Improving quantitative management of groundwater resources by aquifer modelling and artificial recharge – AGEPIL

Water scarcity refers to long-term water imbalances, combining low water availability (exacerbated by climate change) with a level of water demand exceeding the supply capacity of the natural system. In 2020, the European Environmental Agency assesses that 1 387 groundwater bodies are currently affected by water abstraction.
Poor quantitative status of groundwater resources increases tension among the water stakeholders may lead to negative impacts such as risk of public water shortages, poor crop yields or poor ecological status of surface water bodies

This project aims at increasing the resiliency of Hauts-de-France toward climate change negative impacts on groundwater resources. It will focus on a specific chalk aquifer which supply 95% of the drinking water in Northern France. Specifically, we aim at carrying out this project in the Aronde watershed located in the Oise district which is affected by significant quantitative issues since 2000’s.

The objectives of this project are to produce knowledge and tools for decision makers to improve the quantitative management of groundwater resources. We specifically aim at:
- WP1: Improve the knowledge about the current water withdrawals from the groundwater to design maps of hot-spots of water withdrawals and identify the seasonality of water abstraction. This WP will be addressed with common tools of geospatial analysis embed in GIS software.
- WP2: Predict the future water withdrawals due to crop irrigation and domestic use, based on the crop rotations and on the rate of urban expansion.This requires specific geospatial analysis. The rate of the urban expansion will be derived from past GIS and census bureau datasets. Determining the crop rotation will be based on successive years of Land Parcel Identification System GIS dataset.
- WP3: Design a tool that can predict the dynamic of the groundwater depth depending on the current and future water withdrawals and the recharge by the precipitations (according to the climatic scenarios). To predict the vertical flow and assess the recharge process, several methods will be set up:
- Analyze long meteorological datasets,
- Perform isotopic tracing and pumping experiments on the UniLaSalle hydrogeological facility,
- Improve existing model created by Zghibi et al. (2016).
- WP4: Explore alternative solutions for artificial groundwater recharge, considering sanitary and environmental risks and writing good practices adapted to the local context. This will be based on a state of the art approach and visit of existing pilot sites in France.

The consortium involves 3 partners with complementary skills:
- Institut Polytechnique UniLaSalle (coordinator). The research group involved is AGHYLE that studies the critical zone by characterizing cycles of water and chemical elements to understand ecosystems and agrosystems functioning. AGHYLE accesses a hydrogeology facility equipped with boreholes to monitor the groundwater depth, or perform specific experiments and pumping tests.
- Université Technologique de Compiègne, UTC. The consortium includes 2 research groups of UTC: "Transformations Intégrées de la Matière Renouvelable" (EA 4297 TIMR) and “Avenues”. They develop research activities on hydrological modelling, chemical engineering and water/soil and supply engineering.
- Syndicat Mixte Oise Around. SMOA is a local board in charge of the management of the water resources in the Oise-Aronde watershed (788 km²). SMOA is specifically in charge of the Aronde watershed which suffer from excessive groundwater abstraction.

This project aims at providing the following deliverables:
- provide a predicting tool of water withdrawals and aquifer recharge to local decision makers and water management boards.
- writing an action program to secure the public water supply and the crop irrigation.
- writing good practices of aquifer artificial recharge adapted to the local context.
- scientific dissemination (conference).