Sand is one of the most extracted natural resources worldwide, and demand continues to rise along with population and infrastructure development. In Argentina, the Lower Paraná Delta has become a key source of sand for both construction and hydraulic fracturing (fracking) activities. While sand mining can generate short-term economic benefits, its environmental and socioeconomic impacts on the delta remain poorly understood. Therefore, this study aims to answer the following research question: ”What are the morphological and socioeconomic effects of sand extraction in the Lower Paraná Delta and how can these be managed to secure a sustainable future?”. Both river and land-based sand mining and their respective effects on the delta were researched.

The research applied a multidisciplinary approach combining hydraulic, geotechnical, and structural engineering perspectives. Quantitative analyses were based on field measurements, sediment sampling, and hydrodynamic modelling with Delft3D. Additionally, stakeholder interviews and data from the Automatic Identification System (AIS) of vessels were used to assess extraction volumes and local perceptions. This combination allowed for a comparative evaluation of river and dry sand mining.

Results show that river sand extraction remains relatively stable across large parts of the study area, while local government intervention has effectively halted dredging activities in the Paraná Ibicuy, in the northern section of the delta. Current extraction volumes are estimated at approximately 588,000 tons
per year. In contrast, dry sand mining has increased sharply, reaching about 2.3 million tons in 2025 in Ibicuy, primarily driven by the growing demand for fracking sand from the Vaca Muerta formation. The established sediment balance of the Paraná Guazú River indicates a negative change in sediment storage of roughly 15,400 tons per day, suggesting a general trend of sediment depletion.

Erosion rates in the study area range between 3 and 7 meters per year, which, although significant, are considerably lower than values reported by some stakeholders. Analyses indicate that natural processes, including river meandering and flood-induced bank instability, are the dominant drivers of bank erosion, while river sand mining does not appear to play a substantial role. Because of their larger scale and intensity, the socioeconomic impacts of dry sand mining are more pronounced, leading to groundwater overuse, road deterioration, and habitat loss. Additionally, low taxation on sand mining activities has enabled these impacts to persist with limited mitigation or compensation. To mitigate erosion, a structural solution in the form of a sheet pile was proposed. Furthermore, Nature-based mitigation strategies have been proposed, the focus lies on floodplains, vegetation and riparian buffer zones.

The accuracy of the study is constrained by the short temporal coverage of field data and the simplified representation of hydrodynamics and sediment transport in the numerical model. To build on these findings, future research should include long-term monitoring, enhanced sediment datasets, and morphodynamic modeling to assess feedbacks between extraction and river response. Integrating Naturebased solutions with targeted structural measures, supported by cost–benefit analyses, would provide a more comprehensive framework for sustainable sand mining management in the Lower Paraná Delta.

In the Port of Emden, maintenance of the nautical depth is carried out by continuous re-circulation of sediment, creating a navigable fluid mud layer in the water and thereby facilitating safe navigation for ships. The sediment naturally contains organic matter, which to a certain extent is degradable by sediment microorganisms. Depending on the availability of oxygen, the degradation process generates carbon dioxide only (aerobic conditions) or methane and carbon dioxide (anaerobic conditions). This thesis aims to quantify the production of carbon dioxide and methane from fluid mud in the Port of Emden and analyze its seasonal variability to support carbon footprinting of sediment management activities. In this thesis, an experiment was carried out to determine the carbon production of Emden samples at different temperatures. Results were used and, based on the fluid mud temperatures throughout the year, monthly carbon production was calculated. These values were adjusted for seasonal variations in organic matter availability and finally extrapolated to give the total monthly carbon production for the port. Using data from previous research, upper and lower bounds for this production were found. The findings indicate that carbon production in the Port of Emden, due to micro-organisms in the fluid mud layer, varies significantly over the year. Specifically, the generated carbon was found to differ between 243 tons in February and 958 tons in August, with the upper bound being 7.2 times greater than these values and the lower bound 1.3 times smaller. From April until October, carbon generation was found to be considerably higher than from November until March, due to higher water temperatures and likely a greater availability of organic matter. Finally, the carbon production under aerobic conditions was found to be 2.7 to 2.8 times greater than under current conditions, with similar seasonal variability. Limitations of this thesis include assumptions about uniform seasonal scaling of organic matter availability and incomplete data on fluid mud temperature variations across the year. Future research could address these limitations by gathering and incorporating more data on these parameters. Finally, future studies should focus on applying the findings of this thesis to explore strategies for reducing the carbon footprint of sediment management activities.