The regional or national assessment of groundwater quality is vital when planning to exploit groundwater for drinking purposes. Especially in developing countries, detailed surveys on groundwater quality are often lacking or incomplete. Therefore, there is a demand for tools capable of assessing groundwater quality on larger scales, for example to identify hot-spots for geogenic contamination.
Using GIS methods, it is possible to model the probability of groundwater being contaminated by arsenic or fluoride on large scales (regional and global).
This approach combines raster data containing layers on geology, hydrology, soil types, climate and land use with point measurements of fluoride or arsenic in groundwater to investigate the possible relationship between these parameters.
The results are depicted as risk maps showing the probability of fluoride/arsenic contamination in a certain region.