A New Spatiotemporal Risk Index for Heavy Metals: Application in Cyprus

The main aim of this research was to improve risk mapping of heavy metals by taking account of erosion effects. A new spatiotemporal index, namely the G2met index, is introduced, with integration of pre-existing methodologies (Hakanson, EPM, and G2). The G2met index is depicted as a series of risk maps for each heavy metal on a month-time step. The southern part of Cyprus Island was selected as a study area. Concentration of major heavy metals was extracted with soil sampling in a grid of 5350 sites. Rainfall, vegetation, soil, land use, topographic, and hydrologic data were collected from existing European or global databases (WorldClim, BioBar, REDES, ESDAC, CORINE, ASTER GDEM, and USGS). A large number of regional-scale risk maps (with 500-m cell size) were created: one for each heavy metal and totally per month and annually; in addition, choropleth maps in terms of statistics per river basin were produced for every metal. Generally, the G2met maps resulted in different spatial patterns in comparison to those depicted by the Hakanson index alone.