MAR has emerged as a key adaptation strategy to reinforce sustainable groundwater management by maintaining water storage, improving water quality, supporting groundwater-dependent ecosystems, counteracting land subsidence and salinization, and creating hydraulic barriers against seawater intrusion or contaminant migration. At the same time, ecosystem restoration measures can improve soil structure, reduce sediment and pollutant loads, enhance infiltration, and promote natural groundwater replenishment while delivering co-benefits for biodiversity, carbon sequestration, and ecosystem services.
For both MAR and restoration-based recharge enhancement to achieve long-term sustainability, it is essential to adapt approaches to local hydrogeological, climatic, ecological, and socio-economic conditions, supported by robust monitoring, modelling, and evaluation frameworks. This joint session aims to highlight advances, applications, and lessons learned at the interface of engineered and nature-based solutions for sustainable groundwater management under climate change.
We welcome contributions focusing on:
• Ecosystem restoration interventions that enhance groundwater recharge, such as soil restoration, erosion control, river, floodplain, and wetland rehabilitation.
• Impacts of restoration measures on groundwater quantity, chemical and microbiological quality, and groundwater safety.
• Environmental and ecosystem co-benefits of restoration.
• Innovations in MAR methods.
• Case studies and lessons learned from MAR schemes in different hydrogeological and climate settings.
• MAR and water quality issues, including impacts on groundwater quality, treatment system effectiveness, and clogging challenges.
• Monitoring, modelling, and assessment approaches for evaluating recharge, water quality, and long-term sustainability.
• Socio-hydrological, governance, and economic aspects, including cost-effectiveness and decision-support tools.
This joint session merges the former sessions HS8.1.3 Sustainable water management with managed aquifer recharge (MAR) and HS8.1.7 Ecosystem restoration for aquifer recharge, groundwater quality, and climate resilience.
Orals: Tue, 5 May, 16:15–18:00 | Room 2.44
In regions with thick unsaturated zone and arid climate, the complicated subsurface hydrological processes and little water flux challenge the studies related to groundwater recharge. It is necessary to explore the recharge mechanism from different scales with multiple methods. The Loess Platea has loess deposits with mean thickness of ~100 m, and the groundwater recharge mechanism remains controversial in the past. We employed traditional monitoring of soil water and water table with multiple tracers to explore the connectivity among precipitation, soil water and groundwater. Vegetation change can substantially alter the hydrological connectivity. Because of the Grain for Green Project, the Loess Plateau has experienced large-scale vegetation change including increased vegetation cover and conversion from shallow- to deep-rooted plants. Previous studies have shown that the soil water has been depleted, however, its impacts on groundwater recharge remain unclear. We thus develop different techniques to quantify how vegetation changes influence the subsurface hydrological processes. The precipitation-soil water-groundwater connectivity is identified, and the impacts of vegetation change on the connectivity has been investigated.
How to cite: Li, Z., Wang, W., and Huang, Y.: Precipitation-soil water-groundwater connectivity under changed vegetation pattern in China's Loess Plateau, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4572, https://doi.org/10.5194/egusphere-egu26-4572, 2026.
Increasing hydroclimate extremes and land degradation have intensified concerns over aquifer recharge, water quality, and climate resilience in lowland continental regions across Western and Central Europe, as these are vital areas for agricultural production. Concurrently, the re-colonization of beavers in Germany and across Europe has revived interest in their function as natural ecosystem engineers and their ability to support ecosystem restoration. Despite mounting evidence of beavers’ impacts on restoration of wetlands and natural riparian areas, evidence from agriculturally impacted lowlands remains limited. In this study, we explore how catchment structure, hydrogeology, and land use mediate beaver activity, and how in turn beavers impact hydrology and water quality, as well as drought resilience, in two topographically contrasting lowland agricultural catchments; the Sophienfliess and the Demnitz Mill Creek in eastern Brandenburg, Germany.
Integrative assessments of water quality, water sources and flowpaths, as well as landscape settings have revealed differential impacts of beavers in both catchments. In the Sophienfliess catchment, extensive beaver dam cascades in the lower catchment significantly impacted downstream water quality, indicating strong denitrification and reduction of organic carbon, as well as fertilizer-based nutrients. Furthermore, increased water retention and storage in beaver ponds has resulted in strong surface-groundwater connectivity and increased aquifer recharge. In contrast, lower dam density and spatially diverse dynamics of nutrient fluxes in den Demnitz Mill Creek catchment revealed a strong influence of local hydrological conditions on mobilization processes and water quality dynamics. As a result, changes in water quality and groundwater recharge could only be partially linked to beaver activity. Ultimately, understanding these relationships is crucial for evaluating the role of beavers in ecosystem restoration, how their engineering efforts modify catchment hydrology, infiltration, and groundwater recharge across different topographic settings, and whether they can sustainably contribute to groundwater management, drought resilience and ecosystem restoration of degraded agricultural lowland catchments under ongoing climate change.
How to cite: Warter, M. M., Tetzlaff, D., Goldhammer, T., and Soulsby, C.: Impact of beaver re-colonization on aquifer recharge and water quality in two topographically contrasting lowland agricultural catchments , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-94, https://doi.org/10.5194/egusphere-egu26-94, 2026.
As climate change exacerbates the frequency and intensity of hydrological extremes, the restoration of natural river dynamics—such as stream meandering—has emerged as a promising nature-based solution (NBS) to enhance water retention, reduce flood risks, and sustain low flows. While local experiments demonstrate the benefits of meandering for ecosystem resilience, their large-scale impacts on groundwater recharge and regional hydrology remain poorly understood.
Within the European NBRACER project, we explore the potential of upscaling stream meandering across France using the IPSL land surface model ORCHIDEE. However, the model’s initial groundwater representation lackscritical processes, including horizontal flow between grid cells and feedbacks between groundwater, soil moisture, and rivers. To address these limitations, we implemented an enhanced groundwater scheme [1] incorporating lateral exchanges and retroactive river-aquifer coupling. Using a regional configuration over continental France and the high-resolution hydrogeological dataset BDLISA, we simulate the hydrological effects of increased river length on groundwater recharge and low flows.
This study highlights the technical challenges of integrating subgrid-scale processes in large-scale simulations and provides insights into the scalability
of stream meandering as an NBS. Our findings aim to inform water management strategies and climate adaptation policies by assessing the broader
hydrological impacts of river restoration.
[1] Vergnes, J.-P., Decharme, B., Alkama, R., Martin, E., Habets, F., & Douville, H. (2012). A simple groundwater scheme for hydrological and climate applications: Description and offline evaluation over France. Journal of Hydrometeorology, 13(4), 1149-1171. https://doi.org/10.1175/JHM-D-11-0105.1
How to cite: Lang, S., Lanet, M., Dupuy, A., and Li, L.: Integrating a New Groundwater Module into ORCHIDEE: Regional Effects of Stream Meandering on Groundwater Recharge, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7718, https://doi.org/10.5194/egusphere-egu26-7718, 2026.
Managed aquifer recharge has been the primary source for drinking water for decades in the most populated, western part of the Netherlands. In the coastal dune areas, pre-treated surface water is infiltrated and, after a residence time of months, abstracted through wells or open channels. Due to increasing drinking water demands and extended periods of drought, this sustainable water source is under pressure.
To increase water availability, research is ongoing to enlarge the subsurface freshwater lens in the dunes through extraction of anaerobic brackish groundwater at the fresh-saline interface. Consequently, the freshwater lens will be pulled downward, with the added benefit that the abstracted brackish groundwater itself can serve as a source for drinking. This new drinking water source, however, contains elevated levels of salinity, as well as ammonium (NH4+) and manganese (Mn2+) above drinking water standards, which thus needs treatment.
A sustainable treatment method for NH4+ and Mn2+ is aeration followed by biofiltration, to be combined with reverse osmosis for salts removal. There is, however, only limited knowledge on biofiltration of saline waters, hampering its uptake by water utilities.
In this study we therefore investigated the growth of NH4+ and nitrite (NO2-) oxidizing bacteria in aerated biofilters under fresh and saline conditions, to understand their conversion kinetics, interaction with Mn2+ oxidizing bacteria and metal reaction products.
Results demonstrated that under saline conditions, both nitritation and nitration did not develop spontaneously. After inoculation, growth of NO2- oxidizers was extremely slow and more sensitive to salinity than NH4+ oxidation. Upon the onset of NO2- production, immediate Mn2+ release was observed, presumably caused by chemical reduction of Mn oxides present on the filter sand grains.
These results suggest that salinity strongly constrains nitrification and alters manganese cycling, which must be considered when implementing biofiltration for anaerobic brackish groundwater as a drinking water source. Furthermore, this insight helps to understand the fate of NH4+ and Mn2+ in natural saline environments where they interact with NO2-oxidizing bacteria, including coastal marshes and ocean sediments.
How to cite: van Halem, D., van der Poel, S., van Loosdrecht, M., and Laureni, M.: How salinity affects drinking water biofiltration of anaerobic brackish aquifer recharge water, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-10816, https://doi.org/10.5194/egusphere-egu26-10816, 2026.
In a context of intensified pressures on the groundwater resource, managed aquifer recharge (MAR) has emerged as a strategic mean to enhance water security and strengthen the resilience of groundwater systems under changing climatic conditions. MAR encompasses a range of techniques for intentionally enhancing aquifer recharge using various kind of source water through infiltration basins, injection wells, induced riverbank filtration, and other engineered systems. When appropriately designed and operated, MAR can maintain groundwater levels, increasing storage, improve water quality, mitigate land subsidence, combat seawater encroachment in coastal aquifers, and sustain groundwater-dependent ecosystems. These often multifunctional benefits position MAR at the interface between climate change adaptation, integrated water resources management, and ecosystem conservation.
Still several issues prevent MAR systems to be adopted at full scale. Among the most relevant, governance and regulatory barriers discourage investment and slow project approval and scaling. MAR projects often fall between surface water and groundwater regulatory frameworks, leading to unclear institutional responsibility. Permitting/authorisation processes are frequently complex, fragmented, poorly aligned with MAR practices, or lacking. Even if MAR construction costs are relatively low, compared to traditional water infrastructures, the benefits deriving from MAR are less visible and often long-term. Furthermore, the lack of funding mechanisms, especially in Europe, limits expansion beyond pilot or demonstration projects. Concerns persist around risks such as groundwater contamination, and even in cases when risks are technically manageable (as for many other types of waterworks), these perceived risks remain a major obstacle to large-scale adoption. Finally, social acceptance and stakeholder understanding of MAR is often low, particularly when reclaimed water is proposed for recharge.
On the other hand, recent years have seen a surge in pilot and demonstration schemes and the regulatory point view started gaining attention. Moreover, the need for low-carbon and low-cost solutions may sustain the widespread adoption of MAR schemes. Two more elements may drive the change. The first one is the likely possibility that MAR qualifies as a nature-based solution. Yet, many MAR schemes mimic natural processes to enhance recharge. However, the debated question now relates to the fact whether MAR infrastructures may directly provide net biodiversity gains. Achieving the biodiversity gain, thanks to the geoengineered infrastructure, by, i.e., supporting wetland ecosystems, providing more water to riverine ecosystems during period of low-flow, would constitute a positive value, and likely position MAR waterworks in a prominent position respect to other options. Second, so called Agricultural-MAR may constitute a cornerstone for scaling up at watershed level. To this, significant discussion and capacity building need to be set with the agricultural world. Relevant scientific questions need to be addressed, such as those related to potential aquifer contamination by nutrients and plant protection products/pesticides, and the impact on crops produced by the recharge techniques.
Advancing MAR from niche applications to a mainstream water management practice will require a shift from project-by-project implementation toward coordinated, cross-sectoral strategies. Embedding MAR within broader climate adaptation, land-use, and agricultural policies, while strengthening the science–policy interface, can help translate its conceptual potential into measurable and durable benefits.
How to cite: Rossetto, R.: Managed Aquifer Recharge: Bridging Climate Change, Water Security, and Ecosystem Conservation, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-15100, https://doi.org/10.5194/egusphere-egu26-15100, 2026.
Agricultural managed aquifer recharge (Ag-MAR) harnesses agricultural settings and practices to infiltrate additional water replenishing groundwater systems. Can this method be used as an adaptation measure to current and future climate changes, posing a threat to water resources availability worldwide? Which are its requirements and limitations in an agri-urban context, characterized by a coexistence and sometimes a conflict of ecosystems and human activities with their needs and risks?
To address these questions, a two-year field experiment was conducted near Milan (Northern Italy), a densely urbanized area that still hosts intensive agricultural activities. In the area, and throughout the Po plain, summer crop water demand is met through surface irrigation, diverting river and stream water via a capillary network of canals. By providing additional water to the aquifer during autumn and winter, periods of high surface water availability, the enhanced groundwater reserves could be managed to cover the demand during hydrological droughts, avoiding the need for new reservoirs and their associated impacts on the water cycle.
The existing canal network served as the infrastructure for the experiment: during the 2023-2024 and 2024-2025 winters, water was diverted into canals and onto agricultural fields with the collaboration of local farmers, while groundwater levels and groundwater-dependent ecosystems were monitored. The collected data was then utilized to build a numerical groundwater flow model (MODFLOW) and an agro-hydrological model (IdrAgra), capable of estimating groundwater recharge through the simulation of irrigation management and irrigation-groundwater interactions, even under climate change conditions. Outputs (precipitation, temperature, humidity) from three regional circulation models were downscaled to generate a cascade of scenarios: future surface water availability and irrigation diversion, groundwater recharge, and groundwater levels. Multiple Ag-MAR configurations were then tested to assess their effectiveness in increasing groundwater storage and water table levels, while balancing infiltration targets with canal system capacity and minimizing risks to underground infrastructure.
We found that the spatial distribution of the irrigated fields plays a key role in the net groundwater storage increase, since groundwater-dependent ecosystems (lowland springs locally known as fontanili) scattered around the area can drain part of the additional recharge. Despite the losses, the measure increases the water available for the following summer months, enabling emergency withdrawals in case of drought. Results indicate that, even using only the volumes applied during the field tests, well below the system’s full potential, Ag-MAR could have supplied approximately 20% of the unmet water demand recorded in the study area during the 2022 drought. This contribution increases under the scenarios considered. These findings provide a basis for regional authorities and local communities to develop long-term strategies for implementing Ag-MAR as an aquifer-based climate change adaptation measure.
This research was carried out as a Pilot Action of the MAURICE Interreg project (CE0100184).
How to cite: Colombo, P., Medina Montecinos, C., Mazzon, P., Riva, R. E., Weber, E., Piuri, V., and Alberti, L.: Leveraging irrigation–groundwater interactions for climate change adaptation: results from an Ag-MAR application in a complex agri-urban setting, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-13175, https://doi.org/10.5194/egusphere-egu26-13175, 2026.
The largest managed aquifer recharge operation in Israel is the Shafdan system where ~ 130*106 m3 of secondary effluents percolate from surface and recovered through ~ 150 wells annually, to be used for unlimited irrigation (i.e. as freshwater). The residence time of effluents in the subsurface, during their passage in a Soil Aquifer Treatment (SAT) system, from the infiltration pond to the pumping wells' screens is a concern of health regulators. Therefore, a large-scale tracer test in a segment of the Shafdan SAT system was initiated in July 2024 and still ongoing. Various estimates of the residence time were done during the >40 years of operation of the Shafdan SAT, nevertheless, this is the first time a tracer test is performed, to directly derive travel-time distributions from soil surface to the first ring of recovery wells (200-500 m laterally, 50-80 m vertically).
A subgroup of 4 infiltration ponds with a total area of 5.6 hectare was chosen for spread of tracers. The first ring of working production wells surrounding these infiltration basins includes 6 wells. Four observation wells at smaller distances than 200m from the infiltration basins were also used for monitoring. Two tracers were applied: the anion Bromide (Br-) and the fluorescent organic salt known as Uranine (Na-fluorescein). Additionally, the cheaply monitored water characteristic, electrical conductivity (EC), is used as a precursor for the tracers. A total of 47 tons of the 3 salts NaBr, NaCl and CaCl2 (introducing Br-, elevating EC and keeping SAR low) and 75 kg of Uranine were spread evenly over the 5.6 ha of the infiltration pond's surface using a mechanized broadcast fertilizer.
Uranine is still observed in pumped water of this sandy aquifer 18 months after application. Nevertheless, it was retarded in comparison to Br- by ~10 days in the closest observation well and by 30-115 days in the furthest production wells. First arrival (Br-) in a production well was observed 164 days after tracer application at surface, easing health regulators concern (90 days). EC was found correlated good with Br- in most production wells, but not in observation wells. Only ~ 1% of tracers' mass was recovered in wells after 280 days, and ~ 10% after 400 days. The main conclusion so far is residence time in sub surface is long enough, mixing and dilution of effluents in the recovery wells is very high enhancing the effectiveness of the physical and bio-chemical processes of the SAT system. Stay tuned for more results in May at Vienna.
How to cite: Kurtzman, D., Rudnik, G., Nitsan, I., Brody, S., Gabay, R., and Negev, I.: A large-scale tracer test in a SAT system verifying residence time of effluents in the subsurface, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-11118, https://doi.org/10.5194/egusphere-egu26-11118, 2026.
Managed aquifer recharge (MAR) can improve water availability by enhancing storage, and water quality through biodegradation and filtration processes. Impaired water sources such as WWTP effluent often contain trace organic chemicals (TOrCs) which may have adverse effects on the environment and human health. Removing TOrCs using activated carbon or ozonation is costly and energy intensive. Instead, biodegradation of TOrCs in the aquifer can be enhanced by changing the environmental conditions e.g. via sequential managed aquifer recharge technology (SMART). SMART consists of an initial infiltration step (e.g., bank filtration) followed by an aeration step and subsequent infiltration step under oxic and carbon limited conditions. This study aims to implement SMART in a heterogeneous aquifer and demonstrate the attenuation of TOrCs.
SMART was implemented on a demonstration scale at a former waterworks site in Berlin to produce raw water which could potentially be used for later drinking water production. Impaired bank filtrate is aerated and iron and manganese are removed. Then, the water is infiltrated into a 25 m long, 1 m wide, 7 m deep infiltration trench filled with gravel. Two production wells located 25 m away from the trench establish a controlled, homogeneous flow field. Another production well 60 m away hydraulically shields the system. The pumping regime extracts more water (approx. 24 m³/h) than is infiltrated (10 m³/h) to comply with permitting requirements. Hydraulic retention time confirmed by tracer tests is approximately seven days from the trench to the first two wells. Groundwater monitoring wells provide online monitoring data at different depths (groundwater level, electrical conductivity, temperature, and dissolved oxygen (DO)). Due to operational constraints, drinking water was infiltrated for approximately one year, facilitating the establishment of plug-flow conditions and an oxic zone (>1 mg/L of DO) in the subsurface. Pre-treated bank filtrate has been infiltrated since February 2024. Additionally, hydraulic and reactive transport models of the site were created to understand and confirm subsurface processes.
Trace organic contaminants were removed in the flow field and can be categorized into different groups. Persistent compounds such as candesartan showed limited biodegradation potential (removal of less than 30 %). A group of easily degradable and volatile substances was already removed during pre-treatment under oxic conditions. The third group of redox-sensitive compounds such as diclofenac were better removed under the oxic and carbon-limited conditions of SMART with removal between 30 % and up to 80 % from the influent to the monitoring well located 20 m downstream of the trench.
This strong attenuation demonstrates the potential of enhancing biodegradation in a heterogeneous aquifer by actively managing the in-situ redox regime to achieve sustainable TOrCs biodegradation. The demo-scale system is currently in operation and open research questions are being investigated, such as how the microbiome adapts and what is needed for a transfer to new locations. Depending on the local conditions, SMART needs to be combined with further advanced drinking water treatment steps to ensure sufficient TOrCs removal. Overall, this approach is a promising solution to implement water reuse locally.
How to cite: Linke, F., Aniol, J., Knabl, M. A., Sperlich, A., Filter, J., Zerelli, S., König, A., Gnirss, R., Greskowiak, J., and Drewes, J. E.: Sequential managed aquifer recharge technology (SMART) for enhancing biodegradation of trace organic chemicals in a heterogeneous aquifer , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16700, https://doi.org/10.5194/egusphere-egu26-16700, 2026.
The Cuneo Plain, located in Northwestern Italy, hosts a vast unconfined alluvial aquifer mainly exploited for agrozootechnical activities. Besides conventional pumping wells, groundwater is conveyed to the irrigation network through lowland springs, locally known as fontanili. These drainage trenches were excavated since the Middle Ages to reclaim marshy lands by intercepting the shallow aquifer and lowering its water table. In recent years, some lowland springs have run dry during severe summer droughts, fostering the experimentation of Managed Aquifer Recharge (MAR) to recover their former discharges.
As a result, a pilot injection trench consisting of a 100 m long perforated pipe enables the infiltration of the surplus surface water that is circulated in the canals off the irrigation season. After a few months of testing, the first results regarding injected volumes and aquifer response are available. Preliminary findings highlight both the benefits and downsides associated to the high hydraulic conductivity of the studied aquifer. In particular, the time-lag in water table rise and the rapid dissipation of injection effects are key parameters for planning sustainable and effective injection strategies. Moreover, the spatial distribution of monitoring wells and their proximity to the MAR infrastructure proved, in this case, crucial to detect the water table rise and its spatial extent.
A monitoring network is currently being developed to enable real time visualization of data from monitoring wells, water levels in the lowland springs and infiltrated volumes. This is particularly useful to verify proper operation of the injection trench and implement alert systems able to identify and communicate malfunctions (e.g. clogging of the inlet), allowing prompt intervention.
Finally, a groundwater flow model has been developed for multiple purposes: to better interpret the interaction between the lowland spring and the aquifer; to validate the effects of the artificial recharge; to plan injection times based on the spring response time lag; and, ultimately, to explore possible developments in the MAR injection method. The model simulates the main hydrogeological features of the study area: the lowland spring, the surrounding streams, and the artificial recharge. The model was calibrated based on a piezometric map produced in October 2025 and having high spatial resolution thanks to the engagement of citizens from surrounding municipalities, who granted access to their private wells, providing dense observation points and demonstrating the effectiveness of citizen science initiatives.
How to cite: Amendola, A., Taramasso, M. A., Miraldi, F., Gallia, L., Giordano, N., Coha, M., Casasso, A., Sethi, R., and Tosco, T.: Pilot site of a MAR injection trench in Northern Italy: preliminary lessons learned from field monitoring and modelling, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12489, https://doi.org/10.5194/egusphere-egu26-12489, 2026.
Posters on site: Tue, 5 May, 14:00–15:45 | Hall A
Ecological restoration and managed aquifer recharge (MAR) are widely promoted to enhance groundwater resources and buffer hydrological extremes, yet quantitative evidence on their effectiveness and co-benefits remains fragmented across land-use types and disciplinary silos. Existing reviews rarely compare not only hydrological responses but also side-benefits such as flood peak reduction, carbon sequestration, water quality improvements, biodiversity gains, and associated implementation costs across contrasting land-use/land-cover (LULC) settings. This study presents a systematic literature review that (i) maps the global evidence base on groundwater recharge responses to restoration and MAR, (ii) compares co-benefits and trade-offs across major LULC classes (river lowlands, wetlands, mountainous aquifers, forests, urban areas, cropland, pasture), and (iii) evaluates how study design, metrics, and cost information influence the strength of inference and decision relevance.
Searches in three bibliographic databases follow a pre-specified protocol with semi-automated deduplication and AI-assisted screening. Two reviewers independently screen titles/abstracts and full texts in a dedicated review platform, targeting substantial to almost perfect agreement (Cohen’s κ ≥ 0.7 for titles/abstracts; κ ≥ 0.8 for full texts). Eligible studies are coded for hydroclimatic region, LULC, intervention type, study design (before–after, control–impact, paired-catchment, BACI), and methodological approach (field monitoring, tracer tests, modelling). Extracted response variables include quantitative metrics of groundwater recharge, baseflow and storage, flood peak attenuation, carbon-related indicators, water quality parameters, biodiversity indices where available, and reported capital and operational costs or cost proxies. Risk of bias and inferential strength are appraised using criteria adapted for quasi-experimental hydrological studies and economic evaluations.
The review is expected to yield a sufficient number of primary studies (on the order of 80-150) to enable cross-LULC comparisons of hydrological effectiveness, co-benefits, and costs. Anticipated outputs include evidence maps identifying LULC-intervention combinations with robust multi-benefit support versus critical gaps, and syntheses highlighting where relatively small investments deliver disproportionately high recharge gains and side-benefits. These insights will inform the design of future experiments and models and support practitioners and policy-makers in prioritising restoration and MAR options that maximise groundwater recharge while delivering broader ecosystem and societal benefits.
How to cite: Julia, D., Merz, R., Farnleitner, A., and Boano, F.: Hydrological and multi‑benefit outcomes of ecological restoration and managed aquifer recharge across land‑use types: a systematic literature review, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-22694, https://doi.org/10.5194/egusphere-egu26-22694, 2026.
We assess the applicability of the InVEST model suite to quantify the benefits of managed aquifer recharge (MAR) for groundwater-dependent ecosystem services (GDES). GDES are of high importance for a wide range of human activities and therefore should be assigned substantial value and integrated into sustainable groundwater management planning.
Given the growing need to enforce sustainable groundwater management, a tool that enables the environmental impact assessment of MAR operations—and thus the quantification of MAR impacts on GDES—would be highly beneficial. Such a tool could facilitate and accelerate the integration of MAR’s positive effects on GDES into management and planning processes.
The selected pilot region is located in the pre-alpine foreland in southern Bavaria. This region strongly depends on local GDES, particularly for agricultural and tourism-related purposes. Since 2014, a large-scale flood protection concept with a total retention volume of approximately 7.5 million m³ of floodwater has been under development. In our project Smart-SWS² we have developed a concept to couple flood protection and MAR.
In this study, we apply the InVEST model suite¹ as an evaluation framework to compare different scenarios and their capacity to safeguard regional water resources and associated GDES. The baseline scenario represents conditions prior to the implementation of the flood protection concept, while the other scenarios incorporates the retention basins and the planned MAR systems. For these scenarios, we evaluate the model outputs and the feasibility of quantifying GDES using InVEST.
¹ Natural Capital Project
² Augusting & Baumann, 2024
How to cite: Schultze, A., Dietmaier, A., and Baumann, T.: Testing the quantification of groundwater-dependent ecosystem services enhanced through managed aquifer recharge via the InVEST model suite, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2925, https://doi.org/10.5194/egusphere-egu26-2925, 2026.
Restoration strategies in boreal rivers should aim to enhance ecosystem resilience to climate change. This requires better understanding of fish habitat preferences, protection of thermal refuges, and mitigation of habitat loss.
In TRIWA LIFE-project, we examined the role of ground water in boreal rivers for brown trout (Salmo trutta). The streams surveyed varied in ecological status, ranging from near natural to restored and channelized conditions. To assess trout habitat, use and availability, we employed innovative methods including thermal infrared imaging, machine learning, alongside electrofishing surveys.
Preliminary results indicate that trout were more abundant in stream sections characterized by higher sinuosity and the presence of groundwater. Machine-learning models further revealed that trout occurrence was strongly associated with thermal conditions and habitat structure, with temperature metrics, coarse gravel substrate, water depth, and flow velocity emerging as the most influential predictors. Model performance was high (AUC > 0.9), indicating robust discrimination of suitable habitats and highlighting the combined importance of thermal heterogeneity and geomorphological complexity for trout habitat use.
How to cite: Hailemariam, S., Marttila, H., Louhi, P., and Torabi Haghighi, A.: Thermal Heterogeneity and Habitat Complexity as Drivers of Brown Trout Resilience in Boreal River Restoration, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21772, https://doi.org/10.5194/egusphere-egu26-21772, 2026.
Groundwater depletion and Flooding are increasingly co-located problems: flood risks rise with more frequent and intense rainfall extremes, while underlying aquifers decline due to persistent abstraction. Managed Aquifer Recharge (MAR) offers a pathway to improve groundwater sustainability, yet site selection is commonly guided by recharge volume and subsurface feasibility, with limited quantification of how recharge operations influence surface inundation during flood events. This separation constrains conjunctive strategies that can simultaneously relieve flood impacts and support aquifer recovery.
This study explores a conjunctive planning approach that redesigns MAR from a basin-centric focus on recharge maximisation to an inundation-centric focus on minimising flood impact. We employ the integrated MIKE SHE modeling system to simulate rainfall-runoff, overland flow routing, unsaturated-zone processes, and groundwater flow in a single dynamical representation. The proposed framework systematically searches where recharge structures could be placed to intercept floodwater and reduce overall flood damages in high-impact locations, while remaining consistent with hydrogeological feasibility and operational constraints. Historical flood events are used as scenario datasets for representative Indian basins, allowing event-based stress testing of candidate locations under realistic forcing.
The simulations show that MAR benefits are highly site- and event-dependent: some locations yield meaningful reductions in local inundation while contributing to groundwater replenishment, whereas others primarily increase subsurface storage with limited flood response. Strategically identified recharge zones produce measurable reductions in peak flood depths in localized high-risk areas, while simultaneously yielding substantial increases in groundwater recharge relative to baseline conditions. The findings underscore the value of reframing MAR to evaluate recharge interventions in support of flood resilience and long-term water security.
How to cite: Mishra, S., Dubey, S., Kapadia, V., and Bhatia, U.: Reframing Managed Aquifer Recharge for Conjunctive Flood-Groundwater Resilience, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-20313, https://doi.org/10.5194/egusphere-egu26-20313, 2026.
Groundwater recharge in arid and semi-arid regions is very important component to quantify, however, it is highly episodic, spatially heterogeneous, and subject to substantial uncertainty. This study estimates groundwater recharge in the South Al Batinah (SAB) Basin of northern Oman using a soil-moisture mass balance framework driven by long-term remote sensing and land surface model data. Monthly water-balance components—including precipitation, evapotranspiration, runoff, and soil moisture storage change—were derived from the FLDAS Noah land surface model for the period 1990–2023 and aggregated at the basin scale. Recharge was computed as the residual of the water balance and uncertainty was quantified using Latin Hypercube Sampling (LHS) with 5,000 realizations per month. To further constrain recharge estimates and reduce physically implausible outcomes, a Physics-Informed Bayesian Neural Network (PI-BNN) was developed, integrating mass-balance constraints, non-negativity conditions, near-dry penalties, and Bayesian uncertainty quantification within a unified probabilistic framework.
Results indicate that groundwater recharge in the SAB Basin is strongly seasonal and highly variable, with negligible recharge during most dry months and irregular recharge pulses associated with intense rainfall events in winter and mid-summer. Mean monthly recharge is generally low, with the highest values occurring in December (≈5–6 mm) and moderate recharge in February–March and July. Uncertainty analysis show that precipitation variability is the dominant control on recharge uncertainty, accounting for more than 70% of total variance during wet months, followed by evapotranspiration, surface runoff, and soil storage change. The PI-BNN produces recharge estimates consistent with the water-balance approach but with a reduced uncertainty bounds, effectively ruling out implausibly large recharge values while preserving physically realistic variability.
The results show that groundwater recharge mechanism in the SAB Basin is dominated by rare, high-intensity rainfall events. The combined use of remote sensing, stochastic sampling, and physics-informed machine learning provides a good framework for recharge estimation and uncertainty reduction in data-scarce arid environments.
How to cite: Baalousha, H. and Khan, M. S.: Physics-Informed Bayesian Neural Network for Groundwater Recharge in South Al-Batinah Aquifer, Oman., EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4358, https://doi.org/10.5194/egusphere-egu26-4358, 2026.
Managed aquifer recharge (MAR) is a state-of-the-art strategy to maintain groundwater levels and sustain groundwater-dependent ecosystem services. Increasing rainfall intensity and prolonged drought periods caused by climate change put the availability of river water for MAR at risk. To adapt, MAR has to include stormwater as a source. This requires to infiltrate high volumes of water with high recharge rates, increase buffer and retention capacity and times, and maintain water quality. In the project Smart-SWS we have developed a stormwater-based MAR scheme which consists of an infiltration ditch connected to a stream and a geotechnical barrier set in the aquifer. Water quality issues were addressed with a combination of catchment risk analysis, on-line monitoring backed by extended laboratory analyses, and tailored treatment techniques.
The site is located downstream of a flood retention basin (FRB) in the Bavarian alpine foreland. The upstream catchment is 16 km². The maximum discharge from the FRB at a 100-year event is 4.7 m³/s. The aquifer is composed of highly conductive quaternary gravel with a thickness of 10 to 20 m in the storage area. The hydrogeological model was transformed into a numerical groundwater model which was used to find the optimal position for the infiltration ditch (1400 m long) and the geotechnical groundwater flow barrier (1100 m long, top 3 m b.s.l.).
A first real-world proof-of-concept for the design and model was established during the 100-year flooding event in June 2024. The recorded water levels were modeled with an infiltration rate of 1.1 m³/s along a 630 m relief diversion from the main stream which runs along the planned infiltration ditch. Water quality during the flooding event was better than expected and met the criteria for infiltration.
A modeled extreme drought situation (no recharge for six months) showed that Smart-SWS will be able to still buffer up to 130.000 m³ of groundwater which is sufficient to supply drinking water for 2.600 capita. The geotechnical barrier prevents flooded basements in the village and helps to sustain ecosystem functions in the nearby wetlands.
How to cite: Baumann, T., Bartels, J., Augustin, L., Vieira, S., and Schultze, A.: Stormwater MAR in pre-alpine catchments, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1990, https://doi.org/10.5194/egusphere-egu26-1990, 2026.
Managed Aquifer Recharge (MAR), defined as the intentional and controlled infiltration of water into aquifer, has been successfully applied to enhance groundwater quantity and quality, restore overexploited system, prevent saltwater intrusion, limit land subsidence, mitigate flooding and support other environmental benefits.
The planning phase and the correct site selection are essential for creating a fully functional MAR system. During this phase, several parameters are usually considered, involving geomorphology, water management aspects, hydrology, groundwater quantity and quality, and aquifer characteristics. However, the latter is often limited to a few hydrogeological features of the aquifer, such as storage capacity, hydraulic conductivity, and lithology.
This study aims to highlight the importance of detailed stratigraphic knowledge of the aquifer system for MAR site selection, through a 3D geological modelling approach focused on understanding the geometries, volumes and the degree of interconnection between aquifer bodies. These data are crucial for identifying areas where subsurface conditions are most favorable for MAR development.
The 3D geological modelling approach is proposed for the Middle Pleistocene–Holocene gravelly fluvial deposits located at the margin between the uplifting Apennine chain and the subsiding Po Plain, in northern Italy. Stratigraphy of alluvial deposits of the Secchia River, one of the main tributaries of the Po River, was reconstructed through a grid of seven stratigraphic cross-sections covering an area of about 650 km², subsequently implemented in a 3D model using the software Leapfrog Geo.
The 3D geological modelling was based on stratigraphic correlations between outcrops, boreholes and water-well data down to 350 m depth, most of which are available in a regional geological database.
Results highlight a cyclic alternation of gravel bodies and mud layers. Mud layers increase in thickness away from the river-valley outlet, whereas gravel bodies show a parallel decrease in thickness and in their degree of interconnection. Moreover, an overall upward increase in thickness and degree of interconnection is observed. Gravels are poorly sorted and clast-supported, with clasts ranging from a few centimetres to half a metre, often showing imbrication. The mud layers, which locally contain thin pebble layers and carbonate concretions, may laterally transition to lens-shaped gravel or sand bodies with fining-upward trends.
Overall, the gravel bodies represent efficient groundwater reservoirs, while the muddy horizons may act as hydraulic barriers to subsurface flow. By integrating stratigraphic results with information on water table fluctuation, it is possible to identify areas where hydrogeological conditions, lithology, and aquifer-body connectivity are most favorable for MAR development.
How to cite: Mainini, A., Demurtas, L., Ronchetti, F., and Bruno, L.: The importance of 3D geological modelling for MAR planning: An example from the Po valley margin (northern Italy), EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-6432, https://doi.org/10.5194/egusphere-egu26-6432, 2026.
This study provides a detailed investigation of emerging contaminants of concern (CECs) in surface water and groundwater within the semi-arid Mediterranean basin of Kasserine (central Tunisia, North Africa). During a monitoring campaign conducted in May 2023, 368 CECs were analysed, of which 101 compounds were detected across the sampled waters. Detection frequencies and concentrations were generally higher in surface waters, indicating that wastewater inputs to river systems constitute the main source of organic contamination. Pharmaceutical compounds were the most commonly detected class, reflecting their widespread occurrence in the aquatic environment. Hydrophobic CECs showed the highest concentrations and detection frequencies, while hydrophilic compounds, although more readily biodegradable, exhibited greater mobility and were efficiently transported towards downstream areas of the catchment. The shallow Plio-Quaternary aquifer, characterised by highly permeable sand and gravel formations, is hydraulically connected to surface waters, enabling rapid contaminant transfer from surface sources to groundwater. This geological context strongly enhances aquifer vulnerability to contamination. Based on these findings, a conceptual model is proposed to characterise aquifer sensitivity to urban pressures and to assess the potential impacts of future urbanisation on groundwater quality. The results emphasise the necessity for strengthened monitoring and management strategies to mitigate CEC contamination and safeguard water resources in vulnerable semi-arid environments.
How to cite: Hayouni, W., Pistre, S., Chkir, N., and Zouari, K.: Contaminants of Emerging Concern as Tracers of Pollution and Hydrological Processes in an Anthropized Mediterranean Basin: The Kasserine Basin (Central Tunisia), EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7420, https://doi.org/10.5194/egusphere-egu26-7420, 2026.
Fecal water pollution is a global problem, as it is associated with risks to human health. For more than 100 years now, so-called fecal indicator bacteria (FIB), usually E. coli and intestinal enterococci, have been used to assess microbiological water quality. However, as these bacteria are ubiquitous in the digestive tract of humans and animals, the identification of the contamination source, which plays an important role in risk assessment, is impossible. Since the early 2000s, aided by rapid advances in molecular biology methods, techniques have been developed that allow targeted source detection via host-associated markers. These MST (microbial source tracking) methods are increasingly used for the analysis and modeling of microbial hazards and risks to support decision-making in water management. In addition, the feasibility of organic micropollutants for risk assessment (chemical source tracking) has been discussed. However, there are currently no comprehensive studies that have systematically compared the performance of these parameters along the full fecal pollution gradient (groundwater to untreated wastewater). In this study, a unique sample set was compiled and examined, covering the entire fecal contamination gradient for the first time. It included untreated and conventionally treated municipal wastewaters, various surface waters, and a broad set of porous groundwater resources covering a gradient from non-influenced (i.e., deep wells) to surface-influenced resources (i.e., shallow wells).
The results showed that the human-associated contamination gradient could be accurately represented using cultivation-based FIB markers (E. coli, enterococci). No FIB were detected in deep wells or wells, sporadic detections were encountered in surface influenced wells and continuous detections in surface waters and raw and treated wastewater. FIBs determined by molecular techniques (qPCR) corresponded well with those of the cultivation-based methods. All genetic markers used (human-associated: BacHum, HF183/BacR287, wastewater associated: Lachno3) also accurately represented the gradient, but the concentrations detected were higher than those for the classical FIB. This is due to their significantly higher concentrations in feces and represents a clear advantage for detection in the environment. In contrast, the mitochondrial marker (mtDNA_hum) appeared in significantly lower concentrations compared to the bacterial markers. Of the 37 investigated chemical substances, it was mainly small traces of artificial sweeteners that could be detected even in some deep wells. In rivers, treated and raw wastewater nearly all determined compounds (predominantly pharmaceuticals) were detected. Regarding concentrations of these tracers the pollution gradient also became apparent. To summarize, applicable genetic MST markers follow the same gradient as standardized FIB and are equally sensitive (no false positives in no-influenced habitats). They exhibit comparable sample limits of detection in equivalent sample volumes, but with the advantage that they can directly track the municipal wastewater path (source specific detection of human fecal pollution). This makes them an ideal complement to the FIB approach. Chemical tracers can be a useful aid, but they must be chosen carefully because, unlike genetic MST markers, they do not occur ubiquitously in municipal raw sewage (primary sources of pollution). Regional differences due to the use of different therapeutic agents play a major role.
How to cite: Linke, R., Steinbacher, S., Savio, D., Karl, M., Kandler, W., Kirschner, A., Sommer, R., and Farnleitner, A.: Comprehensive evaluation of genetic fecal markers and pharmaceutical tracers along the full municipal (=human) fecal pollution gradient for water quality monitoring and management of tomorrow, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9991, https://doi.org/10.5194/egusphere-egu26-9991, 2026.
Groundwater resources worldwide are under increasing stress, particularly in arid and semi-arid regions. Urbanisation, intensive agriculture, and industrial development place heavy pressure on the fossil groundwater, resulting in depletion of major aquifers worldwide, with more severe consequences in arid regions such as Saudi Arabia. This study aims to evaluate the feasibility of Treated Wastewater (TWW) for sustainable managed aquifer recharge (MAR) in the eastern coastal region of Saudi Arabia using an experimental approach. Twelve 1D MAR experiments were conducted to assess the efficiencies of various treated wastewater effluents for groundwater replenishment in the coastal sandy aquifer in the eastern region of Saudi Arabia. Three recharge scenarios (low, medium, and high) and two types of TWW (tertiary and secondary) were evaluated to optimise the MAR system. Clogging materials and water quality change were evaluated to determine the optimal recharge scenario. The results showed that the tertiary treated wastewater with low recharge scenarios was the optimal case with minimal impact on groundwater quality and aquifer integrity. In contrast, the high recharge scenarios with either tertiary or secondary treated wastewater showed a significant reduction in the hydraulic performance of aquifer materials, thus, the efficiency of the recharge system. The study found that the tertiary treated wastewater from the eastern region of Saudi Arabia is suitable for aquifer recharge with minimal pretreatment to remove nutrients, ions, and emerging contaminants (e.g., microplastics). The study findings provide insights into effective water resource management strategies that reduce water scarcity risks and strengthen long-term water security in arid environments. Moreover, the study demonstrated that implementing MAR with TWW can reduce non-renewable groundwater withdrawals by up to 30% in eastern Saudi Arabia, mitigating aquifer depletion and ensuring a more sustainable water supply.
How to cite: Benaafi, M., Fatima, Z., Tawabini, B., Hanifi, S., and Basaleh, A.: Groundwater Replenishment through Aquifer Recharge with Treated Wastewater: Enhancing Water Security in Arid and Semi-Arid Regions, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12097, https://doi.org/10.5194/egusphere-egu26-12097, 2026.
Aquifer storage and recovery (ASR) is used to sustain the quality and quantity of groundwater by means of the injection of high-quality water. However, these systems face challenges such as physical clogging and poor recovered water quality. This study investigates the outcomes of injecting a low ionic strength water source into a clastic nitrate contaminated aquifer. The investigation is conducted by using a column experiment. We implemented six runs, representing a combination of two soil mixtures (loamy sand with clay content of 10% and 12% respectively), and three nitrate concentration in the injected groundwater (resp. 71, 114 and 187 mg/l).
Each of the six runs consists of two phases: in the first phase the contaminated groundwater flows through the soil column for an average of 13.8 pore volume units, which followed by a phase in which the low ionic strength water flows through for an average of 12.5 pore volume units. The results of the experiment indicate that the hydraulic conductivity decreases from an average of 0.31 cm/min to 0.25 cm/min after the introduction of the low ionic strength water. The nitrate breakthrough curves display a delay in the equilibrium which can be explained by dispersion and the creation of soil immobile zones.
Subsequently, these breakthrough curves are analysed using HYDRUS 1D with physical nonequilibrium transport model to determine the dispersivity, the immobile water content and the mass transfer coefficient. Our finding highlight that these parameters generally increased after the introduction of the low ionic strength water. Also, these parameters tended to increase, on average when the soil’s clay content increased. Our results enable the prediction of change in the recovery efficiency of the ASR systems.
How to cite: Sadeqi, D. and Buytaert, W.: Interaction between nitrate and clay during an Aquifer Storage and Recovery cycle, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-13115, https://doi.org/10.5194/egusphere-egu26-13115, 2026.
Groundwater resources in Mediterranean semi-arid basins are increasingly challenged by climate variability and agricultural intensification, yet recharge processes in multi-aquifer systems remain insufficiently constrained. This contribution presents research from Central-Western Tunisia focusing on the Sidi Marzoug–Sbiba basin, a strategic agricultural area dependent on cascading Cretaceous, Miocene, and Mio-Plio-Quaternary aquifers.
A multi-tracer approach was implemented combining piezometric mapping, major-ion geochemistry, and stable and radioactive isotopes (δ¹⁸O, δ²H, ³H, ¹⁴C). The data reveal a coherent regional flow from SW highlands toward the NE Sbiba plain, controlled by major faults and fractured outcrops that enhance lateral hydraulic connectivity. The upstream sector stores isotopically young waters with homogeneous compositions, indicating active meteoric recharge originating from relatively high elevations during the wet season (November–April). Downstream, decreasing ³H and ¹⁴C values together with higher TDS and sulfate-rich facies reflect older, slowly circulating groundwater affected by dissolution of surrounding gypsum-bearing formations and mixing with evaporated surface water from dams. Localized nitrate levels exceeding the 50 mg/L WHO guideline highlight emerging contamination risks despite the overall dominance of geogenic salinization.
These findings demonstrate how complementary tools can be jointly used to reduce uncertainty in recharge assessment of complex Mediterranean semi-arid aquifers and to guide sustainable management and monitoring priorities.
How to cite: Khaoula KHMILA, K., Trabelsi, R., Pistre, S., and Zouari, K.: Hydrodynamic functioning of a Mediterranean multi-aquifer system inferred from isotopic and hydrochemical tracers, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7432, https://doi.org/10.5194/egusphere-egu26-7432, 2026.
Floodplain hydrology regulates soil carbon dynamics and is a key factor in ecosystem restoration strategies for climate regulation. In Belgium, floodplains have been extensively modified by drainage and land-use change, yet the combined effects of hydrology, land use, and soil carbon quality on greenhouse gas (GHG) fluxes remain unclear. In the Dijle valley, located in central Belgium within the Belgian loess belt, we conducted a comprehensive study combining in situ GHG flux measurements with soil carbon quality characterization.
We measured soil carbon dioxide (CO2) and methane (CH4) fluxes during the wettest year on record across three hydrological zones: (i) a moderately drained floodplain with fluctuating water table (Fluctuating WT), (ii) a poorly drained floodplain with shallower water table (High WT), and (iii) freely drained soils of the adjacent plateau. Representative land uses included forest, grassland, cropland, and marsh. Temperature sensitivity (Q10) varied with soil moisture and water regime: under Fluctuating WT, Q10 decreased with increasing moisture, whereas under High WT, Q10 increased as moisture declined. CH4 contributed substantially to total GHG emissions only in High WT sites, though its relative impact declined under very wet conditions. Maintaining water tables below but close to the soil surface through rewetting could therefore reduce soil CO2 emissions and their temperature sensitivity, primarily by imposing environmental constraints on microbial activity. This highlights the importance of floodplain rewetting as a management strategy for climate regulation through the control of soil GHG emissions.
We also explored soil carbon quality and its possible relationship to C-specific basal respiration (R10, µg CO2-C gC-1 h-1). Soil samples (0–10 cm) were analyzed for organic carbon (C), nitrogen (N), and C/N ratio. Thermal properties were assessed using differential scanning calorimetry (DSC), including Energy Density (ED, J mgC-1) and T50 (temperature at 50% energy release). ED varied along the hydrological gradient (High WT < Fluctuating WT < Plateau), while T50 followed High WT < Plateau < Fluctuating WT. In addition, R10 was negatively correlated with C/N, slightly positively correlated with ED, but not with T50. These patterns suggest that hydrology shapes the energetic quality and thermal stability of soil carbon, which may partially explain variations in respiration.
Combining field flux measurements with energetic characterization provides a novel perspective on links between hydrology, land use, and soil carbon quality. Appropriate floodplain management, including rewetting, can enhance their contribution to climate regulation by limiting soil GHG emissions and influencing carbon cycling.
How to cite: Kovacs, N., Leifeld, J., Vancampenhout, K., Verstraeten, G., Colinet, G., Longdoz, B., Lettens, S., Raman, M., and Meersmans, J.: Hydrological controls on greenhouse gas fluxes and soil carbon quality in a Belgian floodplain, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-18773, https://doi.org/10.5194/egusphere-egu26-18773, 2026.
Drought is the primary ecological-hydrological stress in arid regions, and its impacts are often not confined to a single hydrological component but are transmitted through various land surface system components, leading to cumulative effects. To explore the continuous coupling between different types of droughts and their differential propagation mechanisms across various ecosystems, this study focuses on the Three-North region. Based on the Standardized Precipitation Evapotranspiration Index (SPEI), Standardized Runoff Index (SRI), Surface Soil Moisture Drought Index (SMDIs), Root-zone Soil Moisture Drought Index (SMDIrz), and Groundwater Drought Index (SGI), the study introduces Convergent Cross Mapping (CCM) to systematically characterize the causal coupling relationships between different types of droughts and their propagation structural characteristics across different vegetation types.
The results show that significant continuous coupling relationships exist between different types of droughts, generally presenting the structural pattern of SPEI ↔ SRI ↔ SMDIs ↔ SMDIrz ↔ SGI. This indicates that drought signals in the “meteorological—runoff—soil—root-zone—groundwater” system do not evolve in isolation but are continuously transmitted through various components of the land surface system, forming a typical long-chain drought propagation process. At the regional level, root-zone soil moisture plays the most crucial role in the drought propagation network. It not only significantly responds to upstream meteorological and hydrological droughts but also has an important modulation effect on groundwater drought, acting as a key intermediary between surface hydrological processes and the groundwater system. Significant differences in drought propagation structures exist under different vegetation types: in forest and shrubland areas, the causal effect of runoff drought on root-zone soil moisture drought is the strongest, reflecting the critical control of deep moisture processes on plant-available water. The coupling intensity is relatively weak in grassland systems, exhibiting drought dynamics with rapid response and weak memory. In areas with sparse vegetation and bare soil, there is a high degree of bidirectional coupling between runoff drought and surface soil moisture drought, indicating that the drought process is mainly driven by surface hydrological processes.
How to cite: Liu, X.: Decoding Drought: The Full-Chain Propagation Process from Atmosphere to Groundwater in Arid Ecosystems, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19413, https://doi.org/10.5194/egusphere-egu26-19413, 2026.
Posters virtual: Tue, 5 May, 14:00–18:00 | vPoster spot A
EGU26-19818 | ECS | Posters virtual | VPS8
Vertical transformation of fluorescent dissolved organic matter within the soil profile of a soil aquifer treatment basinTue, 05 May, 14:03–14:06 (CEST) vPoster spot A
Soil Aquifer Treatment (SAT) relies on biogeochemical processes occurring within the vadose zone to improve the quality of secondary treated wastewater during infiltration. Dissolved organic matter (DOM) is a key driver of these processes; however, its depth-dependent transformation within the soil profile remains insufficiently resolved at the molecular level under field conditions.
In this study, we investigated the vertical evolution of fluorescent dissolved organic matter (fDOM) within the soil profile of a full-scale SAT infiltration basin. Soil samples were collected from successive depths along the vadose zone, representing progressive stages of soil–water interaction during infiltration. DOM composition was characterized using excitation–emission matrix (EEM) fluorescence spectroscopy with inner-filter correction and Raman normalization. Fluorescence data were analysed using Coble peak integration and Parallel Factor Analysis (PARAFAC) to resolve independent fluorescent components and assess their depth-dependent behaviour.
The results reveal pronounced vertical stratification of DOM composition within the soil profile. Shallow soil layers are dominated by protein-like fluorescence associated with labile, wastewater-derived organic matter. With increasing depth, these protein-like signals show strong attenuation, while humic-like fluorescence becomes increasingly dominant. Coble peak analysis indicates preferential removal of tryptophan- and tyrosine-like peaks (B and T), whereas humic-like peaks (A, C, and M) persist at depth. PARAFAC modelling further identifies distinct fluorescent components exhibiting contrasting depth trends, with protein-like components rapidly decreasing in intensity and humic-like components remaining relatively stable or proportionally enriched.
These findings demonstrate that SAT acts as a selective biogeochemical filter within the soil profile, where biodegradation and sorption processes preferentially remove reactive DOM fractions in the upper vadose zone while more refractory humic material persists at depth. The combined use of EEM–PARAFAC provides mechanistic insight into DOM transformation pathways during soil aquifer treatment and highlights the importance of depth-resolved fluorescence analysis for improving process-based understanding of SAT performance.
How to cite: Adler, O.: Vertical transformation of fluorescent dissolved organic matter within the soil profile of a soil aquifer treatment basin, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-19818, https://doi.org/10.5194/egusphere-egu26-19818, 2026.
EGU26-3097 | ECS | Posters virtual | VPS8
sMARt riverbank filtration monitoring: how environmental tracers and high-resolution data support resilient drinking water supplyTue, 05 May, 14:48–14:51 (CEST) vPoster spot A
Riverbank filtration (RBF) is a managed aquifer recharge (MAR) technique applied worldwide, operating at the river–groundwater interface and offering the potential to enhance both groundwater quantity and quality, thereby improving drinking water supply security. However, its sustainable implementation requires a robust understanding of hydraulic interactions between surface water and groundwater as well as hydrochemical processes, supported by targeted local and regional monitoring strategies. Moreover, recharge efficiency and water quality benefits may vary in response to seasonal and event-based fluctuations in river flow, upstream contaminant inputs, and site-specific aquifer heterogeneity. In our study, we investigated river water–groundwater mixing, along with bank filtrate residence times, to improve the understanding of recharge dynamics at the Kępa Bogumiłowicka RBF site, a key regional water supply system located near Tarnów, southern Poland. Environmental tracers, including stable water isotopes, chloride concentration, water temperature and specific electrical conductance, were combined with high-resolution hydrological, meteorological and groundwater abstraction records. The results demonstrate that RBF is the dominant aquifer recharge mechanism, contributing more than 90% of the year-round yield from seven production wells located near the riverbank. Based on this case study, we propose a practical and transferable framework for efficient RBF monitoring and management. The approach integrates multi-tracer observations with ensemble end-member mixing analysis (EEMMA), combining discrete sampling with continuous physicochemical and hydrometeorological monitoring over at least one hydrological year. This cost-effective workflow enables robust recharge-source assessment, supports the evaluation of both quantitative and qualitative groundwater status, and facilitates proactive responses to upstream pollution events and rapid hydrological changes. As such, it provides a valuable template for the long-term, sustainable and resilient management of MAR-based drinking water resources in shallow alluvial aquifers.
How to cite: Janik, K., Rein, A., and Sitek, S.: sMARt riverbank filtration monitoring: how environmental tracers and high-resolution data support resilient drinking water supply, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3097, https://doi.org/10.5194/egusphere-egu26-3097, 2026.
