Abdelrahman et al. (2026) Managed aquifer recharge in confined multi-layer aquifers: a scalable framework for drought resilience in central Europe

Identification

• Journal: Natural hazards and earth system sciences
• Year: 2026
• Date: 2026-09-30
• Authors: Abdelrahman Ahmed Ali Abdelrahman, Hagen Koch, Mobarok Hossain, Ronjon Heim, Clara Hauke, Irina Engelhardt
• DOI: 10.5194/nhess-26-4641-2026

Research Groups

• Hydrogeology Department, Institute of Applied Geosciences, Technische Universität Berlin, Berlin, Germany
• Department of Geology, Faculty of Science, Zagazig University, Zagazig, Egypt
• Potsdam Institute for Climate Impact Research, Potsdam, Germany
• Adelphi research gGmbH, Berlin, Germany
• Institute of Meteorology, Freie Universität Berlin, Berlin, Germany

Short Summary

This study develops a scalable framework to assess the feasibility of Aquifer Storage, Transfer and Recovery (ASTR) in confined multi-layer aquifers for drought resilience in central Europe. It finds that 62.8% of the Berlin-Brandenburg region is viable for ASTR, with a mean annual recharge potential of 18.2–23.0 million cubic meters, offering significant cost savings compared to conventional water supply.

Objective

• To develop and apply a scalable, integrated framework for evaluating the feasibility of Aquifer Storage, Transfer and Recovery (ASTR) in confined multi-layer aquifers under drought stress, specifically in the Berlin-Brandenburg region, by integrating hydroclimatic drought assessment, GIS-based multi-criteria decision analysis for site suitability, and surface water availability quantification with ecological flow thresholds.

Study Configuration

• Spatial Scale: Berlin-Brandenburg region, Germany, focusing on a study catchment of approximately 3500 square kilometers southeast of the Berlin metropolitan area, with a particular emphasis on the confined Aquifer 2.
• Temporal Scale:
  • Meteorological and hydrological data: 1980–2024
  • Mean annual precipitation, evapotranspiration, and groundwater recharge: 1991–2020
  • Groundwater level declines: 2003–2022
  • Future water demand projections: 2025–2050

Methodology and Data

• Models used:
  • Standardized Precipitation Evapotranspiration Index (SPEI)
  • Standardized Groundwater Index (SGI)
  • GIS-based Multi-Criteria Decision Analysis (MCDA)
  • Soil and Water Integrated Model (SWIM)
• Data sources:
  • Precipitation and potential evapotranspiration (PET): Deutscher Wetterdienst (DWD) 1 km gridded datasets, ERA5 reanalysis (European Centre for Medium-Range Weather Forecasts – ECMWF)
  • River and stream discharges, lake levels, ecological flow thresholds: State Office for the Environment Brandenburg (LfU)
  • Groundwater heads: 176 long-term monitoring wells from LfU
  • Aquifer characteristics (thickness, depth, hydraulic conductivity): 3D hydrogeological model (Abdelrahman et al., 2026)
  • Historical water use data and future demand projections: Berliner waterworks (BWB), Adelphi Research, Office for Statistics Berlin-Brandenburg (AFS), German Technical and Scientific Association for Gas and Water (DVGW), Leibniz Centre for Agricultural Landscape Research (ZALF), LfU
  • Land-use maps: CORINE Land Cover 2018 (European Environment Agency – EEA/Copernicus)
  • Soil types: State Office for Mining, Geology and Raw Materials Brandenburg (LBGR)

Main Results

• Groundwater-level anomalies in the confined multi-layer system (SGI) are strongly coupled to annual-scale climatic water-balance anomalies (SPEI-12), showing a Pearson correlation coefficient of 0.734 at zero lag.
• The Berlin-Brandenburg catchment exhibits a mean hydrological water balance deficit of approximately -91.2 millimeters per year (equivalent to ~319 million cubic meters per year) during 1980–2024.
• GIS-MCDA identified 62.8% (2154 square kilometers) of the study area as viable for ASTR implementation, with 19.5% (670 square kilometers) classified as highly suitable.
• Highly suitable zones are characterized by Aquifer 2 storativity greater than 5 × 10⁻³, horizontal hydraulic conductivity greater than 30 meters per day, depth to Aquifer 2 less than 20 meters, proximity to rivers between 500–800 meters, and minimal land-use conflicts.
• Flow-threshold analysis at 27 gauging stations revealed a mean annual Managed Aquifer Recharge (MAR) potential of 1.6–4.3 million cubic meters at high-potential downstream sites, capable of offsetting 6%–79% of local groundwater extractions.
• At the catchment scale, the total mean annual available recharge volume is estimated at 18.2–23.0 million cubic meters, increasing to 49.8–61.9 million cubic meters during high-flow conditions.
• During severe drought years (e.g., 2018), available recharge volumes decreased substantially by 40%–100% across sites and thresholds.
• Literature-based cost estimates for ASTR (0.30–0.60 EUR per cubic meter) are significantly lower than regional drinking water production costs (approximately 1.80 EUR per cubic meter), suggesting potential annual savings of 21.6–34.5 million EUR at mean annual volumes, and up to 82.7–105.5 million EUR in wet years.

Contributions

• Development of a scalable and generalizable framework for evaluating Aquifer Storage, Transfer and Recovery (ASTR) feasibility in confined multi-layer aquifers under drought stress.
• Integration of hydroclimatic drought assessment (SPEI/SGI), GIS-based multi-criteria decision analysis (MCDA) for site suitability, and dynamic surface water availability quantification with ecological flow thresholds into a single spatiotemporal framework.
• Demonstration of extensive, largely untapped ASTR potential (62.8% of the area) in a water-stressed Central European region (Berlin-Brandenburg), challenging the perception of ASTR's limited applicability.
• Quantification of the economic attractiveness of ASTR as a drought resilience strategy, showing substantial cost savings compared to conventional water supply.
• Provision of a transferable blueprint for strategic planning and sustainable deployment of ASTR in similar sedimentary basins across Europe.

Funding

• SpreewasserN project, funded by the German Federal Ministry of Education and Research (BMBF).
• Bundesministerium für Forschung, Technologie und Raumfahrt (grant no. DKKV-the WAX collection).
• Open Access Publication Fund of TU Berlin.
• Scholarship from the Ministry of Higher Education and Scientific Research of Egypt (for the first author).

Citation

@article{Abdelrahman2026Managed,
  author = {Abdelrahman, Abdelrahman Ahmed Ali and Koch, Hagen and Hossain, Mobarok and Heim, Ronjon and Hauke, Clara and Engelhardt, Irina},
  title = {Managed aquifer recharge in confined multi-layer aquifers: a scalable framework for drought resilience in central Europe},
  journal = {Natural hazards and earth system sciences},
  year = {2026},
  doi = {10.5194/nhess-26-4641-2026},
  url = {https://doi.org/10.5194/nhess-26-4641-2026}
}