Monitoring of mining areas and associanted dam stability, has become increasingly important as the awareness of safety and environmental protection is rising. An appropriate monitoring scheme is necessitated to legally activate, reactivate, or terminate mining operations. The project Integrated Mining Impact Monitoring (i²Mon) aims to identify and analyze mining-induced impact, in particular its ground deformation. The monitoring system comprises terrestrial measurement and remote sensing: levelling, GPS, LiDAR scanning, UAV survey, and SAR interferometry. For interpretation and prediction, modelling will be used to simulate local displacements by different factors. The final goal is to launch an interactive GIS-based platform as an early warning and decision making system for mining industry. Currently, the project is proceeding from a preparatory phase. This paper focuses on spaceborne SAR interferometry, whereby we can cost-effectively monitor ground movement at millimeter level over a large area. We introduce the prototype of our InSAR monitoring system. The test result from Sentinel-1 images shows the surface movement during 2018 at a deactivating open-pit coal mine in Germany. We discuss the current status, ongoing works, planned test sites in Poland, and how we integrate data from different sensors and approaches.

Integrated geo- and environmental monitoring in mining represents a high-dimensional challenge (location, altitude/depth, time and sensors). This is challenging for experts but poses great problems for a multitude of participants and stakeholders in building up a complete process understanding. The Epe research cooperation aims to elucidate the ground movement at the Epe cavern storage facility with a public participation process. The research cooperation was founded by the city of Gronau, the citizens’ initiative cavern field Epe, the company EFTAS, Münster, and the Research Center of Post-Mining at the Technische Hochschule Georg Agricola, Bochum. This research cooperation is the first in Germany to involve direct collaboration between science and the public. In the cavern field, which has been in operation since the 1970s, brine is extracted, and at the same time natural gas, crude oil and helium, as well as hydrogen in the future, are stored in the subsurface. The technical focus of this work was the development of a high-resolution spatiotemporal analysis of ground movements. The area is monitored annually by the mining company’s mine surveyor. The complexity of the monitoring issue lies in the fact that the western part is a bog area and a former bog area. Furthermore, the soils in the eastern part are very humus-rich and show strong fluctuations in the groundwater and therefore complex hydraulic conditions. At the same time, there are few fixed scatterers or prominent points in the area that allow high-resolution spatiotemporal monitoring using simple radar interferometry methods. Therefore, the SBAS method (Small Baseline Subset), which is based on an aerial method, was used to analyze the radar interferometric datasets. Using an SBAS analysis, it was possible to evaluate a time series of 760 scenes over the period from 2015 to 2023. The results were integrated with the mine survey maps on the ground movement and other open geodata on the surface, the soil layers and the overburden. The results show complex forms of ground movement. The main influence is that of mining. Nevertheless, the influence of organic soils with drying out due to drought years and uplift in wet years is great. Thus, in dry years, ground subsidence accelerates, and in wet years, ground subsidence not only slows down but in some cases also causes uplift. This complexity of ground movements and the necessary understanding of the processes involved has been communicated to the interested public at several public information events as part of the research cooperation. In this way, an understanding of the mining process was built up, and transparency was created in the subsurface use, also as a part of the energy transition. In technical terms, the research cooperation also provides a workflow for developing the annual mine survey maps into an integrated geo- and environmental monitoring system with the development of a transparent participatory geomonitoring process to provide resilience management to a mining location.

Digital Twin has gained significant attention for future urban management. Since 2020, Building Information Modelling (BIM) has become the standard for high-rise buildings and infrastructures in Germany. Our project BIMSAR is to combine BIM data and SAR-derived movement for urban movement monitoring. The so-called persistent scatterer (PS) points are extracted from a SAR image stack based on PSI. These PS-points, considered pseudo-substructures of buildings, contain geoinformation such as geographic position and movement estimates. They are integrated into the BIM models for various self-contained units like façades and roofs. This fusion step is implemented by machine learning, employing a novel distance metric adapted through dimensionality reduction. To provide a user-friendly analysis tool, the fused data are displayed in 4D (position + movement) on a GIS-based platform, along with other geodata, e.g., geological maps, hydrological maps, underground mining structures. This paper shows the current results around Ahlen in Ruhr region, where many damages to buildings, bridges, and highways are associated with the abnormal deformation. We created the BIM models ourselves by converting open-source 3D models, adhering to Industry Foundation Classes (IFC) format. The SAR data contain Sentinel-1, TerraSAR-X, and PALSAR-2 for a cross-analysis. The primary application is to assist stakeholders with an early warning system to evaluate whether unusual or long-term deformations cause structural damages and thereby threaten the safety of life and property. We demonstrate some examples towards this application.

Underground gas storage (UGS) in salt caverns is increasingly important for a flexible and secure energy supply and for stabilizing the gas market. However, cavern operations can induce surface ground movements that must be monitored to safeguard infrastructure integrity and environmental compatibility. This research analyzes horizontal (W–E) and vertical ground movements above the cavern field Gronau-Epe in northwestern Germany, using radar interferometry (InSAR), specifically the SBAS (Small Baseline Subset) approach, combined with clustering and multi-criteria analysis. The study was conducted in cooperation between Uniper Energy Storage GmbH, the Research Center for Post Mining at THGA Bochum, and the company EFTAS. Freely available Copernicus Sentinel 1 data were integrated with public soil maps and operational storage information. A multistage workflow quantified deformation patterns, classified coherent deformation zones via clustering, and evaluated geological and technical drivers using multi-criteria analysis to better distinguish operational (primary) from overburden (secondary) influences. Results reveal long term deformation trends closely linked in time and space to injection/withdrawal cycles. Locally confined vertical and horizontal movements near caverns are attributed to salt convergence triggered by cyclic pressure changes, but they are linked to (hydro)geological and pedological factors. The developed approach shows strong monitoring potential in addition to classic mine surveying.

Following the severe flood event over the 2023/2024 New Year period, the Lower Saxony Ministry of Food, Agriculture, and Consumer Protection initiated a flood subsidy program for agricultural businesses. To evaluate the extent and duration of flooding across approximately 10,000 parcels, manual assessment was impractical. EFTAS leveraged Synthetic Aperture Radar (SAR) data, primarily from Sentinel-1, to develop a semi-automated process for detecting and quantifying flood coverage over multiple time points. The workflow is designed to integrate modules from SNAP and custom algorithms on a cloud-computing platform, generating backscatter coefficients to distinguish flooded and non-flooded areas. A GIS-based decision tree further refined the results by excluding permanent water bodies. Our project covers an area of 47,618 km², utilizing 45 Sentinel-1 image packages, with observations every 3–5 days. The image quality was enhanced through adaptive non-local filtering. The results included precise flood extents, exemplified by dynamic changes near Lake Dümmer. The additional datasets, such as Sentinel-2 imagery and local photos, validated our flood evaluations. Our operational workflow demonstrates the adaptability of SAR for diverse applications, from post-event flood evaluation to near real-time emergency response. Future improvements include incorporating high-resolution imagery for urban assessments and leveraging rapid-revisit SAR constellations like Capella and ICEYE. This project underscores the cost-effectiveness and reliability of SAR-based flood detection, aiding decision-makers in subsidy allocation while paving the way for broader applications in disaster management.