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The aim of COST Action TU1208 was to share and increase scientific-technical knowledge and experience of Ground Penetrating Radar (GPR) techniques in civil engineering, whilst promoting a wider and more effective use of this safe and non-destructive method in the monitoring of structures. The COST Action TU1208 started in April 2013 and ended in October 2017. We were invited to participate in 2014. Our main efforts were directed towards several areas:- Expanding the network of researchers involved in GPR technology and its applications- Joint work with other participants on research, implementation of GPR technology and its applications, as well as publishing in conferences and scientific journals- Participation in founding of TU1208 GPR Association as a follow up initiative of COST Action TU1208. Association is open to experts from all over the world, and its goals are to keep scientific network alive and cohesive, continue the work that was done in the framework of the Action, and further support of cooperation between universities, research centers, private companies and public agencies active in the GPR field. - Development of "Guideline for the detection and the mapping of underground utilities and voids using Ground Penetrating Radar (GPR), with a particular focus to urban areas". This document incorporates elements from various standards, recommendations and good practice from countries where the usage of GPR technology is regulated and is aimed to represent a basic document for development of standards in countries where GPR technology is fully recognized. - Participation in GPR antenna testing campaign. Testing was done based on "GPR system performance compliance tests" which were developed within COST TU 1208 Action. - Development of educational materials "GPR in civil engineering applications - Detection of underground utilities" and "GPR survey – Integration of GPR with other remote sensing technologies" which can be used in introducing of GPR technology to a wider audience.- Organizing 'GPR Workshop - European experiences, standards and recommendations in application of Ground Penetrating Radar', Road Show event where GPR technology was presented to stakeholders, private companies, professionals and other interested parties. [ABSTRACT FROM AUTHOR]

The use of citizen observatories in urban flood management has gained momentum in recent years. Knowing how difficult and expensive it can be to collect professional long-term flood data in urban areas, it is worth looking at alternatives such as citizen observatories. The latter can provide valuable spatiotemporal information during and after flood events. In this study, ten years of citizen flood reports collected in the city of Rotterdam were analyzed. The dataset is comprised of about 70,000 flood reports received via telephone, mobile app, email, and webpage. These reports were compared with high-resolution rainfall observations from national weather radars and the results were used to train a binary classification tree for predicting the number of flood reports based on maximum rainfall intensities across different temporal scales. The result shows that the occurrence of urban pluvial flooding can be best predicted by using a combination of short and long-duration rainfall intensities (e.g., 5-min rainfall > 1.76 mm and daily rainfall > 7.64 mm). By contrast, predictions based on rainfall intensities at a single time scale did not result in acceptable performance. Apart from the fact that accurate flood prediction requires multiscale rainfall data, our study suggests that citizen observatories can be a very valuable source of information for filling the current gap in urban hydrological records. [ABSTRACT FROM AUTHOR]

The role of the applied geophysics for the new scenario of the global urbanization is going to be important. In fact, a high-resolution observation point of the shallow geological subsoil and its iteration with the urban infrastructures became a fundamental point of view. The reinforced concrete (RC) technologies has become the most used technology into the engineering infrastructures. However, RC technology is affected by degradation phenomena that could reduce strongly the life time of engineering structures. This weakness is due to corrosion for flow of chloride ions, cracks, fractures or delamination induced by mechanical stresses, voids or carbonation due to water or moisture coming from the subsoil. Therefore, it is important to develop a new approach less invasive and with fast detection that taking in account not only the structure but also the "infrastructural critical zone" in order to considers the interactions between geology and foundations and the static and dynamic aspects of structures and infrastructures. A novel sub-discipline, called Urban Geophysics, has recently been developing in the field of geophysics for analyzing limits and potentialities of well-known geophysical techniques in urban and industrialized areas. Unfortunately, not all the geophysical techniques are applicable in urban areas for the strong noise due to the presence of metallic structures. However, good results are achievable with applications of electrical resistivity measurements and ground penetrating radar so much to investigate structural elements as to monitor the stability of civil structures. The work presents an experimental approach on full-scale engineering structures and some real cases where the electrical resistivity technique and ground penetrating radar were jointly applied for civil engineering issues. [ABSTRACT FROM AUTHOR]

The weather radar has the advantage of providing a very high spatial resolution of rainfall information. Recently, radar precipitation has been widely used in the field of hydrology especially for flood warnings and flash flood in urban areas. Radar rainfall is routinely estimated by using the existing reflectivity-rainfall intensity relationship so that there may be biases in their measurements. In this study, a generalized linear model (GLM) for calibrating the radar rainfall is proposed within a Bayesian framework. The biased corrected radar rainfall from the GLM can lead to more accurate rainfall estimates than the existing mean field biased correction method. Moreover, we explored the variability in the bias correction parameters corresponding to the geomorphological characteristics (e.g. latitude, longitude, altitude and separation distance) and further proposed a regionalized formula of the bias correction factors with the height and the separation distance. KEYWORDS: Radar rainfall, Bias correction, Bayesian, Generalized linear model, RegionalizationAcknowledgementThis research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2018R1A6A3A11047264). [ABSTRACT FROM AUTHOR]

The Earth Observation (EO) scenario is experiencing a real revolution, thanks to the huge volume of radar remote sensing data nowadays available, and is moving fast towards a Big Data context, opening promising investigation opportunities.Among several EO applications, the advanced Differential Synthetic Aperture Radar Interferometry (DInSAR) technique referred to as Small BAseline Subset (SBAS) algorithm has already largely demonstrated its effectiveness to generate displacement maps and long-term deformation time series at both regional (low resolution analysis) and local (full resolution analysis) spatial scales. Moreover, it covers a wide range of applicability fields, from the natural hazard risk mitigation and prevention, to the management of many anthropogenic actions, such as ground-water exploitation, oil and gas extraction, mining activities, tunnelling, buildings, dams construction, transportation.In this scenario characterized by large collections of satellite SAR data, the aspects related to their management and storage, efficient processing and deep exploitation are becoming high priorities, requiring the use of High Performance Computing (HPC) from distributed infrastructures (such as Clusters, Grid and Cloud Computing) to handle and process these large SAR data flows, guaranteeing high efficiency in terms of portability, scalability and velocity. On the other hand, the development of hardware and software tools (Graphical Processing Units (GPU) acceleration, Machine and Deep Learning (ML, DL) approaches) can have a great impact in extracting and creating value added information from the generated DInSAR products, thus maximizing and optimizing their exploitation.This work is aimed at developing innovative Differential SAR Interferometry (DInSAR) solutions exploiting parallel programming techniques (multi-node, multi-core, GPU) and Machine/Deep Learning algorithms, based on the exploitation of distributed HPC environments, to be implemented within an automatic full resolution SBAS-DInSAR processing pipeline to massively analyze surface deformation phenomena in extended urban areas at the scale of single buildings, starting from large EO SAR datasets acquired by the COSMO-SkyMed constellation. Such a processing chain exploits several parallel programming strategies in order to take full advantage of distributing computing infrastructures and, in particular, of Cloud Computing platforms. Specifically, we consider a coarse/medium-grained parallelization strategy, based on multi-node and multi-core programming techniques, addressed to parallel distribute the computational load among different computing nodes and/or CPUs. Moreover, a fine-grained parallelization approach, focused on the use of Graphical Processing Unit (GPU), is also exploited.A relevant impact of this work is the creation of a bridge between the EO community and the HPC infrastructures and tools, which are particularly suitable for Big Data processing and analysis. The possibility to massively perform high-resolution DInSAR analyses in automatic way, at wide spatial scale and in short time frames, will pave the way to new resilience scenarios for the territory monitoring. [ABSTRACT FROM AUTHOR]

Rapid urbanization and climate change increase the extreme flooding risks in urban areas, which has become a significant problem all over the world and a big challenge widely faced by most cities. UN 2030 Agenda and following international agreements (in particular Habitat III) aim therefore to greatly enhance urban resilience, see for instance the UN Sustainable Development Goal 11. Thus, Nature-based solutions (NBS) are more and more considered as the key solution to achieve this goal. However, there is the need to qualitatively reduce the many uncertainties on the effective performance of NBS, which are largely associated to the complexity of both the urban fabric and precipitation. We therefore show the potentials of combining integrated modelling and multifractal analysis on the case study of a 520 ha peri-urban catchment (Guyancourt) along the Bièvre River in the southwest of Paris. The methodology has three steps: (1) to identify the suitable areas that can be covered by NBS practices (porous pavement, green roof, rain garden, as well as the combination of the three) with high resolution GIS data; (2) to assimilate these data in the integrated modelling platform Multi-hydro (developed by École des ponts ParisTech) and X-band and C-band radar data of three rainfall events from to simulate the hydrological impacts of NBS scenarios on the catchment; (3) the simulated surface runoffs for the different NBS scenarios are compared and analysed with the help of a Universal Multifractal (UM) analysis. The results suggest that the UM parameters can well evaluate the effect of NBS practices and temporal and spatial distribution of precipitation on the runoff, which can contribute to the decision–making process of design of NBS practices in urban planning. [ABSTRACT FROM AUTHOR]

The coast of Granada (southern Spain) has already been the subject of several studies about landslides in urban areas. This is the case of (1) Cármenes del Mar, (2) Marina del Este, (3) Alfamar and (4) Monte de los Almendros resorts. Previous studies evidence that Cármenes del Mar and Marina del Este resorts were built in hillsides affected by quiescent landslides that were reactivated after their construction. By means of DInSAR, both areas were monitored from May 2003 to December 2009, showing displacements between 4 and 10 mm/year. Related to Alfamar and Monte de los Almendros sorts, other study documented the existence of ground instability in both locations by applying the on-line SBAS InSAR service of the Geohazard Exploitation Platform (European Space Agency). In this study, images from March 2003 to December 2009 were used and the derived displacement map showed values higher than 8 mm/year. In all the four sorts, moderate and severe damages in buildings were found and evaluated, what shows the relevance of these phenomena in these areas. On the point of this, we continued analyzing these areas to obtain more recent displacement rates and thus, to check the activity of these landslides. We produced a surface velocity map and displacement time series of all the measured points by processing 139 radar images of the Sentinel-1 (A and B) satellite on ascending orbits from 10 March 2015 to 20 September 2018. A procedure designed in the CTTC (Centre Tecnològic de Telecomunicacions de Catalunya) was applied to process the images and measure the surface displacements.High displacement rates were found in all the four sorts: (1) Cármenes del Mar shows deformation velocities between 4 and 8 mm/year, reaching around 15-20 mm/year in the lower part of the landslide. (2) Marina del Este shows velocities between 3 and 6 mm/year, being the highest values in the upper part of the landslide. (3) Alfamar velocities range between 3 and 8 mm/year, being the deformation homogeneously distributed along the slope (4) Monte de los Almendros shows values between 3 and 9.5 mm/year, reaching around 11 mm/year in the lower part of the sort and even 14 mm/year in the upper part. Our analysis not only improves the resolution and level of detail in comparison with the previous studies, as we have been able to obtain a higher number of measurement points with the Sentinel-1 images, but also confirm the instability in all the urbanized slopes, 9 years after the last monitoring. These results offer another example of how InSAR techniques represent an effective tool to identify, delimit and control slope movements that may generate damages in buildings. The gathered measurements also provide new information about the ground conditions in the stable and unstable areas. As the urban development continues growing in the analysed coast, this information may help in the future land management in the region. [ABSTRACT FROM AUTHOR]

Land subsidence due to overuse of groundwater is a common problem in urban areas built on thick, unconsolidated loose soil as is the case in the Konya plain. In this study, we characterize the hydrologically induced time-dependent ground deformation using Sentinel 1 A-B radar images collected between 2014-2018 on both ascending and descending orbits. The vertical velocity fields obtained through the decomposition of two tracks (T160 and T167) show that the Konya plain is sinking at rates up to 5 cm/yr. Two prominent subsidence lobes fall primarily into the urban area of Konya and both of them largely result from groundwater exploitation. Combining InSAR-derived ground deformation and groundwater level pressure head variations in the aquifer throughout the subsidence basin, we analyzed the aquifer system properties such as compressibility and storativity (storage coefficient) properties of the underlying basin. [ABSTRACT FROM AUTHOR]