Hydrogeological Risk Research Articles

Substantiation of environmental safety in metro facility operations considering hydrogeological risks

Substantiation of environmental safety in metro facility operations considering hydrogeological risks

An Iterative 3D Correction plus 2D Inversion Procedure to Remove 3D Effects from 2D ERT Data along Embankments.

This paper addresses the problem of removing 3D effects as one of the most challenging problems related to 2D electrical resistivity tomography (ERT) monitoring of embankment structures. When processing 2D ERT monitoring data measured along linear profiles, it is fundamental to estimate and correct the distortions introduced by the non-uniform 3D geometry of the embankment. Here, I adopt an iterative 3D correction plus 2D inversion procedure to correct the 3D effects and I test the validity of the proposed algorithm using both synthetic and real data. The modelled embankment is inspired by a critical section of the Parma River levee in Colorno (PR), Italy, where a permanent ERT monitoring system has been in operation since November 2018. For each model of the embankment, reference synthetic data were produced in Res2dmod and Res3dmod for the corresponding 2D and 3D models. Using the reference synthetic data, reference 3D effects were calculated to be compared with 3D effects estimated by the proposed algorithm at each iteration. The results of the synthetic tests showed that even in the absence of a priori information, the proposed algorithm for correcting 3D effects converges rapidly to ideal corrections. Having validated the proposed algorithm through synthetic tests, the method was applied to the ERT monitoring data in the study site to remove 3D effects. Two real datasets from the study site, taken after dry and rainy periods, are discussed here. The results showed that 3D effects cause about ±50% changes in the inverted resistivity images for both periods. This is a critical artifact considering that the final objective of ERT monitoring data for such studies is to produce water content maps to be integrated in alarm systems for hydrogeological risk mitigation. The proposed algorithm to remove 3D effects is thus a rapid and validated solution to satisfy near-real-time data processing and to produce reliable results.

Geomatics-enabled Interdisciplinary Approach Based on Geospatial Data Processing for Hydrogeological Risk-analysis

Hydrogeological risks that are associated with rivers have emerged as a significant concern worldwide, impacting both natural ecosystems and human settlements. This contribution presents an interdisciplinary project that leverages many technologies for data-acquisition and modeling to comprehensively analyze and manage risks in riverine environments. The project integrates geomatics, geological, and hydrological techniques to provide a holistic understanding of river dynamics and their associated hazards. As a central component of this project, geomatics plays a pivotal role in instrumental field surveying through the deployment of photogrammetry and LiDAR instruments. Remote-sensing data from satellite imagery further enriches the project’s temporal analysis capabilities. By analyzing this data over time, researchers can monitor changes in river patterns, land use, and climate-related variables; this helps identify trends and potential triggers for hydrological events. To manage and integrate the vast amount of geospatial information that is generated, a geodatabase within a geographic information system (GIS) has been established. It enables efficient data storage, retrieval, and analysis, fostering collaboration among multidisciplinary researcher teams. This system offers tools for risk-assessment, modeling, and scenario planning; these allow for proactive measures for mitigating hydrological risks.

Does Reduced Space Result in Fewer Rights? Controlled Shrinking in the Urban Renewal of Genoa

This article explores three examples of urban design initiatives in Genoa in an attempt to highlight the potential and possible contradictions that controlled shrinking projects pose for the future of contemporary cities. Genoa, a symbol of Italian shrinking cities, has been strongly defined over the years by post-industrialisation transformations and by long-standing conditions of urban shrinkage. Despite facing continuous shrinkage, local urban development policies have historically focused exclusively on urban growth and expansion. Only recently have some areas in Genoa started to adopt spatial planning experiences that actively pursue degrowth policies, aiming to reduce existing urban fabric and decrease urban density. These initiatives are adopted in specific areas affected by demographic decline, hydrogeological risks, pollution, or catastrophic events. These spatial strategies justify their existence by invoking concepts like smart shrinkage and degrowth, promising improvements in both environmental and social conditions. However, this article notes how these concepts in Genoa are not aligned with the actual social and environmental challenges that these considerations and positions pose. In fact, the urban renewal initiatives introduced by institutions, in reality, lean towards a strategy of shrinkage and demolition of residential complexes, transportation infrastructure, and productive spaces, with diverse and conflicting results. The observed controlled shrinking projects neglect the synthesis of the territory as a palimpsest, ignore new ecological sensitivities, and lack awareness of the social implications associated with the concepts of smart shrinkage and degrowth. Instead, the three instances introduce a spatial project that still adheres to the underlying principles of growth and exploitation, presenting a shrinkage of the existing urban fabric that is mere illusion. It involves clearing out the deteriorated spaces only to fill them with capitalist rhetoric and models that, instead of creating space, undermine fundamental rights. Nonetheless, a closer examination of these three missed opportunities sheds light on the necessary knowledge, actions, and design approaches for a city to navigate urban shrinkage adeptly. This exploration also reveals the potential for the city to transform into a framework and platform, inspiring and guiding new urban planning paradigms for sustainable development.

Tectonic, Geological and Hydrogeological Risks of CO2 Placement in Aquifers in the South of Sakhalin Island

The tectonic, geological and hydrogeological features of the south of Sakhalin Island have been considered in connection with the assessment of the possibility of placing CO2 in aquifers. It has been found that at the regional and zonal level of criteria, this territory can be classified as unpromising one. It has been concluded that implementation of landfill projects for the placement of CO2 in aquifers will face great geological risks for the drinking water supply to the population, and can also lead to serious environmental consequences for nature, including a shift in the balance in the aquatic ecosystem of Aniva Bay.

Influence of karst conduit’s geometry and morphology on 3D flow and transport processes: Insights from 3D tracer tests and numerical modelling

In karst, the characterization of subsurface solute and contaminant transport is a major issue that has been widely investigated due to the high vulnerability of these hydrosystems. In former studies, several researchers addressed these needs with different approaches such as laboratory experiments, field experiments, or groundwater flow and transport simulations. The objective of such approaches is to improve knowledge of transport processes in karst hydrosystems, and propose solutions to limit the downstream hydrogeological risks (contamination of water resources). In this study, we performed the 3D mapping of the karst conduit, which outlet is the Lez spring (southern France) to get the precise geometry and morphology of this fully water-filled karst conduit. Then we injected a dye in the water-filled karst conduit and performed a continuous monitoring of dye tracer recovery at three different cross-sections located downstream the injection spot, at a distance of 40 m, 90 m and 160 m, respectively. In each cross-section, five submersible fluorometer probes were positioned at different locations (top, right, down, left and central parts) along the cross-section of the karst conduit. Experimental data allowed to reconstruct the transient spatial distribution of concentration for each cross-section, which allowed assessing the propagation and evolution of solute plume over time. Monitored data also provided information about dye mixing along the karst conduit and were used to investigate the effect of karst conduit geometry, flow turbulences and velocity profiles on the mixing processes and propagation of solute plume along the conduit with numerical models. Modelling results showed that the consideration of 3D mapped karst conduit geometry and morphology allows a much better reproduction of observed transport processes and breakthrough curves, than the one obtain when considering simplified conduit geometry and morphology.

Addressing land use planning: A methodology for assessing pre- and post-landslide event urban configurations

With urban areas projected to accommodate 68 % of the global population by 2050, the imperative for inclusive, safe, and sustainable cities becomes paramount. In the timeline of urban centers, landslides represent one of the most destructive phenomena, involving several resources allocation with private and public investments, sometimes claiming human lives. By synergically connecting environmental, planning, and configurational spheres, this study seeks to support the proactive management of landslide risk. The proposed three-step methodology allowed to quantify the environmental features involved in landslide occurrence, evaluate planning framework vulnerabilities, and suggest alternative configurations for urban areas that experienced landslides.The methodology has been applied to the case study involving a tragic landslide in Casamicciola Terme (Italy) in November 2022.First, the stream network and the drainage basin corresponding to confluence point of the landslide into the sea have been calculated (environmental elaborations). Subsequently, these elaborations have been overlapped with the runoff mitigation and the sediment deposition layers, extracted through the INVEST software. Secondly, the reconnaissance of the local and superordinate planning levels has been realized, to deepen planning tools cogency on the study area, contextually deepening the constraints that characterize it. From the overlapping of these two steps, free landslide risk areas have been located. Finally, based on the available territorial surface (Sta) and the territorial cover ratio (Rct), two territorial configuration scenarios have been proposed, envisaging the relocation of the buildings involved into the landslide. Results show that landslide originated by three out of five gullies. Some portions of the urban areas of Casamicciola Terme are still under high and very high hydrogeological risk. Contextually, it emerges poor attention from the local planners to the superordinate planning framework. Historic settlement has an Rct of 33.64 %, while areas in which relocate the built up show an Rct of 32,45 % for scenario 1 and 27,9 % for scenario 2.The methodology resulted useful to address planning vulnerabilities, supporting the realization of alternative configurational scenarios. We expect our research to contribute to the evolving field of disaster risk reduction, by providing a systematic approach to manage landslide risk.

An Energy Self-Sufficient Alpine Hut: The Refurbishment of an Ex-Tobacco Farm Using Building Integrated Photovoltaics

The abandonment and deterioration of historic rural buildings in Europe raise significant issues, including hydrogeological risks, the loss of productive land, and cultural heritage decline. Despite being underestimated, these structures hold significant potential for cultural and productive activities. Renovating these structures is crucial for local communities committed to preserving their heritage, and it is a more sustainable approach than constructing new buildings. This study explores activities undertaken in the Interreg IT/AT project “SHELTER” in Valbrenta (IT): through a participatory approach involving communities, stakeholders, designers, and researchers, an energy concept is developed for refurbishing an abandoned tobacco farm, chosen by the community, to be an alpine hut. Due to the inability to connect to the city electricity grid, the new energy concept focuses on minimizing consumption through envelope refurbishment, efficient heating, and domestic hot water systems. Additionally, the integration of renewable energy sources, particularly Building Integrated Photovoltaics (BIPV), is emphasized to preserve the building’s original appearance. This study demonstrates the feasibility of meeting seasonal energy needs entirely through renewables and explores the potential integration of biomass for meeting annual energy requirements.

A Review of Climate Change Adaptation in the Arctic

The Arctic is experiencing rapid climate change impacts necessitating adaptation. This systematic literature review provides an overview of the recent climate change indicators necessitating adaptation and the actions implemented in response. Articles included in the review focused on communities across the Arctic and were published between the years 2000 and 2020. Through qualitative analysis of the literature, four indicators of climate change were presented through a social-ecological lens: (1) the degradation of ice, (2) changes in ecosystems, (3) changes in weather patterns, and (4) changes in hydrogeological risk. Further, three main types of adaptation were presented: (1) behavioral changes, (2) regulatory initiatives, and (3) changes to livelihoods or economics. Critically, most of these adaptation actions were implemented at an individual level.

Safety Assessment of Bridges: Analysis and Criticalities of the Guidelines for Hydraulic Risk Management

Italian territory is characterized by a high fragility in terms of hydrogeological risk. Therefore, the national structural heritage needs the implementation of risk assessment plans. Specifically, the interaction between infrastructures and water has been identified as a significant factor contributing to recent collapses and failures. The existing Italian national guidelines for evaluating infrastructure vulnerability may fail in accurately reflecting the actual hydraulic conditions. This study aims at evaluating the strengths and limitations of the analyses pursued according to the guidelines and conducted on an impressive dataset comprising 51 bridges located in Italy. Common critical issues have been identified which potentially lead to incorrect estimations of the associated risk level. An erroneous risk assessment can result in misallocation of time and financial resources. One major challenge lies in the difficult tracing of original design documentation, which negatively impacts the assessment process and it may results in overestimating vulnerability to both generalized and localized erosion. Other significant challenges include the lack of specific directions for particular cases and difficulties in accessing the bridges (e.g. the morphology of the terrain or the dense vegetation in floodplain areas). While the guidelines provide an effective framework for risk analysis and damage prevention, they should be used in a critical way to identify and address any deficiency. This assessment may lead to an integration of the methodology and thus, of the guidelines, ensuring improved reliability and ease of application. Our study presents statistical metrics of infrastructure vulnerability estimated based on the guidelines. These analyses have successfully identified several strengths as well as critical aspects related to evaluating hydraulic risk based on guidelines implementation leaving space for opportunity of improvements.

Mapping Urban Flood-Prone Areas’ Spatial Structure and Their Tendencies of Change: A Network Study for Brazil’s Porto Alegre Metropolitan Region

Historically, the main cause of urban disasters in Brazil is flooding events, which are becoming more recurrent due to climate changes and intensive urbanization, causing extensive infrastructure, economic and life losses. The formation of Brazilian Metropolitan Areas goes back to the early twentieth century, with urban expansion following river basins, as regional transportation relied on inland navigation. The transition to road-based transport structured further urban sprawl from the mid-twentieth century onward, as road-circulation axes expanded across flood-prone areas. Mapping those hydrogeological risks is important to understand their effect on the existent road-circulation network structure cohesiveness. From the hydrogeological risk assessment data, this article evaluates potential changes imposed by extreme flood events on the road infrastructure at municipal and metropolitan scales. Space Syntax methods applied to an empirical case – the Porto Alegre Metropolitan Region – allow for comparative analyses between the urban network of current and flooding-event simulations and depict (a) the urban grids’ structural transformations under flooding, (b) the road elements at risk, and (c) the system’s spatial integrity and circulation disruptions. The resulting cartography can subside governance and urban planning strategies to cope with floodings at different territorial scales, addressing changes on local–regional circulation patterns, system breaking points and tendencies of urban land parcelling on vulnerable areas.

Mapping socio-environmental pressures to assess Portuguese soil vulnerability

Soil degradation has concerning impacts on ecosystem functions and biodiversity, decreasing essential processes such as food production or sustaining water quality. We studied eight soil threats to assess degradation processes: hydrogeological risks, soil sealing, salinization, desertification, contamination, compaction, erosion and decline in soil organic matter. A knowledge-based methodology was used measure the importance of 15 anthropogenic and environmental variables, with top weights of water availability (0.11), rate of land use change (0.09) and agricultural practices (0.09). Variables were combined into one additive model per threat to assess its distribution in Portugal. Merged soil threat vulnerability maps provided a spatial representation of the distribution of aggregated soil vulnerability, to find a 58% of moderate vulnerable soils where multiple threats coexist and are key for future management changes, a 32% of low vulnerable soils with reduced levels of soil threats, where temperature and precipitation are the main drivers of soil degradation and a 10% of highly vulnerable soils, which encompasses populated urban areas and rural civil parishes, where contamination and high rates of land turnover are the main drivers. Our maps can be used to make informed decisions on soil management and establish strategic policies for a sustainable use of land.

Tracking a Decade of Hydrogeological Emergencies in Italian Municipalities

This dataset collects tabular and geographical information about all hydrogeological disasters (landslides and floods) that occurred in Italy from 2013 to 2022 that caused such severe impacts as to require the declaration of national-level emergencies. The severity and spatiotemporal extension of each emergency are characterized in terms of duration and timing, funds requested by local administrations, funds approved by the national government, and municipalities and provinces hit by the event (further subdivided between those included in the emergency and those not, depending on whether relevant impacts were ascertained). Italian exposure to hydrogeological risk is portrayed strikingly: in the covered period, 123 emergencies affected Italy, all regions were struck at least once, and some provinces were struck more than 10 times. Damage declared by local institutions adds up to EUR 11,000,000,000, while national recovery funds add up to EUR 1,000,000,000. The dataset may foster further research on risk assessment, econometric analysis, public policy support, and decision-making implementation. Moreover, it provides systematic evidence helpful in raising awareness about hydrogeological risks affecting Italy.

Spatial Multi-Criteria Analysis for Discovering Nature-Based Solutions Location for Urban Flood Mitigation in Accra

In recent years, Nature-Based Solutions (NBS) have become instrumental in restoring ecosystems and reducing the negative effects of hard surface developments. Existing studies have shown the potential of NBS in mitigating urban floods and reducing overall hydrogeological risks, especially in high-income areas. However, there is limited knowledge on area-specific NBS implementation and the locational suitability of areas to support different NBS for urban flood mitigation in medium to low-income regions. A methodology based on Spatial Multi-Criteria Analysis (SMCA) has the potential to spatially combine and synthesize information to elicit spatially-specific opportunities for NBS implementation. However, an SMCA tool to determine suitable locations for different NBS measures for urban flood mitigation does not yet exist. In order to address this research gap, this study developed an SMCA methodology to identify different target areas where specific urban flood-related NBS measures can be implemented to minimize urban flood occurrence in Accra, Ghana. The study revealed different locations where urban flood-related NBS measures could be applied. It also demonstrated how specific NBS measures could be tailored to the characteristics of different areas in Accra to ensure effective urban flood mitigation. The suggested methodological approach provides a spatial knowledge base for flood management institutions to integrate NBS into flood management schemes. The approach has application potential for other geographic contexts facing urban flood risks. Future research could focus on possible ways of integrating NBS into the spatial development of cities.

Geophysical Constraints to Reconstructing the Geometry of a Shallow Groundwater Body in Caronia (Sicily)

The characterization of a groundwater body involves the construction of a conceptual model that constitutes the base knowledge for monitoring programs, hydrogeological risk assessment, and correct management of water resources. In particular, a detailed geological and geophysical approach was applied to define the alluvial Caronia Groundwater Body (CGWB) and to reconstruct a hydrogeological flow model. The analysis of the CGWB, located in north-eastern Sicily, was initially approached through a reanalysis of previous stratigraphic (boreholes) and geophysical (vertical electrical soundings and seismic refraction profiles) data, subsequently integrated by new seismic acquisitions, such as Multichannel Analysis of Surface Waves (MASW) and horizontal-to-vertical seismic ratio (HVSR). The analysis and reinterpretation of geoelectrical data allowed the construction of a preliminary 3D resistivity model. This initial modeling was subsequently integrated by a geophysical data campaign in order to define the depth of the bottom of the shallow CGWB and the thickness of alluvial deposits. Finally, a preliminary mathematical model flow was generated in order to reconstruct the dynamics of underground water. The results show that integration of multidisciplinary data represent an indispensable tool for the characterization of complex physical systems.

GEV Analysis of Extreme Rainfall: Comparing Different Time Intervals to Analyse Model Response in Terms of Return Levels in the Study Area of Central Italy

The extreme rainfall events of recent years in central Italy are producing an increase in hydrogeological risk, with disastrous flooding in terms of human lives and economic losses, as well as triggering landslide phenomena in correspondence with these events. A correct prediction of 100-year return levels could encourage better land planning, sizing works correctly according to the expected extreme events and managing emergencies more consciously through real-time alerts. In the recent period, it has been observed that the return levels predicted by the main forecasting methods for extreme rainfall events have turned out to be lower than observed within a few years. In this context, a model widely used in the literature, the generalised extreme value (GEV) with the “block maxima” approach, was used to assess the dependence of this model on the length of the collected precipitation time series and the possible addition of years with extreme events of great intensity. A total of 131 rainfall time series were collected from the Adriatic slope in central Italy comparing two periods: one characterised by 70 years of observations (1951–2020), the other by only 30 years (1991–2020). At the same time, a decision was made to analyse what the effect might be—in terms of the 100-year return level—of introducing an additional extreme event to the 1991–2020 historical series, in this case an event that actually occurred in the area on 15 September 2022. The results obtained were rather surprising, with a clear indication that the values of the 100-year return level calculated by GEV vary according to the length of the historical series examined. In particular, the shorter time series 1991–2020 provided higher return level values than those obtained from the 1951–2020 period; furthermore, the addition of the extreme event of 2022 generated even higher return level values. It follows that, as shown by the extreme precipitation events that have occurred in recent years, it is more appropriate to consider a rather short period because the ongoing climate change does not allow true estimates to be obtained using longer time series, which are preferred in the scientific literature, or possibly questioning the real reliability of the GEV model.

The Multidisciplinary Approach in the Study of Landscape Evolution: The Fluvial Capture of the San Donato Creek (Gubbio, Central Italy), an Example of Hydrological Regime and Hydrogeological Risk Changes

Historical maps, especially those at a small scale and rich in detail (e.g., the old “Cadastres”), represent an exceptionally important tool for understanding the recent historical evolution of landscapes. The note describes the example of the territory of Gubbio, in Umbria (Central Italy), where a map from the end of the 16th century shows a drawing of the hydrographic network partially different from the current one. A multidisciplinary study based on field surveys, observations of satellite images, archaeological discoveries, and archival research proved useful to confirm what was reported by the cartographer at the time. The possible causes that led to this variation of the surface hydrography up to its current configuration are then discussed in the light of other documentary finds from the archives, taken from the chronicles of the time, which have made it possible to identify, with sufficient approximation, the period where this change occurred. All this leads to a highlighting of a profound evolution of fluvial and slope morphogenetic processes that have affected the study area in recent centuries, in which the regulation of surface waters and afforestation, conducted during the 20th century, have played a decisive role.

Modeling and forecasting traffic flows with mobile phone big data in flooding risk areas to support a data-driven decision making

AbstractFloods are one of the natural disasters which cause the worst human, social and economic impacts to the detriment of both public and private sectors. Today, public decision-makers can take advantage of the availability of data-driven systems that allow to monitor hydrogeological risk areas and that can be used for predictive purposes to deal with future emergency situations. Flooding risk exposure maps traditionally assume amount of presences constant over time, although crowding is a highly dynamic process in metropolitan areas. Real-time monitoring and forecasting of people’s presences and mobility is thus a relevant aspect for metropolitan areas subjected to flooding risk. In this respect, mobile phone network data have been used with the aim of obtaining dynamic measure for the exposure risk in areas with hydrogeological criticality. In this work, we use mobile phone origin-destination signals on traffic flows by Telecom Italia Mobile (TIM) users with the aim of forecasting the exposure risk and thus to help decision-makers in warning to who is transiting through that area. To model the complex seasonality of traffic flows data, we adopt a novel methodological strategy based on introducing in a Vector AutoRegressive with eXogenous variable (VARX) model a Dynamic Harmonic Regression (DHR) component. We apply the method to the case study of the “Mandolossa”, an urbanized area subject to flooding located on the western outskirt of Brescia, using hourly-basis data from September 2020 to August 2021. A cross validation based on the hit-rate and the mean absolute percentage error measures show a good forecasting accuracy.

“Guidelines for the classification and management of risk, for the evaluation of safety and for the monitoring of existing bridges”. Critical analysis and identification of innovative methods to improve the classification of landslide risk.

The structural collapses occurred in recent years in Italy have highlighted the need for maintenance on road bridges. To ensure a uniform risk management system, guidelines and related operating instructions have been issued for classification, safety assessment and monitoring of existing bridges. The central focus of the approach is the determination, for each bridge, of the so-called "Overall attention class" that derives from the combination of four partial attention classes that covers: structural and foundational risk, seismic risk, landslide risk and hydraulic risk. This work concerns the identification and subsequent classification of landslide risk for existing bridges. An analysis of the calculation parameters of the attention class relating to hydrogeological risk is illustrated, in order to optimize the evaluations by limiting the subjectivity in the processing. The work therefore presents some methods to determine the propensity for failure of the investigated area in order to avoid incorrect execution of the risk analysis and a proposal to improve the guidelines indicating some innovative methods to estimate the parameters necessary for determining the level of hazard associated with the landslide attention class.

Processing the Gregorian Cadastre and the historical cartography to reconstruct the ancient hydrographic network of the Rieti Plain

Historical cartography is a pivotal factor to reconstruct land use. The Gregorian Cadastre is the first attempt at a geometric-parcel cadastre of the Papal State (realised since 1820 but in force from 1835). The comparison between the Gregorian Cadastre, the first edition of the Topographic Map of Italy (1875- 1903), and its later edition (1940) allowed us to reconstruct many useful details for understanding the spatial planning of intensively anthropised lands during the 19th and 20th century.The study case is the Rieti plain, occupied mainly by the Lacus Velinus in ancient times. Large-scale hydraulic works were made to drain the plain since Roman times, starting from the work of the Consul Curio Dentato in 271 B.C., with works that have continued up to our times. Despite these continuous reclamations, the plain is subject to high hydro-geological risk. Reconstructing the recent evolution of the hydrographic network of the Rieti plain is a potential tool to mitigate the flood risk and better understand the geology of Rieti's urban area.