GeoHazards, Volume 5, Issue 2 (June 2024) – 4 articles

A landslide is the movement of rocks, debris, and/or soils down a slope, which often includes falls, topples, slides, flows, and spreads. Landslides, a serious natural hazard to human and human activity, often occur in the coastal and mountainous areas in the United States. Although there are some studies that have explored the landslide probability, which is typically directly modeled by inputting potential environmental variables into statistical regression models, this study designed an alternative geospatial analysis and modeling approach. We first conducted statistical diagnostic tests to examine the significance of potential driving factors including landform, land use/land cover, landscape, and climate. In eastern Tennessee, USA, we first applied the t-test and chi-squared test to select the significant factors driving landslides, including slope, clay percentage in the soil, tree canopy density, and distance to roads, having a p-value of less than 0.05. We then incorporated the four identified significant factors as covariates into logistic regression to model the relationship between these factors and landslides. The fitted logistic model, with a high area under the ROC (AUC) score of 0.94, was then applied to predict landslides and make a regional landslide susceptibility map for eastern Tennessee. The landslide’s potential impacts on eastern Tennessee were also discussed, and implications for local governments and communities for current physical infrastructure protection and new infrastructure development were summarized. Full article

The work detailed here is part of an international initiative on the evaluation of dam safety simulation software for internal erosion performance and best practices. The primary experiments involve simulating uncertainty in the failure events of two dams with two different models: DLBreach and WinDAM C. DLBreach is a physically-based dam/levee breach model developed by Wu. WinDAM C is also a physically based dam breach model capable of analyzing both dam overtopping and internal erosion. The dams selected for the analysis include a 1.3 m high dam tested in the lab and a larger 15.56 m high dam, which suffered a failure in the field. The findings from these experiments are extended with a further analysis on variance, sensitivity, and optimization. Finally, a regression model is trained using the results of these simulators as an inquiry into how well such a system can be captured using machine learning techniques. The results of these experiments, together with the results of the other members of the initiative, improve our understanding of the influences that users bring to using these tools. Full article

During the last 10 kyr, significant subsidence and uplift occurred on Mayotte Island in the Comoros archipelago (Indian Ocean), but the role of volcanic processes in Holocene vertical movements has been neglected in the research so far. Here, we show that an abrupt subsidence of 6–10 m occurred between 9.4 and 10 kyr ago, followed by an uplift of the same amplitude at a rate of 9 mm/yr from 8.1 to 7 kyr ago. A comparison of the relative sea level of Mayotte and a reference sea level curve for the global ocean has been conducted using a modeling approach. This shows that an increasing and decreasing pressure at depth, equivalent to the process caused by a deep magma reservoir (50–70 km), was responsible for ~6–10 m subsidence and 6–10 m uplift, whereas loading by new volcanic edifices caused subsidence during the last few thousand years. Surface movements and deep pressure variations may be caused by pulses from the deep mantle, related to superplume activity, but uncertainties and unknowns about these phenomena are still present and further studies are needed. A better understanding of the volcano-tectonic cycle may improve assessments of volcanic hazards. Full article

This paper delves into the potential advantages of integrating gamification into seismic risk management education, with a specific emphasis on the efficacy of serious games in augmenting the learning process. It offers an illustration of gamification within the framework of a seismic risk preparedness project involving multiple countries, languages, and cultures and across the time of the COVID-19 pandemic. The innovation of this approach largely lies in shifting the focus from competition, which is typical in most games, to collaboration. Three digital serious games were implemented to tackle facets of seismic risk management that are particularly favourable for empowering communities at risk. These games were first used in a hybrid event where students from Algeria, Morocco, and Italy engaged in gameplay both in person within their respective classrooms and remotely with classes in each country. The evaluation study showed the positive impact of gamification in captivating young participants and thereby instilling best practices in seismic risk management. Full article