HOVER – Web tools and maps

In order to build the Web Services with multi-lingual legend concerning thermal waters and natural mineral waters a suitable methodology to organize and visualize data on natural mineral and thermal waters is described. International standards like the international standard legend for hydrogeological maps, INSPIRE etc. are considered and technical options to implement a multi-lingual legend are discussed. The Web services include data on physico and chemical parameters of thermal and natural mineral waters from 13 countries.

Nitrate is one of the more important quality issue for European groundwater. Despite many years of efforts to reduce this contaminant in the environment it remains present in high concentration in many aquifers. Two of the processes playing a major role in the variability of nitrate concentration in groundwater despite pressure intensity were studied in HOVER, denitrification and transfer. The maps of groundwater-N travel time is based on a series of common, evidence-based conceptual models for nitrate transport in the shallow subsurface (https://repository.europe-geology.eu/egdidocs/hover/hover+d5_1_final_v10.pdf).  Travel time was calculated for United-Kingdom, Denmark, The Netherlands and France (see nitrate in the unsaturated zone maps).

Based on data available and methods applied in participating countries completed by literature review a simple common approach was proposed to define the oxic and anoxic environment or mix condition at each sampling point and to map this information at large scale. Once estimated at sampling points the calculation was applied at groundwater body and, where relevant at national scale in order to elaborate the redox potential map (denitrification groundwater body data).

A collection of more than 20 use cases of the environmental tracers for groundwater age distribution allowed preparing a good practice guidance and age indicator sampling guide. A map permits locating each case studies and description. The document and map associated provides a range of applications of the groundwater dating tracers collected across Europe demonstrating their value in groundwater management and research not the least when combined with groundwater flow modelling.

Finally, HOVER project enabled the vulnerability assessment of the upper aquifer to pollution at pilot areas scale. The workflow and methodologies used to first obtain the final DRASTIC and COP vulnerability indexes which are comparable between pilots and also with the pan-European DRASTIC map and second to analyse, from a numerical point of view, the results by computing main statistical parameters and by performing a sensitivity analysis of the 7 DRASTIC parameters indexes were included in a report (https://repository.europe-geology.eu/egdidocs/hover/hover_7-3_vulnerability_pollution_final.pdf) linked to the specific maps.