Abstract

For decades, the Příbram district in the Czech Republic has been affected by industrial and mining activities, which are the main sources of heavy metal pollutants and negatively affect soil quality. A recent study examined visible–near-infrared (VNIR), shortwave-infrared (SWIR), and X-ray fluorescence (XRF) spectroscopy to model soil lead (Pb) content in a selected area located in Příbram. Following that study, and using the data, we examined the spatial distribution of Pb content in the soil, with a combination of traditional techniques (Moran’s I, hotspot analysis, and Kriging). One of the novel points of this work is the use of the Getis–Ord hotspot analysis before the execution of Kriging interpolation to better emphasize clustering patterns. The results indicated that Pb was a spatially dependent soil property and through extensive in-situ sampling, it was possible to generate an accurate interpolation model. The high-Pb hotspots coincided with topographic obstacles that were modeled using topographic profiles extracted from Google Earth, indicating that Pb content does not always exhibit a direct relationship with topographic height as a result of runoff, due to the contribution of topographic steps. This observation provides a new perspective on the relationship between Pb content and topographic patterns. Highlights Different spatial analyses were executed to examine the spatial distribution of Pb Extensive in-situ sampling provided an accurate Kriging interpolation model of Pb Pb hotspots with field soil data were mapped with a high degree of certainty The Pb hotspots coincided with topographic obstacles modeled using Google Earth

Keywords

• lead
• kriging
• hotspot analysis
• interpolation
• spatial distribution