For this purpose we focused on an in-depth assessment of depositional environments in Southeast Asia. We applied a logistic regression approach based on relationships between sedimentary information, soil maps and measured groundwater As data of Bangladesh, Cambodia and Vietnam, to assessthe relative importance of the different surfaceproxies in these countries. These relationships were used to set up prediction maps of As contamination in Southeast Asia including Indonesia (Sumatra) and other countries where groundwater quality data is scarce (Myanmar and Thailand). Finally, we verified the model prediction in South Sumatra, where groundwater has not previously been tested for the presence of As.