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The survey, construction, operation and maintenance of railway construction in complex and dangerous mountainous areas are difficult, and geological hazards along the line occur frequently. The geological hazards at slopes of the tunnel entrance and exit are particularly prominent, which are characterized by dispersion, frequent occurrence and great harm, and have become the key risk factors restricting the construction and operation of railway tunnels. Based on the concept of risk prevention and control of gateway forward and whole life cycle, InSAR technology, low-altitude UAV technology, and analytic hierarchy process are applied to assist the monitoring of slopes, identification of geological hazards and risk assessment of dangerous rocks in the stages of site selection, tunnel access construction and operation. It is helpful to systematically and efficiently grasp the development and distribution characteristics of geological hazards in the tunnel site area, especially for the precise prevention and control of various geological risks on slopes of the tunnel site area. After the practical application in the Chengdu-Kunming railway double track and other railway tunnel projects, the ultra-remote automatic monitoring accuracy has reached millimeter level, the identification accuracy of potential or existing geological disasters has been greatly improved, and the identification accuracy of dangerous rock risk sources on the tunnel slope can effectively guide the geological risk prevention and control at the tunnel portal. [ABSTRACT FROM AUTHOR]

This paper offers an overview of methods for assessing geological risks in the development of domestic deposits of carbonate rocks and an example of calculation for one of the deposits of the Kherson region. Conducting geological exploration at each stage of deposit development is accompanied by certain risks, which by their characteristics belong to geological and investment risks, which together make up the group of risks of the mining business. The purpose of determining geological and economic risks when carrying out geological exploration works is to take into account those negative characteristics of the subsoil area, which can objectively reduce the quantity or affect the quality of the mineral. The listed methods of taking risks into account are possible for use at the final stages of geological and economic assessment during detailed exploration of deposits. Geological risk is defined as the probability of not confirming the quantitative and qualitative characteristics of the deposit's reserves. The degree of uncertainty is quantified through the coefficient of variation of resources. For relatively well-studied objects, it is small – 0-0.2, for medium-studied ones – 0.1-0.4, for poorly studied ones – from 0.3 to 1 and more. Intervals of values overlap because they depend on the complexity of the geological structure of the object. According to the results of calculations, the assessed area has low risks of quality loss, which is ensured by the even distribution of the useful component. Fluctuations in the contents of SiO₂ and MgCO₃ can have negative consequences, because for this deposit the increased amounts of mass for SiO₂ + Al₂O₃ if we evaluate the raw material as flux. By lithological varieties, the greatest risks of non-confirmation of quality were recorded for oolite limestones and pelitomorphic shell limestones.

An evaluation of the areas susceptible to the occurrence of landslides in the coastal zone and representative hydrographic basins of the Guamá municipality was carried out. The Mora-Vahrson method was used through a Geographic Information System, with modifications to the original proposal according to the characteristics of the area. The susceptibility map was obtained, categorized into four levels: Low, Moderate, High and Very High. As a result of the zoning, it was obtained that high susceptibility is the most representative (52%); Towns such as El Macho, La Plata, Uvero, Montompolo and El Francés are located there. The result constitutes an update of the danger for the Guamá municipality and creates the bases for the development of local strategies for management and mitigation of impacts. [ABSTRACT FROM AUTHOR]

This paper offers an overview of methods for assessing geological risks in the development of domestic deposits of carbonate rocks and an example of calculation for one of the deposits of the Kherson region. Conducting geological exploration at each stage of deposit development is accompanied by certain risks, which by their characteristics belong to geological and investment risks, which together make up the group of risks of the mining business. The purpose of determining geological and economic risks when carrying out geological exploration works is to take into account those negative characteristics of the subsoil area, which can objectively reduce the quantity or affect the quality of the mineral. The listed methods of taking risks into account are possible for use at the final stages of geological and economic assessment during detailed exploration of deposits. Geological risk is defined as the probability of not confirming the quantitative and qualitative characteristics of the deposit's reserves. The degree of uncertainty is quantified through the coefficient of variation of resources. For relatively well-studied objects, it is small - 0-0.2, for medium-studied ones - 0.1-0.4, for poorly studied ones - from 0.3 to 1 and more. Intervals of values overlap because they depend on the complexity of the geological structure of the object. According to the results of calculations, the assessed area has low risks of quality loss, which is ensured by the even distribution of the useful component. Fluctuations in the contents of SiO2 and MgCO3 can have negative consequences, because for this deposit the increased amounts of mass for SiO2 + Al2O3 if we evaluate the raw material as flux. By lithological varieties, the greatest risks of non-confirmation of quality were recorded for oolite limestones and pelitomorphic shell limestones. [ABSTRACT FROM AUTHOR]

This paper presents a multi-temporal comparison of high-resolution 3D digital models from two urban areas susceptible to landslides in three time periods. The study areas belong to the São Paulo landslide risk mapping database and are named "CEU Paz" (CP) and "Parque Santa Madalena I" (PSM). For each area, a lidar digital surface model (DSM) (2017) and two structure-from-motion multi-view stereo DSMs (2019 and 2022) built from drone imagery were combined using raster algebra to generate three digital surface models of differences (DoDs). The DoDs were able to highlight changes in vegetation cover and buildings, which are important characteristics for evaluating geological risks in an urban context. Still, they were unable to highlight changes in the ground surface. The results demonstrate that the method greatly supports monitoring, allowing for greater detail and ease of detecting large-scale changes. Even with promising results, this technique should be understood as one more tool for mapping risk areas without replacing fieldwork. [ABSTRACT FROM AUTHOR]

Post-drilling evaluation is an important part of prospect evaluation in the oil and gas exploration processes. With the comparative analysis of pre-drilling prediction and post-drilling results, the experience is summarized, and the deficiencies in pre-drilling evaluation and prediction are corrected and improved, so that the pre-drilling evaluation and prediction results of exploration targets are more accurate, and the success rate for the coming oil and gas exploration can be improved. Based on introducing the main contents and methods of post-drilling evaluation, the problems and solutions that need to be focused on in post-drilling evaluation are summarized in this paper. By analyzing the geological risk factors and reserve parameters of both successful and failed drilling, the key elements of large deviation between pre-drilling prediction and post-drilling estimation are compared, and the causes for the deviation are discussed and improved, which can be helpful on improving the geological explorers' ability of prediction and enhancing the success ratio of exploration in the following work.

ABSTRACT. Anthropogenic radioactive pollution of the environment resulting from the research and exploitation of uranium resources is a topical issue for the scientific community because it represents a threat to people’s health conditions and has a highly negative impact on the environment. The sources of radioactive pollution are due to the presence of low-level radioactive tailings and poor ore dumps resulting from the exploration and exploitation of uranium ore deposits. Uranium under the action of environmental factors can reach the groundwater, the river network, and the food chain, respectively. The contaminated food and water may cause diseases and even cancer. An important role in the pollution spreading is played by geological phenomena, the most important being landslides. Thus arises the need for geological risk management. The present study aims to implement a geological risk management system through methods of assessment, monitoring, and prediction of geological risk for a chosen uranium site. The waste rock and water samples analysis pointed out the radioactive contamination risk. The simulated scenarios in the area exposed to subsidence phenomena showed the activity of increasing the concentration of radioactive waste in the hydrographic system’s groundwater in the studied site, in a time interval of 4120 days (11.29 years): it rapidly increased in the first 1000 days (from 0.0 to 0.0033), after which it decreased in intensity until day 2500 (from 0.0033 to 0.0048), and it is supposed to stagnate after day 2500 until day 4120 when the simulation ended. The results emphasised the radioactive contamination spreading risk in the case when the subsidence phenomenon takes place.

Despite a decades long push to develop what is seen as the vast untapped hydropower potential of the Indian Himalayas, hydropower capacity addition has been delayed and become increasingly expensive in India. Policy documents cite "poor" geology as a major reason for these delays. As hydropower in the form of run-of-river projects expand into the Himalayas, their construction activities encounter poor geology more frequently. This paper analyses hydropower development as an assemblage and examines how risk, especially geological risk, is negotiated to allow hydropower development to continue in the Indian Himalayas. We show how the category of "geological surprises" emerges as an institutional response to the problems of run-of-river based hydropower development in a seismically vulnerable landscape. We further show how "geological surprises" act as a boundary object between hydropower policy, project development, infrastructural finance, and hydropower knowledge, allowing for cooperation and negotiation, to allow hydropower development to continue in the geologically complex Himalayas. [ABSTRACT FROM AUTHOR]

This paper presents a multi-temporal comparison of high-resolution 3D digital models from two urban areas susceptible to landslides in three time periods. The study areas belong to the São Paulo landslide risk mapping database and are named “CEU Paz” (CP) and “Parque Santa Madalena I” (PSM). For each area, a lidar digital surface model (DSM) (2017) and two structure-from-motion multi-view stereo DSMs (2019 and 2022) built from drone imagery were combined using raster algebra to generate three digital surface models of differences (DoDs). The DoDs were able to highlight changes in vegetation cover and buildings, which are important characteristics for evaluating geological risks in an urban context. Still, they were unable to highlight changes in the ground surface. The results demonstrate that the method greatly supports monitoring, allowing for greater detail and ease of detecting large-scale changes. Even with promising results, this technique should be understood as one more tool for mapping risk areas without replacing fieldwork.

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Geological mining data resulted from exploration-prospecting and testing operations at Umid gas condensate field as one of important projects of the State Oil Company of the Azerbaijan Republic (SOCAR) have been systemized and analyzed in the article. There conducted uncertainty analyses of the obtained geophysical and mining data and hydrocarbon reserves on horizons have been estimated. Impact of uncertainties to hydrocarbon reserves of the field have been studied through modern approaches and geological risks have been assessed by usage of new risk matrix. Also, strategy of actions has been proposed in order to mitigate geological risks.

Geological–geotechnical risks studies are a traditional approach in Earth Sciences and Engineering areas. Its main focus is understood the environmental dynamics related to risk situations and the consequences of these environmental dynamics for the well-being. This article focuses on discussing the probability of the occurrence of an environmental phenomenon that endangers population and considering how socioeconomic and political factors are associated with such occurrences. The proposed analysis shows how geological–geotechnical risk studies consider basic principles of sustainability in their applications and the potential of these studies in demonstrate how effective risk monitoring and management can contribute to socially responsible policies. The bibliometric research presented allowed us to identify tendencies and emerging knowledge; specific related journals; people and institutions acting and the mean life of scientific literature in this area. We could establish a proper relationship between this contribution and the recent context of research conducted in these areas. However, limitations of data access resulting from journals and congress proceedings not being fully open access remain as barriers to deeper analysis. [ABSTRACT FROM AUTHOR]

Estimation of deposits cost or subsurface areas is performed income method at a discount rate that takes into account “risk increase”. However, this approach is considered to be subjective, since it is not clear how to calculate the “increase” in each particular case. It is proposed a simple method of risk accounting in the discount rate on the theory of probability and fuzzy logic elements, comprising administering of the certainty coefficient of the adverse factors (events) impact on the field development economic results.

A robust and effective evaluation on geological risk and favorability of hydrocarbon occurrence contributes to a meaningful exploration decision. This paper systematically reviewed and discussed the evaluation units, evaluation variables and evaluation models relevant to geological risk and favorability evaluation, and presented a data-driven procedure using logistic regression method. In this method, quantitative logistic regression relationship between the hydrocarbon occurrence and key geologic factors are obtained by integrating available geoscience information and current exploration results. It offers significant convenience to derive the probability of hydrocarbon occurrence in a straightforward and simple form with a more objective and reproductive result. The proposed method and workflow are further illustrated using an example from the first member of Dainan Formation in Yong'an area of Gaoyou Sag of Subei Basin in China. This case study not only quantified the geological risk and favorability of specific exploration target, but also revealed their spatial variation and highlighted the favorable area for further exploration by the resultant maps. The evaluation results and actual observation displayed a good correspondence and the overall evaluation accuracy was 94.0%, indicating that such an approach could capture the essential spatial characteristics of hydrocarbon accumulations and provide a useful tool in resources appraisal. [ABSTRACT FROM AUTHOR]

Geological risk assessments have been routinely carried out for exploration and development in oil and gas since 1990s. Because of our lack in sufficient information and knowledge of subsurface resources, the geological risk is quantitatively evaluated using probabilistic techniques. Even though the methodologies of risk assessments look well established already, some issues still remain in their actual execution and application and three key issues are highlighted here: geological chance of success, cognitive biases and post-well evaluation. Geological chance of success may be regarded as relatively a simple concept of risk evaluation, but its proper understanding and implementation can't be easily achieved as it is not an absolute number and its assessment depends on quality/quantity of information and technical skills/experiences of evaluators. As subsurface evaluation relies on fairly limited information under great uncertainties, it is very susceptible to cognitive biases including anchoring, availability heuristic, conjunction fallacy, overconfidence and hindsight bias. Post-well evaluation is a crucial part of the risk analysis and required to be conducted so as to improve the quality of risk evaluation. [ABSTRACT FROM AUTHOR]

DOI: 10.17014/ijog.v5i4.107Analytical Hierarchy Process (AHP) is a Multi Criterion Decision Making (MCDM) Technique. It can handle any complex, multicriterion, and multiperson problems. In AHP, the problems are decomposed into a hierarchically structure and are given the weights according to its importance. Thus, the strength with which one alternative dominates another with respect to a given criterion can be identified. The output is a priority ranking indicating the overall preference for each decision alternative. This paper describes the application of AHP to select a geothermal prospect in Sulawesi Island to be developed in the near future. The alternatives consist of three geothermal prospects. i.e., Suwawa, Pulu, and Marana. Three major criteria are used and applied into those three prospects: Geoscience, Infrastructure, and Social-culture aspects. Under each of these major criteria, there are several subcriteria. Geoscience criterion which consists of Resources, Geothermal System, and Geological Risk Subcriteria is given the highest weight with the assumption that if resources are large and can be developed commercially, then there is no reason not to be exploited; the technology and other infrastructure aspects are no longer an obstacle. The result shows that Suwawa Prospect is the best option to be developed in the near future. The second option or rank is Marana Prospect, and the third is Pulu Prospect. This result is in agreement with the future plan of the development of Sulawesi Island. If the regulation and plan of development were suddenly changed, the goal of this AHP might not be appropriate anymore, and the second or third option might replace the first rank. The benefits of using AHP are (1) the facts and reasons behind the decision are well documented, (2) able to handle quantitative and qualitative inputs, (3) able to accommodate environmental, social and other influences, and (4) able to handle subjective judgments of individuals. Lessons learned from AHP application for geothermal prospect selection could be extended into multi criterion decision making at a group level.

Three-quarters of the world population suffered natural disasters at least once between 1980 and 2000. Furthermore, last years' chronicles showed us several geological events that repededly affected urban landscapes. As a consequence beside the loss of human lives and environmental degradation, lots of students were excluded from school, many of whom never to return. Natural hazards have physical, educational, economic and psychosocial impacts. Nowadays it is well ascertained that to decrease this impact by means of structural interventions requires considerable economic resources. Nevertheless, the comparision consequences of similar events in different contexts, it emerges that risk awareness of the population and education to emergency procedures have a positive impact on the occurrence of victims. It follows that the ability of school occupants exposed to hazards to resist and recover from the effects of a hazard in a timely and efficient manner plays a key role to reduce risk, moreover resulting in a cheaper and faster strategy of intervention.This paper presents a new cost-effective methodology and procedure to rapidly assess the geohazard safety classification (GSC) of schools and provides useful information to local decision makers. The GSC, based on the concepts of hazard, vulnerability and resilience, can be calculated integrating ancillary data by means of rapid and not invasive field surveys and questionnaires distributed to the schools employees. Moreover, it can be easily read and understand since it uses the same type of scale as energy efficiency, to indicate the occupants' safety in case of adverse events related to geo-hydrologic hazards.This new rapid assessment methodology have been tested on 10 schools in Tuscany (Italy) and the present paper shows how the GSC can be strongly affected by the lack of ancillary information or the incompleteness of the Risk Assessment Document as well as the school occupants poor perception of geo-hydrologic risk. However, this limitation is at the same time one of the strengths of the GSC: investing in education is a cost-effective way to increase substantially the GSC. [ABSTRACT FROM AUTHOR]

In the analysis of geological risks of Jardim Fortaleza (Guarulhos, SP) was applied the combination of two methods: the phenomenological model of the basin, which identified susceptibility to landslides and risks depending on the terrain characteristics, the geological substrate of the occupation and the produced artificial ground; and geological and geotechnical characterization of the most significant risk area associated with the detailed mapping of natural and technogenic layers, the systematic identification of destructive processes indicators and the registration/sectorization of the affected homes. The results show that the intensity of the risk resulting from the combination of susceptibility to occurrence of mass movements with the settlement features are enhanced by the instability of technogenic surface layers and the housing poor constructive patterns. [ABSTRACT FROM AUTHOR]

Three available tectonic models for the Mexico Basin were analyzed. Based on these models a new tectonic model was developed. Engineering structures were identified that could suffer the effects of seismic activity.Guadalupe Dam case is an example of risk from geological structures defined in the tectonic models. History records three stages of repairs of damage due to settlement and cracks that occurred in the dam wall.These settlements and cracks are associated with neotectonic activity of a nearby normal or strike-slip fault.Regional geotectonics is a cause of settlements and cracks, instability and landslides on roads, as well as high permeability zones beneath reservoirs, causing important damage.

Many variables make foundation conditions unpredicted and uncertain in tunnel and underground constructions which could endanger the safety and adversely impact economy of a project. Evaluating and risk assessment of projects such as mechanized tunneling is necessary to manage and respond to the associated risks, hence, identification of risk factors would be required. In this study by contribution of experienced technicians and use of geological study eight (category) levels of risks are considered. Probability and impact factors are used in the ideal risk analysis. Additionally, in this study ideal and some supplementary factors such as uncertainty of estimates and risk manageability are also addressed. Ranking of risks are determined by Multi-Criteria Decision Making (MCDM) techniques like Fuzzy Analytical Hierarchy Process (FAHP). The present research in Golab tunnel is located in the northwest of Esfahan (Iran), shows that squeezing and face tunnel instability have highest level and gas emissions and clogging of clay have the lowest level of risks. [ABSTRACT FROM AUTHOR]

Geothermal energy is one of the renewable sources of energy, which is extremely important from the point of view of the idea of sustainable development. In modern Poland, the use of geothermal energy is so far limited. There are several plants that use geothermal energy for heating purposes, but the cost-effectiveness of this type of investment is low. For several years, a rapid development of so-called thermal parks has been observed, which is related with a newfound fashionability of the healthy lifestyle. Particularly advantageous geological conditions in the region of Podhale, as well as the significant tourist popularity of this area in general all year round, make this type of investment substantially profitable. In other parts of the country, only a few relatively small thermal parks are operational and development is not easy because of the high start-up cost and difficulty of providing adequate financial resources. [ABSTRACT FROM AUTHOR]

Inversion of the Lower Saxony Basin produced large-scale broad antiforms, hosting Germany's largest gas accumulations in stacked Permian and Triassic reservoir systems. Locally, however, several exploration and production wells failed in the upper Permian Zechstein-2-Carbonte (Ca2) due to missing reservoir (hiatus) or formation-water wet conditions despite of drilling the topmost position of the trap structure. Seismic interpretation indicates lateral shear of the structural topmost Ca2 reservoir by oblique inversion-related collision with the overlying rigid sandstone unit of the Triassic Bunter Formation (Fm.), triggering a halokinetic redistribution of Permian Zechstein (Z2-Z4) salt in between. Lateral shear was enabled along a thin Zechstein (Z1) salt decollement, underlying the Ca2 reservoir. This ultimately led to a full detachment of large intra-salt Ca2 allochthonous gas reservoirs ('stringers'), leaving behind areas of Ca2 autochthonous absence ('bald highs'). These kinematics triggered hydraulic connection and gas leakage from both, the 'bald high' margins of the autochthonous Ca2 and the Ca2 'stringers' into the sandstone reservoir of the Bunter Fm. Methane-rich fluid inclusions in sub-horizontal tectonic veins and from within vertical stylolites sampled from cores of wells, which tested the Ca2 reservoir to be formation water-wet, proof gas leakage as a result of inversion. Identification criteria for gas leakage and reservoir presence have been established from this study to frame geological subsurface scenarios for pre-drill risk assessments of inverted settings. The generalized conclusion from this study is that the topmost position of structural highs in inverted salt basins may be actually exposed to the highest geological risk. [Display omitted] • A novel geological risk characterization scheme has been established for hydrocarbon exploration in inverted salt basins. • Highest exploration risk for methane is assigned to the topmost position of inverted trap structures. • Structural re-configuration of extensional traps caused methane leakage as a result of inversion. • Seismic interpretation indicates a strike-slip component during Late Cretaceous inversion. [ABSTRACT FROM AUTHOR]

The current active development of the city of St. Petersburg in Russia has led to high growth rates in both industrial and housing areas, causing an increased load on geological media. Taking into account the rather unfavourable geological conditions of the city area, such a development can entail to an intensification of environmental risks. Sustainable and cost-effective land-use planning requires information on geological conditions. Stakeholders need general geological information on the area of St. Petersburg, hydrogeological information on groundwater and information on geological risks. Geological risk maps help to identify whether an area under consideration requires special measures for geological risk management. This paper describes a first attempt to analyze potential geological risks in the city of St. Petersburg, Russia. The approach is to introduce a methodology for multi-risk assessment to be used in land-use planning. The core of the methodology is a matrix that assigns a certain level of geological risk depending on the combination of land use stipulated by the master plan of St. Petersburg and geological characteristics. Based on the matrix, a map presenting potential integrated geological risk can be created. At the same time, the combination of the integrated geological risk map, single geological risk maps and the matrix allows the retracement of which geological characteristics and which land use types contribute to the resulting risk. Users of the methodology in St. Petersburg were trained and an end-user manual was prepared by the authors. The methodology was introduced to professionals who utilize geological information and assess potential risks related to geology. [ABSTRACT FROM AUTHOR]

Seismometer arrays have been widely applied to record collapse by controlled explosion in mines and caves. However, most underground failures are natural events, and because they can occur abruptly, underground failures represent a serious geological hazard. An accelerometric array installed on 4 September 2008 has been used to manage the geological risk of the Peschiera Springs drainage plant of Rome's aqueduct, which is located in the Central Apennines approximately 80 km from Rome, Italy. The plant occupies a karstified carbonatic slope that is extensively involved in gravitational deformations, which are responsible for underground failures such as cracks and collapses. To distinguish among different types of recorded events, an automated procedure was implemented based on the duration, peak of ground acceleration (PGA) and PGA variation in the recordings of the plant's accelerometric stations. The frequencies of earthquakes and micro-earthquakes due to underground failures are, in general, well correlated. Nevertheless, many underground failure sequences can be directly associated with the continuous deformations that affect the slope. The cumulative Arias intensity trend derived for the underground failures combined with the failure and earthquake frequencies enabled the definition of a control index (CI) that identifies alarming or emergency conditions. The CI can be used as a tool for managing the geological risk associated with the deformational processes that affect the drainage plant. [ABSTRACT FROM AUTHOR]

Geological risk management has special relevance in construction and the creation of new infrastructure in Cuba. The aim of this work was to focus on making some reflections about the multidisciplinarity analysis of geological risk management in the country from a critical perspective. [ABSTRACT FROM AUTHOR]

The intention of this paper is to show how people use metaphors to understand and tolerate geological risk in the State of Colima, Mexico, which has an active volcano and is located in the most seismic zone of the country. This research was carried out from the perspective of Cultural Linguistics, with the methodology of cultural schemas. The understanding of this natural condition is based on four cultural schemas, whose core is made up of metaphors. These metaphors contribute to hiding the geological reality in which the people live, thus providing them with a subjective immunity. [ABSTRACT FROM AUTHOR]