Urban Geochemical Mapping

Stefano Albanese, Domenico Cicchella/ Annamaria Lima, and Benedetto De Vivo  

Definition of Geochemical Background and Baseline at an Urban Scale 155 

GIS aided techniques for urban geochemical data presentation 162 

In this context, modern geographical information systems (GIS) represent an indispensable tool for better understanding the distribution, dispersion and interaction processes of some toxic and potentially toxic elements. Discussion on the use of GIS in the urban environment is, therefore, also provided. 

Heavy metals concentration generally decreases in urban soils away from the main road network and with increasing depth of sampling. This can be explained by the strong dependence of these contaminants on the use of motor vehicles—leaded fuels for Pb, tire wear for Zn and Cd, brake pads for Sb, converters and exhaust systems for platinum group elements (PGEs). 

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Basically an urban geochemical mapping project should aim to ... 

The use of geographical information systems (GIS) has gready enhanced the ability to manage and display geochemical data arising from urban soil mapping activities. 

This S—A method has already been applied in environmental studies on a regional basis by Lima et al. (2003) and Lima (2008), while at urban scale it has been applied by Cicchella et al. (2005) and De Vivo et al. (2006), as specified above. In Fig. 8.6, the baseline geochemical soil maps of Pb, Hg, Se, Tl, V and Zn, representing the... 

Risk maps do not need any peculiar mapping technique to be produced, but are based on the reclassification of geochemical data, represented as dots or interpolated, by means of TAL established by law for each element of concern. The main aim of a risk map is to highlight zones of urban areas that are in excess of TAL values and hence require potential remediation. It should be noted, however, that background values (unaffected by anthropogenic input) may exceed TAL values in some circumstances. 

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