Groundwater vulnerability assessment in the Grand Est region, France.

Groundwater represents the most important freshwater resource. In this paper, we applied a spatial approach based on the Geographical Information Systems (GIS) technology to assess the groundwater vulnerability in the Grand Est region from northeastern France. Aquifers media (AM), potential infiltration map (PIM), pollution load index (PLI), and effective precipitation (EP) were the main parameters used in the calculation of groundwater vulnerability. This study proposes a spatial-temporal analysis including past (1961–1990), near future (2011–2040), and more distant future (2041–2070), thereafter called the 1990s, the 2020s, and the 2050s. To validate the results, groundwater monitoring stations data of Nitrate (NO 3 −), dated from 2005 to 2012, was used as reference datasets. The validation of the groundwater vulnerability map was based on pixel pair comparison (PPC) method and it indicates 42.85% perfect confidence and 50% good confidence for the groundwater vulnerability map in 2020s period. The high groundwater vulnerability was found in the Rhine, Marne, and Aube Valleys, while the low and very low vulnerability was depicted in the Vosges, Ardennes Mountains, and some territories form the central region for all three periods. Application of the proposed framework indicates increases of vulnerability up to 60% between 1990s and 2020s and up to 80% between 1990s and 2050s scenarios. The output maps and findings could be useful for the future environmental plans of the region and, in addition, could help mitigate the problems related to water resources, considering the climate expectations. [ABSTRACT FROM AUTHOR]