Spatial pattern recognition of arsenic in topsoil using high-density regional data

Digital image processing analysis was carried out on As in topsoils of the Campania Region (Italy) to recognise any unknown spatial patterns. The highest As concentration is related to topsoils developed on the NW–SE-trending carbonate massifs overlain by pyroclastic rocks where the highest spatial variability and gradient magnitude of As concentration and the highest fault density were also observed. High As concentrations were also found in topsoils over volcanic rocks which played a control on its distribution pattern. The low As values are associated with topsoils along large fluvial valleys where the activity of rivers disturbed the As pattern by transporting larger grain-sized stream sediments with low As concentrations.