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Copyright of World Nuclear Geoscience is the property of World Nuclear Geoscience Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study assesses subsidence-induced risk to urban infrastructure in three major Italian cities—Rome, Bologna, and Florence—by integrating satellite-based persistent scatterer interferometric synthetic aperture radar (PSInSAR) ground displacement data with urban vulnerability metrics into a novel risk assessment workflow, incorporating land use and population data from the Copernicus Land Monitoring Service (CLMS)—Urban Atlas. This analysis exploits ERS-1/2, ENVISAT, and COSMO-SkyMed PSInSAR datasets from the Italian Extraordinary Plan of Environmental Remote Sensing, plus Sentinel-1 datasets from CLMS—European Ground Motion Service (EGMS), and spans a 30-year period, thus capturing both historical and recent subsidence trends. Angular distortion is introduced as a critical parameter for assessing potential structural damage due to differential settlement, which helps to quantify subsidence-induced hazards more precisely. The results reveal variable subsidence hazard patterns across the three cities, with specific areas exhibiting significant differential ground deformation that poses risks to key infrastructure. A total of 36.15, 11.44, and 0.43 km2 of land at high to very high risk are identified in Rome, Bologna, and Florence, respectively. By integrating geospatial and vulnerability data at the building-block level, this study offers a more comprehensive understanding of subsidence-induced risk, potentially contributing to improved management and mitigation strategies in urban areas. This study contributes to the limited literature on embedding PSInSAR data into urban risk assessment workflows and provides a replicable framework for future applications in other urban areas. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Geomechanics is the property of Journal of Geomechanics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It has been over 20 years since the world entered the 21st century, and the economy and science and technology of various countries have developed rapidly. However, the threat and losses of natural disasters to humanity have never diminished. Global disaster risk is increasing year by year in new forms and scales. Sichuan Province, as one of the provinces with the highest number of geological disasters in China, and its rural settlements, as a high-risk area for geological disasters, are the key and difficult points for disaster prevention in China. This article selects rural settlements in Yibin City, Sichuan Province as the research area. By analyzing historical disasters and local geographical characteristics, statistical methods are used to screen and construct a geological hazard risk assessment model for rural settlements in Yibin City. A quantitative and qualitative analysis was conducted on the key indicators of geological hazard risk in rural settlements in Yibin City. Multiple models were used to comprehensively evaluate the risk of geological hazards in rural settlements in Yibin City and a zoning study was conducted. Then, the accuracy of different models was compared, and the random forest model was selected as the computation model for disaster avoidance site selection in rural settlements in Yibin City. Thus obtaining the zoning map of geological hazard risk level in Yibin City. Finally, we conducted a site selection analysis for Rural settlements with different levels of geological hazard risk. And propose strategies for optimizing site selection.

Objective The mountainous and hilly areas of western Zhengzhou City have a complex geological environment, affected by rainfall and human engineering activities. Geological hazards such as collapses, landslides, and debris flows occur frequently. In particular, the “7·20” extreme rainstorm that occurred on July 20, 2021 caused many geological hazards, resulting in heavy casualties and huge economic losses. Therefore, analyzing and summarizing the development characteristics of geological hazards and conducting a risk assessment is necessary for this region. At present, the risk assessment of geological hazards is mainly conducted using a single method that has limitations including slightly low evaluation accuracy. In addition, an overall geological hazard risk assessment has not yet been conducted in the mountainous and hilly areas of western Zhengzhou City. Methods Based on the research and analysis of the geological environment background and the distribution characteristics of geological hazards in the study area, eight evaluation factors were selected: slope, landform, engineering geological rock group, elevation, distance from fault, distance from river, rainfall, and human engineering activities. The weighted information method which incorporates elements of the information quantity model and analytic hierarchy process, was used to evaluate the risk of geological hazards in the study area. Results The low-, medium-, and high-risk areas are 1387.14 km2, 1803.18 km2, and 1066.47 km2, respectively, accounting for 32.59%, 42.36%, and 25.05% of the total area, respectively. The medium- and high-risk areas are mainly distributed in the tectonic erosion medium-low mountains and loess hills in the central part of the four cities, the tectonic erosion medium-low mountains south of Dengfeng, and the loess hilly areas in northern Gongyi and Xingyang. The terrain has steep slopes and deep gullies, and the main stratigraphic lithology is clastic rocks intercalated with carbonate rocks, soft and hard rock layers, and loess. Fault structures are developed, and geological hazards are prone to occur under the action of inducing factors and are highly dangerous. The majority (93.11%) of geological hazards are distributed in medium- and high-risk areas, with hazard point densities of 0.1752 km−2 and 0.2869 km−2, respectively. The spatial distribution of geological hazard points is consistent with the geological hazard risk assessment results. The rationality of the evaluation results was assessed by a Receiver Operating Characteristic curve, yielding an AUC value of 0.868. The evaluation accuracy met the requirements for hazard assessment. Conclusion Geological hazards have the largest information value in the range of >40° slopes loess hilly landforms, loess engineering geological rock groups, and 24-h maximum rainfall of 500–550 mm. The risk of geological hazards is positively correlated with distance from faults and water systems — the closer the distance, the higher the risk. The risk of geological disasters in the study area is controlled by the terrain slope and landform and is closely related to the lithology of the formation, which is an important factor in inducing geological disasters. The weighted information method, which has high accuracy and rationality, was used to evaluate the geological hazard risk. Significance The results of this study can provide a basis and technical support for geological hazard prevention and management in the mountainous and hilly areas of western Zhengzhou City and serve as a valuable point of reference for urban planning and infrastructure geological hazard risk assessment in the study area.

Copyright of Journal of Engineering Geology / Gongcheng Dizhi Xuebao is the property of Journal of Engineering Geology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Exploring the interplay between the spatial and temporal distribution of geological hazards and the complex hazard-prone environment provides valuable insights for effective management of geological hazards. We analyzed the spatial and temporal distribution characteristics of historical geological hazards in Hunan Province from 2015 to 2022 using standard deviation ellipse, mean nearest neighbor, and kernel density estimation. We also employed three machine learning models to evaluate the susceptibility of geological hazards. Our research reveals that the frequency trends of landslide, debris flow, and collapse over time exhibit highly similar characteristics, and their high-density areas in spatial distribution significantly overlap. Spatial correlation analysis and kernel density estimation show that geological hazards tend to aggregate in certain areas. Central Hunan and its surrounding regions are high-density areas for geological hazards, with the most severe surface collapses occurring in the Loudi area. Geological hazards are more likely to occur at the intersection of various administrative regions, and landslides, in particular, manifest as multi-point distributions, forming a belt around cities—especially in the Hengyang area, surrounded by ridges and mountains. The locus of gravity shift for geological hazards is complex, yet the distance is small, and it primarily concentrates in and around Loudi. Lithology is the most crucial factor affecting geological hazards, followed by elevation and the topographic relief index. The extreme gradient boosting model achieved an AUC value of 0.786, outperforming the random forest and support vector machine models. The susceptibility assessment aligns closely with the kernel density estimation results. This study provides a solid foundation for understanding the spatiotemporal evolution and susceptibility of geological hazards on a local scale, thereby aiding in hazard risk prevention and control. [ABSTRACT FROM AUTHOR]

Geological disasters refer to adverse geological phenomena that occur under the influence of natural or human factors and cause damage to human life and property. Establishing prevention and control zones based on geological disaster risk assessment results in land planning and management is crucial for ensuring safe regional development. In recent years, there has been an increase in extreme rainfall events, so it is necessary to conduct effective geological hazard and risk assessments for different extreme rainfall conditions. Based on the first national geological disaster risk survey results, this paper uses the analytic hierarchy process (AHP) combined with the information method (IM) to construct four extreme rainfall conditions, namely, 10-year, 20-year, 50-year, and 100-year return periods. The susceptibility, hazard, vulnerability, and risk of geological disasters in the Laoshan District in eastern China are evaluated, and prevention and control zones are established based on the evaluation results. The results show that: (1) There are 121 collapse geological disasters in Laoshan District, generally at a low susceptibility level. (2) A positive correlation exists between extreme rainfall and hazards/risks. With the rainfall condition changing from a 10-year return period to a 100-year return period, the proportion of high-hazard zones increased from 20% to 41%, and high-risk zones increased from 31% to 51%, respectively. The Receiver operating characteristic (ROC) proved that the assessment accuracy was acceptable. (3) Key, sub-key, and general prevention zones have been established, and corresponding prevention and control suggestions have been proposed, providing a reference for geological disaster prevention and early warning in other regions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering Geology / Gongcheng Dizhi Xuebao is the property of Journal of Engineering Geology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The methodology of comprehensive risk assessment for natural disasters has been the subject of recent research. The risk assessment process is thoroughly explained and applied to geological hazards (such as landslides, earthquakes, and tsunamis) that have a potential for calamity. Obtaining a complicated risk level for a few geophysical and geological risks in northeast Bulgaria is the major goal. It has been done to clearly identify the many dangers, their effects, the elements at risk, exposure, and vulnerability, as well as to analyze the secondary events that were generated. For the first time in practice, a thorough risk assessment approach is used, and it incorporates the idea of risk perception. The methodology's adaptability enables the presentation of the results as either a risk matrix or a risk profile. It depends on the tasks, challenges, and scientific puzzles that need to be solved as well as expert judgment. The outcome showed strong practical applicability and sustainability. [ABSTRACT FROM AUTHOR]

Wubao County is located in the northeastern part of the loess plateau in northern Shaanxi, geological disasters are developing in the area, which seriously threatens the life and property safety of local residents. On the basis of fully analyzing the geological disaster survey data in Wubao County, the evaluation indicators such as slope, slope aspect, and surface curvature were selected for the whole county scale, and the risk assessment was carried out based on the 25 m×25 m grid unit based on the information model based on the GIS platform. The evaluation results are divided into: extremely high risk area, high risk area, medium risk area and low risk area, accounting for 0.63%, 12.58%, 24.40% and 62.39% of the total area respectively. According to the scale of key areas, the factors of slope and slope height are selected, and the analytic hierarchy process model is used to carry out risk assessment of slope units divided by hydrological method based on GIS platform, including 19 extremely high-risk slopes, 69 high-risk slopes, 145 medium-risk slopes, 359 low-risk slopes. The same area (area A) under the two scales was selected to conduct variance analysis on the risk assessment results. It shows that at different scales and the same geographical location, the evaluation results of risk level may be inconsistent. At the county-wide scale, various mathematical statistical models with predictive functions should be used, but at the smaller key area scale, due to the insufficient number of samples used for training, it is not appropriate to use mathematical statistical models. Correspondingly, the grid unit based on GIS tools can be used as the evaluation unit at the county scale; the actual slope body can be used as the evaluation unit at the key area scale.

Rockfall is a natural process of mountain slope evolution that can endanger human settlements adjacent to rock cliffs. The Morro do Moreno Hill is a granite inselberg with steep faces adjoining a densely populated area located in the Vila Velha city (State of Espírito Santo, southeastern Brazil). A large number of fragmented blocks are found amid vegetation cover in the foothills. In this study, rockfall danger was evaluated by means of 3D numerical simulations to reproduce trajectories followed by blocks coupled with field evidences. In addition, the rockfall risk rating system for settlements—R3S2, which is used for rockfall risk analysis of populated areas, has been applied. Only the SE and SW-facing slopes were analyzed, as they were considered the most critical. Numerical simulation revealed block trajectories reaching the urban area with high kinetic energy. The application of the R3S2 indicated high rockfall risk levels. In addition, an extensive talus slope deposit has been identified. Proactive actions have been proposed in order to assist local authorities. Finally, our findings demonstrated that block detachment from rock cliffs is governed by different predisposing factors. [ABSTRACT FROM AUTHOR]

The article briefly discusses the experience of large cities in the integrated development of underground space together with ground construction. This document lists the major cities of Russia in which underground systems operate or are being designed. Based on the existing classification of geological and construction risks of megacities - Moscow and St. Petersburg, the necessity of continuous monitoring and risk management in the development of underground space is shown. The existing latest methodological documents are considered, on the basis of which, construction risks are managed, as well as geotechnical monitoring during the construction and operation of underground structures. Promising directions in developing means and methods of scientific and technical support of underground construction are shown. [ABSTRACT FROM AUTHOR]

Geological disasters refer to adverse geological phenomena that occur under the influence of natural or human factors and cause damage to human life and property. Establishing prevention and control zones based on geological disaster risk assessment results in land planning and management is crucial for ensuring safe regional development. In recent years, there has been an increase in extreme rainfall events, so it is necessary to conduct effective geological hazard and risk assessments for different extreme rainfall conditions. Based on the first national geological disaster risk survey results, this paper uses the analytic hierarchy process (AHP) combined with the information method (IM) to construct four extreme rainfall conditions, namely, 10-year, 20-year, 50-year, and 100-year return periods. The susceptibility, hazard, vulnerability, and risk of geological disasters in the Laoshan District in eastern China are evaluated, and prevention and control zones are established based on the evaluation results. The results show that: (1) There are 121 collapse geological disasters in Laoshan District, generally at a low susceptibility level. (2) A positive correlation exists between extreme rainfall and hazards/risks. With the rainfall condition changing from a 10-year return period to a 100-year return period, the proportion of high-hazard zones increased from 20% to 41%, and high-risk zones increased from 31% to 51%, respectively. The Receiver operating characteristic (ROC) proved that the assessment accuracy was acceptable. (3) Key, sub-key, and general prevention zones have been established, and corresponding prevention and control suggestions have been proposed, providing a reference for geological disaster prevention and early warning in other regions.

There are many hidden dangers of geological disasters because of complex geological environmental conditions and strong human activities in Beijing area, small in scale, but serious in harm. This paper collects geological, geomorphic and socio-economic data, selects ten evaluation indexes such as landform, formation lithology and geological structure to carry out a comprehensive study on Beijing geological disaster risk evaluation, uses analytic hierarchy process to determine the weight of evaluation factors, gets the geological hazard risk zoning and vulnerability assessment based on the spatial analysis function of ArcGIS, and obtains the results of geological hazard risk zoning in Beijing finally. The research shows that the high-risk areas of geological disasters in Beijing are mainly distributed in the middle of Mentougou, Fangshan, Changping, Shunyi District and other places, in the north of Tongzhou and Miyun District, and in the east of Pinggu District and important trunk roads. The geological disasters mainly include collapse, debris flow, surface collapse and land subsidence, and the impact range is large. It is urgent to establish a group survey and prevention system covering the whole city. [ABSTRACT FROM AUTHOR]

The Hengduan Mountains Region (HMR) is one of the areas that experience the most frequent geological hazards in China. However, few reports are available that address the geological hazard susceptibility of the region. This study developed six machine learning models to assess the geological hazard susceptibility. The results show that areas with medium and high susceptibility to geological hazards as a whole account for almost 21% of the total area, while both are 18% when it comes to the single hazard of landslide and rockfall respectively. Medium and high geological hazard susceptibility is found in three parts of the HMR with different characteristics: (1) the central and southern parts, where the population of the region concentrates; (2) the northern part, where higher geological hazard susceptibility is found along the mountain ranges; and (3) the junction of Tibet, Yunnan, and Sichuan in the eastern part, which is prone to larger-scale geological hazards. Of all the potential influencing factors, topographic features and climatic variables act as the major driving factors behind geological hazards and elevation, slope, and precipitation are crucial indicators for geological hazard susceptibility assessment. This study developed the geological hazard susceptibility maps of the HMR and provided information for the multi-hazard risk assessment and management of the region. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Geological Hazard & Control is the property of China Institute of Geological Environmental Monitoring (CIGEM) Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents methodology for geological risk and multy-risk assessment. It is fully in accordance with IEC 31010:2019 and JRC recommendations and has been already applied in the practice. The methodology demonstrating flexibility, adaptability and sustainability within a set of all geological hazards. It is successfully applied to the complex risk assessment of Primorsko municipality. [ABSTRACT FROM AUTHOR]

As there are many uncertain factors in the geological hazard risk, great challenges are brought to the comprehensive evaluation of it. In order to improve the comprehensiveness and accuracy of geological hazard risk assessment, a cloud fuzzy clustering algorithm is constructed in this paper, which can effectively estimate and evaluate uncertain variables. The weight value of the risk cloud droplets is calculated as the input. By setting up clustering conditions and function output conditions, the cluster weights of the inputs which meet requirements can be obtained by multiple clustering iterations. Through the introduction of time parameters, the influence of time factors on data importance and the risk severity of geological disaster emergencies are fully considered. The experimental results show that the calculated risk degree cluster weights are less than 1, which verifies the feasibility and practicability of the algorithm. The research in this paper shows that the clustering dynamic assessment of geological hazards can help to improve the accuracy of risk assessment and provide reference and help for the prevention and control of regional geological hazards. [ABSTRACT FROM AUTHOR]

Risk evaluation is crucial for the construction projects in the areas with high risk of geological hazards. In this paper, based on the projects of Mengshan tourism area, geological hazard risk evaluation model is put forward based on the analysis of geological and environmental conditions as well as characteristics of construction works. Firstly, typical geological hazards of the area for evaluation are determined as collapse and landslide. And then, based on the comprehensive evaluation, 19 collapse zones and three landslide zones are determined in the area for evaluation. They are all stable at present in general, but some of them have high risk to collapse or landslide under rainstorm, weathering or other external forces in the future. At last, five regions are defined as dangerous, including three regions at level 1 and two regions at level 2. At the same time, some effective engineering measures are introduced to prevent the geological disasters according to the natural conditions and inducing factors of the hazards. Methods, procedure and the result put forward by the paper are useful and effective in risk evaluation of geological hazards, especially for the hilly and mountainous area similar as this case. [ABSTRACT FROM AUTHOR]

Dissolution of underground cavities by ground water (or solutions) may cause environmental problems and geological hazards. Efficient modeling and numerical solving of such phenomena are critical for risk analysis. To solve the cavity dissolution problems, we propose to use a porous medium based local non-equilibrium diffuse interface method (DIM) which does not need to track the dissolution fronts explicitly as the sharp front methods (such as ALE). To reduce the grid blocks when using the DIM method, an adaptive mesh refinement (AMR) method is used to have higher resolutions following the moving fronts. An efficient fully implicit scheme is used by taking care of the velocities across the gridblock interfaces on the AMR grid. Numerical examples of salt dissolution under different flow conditions were performed to validate the modeling and numerical solving. Core-scale and reservoir-scale cases were carried out to study the mass transport and the evolution of the profiles of the dissolution fronts. Gravity-driven physical instabilities are found to be more strong in the infinite channel with upper and lower planes than in the 3D tube configuration under the same condition. The implementations with the AMR method also showed a very good computational efficiency, while obtaining good agreement with the finest-grid solutions. [ABSTRACT FROM AUTHOR]

The Wenchuan earthquake, also known as 2008 Sichuan Earthquake, occurred along the Longmenshan fault zone on 12 May 2008 at 14:28:01.42 CST (06:28:01.42 UTC). It caused serious damage to structures in the region. Beichuan is a town which is within these severely damaged areas. According to the earthquake intensity distribution map of 2008 Wenchuan earthquake officially released by the China Earthquake Administration, the earthquake intensity in Beichuan was XI on the China seismic intensity scale. As the earthquake occurred in a mountainous area, there were thousands of landslides, rockfalls, debris flows, and surface ruptures triggered by the earthquake over a broad area. These secondary geological hazards substantially increased the human, social and economic impact of the earthquake. This paper presents a post-earthquake analysis on the secondary geological hazards in Beichuan. The risk analyses associated with construction of the National Earthquake Memorial Museum in Beichuan are assessed and recommendations on risk mitigations for the mass reconstruction over the ruins are also provided based on this field study. [ABSTRACT FROM AUTHOR]

This work presents the first 3D geological model of the Rome coastal area that integrates available subsurface geological, stratigraphic and geophysical data with surface geochemical data obtained both from the literature and new surveys. The model provides new insights into the stratigraphic and tectonic setting of the area and the geological factors controlling both natural and human-induced gas emissions. This sector of the Italian Tyrrhenian margin has been historically affected by natural emissions of deep CO 2 and thermogenic CH 4 , stored in permeable layers but with local migration to the surface along buried normal faults. In addition to natural processes, human activities can also cause leakage and serious health risks, such as the abrupt gas release in August 2013, that was triggered by borehole drillings near the Rome international airport. The presented 3D reconstruction unveils the link between faults, stratigraphy, lithology and the distribution of the soil gas anomalies. It provides information about the depth of the reservoir that can potentially trap endogenous gases, and the location and geometry of the main faults along which the gas migrates towards the surface. Furthermore, reconstruction of the distribution and thickness of important clay layers better constrains the low permeable areas that prevent gas escape. The 3D model, coupled with the geochemical information, can serve as a useful tool for the local administration to perform land-use planning and manage the local geological and degassing hazards that affect this highly urbanized area near Rome. Furthermore, we estimate that the large amount of CO 2 broadly released in the area also provides a contribution to the budget of natural greenhouse gases in the atmosphere. [Display omitted] • Study approach based on 3D geological modelling and soil gas surveys. • 3D model of the stratigraphic and structural setting of the Rome coastal area. • Identification of areas characterized by soil gas anomalies and controlling factors. • Assessment of the natural and man-induced gas emissions hazards. • Calculation of the volume of CO 2 emission that contributes to the GHG budget. [ABSTRACT FROM AUTHOR]

Fujian Province is a typical mountainous environment, where regional geological hazards occur frequently, posing serious threats to the safety of local residents' lives and property and regional ecological security. Accurately revealing the risk of geological hazards in Fujian Province have important guiding significance for the local government to develop targeted prevention strategies. This study selects 8 indicators including elevation, slope, normalized difference vegetation index (NDVI), lithology, land use type, average annual precipitation, distance from rivers and distance from faults to construct an evaluation index system, and reveal the spatial pattern and its influencing factors of the risk of geological hazards in Fujian Province based on the information quantity model and geodetector method. The results showed that the geological hazards risk of mountainous areas in Fujian Province have an overall trend of high in the southeast and low in the northwest, and a characteristic of significant spatial agglomeration. The proportion of different levels of geological hazard risk is showed as that medium risk > medium-high risk > medium-low risk > high risk > low risk, among which, the combined area with medium and medium-high risk accounts for 76.06%. The occurrence of geological hazards in Fujian Province is the result of the combined effects of the natural environment and human activities, and the night light intensity, elevation, slope, and distance from rivers are the main influencing factors causing geological hazards. In addition, The combination of dominant factors conducive to inducing geological hazards are found, which can provide scientific basis for the formulation of regional geological disaster prevention strategies. • Comprehensive evaluation system was constructed using information quantity model. • Geodetector was conducted to reveal the influencing factors of geological hazards. • Combination of dominant factors conducive to inducing geological hazards was found. • Geological hazard risk show an trend of high in the southeast and low in the northwest. • The geological hazard is affected by both natural environment and human activities. [ABSTRACT FROM AUTHOR]