NUTRI-Karst: a project to study the impact of human activities on transfers of water and nutrients in the karst basins of the Jura Mountains

Challenges and needs

The deterioration in river water quality in Franche-Comté over the last few decades is due in particular to excess nutrients resulting from past and ongoing human activity. In the Jura Mountains, the impact of agricultural practices and domestic and industrial waste disposal is compounded by the vulnerability of karst landscapes where water infiltrates easily, while limiting filtration processes at ground level.

International scientific work on what happens to pollutants in the environment is very poorly documented for karstic environments and few references are available on the environmental impact of human activities in Franche-Comté.

Reducing the exposure of the population and, more generally, the environment, to diffuse pollution involves taking into account the combined effects of human activities and climate change on water resources. To tackle the problem of water contamination by nutrients, we need to know more about the following:

• changes in the quantity and quality of water resources, taking account of hydro-climatic changes, land use and nitrogen and phosphorus discharges;
• the hydrogeological functioning of karst aquifers and exchanges between karst formations and rivers;
• nutrient transfers from the soil to the subsurface, springs and watercourses.

This subsequently involves adapting the area, with remedial measures to reduce agricultural, domestic or industrial discharges.

There are multiple operational benefits. The purpose is to identify areas that contribute to pollution, to determine how the input of nutrients into water can be limited and to guide the management and adaptation of the area.