Improvements in miniaturization and affordability of lidar technology, mainly due to innovation in self-driving cars, means that UAV lidar is now an accessible option for geoscience research. We present applications in which UAV lidar contributes to data collection in ways that would otherwise not be possible in the time frame, budget, and/or with the resolution required.

Volcanoes: Lava flow surface texture can provide information on lava flow dynamics and emplacement. The transition between pahoehoe and a’a flow textures can indicate changes in flow rates and flow thickness, and the morphology of ripples in ropey pahoehoe flows can indicate flow direction. Hell’s Half Acre, Idaho, USA, is a basaltic lava flow that was erupted ~5000 y.a. Analysis of UAV lidar data at this lava field shows lava flow surface texture in sufficient resolution to define cm-scale pahoehoe ripples. In addition, larger scale lava features such as channels and inflation/deflation ridges can be mapped which allows us to understand the dynamics of the lava flow emplacement.

Vegetation: UAV Lidar can be useful for analysis of vegetation canopy, both in stripping canopy (lidar last return) and in using it for tree height (lidar first return). By combining UAV lidar with other airborne data, e.g. multispectral imaging, we can identify and map tree species at Ft de Soto Park, in Florida, USA.

Permafrost: Permafrost thermokarst features can develop rapidly and climate change will cause an increase in these rapid thaw events. With UAV lidar we can strip the vegetation to reveal the underlying ground surface which can then be used to assess and model permafrost processes. UAV surveys are quick and relatively inexpensive (as compared to crewed aviation) and data can be collected in response to a thaw event. We present data from Alaska, USA, at known sites of rapid thermokarst thaw.

UAV lidar, both as a stand-alone dataset, and when integrated with other data streams e.g. multispectral and visible imagery, can provide high-resolution data (both spatial and temporal) on a platform that is relatively low-cost and logistically straightforward to deploy.

How to cite: Rodgers, M., Van Alphen, R., Bakowski, R., Berkey, T., Sadeghi Chorsi, T., Malservisi, R., Connor, C. B., and Dixon, T. H.: UAV lidar: from volcanoes to forests, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13716, https://doi.org/10.5194/egusphere-egu24-13716, 2024.

The CRCS Dunhuang site (40.1821°N, 94.3244°E) is located in the Gobi Desert in northwest China, about 35 km west of Dunhuang City, Gansu Province. Covering approximately 30 km × 30 km, the entire site is formed on a stable alluvial fan of the Danghe River and its surface consists of cemented gravel without vegetation. Dunhuang was chosen as a CRCS site due to its extremely homogeneous surface conditions. The central area (600 m × 600 m) of the site is designed for high spatial resolution visible/near-infrared (VIS/NIR) sensors such as the China-Brazil Earth Resources Satellite (CBERS) series. An extended large area (20 km × 20 km) is used for low spatial resolution sensors such as the Multichannel Visible and Infrared Scanning Radiometer, Visible and Infrared Radiometer, and Medium Resolution Spectral Imager on board the Fengyun-1 and 3 (FY-1/3) series of polar-orbiting satellites. It is also used for the field calibration of the VIS/NIR channels on Chinese geostationary weather satellites (Fengyun-2 or FY-2 series). Field calibration of the FY series of satellites has been conducted operationally since 2001 for only the VIS/NIR channels.

Due to the lack of onboard VIS/NIR calibrators, the in-orbit field calibration based on the CRCS Dunhuang site is still the primary method for China’s satellite sensors’ VIS/NIR channels, such as the FY series satellites, Haiyang (HY) series of Ocean Satellites, Disaster and Environmental Monitoring Satellites (HJ), and CBERS series satellites. However, the traditional satellite-ground synchronous measurement method of surface reflectance is based on car running field observation, which not only consumes a lot of manpower and material resources, easily causes damage to the site surface, but also lacks regional representativeness of the obtained measurement data.

In view of this, CRCS Dunhuang 2016 satellite-ground synchronous observation experiment mainly based on low-altitude surface reflectance measurement by rotor drones, supplemented by car running field measurements, and completed all aspects of whole process test including route design, altitude selection, instrument parameter configuration, sampling strategy, and aviation data processing.

Through this flight test, it can be proved that the use of multi-rotor drones to fly at low altitudes instead of the traditional car running satellite-ground synchronous measurement of surface reflectance not only improves the spatial consistency and representativeness of the ground reflection characteristics, but also improves the measurement efficiency of the ground reflectivity. Using flight measurement method can effectively protect the surface of the precious CRCS Dunhuang Gobi site and greatly save manpower and material resources.

Through the comparisons and analysis of the surface reflectance data measured by aerial flight method and traditional car running field observations, it can be found that the mean values of multiple surface reflectance measurement data are relatively close, and the standard deviation of the airborne measurement data is smaller. The airborne data can replace the car running field data to complete the radiometric calibrations.

How to cite: Zhang, Y., Xu, H., Zhang, L., Qin, D., and Rong, Z.: Low-altitude measurement of CRCS Dunhuang surface reflectance based on multi-rotor electric UAV, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-3536, https://doi.org/10.5194/egusphere-egu24-3536, 2024.

How to cite: Lee, M., Dupuy, B., and Grøver, A.: Snowpack characterization and depth estimates using UAS-mounted ground penetrating radar: A case study from Western Norway , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6730, https://doi.org/10.5194/egusphere-egu24-6730, 2024.

The employment of unmanned aerial vehicles (UAVs) for digital photogrammetry applications (UAV-DP), together with satellite data, has emerged as a pivotal tool for conducting reliable muographic campaigns. This study aims to present a comprehensive workflow designed specifically to plan and support UAV-derived data for muon radiography objectives. Through a real case study conducted at the Etruscan necropolis of Palazzone (Umbria, Italy), this study shows the creation of high-resolution three-dimensional models of the ground surface/sub-surface by integrating UAV-DP, laser scanner and GPS-acquired data. The accuracy of these three-dimensional environment significantly influences the reliability of the simulated muon flux transmission, which is crucial for inferring the relative transmission values and estimating the density distributions. This study highlights the importance of UAV-derived data in the muography process and their potential to enhance or affect the outcomes of muon imaging results. Furthermore, it emphasizes the need for a multidisciplinary approach in muography applications, particularly focusing on the integration and utilization of UAV-based data to improve spatial environment reconstruction.

How to cite: Beni, T., Borselli, D., Bonechi, L., Lombardi, L., Gonzi, S., Melelli, L., Turchetti, M. A., Fanò, L., D'Alessandro, R., Gigli, G., and Casagli, N.: UAV digital photogrammetry as support tool for transmission-based muography, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8611, https://doi.org/10.5194/egusphere-egu24-8611, 2024.

During the last decades, the introduction of Unmanned Aerial Systems (UASs) in civil applications has exponentially grown. Environmental monitoring, mapping, and surveying, agriculture and precision farming, (infra)structure inspection, and medical supplies delivery are some clear examples. For many of these applications, the organization and planning of the missions are very similar: the variables or phenomena are clearly identified, the area of interest is previously defined, the flight plans are meticulously prepared to extract the features of interest (e.g. overlap and constant elevation for high-quality orthomosaics), the payload and on-board instrumentation is previously configured, the crew is informed in advanced about the objective of the missions, and in general, all these missions are executed in really good weather conditions. However, for some applications, like UAS-assisted Mountain Emergency Medicine, these protocols are totally different, because of the type of emergency (search and rescue operation, first kit provision, avalanche search) resulting in a quick and efficient configuration of payloads, accuracy of the reported incident (accuracy of GPS and distress call), preparation and level of stress for the rescue teams operators and adverse weather conditions (poor visibility, unknown terrain, wind, snow, rain). In addition, the physical localization of the UASs is in regional stations, so it is necessary to mobilize equipment and crew in a very short time to guarantee the success of the missions or, ideally, standby at distributed sites for autonomous operation if cleared for take-off from remote. In order to attend any mountain emergency that requires the use of UASs inside of the Province of South Tyrol, Italy (alpine region) to identify the most suitable operations area (vertical port), to elaborate an efficient point-to-point flight plan maximizing the use of its batteries (considering changes of terrain, elevation, and possible obstacles), and delivering a defibrillator (specific use case), here we propose a basic data management system based on Geographic Information Systems (GIS) that create a distributed vertical port stations in the Province and identify the closest point to the distress call. The system is able to plan an efficient flight plan in a mountainous area using a sensor-based data model based on a commercial UAS system (MAVTech Q4X) to provide a dedicated payload (defibrillator). We used the system in two scenarios (winter and summer) and they showed a reduction of nearly 50% of the delivery time of the defibrillator by traditional means.

How to cite: Mejia-Aguilar, A., Parin, R., Ristorto, G., Mayrguendter, S., and van Veelen, M.: How GIS tools and sensor-based data models are impacting the UAS civil missions: Identification of suitable vertical ports and optimal flight planning to quickly deliver defibrillators in alpine terrains, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-9130, https://doi.org/10.5194/egusphere-egu24-9130, 2024.

Measurements for determining terrain surface deformations that are caused by underground mining require high measurement accuracies to be achieved. Uncrewed aerial vehicles (UAVs) have not been widely used for this purpose. The presentation presents the process of selecting optimal bundle block adjustment (BBA) parameters for UAV-acquired data. The analyses were carried out for 25 measurement series on a test field of 2 km². A total of 59 ground control points (GCP) and check points (CP) were used in the study. The analyzed parameters included: 

• the GCP accuracy: 15mm or 25mm, 
• the GCP number: 9 or 23, 
• the tie point accuracy: 1px or 2px,
• the impact of the tie point filtration, 
• the impact of the additional corrections of camera calibration (based on the 96-parameter Fourier series) not included in Brown’s model,
• the accuracy of the coordinates of the projection centers of the images: the values estimated by the GNSS receiver, or 50mm or 100mm.

The final result of the study is the identification of BBA parameters that allow the highest accuracy of UAV photogrammetry products to be achieved.

How to cite: Ćwiąkała, P., Pastucha, E., Puniach, E., and Gruszczyński, W.: Selection of bundle block adjustment parameters in UAV surveys of underground mining-induced displacements, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15700, https://doi.org/10.5194/egusphere-egu24-15700, 2024.

Sustainable solutions are key in dealing with challenges attributed to food security and climate change. The I-Seed project, funded by H2020, strives to pioneer a novel generation of self-deployable and biodegradable soft miniaturized robots. Drawing inspiration from the morphology and dispersion abilities of plant seeds, these robots are designed for cost-effective, environmentally responsible, in-situ detection of crucial environmental parameters in both air and topsoil. In this concept, Unmanned Aerial Vehicles (UAVs), will be utilized to distribute, localize, and capture the fluorescence signal emitted by the artificial seeds. For the aerial read-out of the fluorescence signal, a prototype of UAV-based Active Laser Fluorescence (ALF) Imaging System was designed. It comprises an RGB camera, a spectral and hyperspectral camera, a laser, and a Time-of-Flight (ToF) Lidar. The integrated setup was evaluated in an optical laboratory. The fluorescence emission from the artificial seeds was measured at a distance of 4m, utilizing varying excitation intensities with an integration time of 3s and temperatures ranging from 5 to 40°C. Results showed that as the sample temperature increased, the peak ratio exhibited changes, making it a valuable indicator for temperature estimation. A similar behavior was observed in modulated excitation, where the fluorescence lifetime varied with temperature. Within the constraints of exposure time for non-saturated pixels, data from RGB pixels also provided insights into the sample temperature. In addition, the developed system was also tested on a linear stage mimicking a flight under field conditions. Present work reveals potential for a revolution in the use of UAVs in environmental sensing.

How to cite: Zhang, C., Mustafa, H., Bartholomeus, H., and Kooistra, L.: Towards new frontiers for environmental sensing: a UAV-based Active Laser Fluorescence Imaging System , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13326, https://doi.org/10.5194/egusphere-egu24-13326, 2024.

In recent years, uncrewed aerial vehicle (UAV)-based photogrammetry has developed rapidly and is increasingly used for monitoring and determining displacements. The presentation discusses the author's solutions for the automatic determination of horizontal and vertical displacements of land surface in urban areas, dedicated to very-high-resolution UAV-photogrammetry products. The processing path is based on orthomosaics and digital elevation models and implements normalized cross-correlation for matching multi-temporal images. Its integral part is the process of semi-automatic removal of outliers. As a result of data processing, displacement vectors are determined in a regular grid, which constitute the basis for determining other indices of terrain deformation, such as ground tilts and horizontal deformations. Based on a comparison with reference data, it was estimated that the root mean square error of determining the displacements is 1-2 pixels for the horizontal components and 2-3 pixels for the vertical component. Therefore, the components of ground tilt and horizontal deformation can be determined based on UAV photogrammetry with a root mean square error of 0.3 pixels.

How to cite: Puniach, E., Gruszczyński, W., Ćwiąkała, P., Matwij, W., and Strząbała, K.: Determination of land deformation indices based on UAV-derived very-high-resolution images, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16127, https://doi.org/10.5194/egusphere-egu24-16127, 2024.

We report the results of field and Unoccupied Aerial System (UAS) surveys carried out after the 21 May 2023 eruption of Etna (Italy). This event occurred under terrible weather conditions that prevented its observation by the INGV-OE (Istituto Nazionale di Geofisica e Vulcanologia-Osservatorio Etneo) surveillance video and thermal camera network. After some weeks of Strombolian activity at the South-East Crater (SEC), which started on the 4th of May, a dramatic increase in the volcanic tremor, localized underneath the SEC, marked the onset of lava fountain at 5.30 UTC on the 21st of May. The lava fountain, lasting at least 4 hours, formed a lava flow and a plume about 10 km high, while ash fell on the southwest flank of the volcano. The bad weather condition, that consisted in strong storm and dense clouds covering the summit of Etna, did not permit to observe the phenomenon. Luckily the multi-parameter monitoring stations scattered around the volcano were working. In particular, the volcanic tremor, the clinometric and the borehole dilatometer signals clearly indicated the onset of a lava fountains. An unusual snow fall (considering it was springtime) did not allow any direct survey of the area until two weeks later, and the continuing cloud cover hindered remote observation. When MapLAB staff, of the INGV-OE, finally reached the eruptive scenario to perform a UAS survey, they realized that a volcanoclastic deposit overlapped the middle portion of the lava flow. During the survey, the deposit has been also studied and sampled along its extension. Thanks to a Structure from Motion software a 3D reconstruction of the SEC, the lava flows and the deposit has been done. The data collected allowed for detailed mapping, quantification and characterization of the proximal and distal products (300 m and more than 800 m away from the vent, respectively). The presented results increase knowledge about the SEC instability and collapse phenomena, of which we have become increasingly aware over the past two decades. These hazards could present a significant threat for people walking along touristic path ways near Etna summit craters.

How to cite: De Beni, E., Cantarero, M., Mereu, L., Pioli, L., Proietti, C., Romeo, F., Scollo, S., and Alparone, S.: The hidden eruption: 21 may 2023 Etna (Italy) , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18861, https://doi.org/10.5194/egusphere-egu24-18861, 2024.

Robust and timely assessment of the condition of geotechnical infrastructure assets (e.g. cuttings, embankments, dams) is essential for cost effective maintenance and engineering interventions to prevent failure events. Infrastructure slopes (in transportation, utilities and water management) are experiencing increasingly high levels of failure and require considerable resources to maintain; in the order of hundreds of millions of pounds per year in the UK alone. The issue of accelerating asset deterioration is being exacerbated by the greater prevalence of extreme weather events. Conventional monitoring techniques are still dominated by surface observations, which provide infrequent information and deliver very few insights into subsurface deterioration processes which typically precede surface expressions of deterioration. Here we describe the development of novel geoelectrical imaging technology to monitor and assess the internal condition of infrastructure slopes in four-dimensions. In particular, we outline a workflow in which time-lapse geophysical models are used to inform estimates of soil moisture and suction distributions, and we consider the challenges associated with the deployment of geophysical monitoring systems on operational geotechnical assets. Examples are given from long-term field experiments on transportation and water management earthworks. We propose that novel geophysical monitoring complements more traditional forms of asset assessment to significantly enhance the resilience of safety critical infrastructure through improved subsurface information provision and decision support.

How to cite: Chambers, J., Wilkinson, P., Meldrum, P., Kuras, O., Swift, R., Ngui, J., White, A., Cimpoiasu, M., Harrison, H., Maleki, R., Boyd, J., Dashwood, B., Bruce, E., Donohue, S., Holmes, J., Stirling, R., Whiteley, J., and Binley, A.: Long-term geophysical monitoring of safety critical geotechnical infrastructure slopes, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15113, https://doi.org/10.5194/egusphere-egu24-15113, 2024.

The study of soil-structure or even city-soil interaction is attracting the attention of many researchers, as both numerical simulation results and preliminary results from empirical data indicate their significant effect in determining the level of seismic hazard.

In this study, the wave field radiated from a building to its surroundings, which is due to the interaction of the building with the ground, is identified and extracted using a novel approach. The proposed approach, which is valid for seismic data analysis, combines deconvolution and polarization analysis. It consists of four steps: (1) estimation of building resonance frequencies, (2) deconvolution of seismic recordings of sensors installed in a building and in the surrounding environment, (3) identification of seismic phases, reconstruction of seismic phases, reconstruction of the signal transmitted from the building to the surrounding environment and estimation of its energy, and (4) polarization analysis.

The application of the approach to recordings of an M4.6 earthquake collected by sensors installed in a building and on a nearby athletic field in Matera, Italy, showed that the particle motion of the wave field radiated from the building to the ground was mostly linearly polarized in the radial and transverse planes, while a clear elliptical polarization was observed only in the horizontal plane.

The analysis showed that the wave field radiated from the building and recorded on the ground could be dominated by unconventionally polarized surface waves, i.e. quasi-Rayleigh waves or a combination of quasi-Rayleigh and quasi-Love waves. The results indicated that the energy transmitted from the analyzed vibrating building to the surrounding environment was significant and decreased ground shaking due to the out-of-phase motion between the incoming seismic wave field and that radiated from the building.

How to cite: Parolai, S., Sklodowska, A. M., Petrovic, B., and Romanelli, F.: Evaluation of soil-structure interaction by combining deconvolution of building and field earthquake recordings with polarization analysis: application to the Matera experiment (Italy), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10254, https://doi.org/10.5194/egusphere-egu24-10254, 2024.

The monitoring of groundwater resources and the identification of energy resources play a crucial role in the sustainable development and management of coastal areas. This is a fundamental aspect considering the climate changes occurring in areas particularly exposed to physical hazards resulting from extreme weather events and higher are the risks of coastal erosion, groundwater salinization, flooding and other hazards in low-elevation coastal zones (Oppenheimer et al., 2019).  Currently, 2.15 billion people live in the near-coastal zone and 898 million in the low-elevation coastal zone globally (Reiman and al, 2023). Moreover, coastal freshwater reservoirs can represent a fundamental resource to address water shortages. The hydro-geological potential and economic factors linked to the submarine groundwater are the starting point of the two-year Italian Research Project of National Relevance (PRIN-2022) SUBGEO where the University of Bari (UNIBA) and the two Institutes (IMAA and IRPI) of the National Research Council are involved. The project is focused on the submarine groundwater discharge analysis with an innovative and integrated geophysical approach based on the use of electric and electromagnetic methods for the twofold targets of coastal underground freshwater reservoir non-invasive characterization and to gain useful tools for the optimal and sustainable management of the coastal areas and resources.

Subgeo will develop an innovative geophysical approach to provide spatially continuous and high-resolution information on the subsoil structure from the offshore areas, where the outward fluxes mix with the seawater, to the onshore ones including the urban areas.

The proposed strategy will be tuned by small-scale laboratory experiments and by numerical simulations to define the best acquisition procedures and check the sensitivity of the strategy for different subsurface conditions. The final goal of the project consists of reproducing a high-resolution and detailed hydrogeophysical model for managing the water resources in coastal areas.

References

Oppenheimer M., Hinkel J. et al.: Sea Level Rise and Implications for Low Lying Islands, Coasts and Communities Supplementary Material, http://hdl.handle.net/11554/9280, 2019.

Reimann L, Vafeidis AT, Honsel LE. Population development as a driver of coastal risk: Current trends and future pathways. Cambridge Prisms: Coastal Futures. doi:10.1017/cft.2023.3, 2023;1:e14.

How to cite: Romano, G., Capozzoli, L., Lapenna, V., and Polemio, M.: A new multiscale and multisensory strategy for the characterization of groundwater discharge in coastal areas – the SUBGEO project, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7638, https://doi.org/10.5194/egusphere-egu24-7638, 2024.

The geophysical methodologies can give for providing useful information about the subsoil, environment, buildings, and civil infrastructures and supporting the public administrations in planning interventions in urban scenarios. In the past years, the geophysical prospection methods have been improved for the inspection of foundation soils, civil structure, and engineering infrastructures. Anyway, the potential of geophysical techniques in urban sites is mainly known in characterisation contexts, while a monitoring use has not yet been developed. Therefore, new applications and laboratory experiments are needed to enhance their capability and development.

This work introduces a time lapse three-dimensional Electrical Resistivity Tomography (3D ERT) monitoring on the effects of the standard practice of shallow polyurethane resin injected below the settled foundations of a villa. The application was performed to monitor the effectiveness of the consolidation beneath the building with time. The 3D ERT was applied before and after the injection phase. The geoelectrical acquisitions were performed with electrodes arranged close the external walls with an electrode space of about 1m. Therefore, non-conventional setting of the electrode layout was adopted permitting to obtain a 3D model of the geophysical parameter distribution close the foundations. The time-lapse 3D ERT highlighted the effects of the resin injections. In addition, an experiment was carried out in the laboratory through the creation of a physical model of a foundation placed in a sandbox in which the conditions of resin injection after a subsidence are simulated.

How to cite: Rizzo, E., Boldrin, P., Andreotti, L., and Fornasari, G.: Geophysical monitoring of engineering infrastructure foundations, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8011, https://doi.org/10.5194/egusphere-egu24-8011, 2024.

Ground penetrating radar (GPR) imaging [1] is a well assessed non-destructive technology exploited in many applicative contexts such as structural assessment [2], cultural heritage [3], and others. However, GPR raw data are difficult to interpret since targets do not appear with their geometrical shape but as diffraction hyperbolas because of the probe-target relative motion during the measurement. Linearized Microwave Tomography (MWT) approaches allow retrieving qualitative maps of the probed scene in terms of position and approximate geometry of the targets, thus providing more easily interpretable image of the investigated scenario. Unfortunately, they do not provide quantitative information about the targets in terms of permittivity/conductivity profiles. Recently, deep learning (DL) techniques have been proposed to face this problem. DL approaches are data-driven methods that use proper training data to learn mapping the input data into the desired output. As regards quantitative GPR imaging, different approaches have been proposed in literature, e.g. see [4], [5]. In this contribution, we adopt the well-known Convolutional Neural Network (CNN) U-NET to tackle the quantitative GPR imaging problem. As a novel point compared to the previous works on DL-based quantitative GPR imaging, the network takes in input the linear MWT images instead of the GPR raw data. Such an approach is expected to simplify the learning process as pointed out in [6]. Full-wave simulated data are used for the training of the network and numerical experiments are reported as preliminary assessment of the effectiveness of the proposed strategy.

References

[1] I. Catapano, G. Gennarelli, G. Ludeno, F. Soldovieri, and R. Persico, "Ground-penetrating radar: Operation principle and data processing," in Wiley Encyclopedia of Electrical and Electronics Engineering. Hoboken, NJ: Wiley, 2019, pp. 1–23.

[2] Esposito, G. Gennarelli, G. Ludeno, F. Soldovieri and I. Catapano, "Contactless vs. contact GPR for the inspection of vertical structures," 2023 IEEE Conference on Antenna Measurements and Applications (CAMA), Genoa, Italy, 2023, pp. 164-168, doi: 10.1109/CAMA57522.2023.10352894.

[3] Esposito et al., "The UAV radar imaging prototype developed in the frame of the VESTA project," 2020 IEEE Radar Conference (RadarConf20), Florence, Italy, 2020, pp. 1-5, doi: 10.1109/RadarConf2043947.2020.9266690.

[4] J. K. Alvarez and S. Kodagoda, "Application of deep learning image-to-image transformation networks to GPR radargrams for sub-surface imaging in infrastructure monitoring," 2018 13th IEEE Conference on Industrial Electronics and Applications (ICIEA), Wuhan, China, 2018, pp. 611-616, doi: 10.1109/ICIEA.2018.8397788.

[5] Xie, Q. Zhao, C. Ma, B. Liao, and J. Huo, “U-Net: deep-learning schemes for ground penetrating radar data inversion,” Journal of Environmental and Engineering Geophysics, vol. 25, no. 2, pp.287-292, 2020.

[6] Wei and X. Chen, "Deep-Learning Schemes for Full-Wave Nonlinear Inverse Scattering Problems," in IEEE Transactions on Geoscience and Remote Sensing, vol. 57, no. 4, pp. 1849-1860, April 2019, doi: 10.1109/TGRS.2018.2869221

How to cite: Esposito, G., Catapano, I., Soldovieri, F., and Gennarelli, G.: U-NET for Quantitative GPR Imaging, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10284, https://doi.org/10.5194/egusphere-egu24-10284, 2024.

Active and passive seismic measurements using conventional point sensors (geophones or seismometers) are usually performed to characterize the near surface in urban areas. However, high-resolution studies depending on the measurement scale, require hundreds to thousands of seismic sensors, which involves costly and time-consuming deployments. In recent years, DAS (Distributed Acoustic Sensing) has enabled standard optical fibers to be used as a continuous streamer of seismic sensors, allowing low-cost, high-resolution seismic surveys. The use of DAS technology has become standardized in the oil and gas industry. However, it is still under-exploited in shallow geophysics, where mainly dark fibers (unused telecom fibers) are exploited.
Here, we show preliminary results from a seismic investigation using a combination of DAS and seismic nodes conducted in the vicinity of the Scrovegni Chapel in Padua, Italy. As the site includes buried archaeological remains from various eras, including a Roman amphitheatre, seismic measurements can be used for archaeological prospection. Moreover, to ensure the preservation of this cultural heritage, understanding the mechanical properties of the underlying soil is key for seismic risk assessment.
Active seismic measurements were conducted on November 15, 2023 using a sledgehummer as the active source. Data were recorded using a Silixa iDAS interrogator unit along a 440 m long fiber optic tactic cable deployed in loop configuration inside three 20 m deep boreholes drilled around the chapel connected through a shallow (few cm) horizontal trench. A combination of 1C and 3C seismic nodes were also utilized as surface receivers along six receiver lines, deployed from the well heads and covering different azimuths. Shot points were located every second receiver position along each line. The acquired in-well DAS and surface node data was integrated for a first-arrival travel-time tomography study, allowing the retrieval of compressional-wave velocity vertical sections.

The present study represents the initial phase of our research efforts, which are being conducted partially within the framework of the USES2 project, which receives funding from from the EUROPEAN RESEARCH EXECUTIVE AGENCY (REA) under the Marie Skłodowska-Curie grant agreement No 101072599.

How to cite: Nesterova, O., Barone, I., Cassiani, G., Brovelli, A., Rodríguez Tribaldos, V., Galtarossa, A., Schenato, L., Palmieri, L., Peruzzo, L., Boaga, J., Pavoni, M., Karbala Ali, H., and Deiana, R.: Combined DAS and seismic nodes acquisition for shallow geophysics purposes around the Scrovegni Chapel in Padua, Italy, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11196, https://doi.org/10.5194/egusphere-egu24-11196, 2024.

The plain of Palermo, located along the coastal belt of North-West Sicily, hosts one of the largest and most populous Italian cities. The city experienced a continuous expansion from the 8th century BC, increasing, over time, its population and extent under the control of different dominations; the expansion took place firstly within the historic walls, subsequently outside them. Finally, during the 20th century, the urban area covered most of the plain. The succession of different dominations has produced a clear mutation of the original urban landscape. Numerous streams that once dominated the plain have undergone changes in path, reduced flow, or have been partially embedded or drained.  In addition, after the Second World War, many ruins were accumulated in areas close to the sea causing a deep morphological variation of the coast. Considering that it was only in 1962 that the city had a master plan, the expansion has led to the exacerbation of the natural hazards related to the geological with extensive damage in the neighborhoods where ancient watercourse originally flowed. Moreover, the intense extraction of building stones from underground, which lasted for centuries, has determined the widespread presence of underground cavities in many areas of the city, with negative effects on the stability and safety of buildings. Finally, both because of the uncontrolled urbanization and the geomorphological and geological features of the plain, characterized by important lateral variations of facies, many residential buildings and infrastructure are located in areas subject to seismic risk related to site effects. For all those reasons, defining a geological and geophysical model as much detail as possible is a tool that helps both in the definition of the geological hazard and the associated risk and in planning, design and construction of important civil works. The Department of Earth and Sea Sciences of the University of Palermo is working on the 3D geological modelling of the area of Palermo Plain. The model was built by integrating the numerous borehole data collected in a database and several geophysical acquisitions. The interpolation of the lithological data has allowed to define an initial subsurface model, characterized by strips of alluvial deposits filling incised valleys scoured in a Pleistocene coastal to neritic bioclastic succession.  The model has been integrated using non-invasive geophysical methodologies: recordings of seismic microtremors analyzed according to the Horizontal to Vertical Spectral Ratio technique (HVSR) and Multichannel Analysis of Surface Waves (MASW). These techniques allow to estimate important physical parameters of the subsoil detailing the model without necessarily having to use new drilling and excavations. Indeed, the HVSR data have been inverted in seismographic columns constraining the inversion by means of the S-wave velocities obtained by MASW carried out for the main lithologies outcropping in the plain. The integration of stratigraphic and geophysical data has provided a useful tool for the reconstruction of the geometry and thickness of the geological bodies of the subsoil of Palermo and to define the depth of the seismic bedrock, highlighting the areas subject to geological and seismic risk.

How to cite: Canzoneri, A., Martorana, R., Agate, M., Capizzi, P., Gasparo Morticelli, M., and Alessandra, C.: Geophysical surveys to reconstruct the geological model of the urban area of Palermo, Italy., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13156, https://doi.org/10.5194/egusphere-egu24-13156, 2024.

The Italian Strong Motion Network (RAN Rete Accelerometrica Nazionale) currently comprises 705 stations strategically distributed throughout Italy. Following the seismic events in L'Aquila in 2009, the Civil Protection Department is also working on a project for the implementation of new accelerometric arrays in urban and sub-urban areas along the main Italian basins.

Presently, operational arrays include those in Central and Southern Italy, such as the Aterno Valley Array, Sulmona Basin Array, and in-hole accelerometers in San Giuliano di Puglia. In December 2023, a new accelerometric array was installed in the Crati Valley.

Crati Valley is located in high seismic area of northwestern Calabria, between Cosenza and Rende, and it is recognized as the Crati Basin—an extensional basin dating back to the Plio-Olocene period. The valley is delineated by north-south-trending normal faults (Brozzetti et al., 2017; Tortorici et al., 1995), serving as the boundary between the Sila and Coastal Range Mountain ranges. The Crati Basin, stretching over 60 km, is flanked by the Catena Costiera ridge to the west and the Sila Massif to the east.

In instrumental time the area is characterized by meager seismicity, but historically, the Crati Basin experienced moderate-to large M >~6.0 (1870, Io =10 MCS; 1854, Io =10 MCS; 1184, Io =9 MCS) and moderate earthquakes (1767, Io =8 MCS; 1835, Io =10 MCS; 1886, Io =7 MCS; 1913, Io=8 MCS).

The array in the Crati Valley is composed of 7 stations arranged linearly both longitudinally and transversely along the valley, covering a total extension of 5 km. The average spacing between seismic stations is approximately 2 km. The reference site is located in the old part of the city of Cosenza and was already a part of the national accelerometric network.

The new accelerometric array in the Crati Valley contributes to ongoing seismic monitoring efforts, enhancing our understanding of site response and seismic hazards in the region.

How to cite: Zambonelli, E., Cirillo, D., Talone, D., Filippi, L., Ammirati, A., Sirignano, S., Costa, G., Pazzi, V., Fornasari, S. F., Ferrarini, F., Brozzetti, F., Lavecchia, G., and de Nardis, R.: The new urban strong motion array along the Crati Valley., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19909, https://doi.org/10.5194/egusphere-egu24-19909, 2024.

The vulnerability to landslides of the Basilicata territory (southern Italy) depends on different causes such as the outcropping lithologies, the morphology of the reliefs, neotectonics, seismicity, etc. Currently all 131 municipalities in this region are involved by landslides (IFFI Project 2020) that very often have affected the continuous and discontinuous urban fabric as well as industrial or commercial areas. In many cases, as for example in the Gorgoglione test site, the state of emergency has been declared with evacuation orders for residential buildings and commercial activities (Perrone et al., 2021; Calamita et al., 2023).

Traditional direct techniques, such as geotechnical boreholes, offer point-specific information but can be highly invasive, leading to potential damage to economic and cultural resources such as archaeological sites and underground utilities in the upper layers of the subsoil. In the context of investigating landslides in urban areas, alternative approaches may be more suitable. A significant contribution can be achieved through the combined utilization of remote sensing and in situ geophysical techniques. (Perrone et al., 2006).

In this work, satellite and ground based SAR interferometry, electrical resistivity tomography (ERT) and single-station seismic ambient noise measurements (HVSR) have been integrated for investigating the phenomenon affecting the Gorgoglione urban area (Fig.1), located in the south-western part of Matera Province (Basilicata Region). SAR interferometry results provided information on the activity status of the phenomenon. The ERT and the HVSR allowed the reconstruction of the subsoil geological setting, the identification of physical discontinuities correlated with lithological boundaries and sliding surfaces and the location of high water content areas. This information was used to assess the landslide residual risk, to plan and implement the risk mitigation actions and to correctly design the remediation works.

References

Calamita G., Gallipoli M.R., Gueguen E., Sinisi R., Summa V., Vignola L., Stabile T.A., Bellanova J., Piscitelli S., Perrone A.; 2023: Integrated geophysical and geological surveys reveal new details of the large Montescaglioso (southern Italy) landslide of December 2013. Engineering geology 313 , pp. Art.n.106984-1–Art.n.106984-16.

IFFI Project (Inventario dei Fenomeni Franosi in Italia). ISPRA, Dipartimento Difesa del Suolo, Servizio Geologico d’Italia. Available online: http://www.progettoiffi.isprambiente.it/cartanetiffi/ (accessed on May 2020)

Perrone A., Canora F., Calamita G., Bellanova J., Serlenga V., Panebianco S., Tragni N., Piscitelli S., Vignola L., Doglioni A., Simeone V., Sdao F., Lapenna V.; 2021: A multidisciplinary approach for landslide residual risk assessment: the Pomarico landslide (Basilicata Region, Southern Italy) case study. Landslides 18, 353–365.

Perrone A., Zeni G., Piscitelli S., Pepe A., Loperte A., Lapenna V., Lanari R.; 2006: Joint analysis of SAR interferometry and electrical resistivity tomography surveys for investigating ground deformation: the case-study of Satriano di Lucania (Potenza, Italy). Engineering Geology 88, 260–273.

How to cite: Perrone, A., Bellanova, J., Calamita, G., Falabella, F., Gallipoli, M. R., Gueguen, E., Pepe, A., Piscitelli, S., Serlenga, V., and Stabile, T.: Remote sensing and in situ geophysical techniques for the hydrogeological hazard assessmnet in urban area: the Gorgoglione (Basilicata region, Southern Italy) case study., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-21488, https://doi.org/10.5194/egusphere-egu24-21488, 2024.