Search Results (126)

Hurricane Helene made landfall near Perry (Latitude 30.1 N) in the Big Bend area of Florida with a central pressure of 939 hPa. It moved northwards creating devastating damage and loss of life; however, the greatest damage and number of fatalities occurred well to the north around the City of Ashville (Latitude 35.6 N) where extreme rainfall fell and some of the strongest wind gusts were reported. This paper describes the change in the hurricane’s structure as it tracked northwards, how it gathered tropical moisture from the Atlantic and a turning wind profile between the 850 hPa and 500 hPa elevations, which led to such extreme rainfall. This turning wind profile is shown to be associated with extreme rainfall and loss of life from drowning and landslides around the globe. The area around Ashville suffered 157 fatalities, which is a considerable proportion of the 250 fatalities so far recorded in the whole United Stares from Helene. This is of extreme concern and should be investigated in detail as the public expect the greatest impact from hurricanes to be confined to coastal areas near the landfall site. It is another example of increased death tolls from tropical cyclones moving inland and generating heavy rainfall. As the global population increases and inland centres become more urbanised, run off from such rainfall events increases, which causes greater devastation. Full article

Landslides are one of the most serious problems affecting large parts of the world. There are two approaches that are used to study the organization of these land cover features: firstly, an approach utilizing lithostratigraphic tools, where soils are described and interpreted in accordance with specific geological/lithological patterns, and, secondly, through pedological instruments, where the pedogenetic patterns are identified, and the sequences are identified via standardized criteria and organized according to modern classification systems. In the present review, a comparison between the two above approaches is outlined, using the Campania Apennine reliefs (Southern Italy) as the reference environment because they are periodically and dramatically affected by mass movements mainly associated with rainfall events. These reliefs are strongly influenced by the products emitted by the Phlegraean Fields and the Somma–Vesuvius volcanoes. These products affect surface structures either through their direct alteration, with the formation of pedogenized products, or through their reworking, mainly stimulated by rainfall events, which is also responsible for the movement of pedogenized materials along the slopes. This results in complex surface architectures, knowledge of which is a crucial step in the assessment of robust monitoring systems. This review covers the Cervinara area, located in the central portion of the Campania Apennines, which was overwhelmed by dramatic landslide events in 1999. Our aims were to critically analyze the impact and the potential of lithostratigraphic and pedological approaches in studying the soils of the area in question and to provide an inventory of the scientific papers in which, with different aims, descriptions and interpretations of the local soil covers are reported. We examined and selected the national and international literature available in major scientific online databases, and these were split into groups on the basis of citations and type of approach. The reviewed literature showed that the stratigraphic approach was by far the most preferred, although significant potential was offered by pedological tools in this field of investigation. A high number of hydraulic and geotechnical articles was also found, in comparison to geological and pedological papers, which confirmed the significant levels of interest in the land cover type in question, specifically regarding landslide processes, and in their role in risk mitigation practices. On the whole, the latter approach has been proven to offer a greater exploration potential through the use of rigorous classification systems and, thus, the possibility of identifying and correlating soil properties over large areas. Full article

Studying natural hazards in the context of human-induced landscape transformation is complex, especially in regions with limited information. The narratives of the elderly can play a role in filling these knowledge gaps at the multi-decadal timescale. Here, we build upon a citizen-based elderly approach to understanding natural hazard patterns and landscape transformation in a tropical mountainous environment, the Kigezi Highlands (SW Uganda). We engaged 98 elderly citizens (>70 years old) living in eight small watersheds with different characteristics. Through interviews and focus group discussions, we reconstructed historical timelines and used participatory mapping to facilitate the interview process. We cross-checked the information of the elderly citizens with historical aerial photographs, archives, and field visits. Our results show that major land use/cover changes are associated with a high population increase over the last 80 years. We also evidence an increase in reported natural hazard events such as landslides and flash floods from the 1940s until the 1980s. Then, we notice a stabilization in the number of hazard events per decade, although the two most impacted decades (1980s and 2000s) stand out. Despite this new information, an increase in natural hazard frequency due to land use/cover change cannot yet be quantitatively validated, especially when the probable modulator effect of climate variability is considered. Nevertheless, the increase in the exposure of a vulnerable population to natural hazards is clear, and population growth together with poor landscape management practices are the key culprits that explain this evolution. This study demonstrates the added value of historical narratives in terms of understanding natural hazards in the context of environmental changes. This insight is essential for governments and non-governmental organizations for the development of policies and measures for disaster risk reduction that are grounded in the path dependence of local realities. Full article

Debris flows are a dynamic and hazardous geological phenomenon, as by definition, debris flows are rapid, gravity-driven flows of saturated materials that often contain a mixture of water, rock, soil, and organic matter. They are highly destructive and occur in steep channels, posing a significant threat to infrastructure and human life. The dynamics of debris flows are complex due to their non-Newtonian behaviour and varying sediment–water interactions, making accurate modelling essential for risk mitigation and emergency planning. This paper reports and discusses the results of numerical simulations of back analyses aimed at studying the reconstruction of a real rapid debris flow. The selected test case is the event that occurred on 12 and 16 March 2021 along the Rio Sonno channel, a tributary of the Liri River, following the landslide event of Rendinara (Municipality of Morino, Abruzzo Region, Italy). There are significant flow sources in the area, fed by a highly fractured carbonaceous aquifer that extends immediately upslope of the detachment zone. The continuous flow influences the saturation level in the fine-grained sediments and favours the triggering of the debris flow. This phenomenon was simulated using the commercial RAMMS code, and the rheological model selected was “Voellmy fluid friction”. The modelling approaches used in this research are valid tools to estimate the volumes of materials involved in the flow-feeding process and for the purpose of possible mitigation works (debris flow-type dams, weirs, flow diversion, etc.). Full article

Landslides cause severe damage to life and property with a wide-ranging impact. Infiltration of rainfall is one of the significant factors leading to landslides. This paper reports on a phase creep landslide caused by long-term rainfall infiltration. A detailed geological survey of the landslide was conducted, and the deformation development pattern and mechanism of the landslide were analyzed in conjunction with climatic characteristics. Furthermore, reinforcement measures specific to the landslide area were proposed. To monitor the stability of the reinforced slope, a Beidou intelligent monitoring and warning system suitable for remote mountainous areas was developed. The system utilizes LoRa Internet of Things (IoT) technology to connect various monitoring components, integrating surface displacement, deep deformation, structural internal forces, and rainfall monitoring devices into a local IoT network. A data processing unit was established on site to achieve preliminary processing and automatic handling of monitoring data. The monitoring results indicate that the reinforced slope has generally stabilized, and the improved intelligent monitoring system has been able to continuously and accurately reflect the real-time working conditions of the slope. Over the two-year monitoring period, 13 early warnings were issued, with more than 90% of the warnings accurately corresponding to actual conditions, significantly improving the accuracy of early warnings. The research findings provide valuable experience and reference for the monitoring and warning of high slopes in mountainous areas. Full article

Landslides and their resulting impacts on property and human life have become an ongoing challenge in the hilly regions of Bangladesh. This study aims to systematically review diverse landslide studies in Bangladesh, particularly focusing on landslide disaster management (LDM) from 2008 to 2023, encompassing the pre-disaster, syn-disaster, and post-disaster phases. Several key attributes of landslide studies were considered, including general trends, data types, study scales, contributing factors, methodologies, results, and validation approaches, to investigate challenges and subsequently identify research gaps. This study evaluated 51 research articles on LDM using a systematic literature review (SLR) technique that adhered to the Preferred Reporting Item for Systematic Reviews and Meta-Analyses (PRISMA) framework. Our finding revealed that articles on LDM were dominated by the pre-disaster (76%) and the syn-disaster phases (12%), with the post-disaster phase (12%) receiving equal attention. The SLR revealed a growing number of studies since 2020 that used data-driven methods and secondary spatial data, often focused on medium-scale analyses (district level) that, however, often lacked field-based validation. From the factors examined in various landslide studies, topographical and hydrological factors were found to be the most significant attributes in assessment. This study identified key challenges, such as insufficient landslide inventories including poor site accessibility and a lack of high-resolution geological, soil, and rainfall data. It also highlighted critical research gaps, including the need for advanced technologies in susceptibility mapping for national hazard atlas, the investigation of underexplored causative factors, effective early warning systems, detailed post-event characterization, health impact assessment, risk-sensitive land use planning, and interactive web portals for landslide prone areas. This study would thus aid researchers in understanding the depth of existing knowledge and provide insights into how landslides fit into broader disaster management frameworks, facilitating interdisciplinary approaches. Full article

The 2017 Jiuzhaigou earthquake (Ms = 7.0) struck the eastern Tibetan Plateau and caused extensive concern. However, the reported slip models of this earthquake have distinct discrepancies and cannot provide a good fit for GPS data. The Jiuzhaigou earthquake also presents a good opportunity to investigate the question of how to avoid overfitting of InSAR observations for co-seismic slip inversions. To comprehend this shock, we first used pre-seismic satellite optical images to extract a surface trace of the seismogenic fault, which constitutes the northern segment of the Huya Fault. Then, we collected GPS observations as well as to measure the co-seismic displacements. Lastly, joint inversions were carried out to obtain the slip distribution. Our results showed that the released moment was 5.3 × 10¹⁸ N m, equivalent to Mw 6.4 with a rigidity of 30 GPa. The maximum slip at a depth of ~6.8 km reached up to 1.12 m, dominated by left-lateral strike-slip. The largest potential surface rupture occurred in the center of the seismogenic fault with strike- and dip-slip components of 0.4 m and 0.2 m, respectively. Comparison with the focal mechanisms of the 1973 Ms 6.5 earthquake and the 1976 triplet of earthquakes (Mw > 6) on the middle and south segments of the Huya Fault indicated different regional motion and slip mechanisms on the three segments. The distribution of co-seismic landslides had a strong correlation with surface displacements rather than surface rupture. Full article

When a landslide occurs, the person who discovers it will likely report the disaster; however, a person who receives this report will likely need someone on site to check, since the reporter may have misread the information. This allows third parties to make use of the confirmed information. Facilitating such mechanisms for reporting, confirming, and utilizing disaster information is considered to be necessary for sharing details about one. In this paper, we proposed and analyzed an agent-based model that incorporates disaster behavior into the model of Toriumi et al. The reporting of a disaster refers to submitting articles, the confirmation of the information by another person refers to commenting on the articles, and utilizing the information refers to comments responding to the aforementioned comment using the framework of meta-reward games, based on the prisoner’s dilemma game. We then analyze the costs and rewards to encourage cooperation in several social networks. It is found that reducing the cost of commenting (conforming) encourages the submission of information. The properties of the results do not depend on network structure, which is novel and unexpected, and it is expected that the properties of real social networks will be predictable. Full article

Monitoring surface displacements of landslides is essential for evaluating their evolution and the effectiveness of mitigation works. Traditional methods like robotic total stations (RTSs) and GNSS provide high-accuracy measurements but are limited to discrete points, potentially missing the broader landslide’s behavior. On the contrary, laser scanner surveys offer accurate 3D representations of slopes and the possibility of inferring their movements, but they are often limited to infrequent, high-cost surveys. Monitoring techniques based on ground-based digital photogrammetry may represent a new, robust, and cost-effective alternative. This study demonstrates the use of multi-temporal images from fixed and calibrated cameras to achieve the 3D reconstruction of landslide displacements. The method presented offers the important benefit of obtaining spatially dense displacement data across the entire camera view and quasi-continuous temporal measurement. This paper outlines the framework for this prototyping technique, along with a description of the necessary hardware and procedural steps. Furthermore, strengths and weaknesses are discussed based on the activities carried out in a landslide case study in northeastern Italy. The results from the photo-monitoring are reported, discussed, and compared with traditional topographical data, validating the reliability of this new approach in monitoring the time evolution of surface displacements across the entire landslide area. Full article

This study investigated the climatic risks and vulnerabilities of informal settlements in the Global South, as well as the extent to which these risks impact the vulnerabilities. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 methodology and deductive content analysis, this study critically examined 69 documents, including 28 scholarly journal articles obtained from Scopus and ScienceDirect and 41 web-based releases identified through the Google search engine and snowballing technique. Document inclusion criteria focused on the relevance to climate risks and vulnerabilities, excluding non-peer-reviewed, non-English, and unreliable sources, as well as irrelevant studies. Seven major climate risks impacting informal settlements were identified: floods (44), temperature changes (41), storms (31), sea level rise (30), drought (28), rainfall (23), and landslides (14). The primary vulnerabilities highlighted were poor housing conditions (64), health risks (50), lack of basic services (49), inadequate sanitation (41), inadequate hygiene (39), and limited access to water (38). The combination of vulnerabilities and climate risks creates considerable direct, indirect, and low-level threats to informal settlements. Despite Asia, Africa, and Latin America’s vulnerability, most studies focused on formal and developed areas. The findings highlight the critical need for climate adaptation strategies in informal settlements of the Global South to ensure the United Nations Sustainable Development Goals (SDGs) are met. Full article

Worldwide, landslides claim many lives each year, with an average of 162.6 deaths reported in Japan from 1945 to 2019. There is growing concern about a potential increase in this number due to climate change. The primary source of shallow and rapid landslides within watersheds is the 0-order basins, which are located above the 1^st order drainage system. These active geomorphological locations govern the frequency of mass movement. Despite the recognition of their importance, little attention has been paid to the role of 0-order basins in initiating landslides. Drainage systems can be extracted using the Digital Elevation Model (DEM) in GIS software. However, the effect of DEM resolution on the extraction of 1^st order basins remains unexplained. This research develops an algorithm to assess the impact of DEM resolution on the extraction of first-order basins, channel head points, and the identification of approximate 0-order basins. The study includes algorithms to evaluate the correlation between DEM resolution and 1^st order drainage system extraction using fuzzy classification techniques for approximate 0-order basins. The algorithm was applied in Toho Village, Fukuoka, Japan, defining the most appropriate DEM and stream definition threshold with an 86.48% accuracy and ±30 m error margin for channel head points. Critical slip surfaces were identified inside the 0-order basins and validated with a landslide inventory map with a 91% accuracy. The developed algorithms support hazard management and land use planning, providing valuable tools for sustainable development. Full article

The 4 February 1867 Cephalonia (Western Greece) earthquake is the largest in the Ionian Islands and one of the largest in the Eastern Mediterranean. However, it remained one of the least studied historical events. For reconstructing this earthquake, we reevaluated existing knowledge and used new contemporary and modern sources, including scientific and local writers’ reports and books, local and national journals, newspapers, and ecclesiastical chronicles. The extracted information covered the earthquake parameters, population impact, building damage, and earthquake environmental effects (EEEs). The earthquake parameters included the origin time and duration of the main shock, epicenter location, precursors, aftershocks, and characteristics of the earthquake ground motion. The population impact involved direct and indirect health effects and population change. Building data highlighted the dominant building types and the types, grades, and distribution of damage. The EEEs included ground cracks, landslides, liquefaction, hydrological anomalies, and mild sea disturbances. Field surveys were also conducted for validation. The quantitative and qualitative information enabled the application of seismic intensity scales (EMS-98, ESI-07). The study concluded that since the affected areas were mainly composed of post-alpine deposits and secondarily of clay–clastic alpine formations with poor geotechnical properties, they were highly susceptible to failure. Effects and maximum intensities occurred in highly susceptible areas with a rich inventory. Full article

To mitigate the effects of climate change and increase the resilience of cities, climate risks in urban areas are crucial issues to be addressed. This study analyzes the risks, vulnerability, capacity, degree of exposure, and characteristics of the threats to Panama’s urban areas that result from climate change. Data from DesInventar—a conceptual and methodological tool developed for the construction of databases regarding losses, damages, or effects caused by emergencies or disasters—were analyzed. The main current impacts are floods, landslides, and extreme winds in that order. From 1933 to 2019, Panama recorded 1903 flood reports, 625 landslide reports, and numerous extreme wind events. The affected population totaled 527,394 people, with 101,738 homes impacted. The most affected provinces are Panama, Panama Oeste, and Chiriquí, based on the number of reports. It is expected that in the future, the current effects will increase, and the country’s energy and water security will be put at risk. Strategies to address climate change include enhancing early warning systems and investing in climate-resilient infrastructure. Key measures involve developing public policies for renewable energy and sustainable transportation, preserving ecosystems, and financial mechanisms to support a transition to a sustainable economy. Full article

Intense long-duration rainfall or extreme precipitation in a few hours can provoke many simultaneous shallow landslides. In the past, the term multi-occurrence regional landslides (MORLEs) was proposed to describe such phenomena. In the current study, unmanned aerial vehicles in combination with a global navigation satellite system sensor and geographical information systems seem to be the ideal solution for the rapid assessment of many landslides occurring in Aitoloakarnania Prefecture, Western Greece. Fourteen landslides were accurately mapped within a few working days, and precise orthophotos and reports were created and submitted to the local authorities. The analysis of meteorological data proved that there is a peak in precipitation height that triggers the MORLEs in the specific area. Specifically, the value of the daily precipitation was defined at 80 mm. Full article

Virtual reality is a technological development that, among others, has revolutionized Earth sciences. Its advantages include an opportunity to examine places otherwise difficult or impossible to access and it may also become an important component of education, fostering a better understanding of processes and landforms, geohazard awareness, and an appreciation of geoheritage. This paper reports on the GeoVT project, which aims to create a platform to build and disseminate Virtual Field Trips (VFTs) focused on geomorphology, natural hazards associated with geomorphological processes, and geoheritage sites. To put the GeoVT project in context, an overview of applications of VR in geosciences is provided. This paper subsequently proceeds with a presentation of the project and the GeoVT Authoring application, which is an innovative platform designed to help teachers and students, followed by brief presentations of a number of VFTs developed within the project. They address themes such as fluvial landforms and valley development, coastal landforms, evidence of past glaciation, coastal erosion, wildfire effects, mud volcanoes, and landslides. Full article