This is the sixth parameter for the DRASTIC groundwater vulnerability assessment (Aller et al. 1987) applied at the HOVER WP7 pilot area Tønder (Denmark).

This dataset consists of gridded estimates of travel times for nitrate in the unsaturated zone for Great Britain (UK), France, the Netherlands, Denmark, Croatia and Slovenia. Data for Croatia and Slovenia are presented from a regional scale pilot study, with data from the remaining countries at the national scale. The dataset was developed in Work Package 5 of the GeoERA Groundwater project HOVER.