In the First World War, the region around Ypres (West-Flanders, Belgium) was a battlefield where millions of copper-containing shells were fired. To investigate the consequences of this shelling, we analysed statistically data on the copper (Cu) content in the topsoil (0-0.5 m) of the province of West-Flanders, an area of 3144 km 2 . The measurements had been made on the fine earth (< 2 mm) fraction of 2786 samples. A preliminary screening of the data revealed larger concentrations of Cu in a region of approximately 625 km 2 around Ypres. These concentrations were estimated by ordinary block kriging on the logarithms of the Cu concentration with separate variograms for the battlefield area and the rest of the province and mapped. The median concentration in the battlefield area was 18.0 mg Cu kg À1 compared with 12.0 mg Cu kg À1 elsewhere. We conclude that the current Cu enrichment in the soil around Ypres is the legacy of the millions of shells that were fired in the First World War.

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Regional scale inventories of heavy metal concentrations in soil increasingly are being done to evaluate their global patterns of variation. Sometimes these global pattern evaluations reveal information that is not identified by more detailed studies. Geostatistical methods, such as stochastic simulation, have not yet been used routinely for this purpose in spite of their potential. To investigate such a use of geostatistical methods, we analyzed a data set of 14,674 copper and 12,441 cadmium observations in the topsoil of Flanders, Belgium, covering 13,522 km 2 . Outliers were identified and removed, and the distributions were spatially declustered. Copper was analyzed using sequential Gaussian simulation, whereas for cadmium we used sequential indicator simulation because of the large proportion (43%) of censored data. We complemented maps of the estimated values with maps of the probability of exceeding a critical sanitation threshold for agricultural land use. These sets of maps allowed the identification of regional patterns of increased metal concentrations and provided insight into their potential causes. Mostly areas with known industrial activities (such as lead and zinc smelters) could be delineated, but the effects of shells fired during the First World War were also identified.

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