RAMR2D network scholarship holders

Title:
Modeling the evolution of groundwater resources in a mining environment: the case of the Arlit-Akokan mining area (DenTim Mersoï Basin, Northern Niger).

Summary of scientific project:

In Niger, groundwater resources are essential for water supply and human activities, including agriculture and mining, as the country is one of the world's leading uranium producers. The Arlit-Akokan region, in the Tim Mersoï basin, has been a major mining area since the 1960s. However, the quantitative impacts of these activities on groundwater resources in the Tim Mersoï basin remain poorly studied. This study aims to fill this gap by assessing the impact of mining activities on groundwater resources in Arlit-Akokan, taking into account the dynamics of the regional aquifer system. The results will contribute to better water resource management in the region, notably through the development of a hydrogeological model of the Tim Mersoï basin and the prediction of the evolution of aquifer piezometric levels.

Summary of results:

Analysis of piezometric trends in the aquifers over the last 50 years has revealed a significant disturbance in flow direction and a drop in water level of up to 200 meters. The hydrogeological model of the region shows groundwater reserves and recharge potential. It simulates scenarios taking into account climate, population growth and mining plans, showing the influence of these factors on aquifer piezometry. Mining pumping has a significant impact on aquifer piezometry. The model identifies areas likely to experience increases in levels, helping mine planning and reduce impacts on local water supplies. This tool is intended to be useful both to the private sector (mining companies) for optimizing mining activities and managing groundwater resources, and to decision-making bodies for appropriate policies combining mining and sustainable management of groundwater resources in Niger.

Integration of the thesis project into the local, regional and international scientific community :
Locally, this thesis represents the very first attempt at regional-scale modeling in the study area, with regard to the development of a tool for predicting groundwater evolution in a mining environment and for the sustainable management of these resources. In particular, the quantification of groundwater resources.

This thesis will therefore be a first step towards a better understanding of Niger's groundwater potential, a highly important theme in scientific research and government programs for sustainable environmental management.
On a regional and international level, the methodological approach developed calls for a technology transfer that could contribute to scientific innovation in West Africa and increased scientific production with researchers from elsewhere.

Prospects for the end of the thesis :

This work not only offers valuable insights into the current state of groundwater resources in Niger, but also suggests promising directions for future research. Firstly, improving the hydrodynamic model to incorporate the vulnerability of aquifers to pollution is essential, especially in mining areas where water quality is paramount. Secondly, the hierarchical modeling approach used in this study for the Arlit-Akokan region can be applied to other areas of the Tim Mersoï basin. For example, in future mining operations at DASA starting in 2024, this methodology could be invaluable for effectively assessing and managing groundwater resources. Finally, the use of complementary methods such as Proton Magnetic Resonance (PMR) prospecting for recharge estimation can further refine the accuracy of hydrogeological models. By validating the results obtained from the hydrogeological model with PMR data, researchers can improve the reliability of their conclusions and enhance the overall understanding of groundwater dynamics in the region.

Prospects after completion of thesis :

Future projects will focus on in-depth exploration of groundwater resources in Niger and the Sahel, recognizing their crucial role in the region's socio-economic development. These initiatives will exploit cutting-edge technologies and data science methodologies applied to environmental issues, including water resource management, with the aim of achieving a more nuanced understanding of groundwater dynamics, for a more sustainable and efficient use of this vital resource.

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