Applied Sciences

Research

Jump to: Review, Other

16 pages, 22363 KiB

Open AccessArticle

Dynamic Effect of the Earth Fissure Sites in the Yuncheng Basin, China

by Ge Cao, Yahong Deng, Jiang Chang, You Xuan, Nainan He and Huandong Mu

Appl. Sci. 2023, 13(17), 9923; https://doi.org/10.3390/app13179923 - 1 Sep 2023

Cited by 3 | Viewed by 1280

Abstract

Earth fissures are widely distributed worldwide, and the Fenwei Basin in China is one of the regions with the most significant number and scale of fissures in the world. The Yuncheng Basin is an important constituent basin of the Fenwei Basin in China, [...] Read more.

Earth fissures are widely distributed worldwide, and the Fenwei Basin in China is one of the regions with the most significant number and scale of fissures in the world. The Yuncheng Basin is an important constituent basin of the Fenwei Basin in China, where earth fissures are densely developed and cause severe damage. In particular, the impact of earth fissures on the seismic response of the site is still unknown and is an urgent problem that needs to be solved. Based on microtremor tests, three types of typical earth fissure sites in the Yuncheng Basin were selected for field testing. Through spectrum analysis, the dynamic response characteristics of the earth fissure sites were determined. The results show that the dynamic response of the site is significantly affected by the earth fissures. The dynamic response strength of the site is the largest on both sides of the earth fissures, and it decreases and gradually stabilizes with increasing distance from the fissures. The influence range of the earth fissures on the hanging side is slightly longer than the heading side. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

18 pages, 12515 KiB

Open AccessArticle

Anthropic Action on Historical Shoreline Changes and Future Estimates Using GIS: Guadarmar Del Segura (Spain)

by Marta Fernández-Hernández, Almudena Calvo, Luis Iglesias, Ricardo Castedo, Jose J. Ortega, Antonio J. Diaz-Honrubia, Pedro Mora and Elisa Costamagna

Appl. Sci. 2023, 13(17), 9792; https://doi.org/10.3390/app13179792 - 30 Aug 2023

Cited by 4 | Viewed by 1488

Abstract

A good understanding of historical change rates is a key requirement for effective coastal zone management and reliable predictions of shoreline evolution. Historical shoreline erosion for the coast of Guardamar del Segura (Alicante, Spain) is analyzed based on aerial photographs dating from 1930 [...] Read more.

A good understanding of historical change rates is a key requirement for effective coastal zone management and reliable predictions of shoreline evolution. Historical shoreline erosion for the coast of Guardamar del Segura (Alicante, Spain) is analyzed based on aerial photographs dating from 1930 to 2022 using the Digital Shoreline Analysis System (DSAS). This area is of special interest because the construction of a breakwater in the 1990s, which channels the mouth of the Segura River, has caused a change in coastal behavior. The prediction of future shorelines is conducted up to the year 2040 using two models based on data analysis techniques: the extrapolation of historical data (including the uncertainty of the historical measurements) and the Bruun-type model (considering the effect of sea level rises). The extrapolation of the natural erosion of the area up to 1989 is also compared with the reality, already affected by anthropic actions, in the years 2005 and 2022. The construction of the breakwater has accelerated the erosion along the coast downstream of this infrastructure by about 260%, endangering several houses that are located on the beach itself. The estimation models predict transects with erosions ranging from centimeters (±70 cm) to tens of meters (±30 m). However, both models are often overlapping, which gives a band where the shoreline may be thought to be in the future. The extrapolation of erosion up to 1989, and its subsequent comparison, shows that in most of the study areas, anthropic actions have increased erosion, reaching values of more than 35 m of shoreline loss. The effect of anthropic actions on the coast is also analyzed on the housing on the beach of Babilonia, which has lost around 17% of its built-up area in 40 years. This work demonstrates the importance of historical analysis and predictions before making any significant changes in coastal areas to develop sustainable plans for coastal area management. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

12 pages, 2551 KiB

Open AccessArticle

Influence of Rainfall Intensity and Slope on the Slope Erosion of Longling Completely Weathered Granite

by Haojun Tian and Zhigang Kong

Appl. Sci. 2023, 13(9), 5295; https://doi.org/10.3390/app13095295 - 23 Apr 2023

Cited by 10 | Viewed by 2424

Abstract

Serious slope erosion occurs in the distribution areas of fully weathered granites, and rainfall intensity and slope gradient are important factors affecting slope erosion. In this study, we investigate the erosion characteristics of Longling completely weather granites with a focus on the effects [...] Read more.

Serious slope erosion occurs in the distribution areas of fully weathered granites, and rainfall intensity and slope gradient are important factors affecting slope erosion. In this study, we investigate the erosion characteristics of Longling completely weather granites with a focus on the effects of rainfall intensity and slope gradient. Based on an indoor 60-min simulated rainfall test, we selected four slope gradients (10°, 20°, 30°, and 40°) and three rainfall intensities (50, 80, and 110 mm/h) for evaluation. A total of 12 groups of tests were conducted to analyze the erosion and surface hydrodynamic characteristics of the completely weathered granite slope. The results indicate a significant positive correlation between rainfall intensity and slope gradient, and the correlation between rainfall intensity and flow velocity became stronger as the slope gradient increased. The peak sediment yield rate represents the moment at which the change in slope shape is maximized. After the peak appears, the slope will no longer undergo great deformation, and the sediment yield rate will decrease and then become stable. Finally, rainfall intensity and slope gradient, which are the two key factors that determine slope flow velocity, are described using a binary function. The findings provide a reference for the study of slope erosion in completely weathered granites. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

23 pages, 11611 KiB

Open AccessArticle

A Multi-Criteria Decision Analysis (MCDA) Approach for Landslide Susceptibility Mapping of a Part of Darjeeling District in North-East Himalaya, India

by Abhik Saha, Vasanta Govind Kumar Villuri, Ashutosh Bhardwaj and Satish Kumar

Appl. Sci. 2023, 13(8), 5062; https://doi.org/10.3390/app13085062 - 18 Apr 2023

Cited by 26 | Viewed by 3701

Abstract

Landslides are the nation’s hidden disaster, significantly increasing economic loss and social disruption. Unfortunately, limited information is available about the depth and extent of landslides. Therefore, in order to identify landslide-prone zones in advance, a well-planned landslide susceptibility mapping (LSM) approach is needed. [...] Read more.

Landslides are the nation’s hidden disaster, significantly increasing economic loss and social disruption. Unfortunately, limited information is available about the depth and extent of landslides. Therefore, in order to identify landslide-prone zones in advance, a well-planned landslide susceptibility mapping (LSM) approach is needed. The present study evaluates the efficacy of an MCDA-based model (analytical hierarchy process (AHP)) and determines the most accurate approach for detecting landslide-prone zones in one part of Darjeeling, India. LSM is prepared using remote sensing thematic layers such as slope, rainfall earthquake, lineament density, drainage density, geology, geomorphology, aspect, land use and land cover (LULC), and soil. The result obtained is classified into four classes, i.e., very high (11.68%), high (26.18%), moderate (48.87%), and low (13.27%) landslide susceptibility. It is observed that an entire 37.86% of the area is in a high to very high susceptibility zone. The efficiency of the LSM was validated with the help of the receiver operating characteristics (ROC) curve, which demonstrate an accuracy of 96.8%, and the success rate curve showed an accuracy of 81.3%, both of which are very satisfactory results. Thus, the proposed framework will help natural disaster experts to reduce land vulnerability, as well as aid in future development. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

28 pages, 5555 KiB

Open AccessArticle

Hazard Model: Epidemic-Type Aftershock Sequence (ETAS) Model for Hungary

by Péter Szabó, László Tóth and Judith Cerdà-Belmonte

Appl. Sci. 2023, 13(5), 2814; https://doi.org/10.3390/app13052814 - 22 Feb 2023

Viewed by 2394

Abstract

In this article we present a space–time epidemic-type aftershock sequence (ETAS) model for the area of Hungary, motivated by the goal of its application in insurance risk models. High-quality recent instrumental data from the period 1996–2021 are used for model parameterization, including data [...] Read more.

In this article we present a space–time epidemic-type aftershock sequence (ETAS) model for the area of Hungary, motivated by the goal of its application in insurance risk models. High-quality recent instrumental data from the period 1996–2021 are used for model parameterization, including data from the recent nearby Zagreb and Petrinja event sequences. In the earthquake-triggering equations of our ETAS model, we replace the commonly used modified Omori law with the more recently proposed stretched exponential time response form, and a Gaussian space response function is applied with a variance add-on for epicenter error. After this model was tested against the observations, an appropriate overall fit for magnitudes

M \geq 3.0

was found, which is sufficient for insurance applications, although the tests also show deviations at the

M = 2.5

threshold. Since the data used for parameterization are dominated by Croatian earthquake sequences, we also downscale the model to regional zones via parameter adjustments. In the downscaling older historical data are incorporated for a better representation of the key events within Hungary itself. Comparison of long-term large event numbers in simulated catalogues versus historical data shows that the model fit by zone is improved by the downscaling. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

16 pages, 6431 KiB

Open AccessArticle

Revalidation Technique on Landslide Susceptibility Modelling: An Approach to Local Level Disaster Risk Management in Kuala Lumpur, Malaysia

by Elanni Affandi, Tham Fatt Ng, Joy J. Pereira, Ferdaus Ahmad and Vanessa J. Banks

Appl. Sci. 2023, 13(2), 768; https://doi.org/10.3390/app13020768 - 5 Jan 2023

Cited by 6 | Viewed by 2855

Abstract

Landslide susceptibility modelling in tropical climates is hindered by incomplete inventory due to rapid development and natural processes that obliterate field evidence, making validation a challenge. Susceptibility modelling was conducted in Kuala Lumpur, Malaysia using a new spatial partitioning technique for cross-validation. This [...] Read more.

Landslide susceptibility modelling in tropical climates is hindered by incomplete inventory due to rapid development and natural processes that obliterate field evidence, making validation a challenge. Susceptibility modelling was conducted in Kuala Lumpur, Malaysia using a new spatial partitioning technique for cross-validation. This involved a series of two alternating east-west linear zones, where the first zone served as the training dataset and the second zone was the test dataset, and vice versa. The results show that the susceptibility models have good compatibility with the selected landslide conditioning factors and high predictive accuracy. The model with the highest area under curve (AUC) values (SRC = 0.92, PRC = 0.90) was submitted to the City Council of Kuala Lumpur for land use planning and development control. Rainfall-induced landslides are prominent within the study area, especially during the monsoon period. An extreme rainfall event in December 2021 that triggered 122 landslides provided an opportunity to conduct retrospective validation of the model; the high predictive capability (AUC of PRC = 0.93) was reaffirmed. The findings proved that retrospective validation is vital for landslide susceptibility modelling, especially where the inventory is not of the best quality. This is to encourage wider usage and acceptance among end users, especially decision-makers in cities, to support disaster risk management in a changing climate. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

14 pages, 3692 KiB

Open AccessFeature PaperArticle

The Conditional Probability of Correlating East Pacific Earthquakes with NOAA Electron Bursts

by Cristiano Fidani

Appl. Sci. 2022, 12(20), 10528; https://doi.org/10.3390/app122010528 - 18 Oct 2022

Cited by 7 | Viewed by 1631

Abstract

A correlation between low L-shell 30–100 keV electrons precipitating into the atmosphere and M ≥ 6 earthquakes in West Pacific was presented in past works where ionospheric events anticipated earthquakes by 1.5–3.5 h. This was a statistical result obtained from the Medium Energy [...] Read more.

A correlation between low L-shell 30–100 keV electrons precipitating into the atmosphere and M ≥ 6 earthquakes in West Pacific was presented in past works where ionospheric events anticipated earthquakes by 1.5–3.5 h. This was a statistical result obtained from the Medium Energy Protons Electrons Detector on board the NOAA-15 satellite, which was analyzed for 16.5 years. The present analysis, utilizing the same database, translated into adiabatic coordinates during geomagnetic quiet periods, lead to another significant correlation regarding East Pacific strong earthquakes. This new correlation is still observed between high energy precipitating electrons detected by the NOAA-15 0° telescope and M ≥ 6 events of another very dangerous seismic region of the Pacific ring of fire. The particle precipitation that contributed to this correlation was characterized by electron L-shell, pitch-angle, possible disturbance altitudes, and geographical locations. This correlation occurred circa 57 h prior to the East Pacific earthquakes, according to past single cases of reports. The conditional probability corresponding to the cross-correlation peak of 0.024 per binary events reached a value of 0.011. A probability gain of 2 was calculated for earthquakes after an independent L-shell EBs detection, it is therefore applicable for future earthquake forecasting experiments. Moreover, a time-dependent probability gain approaching the correlation peak was estimated. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

17 pages, 12072 KiB

Open AccessArticle

Liquefaction Potential and V_s30 Structure in the Middle-Chelif Basin, Northwestern Algeria, by Ambient Vibration Data Inversion

by Abdelouahab Issaadi, Ahmed Saadi, Fethi Semmane, Abdelkrim Yelles-Chaouche and Juan José Galiana-Merino

Appl. Sci. 2022, 12(16), 8069; https://doi.org/10.3390/app12168069 - 12 Aug 2022

Cited by 9 | Viewed by 2218

Abstract

The Middle-Chelif basin, in northwestern Algeria, is located in a seismically active region. In its western part lies the El-Asnam fault, a thrust fault responsible for several strong earthquakes. The most important being the El-Asnam earthquake (Ms = 7.3) of 1980. In [...] Read more.

The Middle-Chelif basin, in northwestern Algeria, is located in a seismically active region. In its western part lies the El-Asnam fault, a thrust fault responsible for several strong earthquakes. The most important being the El-Asnam earthquake (Ms = 7.3) of 1980. In the present study, ambient vibration data with single-station and array techniques were used to investigate the dynamic properties of the ground and to estimate the

V_{s 30}

structure in the main cities of the basin. Soil resonance frequencies vary from 1.2 to 8.3 Hz with a maximum amplitude of 8.7 in. Collapsing behavior has also been demonstrated west of the city of El-Attaf, reflecting a strong potential for liquefaction. A

V_{s 30}

variation map and a soil classification for each city were obtained mainly by inversion of the HVSR and Rayleigh wave dispersion curves. Finally, an empirical prediction law of

V_{s 30}

for the Middle-Chelif basin was proposed. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

19 pages, 18638 KiB

Open AccessArticle

GIS-Multicriteria Analysis Using AHP to Evaluate the Landslide Risk in Road Lifelines

by Giovanni Leonardi, Rocco Palamara, Francesco Manti and Antonio Tufano

Appl. Sci. 2022, 12(9), 4707; https://doi.org/10.3390/app12094707 - 7 May 2022

Cited by 10 | Viewed by 3318

Abstract

The present paper proposes a new methodology to characterize the landslide susceptibility of the Reggio Calabria metropolitan area. For this purpose, various factors were used, such as land use, slope, rainfall, elevation, lithology, distance from roads and rivers, and thanks to the use [...] Read more.

The present paper proposes a new methodology to characterize the landslide susceptibility of the Reggio Calabria metropolitan area. For this purpose, various factors were used, such as land use, slope, rainfall, elevation, lithology, distance from roads and rivers, and thanks to the use of GIS devices and the AHP method, the landslide risk was defined for the whole territory. The values obtained were classified into four categories: low, moderate, high, and very high. They were then exported into the GIS environment to produce a landslide susceptibility map. The study carried out demonstrates the fragility of the Calabrian territory. From the results obtained, in fact, 66% of the metropolitan territory of Reggio Calabria appears to have a medium–high landslide risk. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

16 pages, 3381 KiB

Open AccessArticle

Landslide Susceptibility Assessment Considering Landslide Volume: A Case Study of Yangou Watershed on the Loess Plateau (China)

by Hang Gao and Xia Zhang

Appl. Sci. 2022, 12(9), 4381; https://doi.org/10.3390/app12094381 - 26 Apr 2022

Cited by 9 | Viewed by 2401

Abstract

Because of the special geological conditions on the Loess Plateau, Landslide erosion is not only the main goal of prevention and control of geological disasters, but also an important erosion mode of soil and water loss in the basin. Thus, landslide susceptibility assessment [...] Read more.

Because of the special geological conditions on the Loess Plateau, Landslide erosion is not only the main goal of prevention and control of geological disasters, but also an important erosion mode of soil and water loss in the basin. Thus, landslide susceptibility assessment before only considering landslide frequency is not far enough for a decision-maker. The study aims to consider both frequency and scale of landslides for a better landslide susceptibility evaluation. Taking the Yangou small watershed as an example, this study used a VR model, RIRA method, and the GIS method to comprehensively consider frequency and scale to analyze landslide susceptibility of the small watershed. Based on the detailed analysis of the existing literature, slope, elevation, NDVI, land-use, lithology, amount distant to road, amount distant to river, profile curvature, and rainfall as landslide are selected as the conditioning factors (CFs) of the landslide, to draw the sensitivity map. The map of landslide susceptibility was classified into five zones: very low, low, medium, high, and very high, and the cover areas occupy 6.90, 12.81, 12.83, 9.42, and 5.87 km², respectively. A total of 60% of the landslide occurred in the zones of high and very high susceptibility, accounting for 87% of the total volume in the study area. The very high susceptibility is the area with a larger relief and along the river and road. The findings will help decision makers to formulate scientific comprehensive policies that take into account disaster prevention and soil conservation measures in specific regions. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

24 pages, 6379 KiB

Open AccessArticle

Linking Short- to Medium-Term Beach Dune Dynamics to Local Features under Wave and Wind Actions: A Northern Portuguese Case Study

by Ana Bio, José Alberto Gonçalves, Isabel Iglesias, Helena Granja, José Pinho and Luísa Bastos

Appl. Sci. 2022, 12(9), 4365; https://doi.org/10.3390/app12094365 - 26 Apr 2022

Cited by 6 | Viewed by 2338

Abstract

Many coasts suffer from prevailing erosion, with them being particularly vulnerable to predicted climate change impacts, threatening coastal ecosystems, their services, infrastructures and populations. Understanding coastal morpho-sedimentary dynamics is thus essential for coastal management. However, coastal vulnerability may differ locally, depending on exposure/protection [...] Read more.

Many coasts suffer from prevailing erosion, with them being particularly vulnerable to predicted climate change impacts, threatening coastal ecosystems, their services, infrastructures and populations. Understanding coastal morpho-sedimentary dynamics is thus essential for coastal management. However, coastal vulnerability may differ locally, depending on exposure/protection and local geological and morpho-hydrodynamical features, suggesting that a local approach to erosion risk assessment is needed to identify and understand local patterns. Digital elevation models of a 14 km long coastal stretch in northern Portugal that were extracted from aerial surveys obtained between November 2008 and February 2019 were analysed to quantify changes in shoreline position and sediment budgets, both for the whole study area and for distinct beach segments. The observed dynamics were subsequently analysed by considering prevailing wave and wind intensities and directions. Overall and during the decade analysed, the beach–dune system of the studied stretch slightly increased in volume (0.6%), although the shoreline retreated (by 1.6 m on average). Temporal variability in coastal dynamics was observed at all of the temporal scales considered—from seasons to 5-year periods—with them being related to variability in ocean and wind patterns. There was a trend from accretional to erosional conditions, with the first 5-year period showing a mean increase in the beach–dune system’s volume of 0.6% and a mean shoreline progradation of 1.5 m, followed by 5-years with 0.0% volume change and 3.1 m shoreline retreat. Locally, the dynamics were very variable, with shoreline dynamics ranging from 24.0 m regression to 51.5 m progradation, and sediment budgets from 213.8 m³ loss to 417.0 m³ gain, per segment and for the decade. Stretches with relatively stable morphologies and others with erosional or accretional trends were found, depending on the beach type, shoreline orientation and the presence of defence structures. Rocky beaches were the least dynamic and sandy beaches the most dynamic, with mean shoreline position changes of 0.0 m and −3.4 m, respectively, and mean sediment budgets of −1.1 m³ and −2.9 m³ per linear meter of coastline, respectively, for the studied decade. The observed dynamics showed how local conditions interacted with meteo-ocean conditions in shaping local morpho-sedimentary dynamics, stressing the importance of a local approach to coastal erosion monitoring and risk assessment. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

16 pages, 4066 KiB

Open AccessArticle

Comparisons of Dynamic Landslide Models on GIS Platforms

by Yuming Wu, Aohua Tian and Hengxing Lan

Appl. Sci. 2022, 12(6), 3093; https://doi.org/10.3390/app12063093 - 17 Mar 2022

Cited by 5 | Viewed by 2703

Abstract

Numerical simulation is one of the methods to assess landslide movement processes, which is beneficial for engineering design and urban planning. With the development of computer technology, GIS has gradually become the mainstream platform for landslide simulation due to data availability and algorithm [...] Read more.

Numerical simulation is one of the methods to assess landslide movement processes, which is beneficial for engineering design and urban planning. With the development of computer technology, GIS has gradually become the mainstream platform for landslide simulation due to data availability and algorithm integrability. However, the dynamic processes of landslides are complicated, which makes integration difficult on GIS platforms. Some assumptions are applied to simplify these dynamic processes and solve this problem. Generally, there are two main types of numerical models on GIS platforms: models based on the Eulerian description and models based on the Lagrangian description. Case studies show that Eulerian models are suitable for flow-like movement, and Lagrangian models are suitable for discrete rigid bodies movement. Different models face different problems: the Eulerian-based models show numerical diffusion and oscillation, and the Lagrangian-based model needs to consider complicated shear and collision processes. In addition, the 3-D model can describe more details in the z-direction, while the depth-averaged model can obtain a reasonable range of motion, depth, and speed quickly. From the view of numerical simulation, inappropriate models, assumptions, and numerical schemes will produce errors. The landslide type refers to several forms of mass wasting associated with a wide range of ground movements, which guides establishing dynamic models and numerical schemes on GIS platforms and helps us obtain results accurately. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

19 pages, 2801 KiB

Open AccessArticle

Modeling the Impact of Extreme Droughts on Agriculture under Current and Future Climate Conditions Using a Spatialized Climatic Index

by Dorothée Kapsambelis, David Moncoulon, Martine Veysseire, Jean-Michel Soubeyroux and Jean Cordier

Appl. Sci. 2022, 12(5), 2481; https://doi.org/10.3390/app12052481 - 27 Feb 2022

Cited by 2 | Viewed by 2920

Abstract

Extreme droughts have a strong impact on agricultural production. In France, the 2003 drought generated records of yield losses at a national scale for grassland (more than 30%) and for cereals (more than 10% for soft winter wheat and winter barley). These extreme [...] Read more.

Extreme droughts have a strong impact on agricultural production. In France, the 2003 drought generated records of yield losses at a national scale for grassland (more than 30%) and for cereals (more than 10% for soft winter wheat and winter barley). These extreme events raise the question of farm resilience in the future. Studying them makes it possible to adapt risk management policy to climate change. Therefore, the objective of this paper was to analyze the frequency and the intensity of extreme drought in 2050 and their impact on crop yield losses (grassland and cereals) in France. We used the DOWKI (Drought and Overwhelmed Water Key Indicator) meteorological index based on a cumulative water anomaly, which can explain droughts and their consequences on agricultural yield losses at a departmental scale. Then, using the ARPEGE-Climat Model developed by Meteo-France, DOWKI was projected in 2050 and grassland, soft winter wheat, and winter barley yield losses were simulated. The results compare the frequency and intensity of extreme droughts between the climate in 2000 and 2050. Our results show that the frequency of extreme droughts (at least as intense as in 2003) doubled in 2050. In addition, the yield losses due to 10-year droughts increased by 35% for grassland and by more than 70% for cereals. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

17 pages, 4486 KiB

Open AccessFeature PaperArticle

Modelling Fire Risk Exposure for France Using Machine Learning

by Baptiste Gualdi, Emma Binet-Stéphan, André Bahabi, Roxane Marchal and David Moncoulon

Appl. Sci. 2022, 12(3), 1635; https://doi.org/10.3390/app12031635 - 4 Feb 2022

Cited by 6 | Viewed by 3862

Abstract

Wildfires generating damage to assets are extremely rare in France. The peril is not covered by the French natural catastrophes insurance scheme (law of 13 July 1982). In the context of the changing climate, Caisse Centrale de Réassurance—the French state-owned reinsurance company involved [...] Read more.

Wildfires generating damage to assets are extremely rare in France. The peril is not covered by the French natural catastrophes insurance scheme (law of 13 July 1982). In the context of the changing climate, Caisse Centrale de Réassurance—the French state-owned reinsurance company involved in the Nat Cat insurance scheme—decided to develop its knowledge on the national exposure of France to wildfire risks. Current and future forest fires events have to be anticipated in case one of the events threatens buildings. The present work introduces the development of a catastrophe loss risk model (Cat model) for forest fires for the French metropolitan area. Cat models are the tools used by the (re)insurance sector to assess their portfolios’ exposure to natural disasters. The open-source national Promethée database focusing on the South of France for the period 1973–2019 was used as training data for the development of the hazard unit using machine learning-based methods. As a result, we observed an extension of the exposure to wildfire in northern areas, namely Landes, Pays-de-la-Loire, and Bretagne, under the RCP 4.5 scenario. The work highlighted the need to understand the multi-peril exposure of the French country and the related economic damage. This is the first study of this kind performed by a reinsurance company in collaboration with a scholarly institute, in this case EURIA Brest. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

13 pages, 8936 KiB

Open AccessArticle

Time-Dependence of the Mechanical Behavior of Loess after Dry-Wet Cycles

by Kai Liu, Tianfeng Gu, Xingang Wang and Jiading Wang

Appl. Sci. 2022, 12(3), 1212; https://doi.org/10.3390/app12031212 - 24 Jan 2022

Cited by 6 | Viewed by 2557

Abstract

The structure, time-dependent mechanical deformation, and strength characteristics of loess, which is loose and porous with well-developed vertical joints, are greatly affected by the dry-wet cycles, which are attributed to periodic artificial irrigation, rainfall, and water evaporation. To better understand the creep characteristics [...] Read more.

The structure, time-dependent mechanical deformation, and strength characteristics of loess, which is loose and porous with well-developed vertical joints, are greatly affected by the dry-wet cycles, which are attributed to periodic artificial irrigation, rainfall, and water evaporation. To better understand the creep characteristics of loess under the effect of dry-wet cycles, Q₂ loess samples obtained from the South Jingyang County, China, were subjected to different dry-wet cycles (0, 5, 10, 15, 20) and sheared in triaxial creep tests. The experimental results revealed that: firstly, the maximum value of the deviatoric stress corresponding to creep failure gradually decreases with an increase in the dry-wet cycles. Secondly, the long-term strength of the loess after dry-wet cycles were obtained through the Isochronous Curve Method. It is found that the long-term strength and the number of dry-wet cycles showed an exponential decreasing relationship. In addition, the creep damage mechanism of loess due to dry-wet cycles is proposed. This study may provide the basis for understanding the mechanical behavior of the loess under the effect of dry-wet cycles, as well as guidelines for the prevention and prediction of loess landslide stability. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

24 pages, 8003 KiB

Open AccessArticle

Stochastic Generator of Earthquakes for Mainland France

by Corentin Gouache, Pierre Tinard and François Bonneau

Appl. Sci. 2022, 12(2), 571; https://doi.org/10.3390/app12020571 - 7 Jan 2022

Viewed by 2653

Abstract

Mainland France is characterized by low-to-moderate seismic activity, yet it is known that major earthquakes could strike this territory (e.g., Liguria in 1887 or Basel in 1356). Assessing this French seismic hazard is thus necessary in order to support building codes and to [...] Read more.

Mainland France is characterized by low-to-moderate seismic activity, yet it is known that major earthquakes could strike this territory (e.g., Liguria in 1887 or Basel in 1356). Assessing this French seismic hazard is thus necessary in order to support building codes and to lead prevention actions towards the population. The Probabilistic Seismic Hazard Assessment (PSHA) is the classical approach used to estimate the seismic hazard. One way to apply PSHA is to generate synthetic earthquakes by propagating information from past seismicity and building various seismic scenarios. In this paper, we present an implementation of a stochastic generator of earthquakes and discuss its relevance to mimic the seismicity of low-to-moderate seismic areas. The proposed stochastic generator produces independent events (main shocks) and their correlated seismicity (only aftershocks). Main shocks are simulated first in time and magnitude considering all available data in the area, and then localized in space with the use of a probability map and regionalization. Aftershocks are simulated around main shocks by considering both the seismic moment ratio and distribution of the aftershock’s proportion. The generator is tested with mainland France data. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

14 pages, 11554 KiB

Open AccessArticle

The Effects of Rainfall, Soil Type and Slope on the Processes and Mechanisms of Rainfall-Induced Shallow Landslides

by Yan Liu, Zhiyuan Deng and Xiekang Wang

Appl. Sci. 2021, 11(24), 11652; https://doi.org/10.3390/app112411652 - 8 Dec 2021

Cited by 26 | Viewed by 5626

Abstract

Landslides are a serious geohazard worldwide, causing many casualties and considerable economic losses every year. Rainfall-induced shallow landslides commonly occur in mountainous regions. Many factors affect an area’s susceptibility, such as rainfall, the soil, and the slope. In this paper, the effects of [...] Read more.

Landslides are a serious geohazard worldwide, causing many casualties and considerable economic losses every year. Rainfall-induced shallow landslides commonly occur in mountainous regions. Many factors affect an area’s susceptibility, such as rainfall, the soil, and the slope. In this paper, the effects of rainfall intensity, rainfall pattern, slope gradient, and soil type on landslide susceptibility are studied. Variables including soil volumetric water content, matrix suction, pore water pressure, and the total stress throughout the rainfall were measured. The results show that, under the experimental conditions of this paper, no landslides occurred on a 5° slope. On a 15° slope, when the rainfall intensity was equal to or less than 80 mm/h with a 1 h duration, landslides also did not happen. With a rainfall intensity of 120 mm/h, the rainfall pattern in which the intensity gradually diminishes could not induce landslides. Compared with fine soils, coarser soils with gravels were found to be prone to landslides. As the volumetric water content rose, the matrix suction declined from the time that the level of infiltration reached the position of the matrix. The pore water pressure and the total stress both changed drastically either immediately before or after the landslide. In addition, the sediment yield depended on the above factors. Steeper slopes, stronger rainfall, and coarser soils were all found to increase the amount of sediment yield. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

21 pages, 55170 KiB

Open AccessArticle

Geometry-Based Preliminary Quantification of Landslide-Induced Impulse Wave Attenuation in Mountain Lakes

by Andrea Franco, Barbara Schneider-Muntau, Nicholas J. Roberts, John J. Clague and Bernhard Gems

Appl. Sci. 2021, 11(24), 11614; https://doi.org/10.3390/app112411614 - 7 Dec 2021

Cited by 10 | Viewed by 3710

Abstract

In this work, a simple methodology for preliminarily assessing the magnitude of potential landslide-induced impulse waves’ attenuation in mountain lakes is presented. A set of metrics is used to define the geometries of theoretical mountain lakes of different sizes and shapes and to [...] Read more.

In this work, a simple methodology for preliminarily assessing the magnitude of potential landslide-induced impulse waves’ attenuation in mountain lakes is presented. A set of metrics is used to define the geometries of theoretical mountain lakes of different sizes and shapes and to simulate impulse waves in them using the hydrodynamic software Flow-3D. The modeling results provide the ‘wave decay potential’, a ratio between the maximum wave amplitude and the flow depth at the shoreline. Wave decay potential is highly correlated with what is defined as the ‘shape product’, a metric that represents lake geometry. The relation between these two parameters can be used to evaluate wave dissipation in a natural lake given its geometric properties, and thus estimate expected flow depth at the shoreline. This novel approach is tested by applying it to a real-world event, the 2007 landslide-generated wave in Chehalis Lake (Canada), where the results match well with those obtained using the empirical equation provided by ETH Zurich (2019 Edition). This work represents the initial stage in the development of this method, and it encourages additional research and modeling in which the influence of the impacting characteristics on the resulting waves and flow depths is investigated. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

26 pages, 9934 KiB

Open AccessArticle

Shallow S-Wave Velocity Structure in the Middle-Chelif Basin, Algeria, Using Ambient Vibration Single-Station and Array Measurements

by Abdelouahab Issaadi, Fethi Semmane, Abdelkrim Yelles-Chaouche, Juan José Galiana-Merino and Anis Mazari

Appl. Sci. 2021, 11(22), 11058; https://doi.org/10.3390/app112211058 - 22 Nov 2021

Cited by 6 | Viewed by 2864

Abstract

In order to better assess the seismic hazard in the northern region of Algeria, the shear-wave velocity structure in the Middle-Chelif Basin is estimated using ambient vibration single-station and array measurements. The Middle-Chelif Basin is located in the central part of the Chelif [...] Read more.

In order to better assess the seismic hazard in the northern region of Algeria, the shear-wave velocity structure in the Middle-Chelif Basin is estimated using ambient vibration single-station and array measurements. The Middle-Chelif Basin is located in the central part of the Chelif Basin, the largest of the Neogene sedimentary basins in northern Algeria. This basin hosts the El-Asnam fault, one of the most important active faults in the Mediterranean area. In this seismically active region, most towns and villages are built on large unconsolidated sedimentary covers. Application of the horizontal-to-vertical spectral ratio (HVSR) technique at 164 sites, and frequency–wavenumber (F–K) analysis at 7 other sites, allowed for the estimation of the ground resonance frequencies, shear-wave velocity profiles, and sedimentary cover thicknesses. The electrical resistivity tomography method was used at some sites to further constrain the thickness of the superficial sedimentary layers. The soil resonance frequencies range from 0.75 Hz to 12 Hz and the maximum frequency peak amplitude is 6.2. The structure of the estimated shear-wave velocities is presented in some places as 2D profiles to help interpret the existing faults. The ambient vibration data allowed us to estimate the maximum depth in the Middle-Chelif Basin, which is 760 m near the city of El-Abadia. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

18 pages, 6040 KiB

Open AccessArticle

Monitoring of Recovery Process at Yeongildae Beach, South Korea, Using a Video System

by Jung-Eun Oh, Weon-Mu Jeong, Kyong-Ho Ryu, Jin-Young Park and Yeon-S. Chang

Appl. Sci. 2021, 11(21), 10195; https://doi.org/10.3390/app112110195 - 30 Oct 2021

Cited by 3 | Viewed by 1936

Abstract

Once a beach is eroded by storm waves, it is generally recovered under milder wave conditions. To prevent or reduce damage, it is therefore important to understand the characteristics of the site-specific recovery process. Here, we present the results, based on a data [...] Read more.

Once a beach is eroded by storm waves, it is generally recovered under milder wave conditions. To prevent or reduce damage, it is therefore important to understand the characteristics of the site-specific recovery process. Here, we present the results, based on a data set from a video monitoring system and wave measurements, of the recovery process in a pocketed beach located inside a bay where the shoreline retreated harshly (~12 m, on average, of beach width) during Typhoon TAPAH (T1917) in September 2019. It took about 1.5 years for the beach to be recovered to the level before the typhoon. During this period, the erosion and accretion were repeated, with the pattern highly related to the wave power (

P_{w}

); most of the erosion occurred when

P_{w}

became greater than 30 kWatt/m, whereas the accretion prevailed when

P_{w}

was no greater than 10 kWatt/m. The recovery pattern showed discrepancies between different parts of the beach. The erosion during storm events was most severe in the southern part, whereas the northern shoreline did not significantly change even during TAPAH (T1917). In contrast, the recovery process occurred almost equally at all locations. This discrepancy in the erosion/accretion process was likely due to human intervention, as a shadow zone was formed in the northern end due to the breakwaters, causing disequilibrium in the sediment transport gradient along the shore. The results in this study could be applied in designing the protection plans from severe wave attacks by effectively estimating the size of coastal structures and by correctly arranging the horizontal placement of such interventions or beach nourishment. Although the application of these results should be confined to this specific site, the method using wave energy parameters as criteria can be considered in other areas with similar environments, for future planning of beach protection. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

21 pages, 4360 KiB

Open AccessFeature PaperArticle

The Manning’s Roughness Coefficient Calibration Method to Improve Flood Hazard Analysis in the Absence of River Bathymetric Data: Application to the Urban Historical Zamora City Centre in Spain

by Julio Garrote, Miguel González-Jiménez, Carolina Guardiola-Albert and Andrés Díez-Herrero

Appl. Sci. 2021, 11(19), 9267; https://doi.org/10.3390/app11199267 - 6 Oct 2021

Cited by 21 | Viewed by 4398

Abstract

The accurate estimation of flood risk depends on, among other factors, a correct delineation of the floodable area and its associated hydrodynamic parameters. This characterization becomes fundamental in the flood hazard analyses that are carried out in urban areas. To achieve this objective, [...] Read more.

The accurate estimation of flood risk depends on, among other factors, a correct delineation of the floodable area and its associated hydrodynamic parameters. This characterization becomes fundamental in the flood hazard analyses that are carried out in urban areas. To achieve this objective, it is necessary to have a correct characterization of the topography, both inside the riverbed (bathymetry) and outside it. Outside the riverbed, the LiDAR data led to an important improvement, but not so inside the riverbed. To overcome these deficiencies, different models with simplified bathymetry or modified inflow hydrographs were used. Here, we present a model that is based upon the calibration of the Manning’s n value inside the riverbed. The use of abnormally low Manning’s n values made it possible to reproduce both the extent of the flooded area and the flow depth value within it (outside the riverbed) in an acceptable manner. The reduction in the average error in the flow depth value from 50–75 cm (models without bathymetry and “natural” Manning’s n values) to only about 10 cm (models without bathymetry and “calibrated” Manning’s n values), was propagated towards a reduction in the estimation of direct flood damage, which fell from 25–30% to about 5%. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

16 pages, 6391 KiB

Open AccessArticle

The Effect of the Wenchuan and Lushan Earthquakes on the Size Distribution of Earthquakes along the Longmenshan Fault

by Chun Hui, Changxiu Cheng, Shi Shen, Peichao Gao, Jin Chen, Jing Yang and Min Zhao

Appl. Sci. 2021, 11(18), 8534; https://doi.org/10.3390/app11188534 - 14 Sep 2021

Cited by 2 | Viewed by 2590

Abstract

Changes in the stress state of faults and their surroundings is a highly plausible mechanism explaining earthquake interaction. These stress changes can impact the seismicity rate and the size distribution of earthquakes. However, the effect of large earthquakes on the earthquake size distribution [...] Read more.

Changes in the stress state of faults and their surroundings is a highly plausible mechanism explaining earthquake interaction. These stress changes can impact the seismicity rate and the size distribution of earthquakes. However, the effect of large earthquakes on the earthquake size distribution along the Longmenshan fault has not been quantified. We evaluated the levels of the b value for the stable state before and after the large earthquakes on 12 May 2008 (Wenchuan, M_S 8.0) and 20 April 2013 (Lushan, M_S 7.0) along the Longmenshan fault. We found that after the mainshocks, the size distribution of the subsequent earthquakes shifted toward relatively larger events in the Wenchuan aftershock zone (b value decreased from 1.21 to 0.84), and generally remained invariable in the Lushan aftershock zone (b value remained at 0.76). The time required for the b value to return to stable states after both mainshocks was entirely consistent with the time needed by the aftershock depth images to stop visibly changing. The result of the temporal variation of b values shows decreasing trends for the b value before both large earthquakes. Our results are available for assessing the potential seismic risk of the Longmenshan fault as a reference. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

17 pages, 9299 KiB

Open AccessArticle

A Case Study of a Large Unstable Mass Stabilization: “El Portalet” Pass at the Central Spanish Pyrenees

by Guillermo Cobos, Miguel Ángel Eguibar, Francisco Javier Torrijo and Julio Garzón-Roca

Appl. Sci. 2021, 11(16), 7176; https://doi.org/10.3390/app11167176 - 4 Aug 2021

Cited by 1 | Viewed by 2260

Abstract

This case study presents the engineering approach conducted for stabilizing a landslide that occurred at “El Portalet” Pass in the Central Spanish Pyrenees activated due to the construction of a parking lot. Unlike common slope stabilization cases, measures projected here were aimed at [...] Read more.

This case study presents the engineering approach conducted for stabilizing a landslide that occurred at “El Portalet” Pass in the Central Spanish Pyrenees activated due to the construction of a parking lot. Unlike common slope stabilization cases, measures projected here were aimed at slowing and controlling the landslide, and not completely stopping the movement. This decision was taken due to the slow movement of the landslide and the large unstable mass involved. The degree of success of the stabilization measures was assessed by stability analyses and data obtained from different geotechnical investigations and satellite survey techniques such as GB-SAR and DinSAR conducted by different authors in the area under study. The water table was found to be a critical factor in the landslide’s stability, and the tendency of the unstable slope for null movement (total stability) was related to the water table lowering process, which needs more than 10 years to occur due to regional and climatic issues. Results showed a good performance of the stabilization measures to control the landslide, demonstrating the effectiveness of the approach followed, and which became an example of a good response to the classical engineering duality cost–safety. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

19 pages, 4934 KiB

Open AccessArticle

Site Response Evaluation in the Trans-Mexican Volcanic Belt Based on HVSR from Ambient Noise and Regional Seismicity

by L. Francisco Pérez-Moreno, Quetzalcoatl Rodríguez-Pérez, F. Ramón Zúñiga, Jaime Horta-Rangel, M. de la Luz Pérez-Rea and Miguel A. Pérez-Lara

Appl. Sci. 2021, 11(13), 6126; https://doi.org/10.3390/app11136126 - 30 Jun 2021

Viewed by 2903

Abstract

The Trans-Mexican Volcanic Belt (TMVB), located in central Mexico, is an area for which low to moderate seismic risk is considered. This is based on the limited instrumental data available, even though large historical earthquakes have damaged some urban centers in the past. [...] Read more.

The Trans-Mexican Volcanic Belt (TMVB), located in central Mexico, is an area for which low to moderate seismic risk is considered. This is based on the limited instrumental data available, even though large historical earthquakes have damaged some urban centers in the past. However, site effects is an aspect that must be considered in estimating risk, because there are some instances of important amplifications that have been documented with serious effects. In this work, ambient noise and earthquake records from 90 seismic permanent and temporary stations are used to analyze site response in the TMVB. The results obtained show a heterogeneous range in the value of the fundamental frequency. When possible, a comparison was made of the results obtained from ambient noise and earthquake records. In almost all these comparisons, no significant differences were observed in terms of the fundamental frequency. However, there were some stations with a flat average HVSR ambient noise curve that contradicted earthquake data results, which showed peaks at some frequencies. Our results are a first step towards categorizing the different site responses in the TMVB but in order to provide finer details, it is necessary to improve the actual monitoring conditions. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

20 pages, 13098 KiB

Open AccessArticle

Detecting Areas Vulnerable to Flooding Using Hydrological-Topographic Factors and Logistic Regression

by Jae-Yeong Lee and Ji-Sung Kim

Appl. Sci. 2021, 11(12), 5652; https://doi.org/10.3390/app11125652 - 18 Jun 2021

Cited by 16 | Viewed by 4147

Abstract

As a result of rapid urbanization and population movement, flooding in urban areas has become one of the most common types of natural disaster, causing huge losses of both life and property. To mitigate and prevent the damage caused by the recent increase [...] Read more.

As a result of rapid urbanization and population movement, flooding in urban areas has become one of the most common types of natural disaster, causing huge losses of both life and property. To mitigate and prevent the damage caused by the recent increase in floods, a number of measures are required, such as installing flood prevention facilities, or specially managing areas vulnerable to flooding. In this study, we presented a technique for determining areas susceptible to flooding using hydrological-topographic characteristics for the purpose of managing flood vulnerable areas. To begin, we collected digital topographic maps and stormwater drainage system data regarding the study area. Using the collected data, surface, locational, and resistant factors were analyzed. In addition, the maximum 1-h rainfall data were collected as an inducing factor and assigned to all grids through spatial interpolation. Next, a logistic regression analysis was performed by inputting hydrological-topographic factors and historical inundation trace maps for each grid as independent and dependent variables, respectively, through which a model for calculating the flood vulnerability of the study area was established. The performance of the model was evaluated by analyzing the receiver operating characteristics (ROC) curve of flood vulnerability and inundation trace maps, and it was found to be improved when the rainfall that changes according to flood events was also considered. The method presented in this study can be used not only to reasonably and efficiently select target sites for flood prevention facilities, but also to pre-detect areas vulnerable to flooding by using real-time rainfall forecasting. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

18 pages, 26420 KiB

Open AccessArticle

A Novel Decomposition-Ensemble Learning Model Based on Ensemble Empirical Mode Decomposition and Recurrent Neural Network for Landslide Displacement Prediction

by Xiaoxu Niu, Junwei Ma, Yankun Wang, Junrong Zhang, Hongjie Chen and Huiming Tang

Appl. Sci. 2021, 11(10), 4684; https://doi.org/10.3390/app11104684 - 20 May 2021

Cited by 45 | Viewed by 3914

Abstract

As vital comments on landslide early warning systems, accurate and reliable displacement prediction is essential and of significant importance for landslide mitigation. However, obtaining the desired prediction accuracy remains highly difficult and challenging due to the complex nonlinear characteristics of landslide monitoring data. [...] Read more.

As vital comments on landslide early warning systems, accurate and reliable displacement prediction is essential and of significant importance for landslide mitigation. However, obtaining the desired prediction accuracy remains highly difficult and challenging due to the complex nonlinear characteristics of landslide monitoring data. Based on the principle of “decomposition and ensemble”, a three-step decomposition-ensemble learning model integrating ensemble empirical mode decomposition (EEMD) and a recurrent neural network (RNN) was proposed for landslide displacement prediction. EEMD and kurtosis criteria were first applied for data decomposition and construction of trend and periodic components. Second, a polynomial regression model and RNN with maximal information coefficient (MIC)-based input variable selection were implemented for individual prediction of trend and periodic components independently. Finally, the predictions of trend and periodic components were aggregated into a final ensemble prediction. The experimental results from the Muyubao landslide demonstrate that the proposed EEMD-RNN decomposition-ensemble learning model is capable of increasing prediction accuracy and outperforms the traditional decomposition-ensemble learning models (including EEMD-support vector machine, and EEMD-extreme learning machine). Moreover, compared with standard RNN, the gated recurrent unit (GRU)-and long short-term memory (LSTM)-based models perform better in predicting accuracy. The EEMD-RNN decomposition-ensemble learning model is promising for landslide displacement prediction. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

19 pages, 4008 KiB

Open AccessArticle

Stabilization Methodology in Foundation Soils by ERT-3D Application in Estepona, South Spain

by Alfonso Gutiérrez-Martín, José I. Yenes, Marta Fernández-Hernández and Ricardo Castedo

Appl. Sci. 2021, 11(10), 4455; https://doi.org/10.3390/app11104455 - 13 May 2021

Cited by 5 | Viewed by 2361

Abstract

The paper proposes a novel methodology for the stabilization of shallow foundations, with a simplified model combined with 3D electrical resistivity tomography (ERT-3D and consolidation injections. To determine its usefulness, the method has been applied in a case located in Estepona (southern Spain). [...] Read more.

The paper proposes a novel methodology for the stabilization of shallow foundations, with a simplified model combined with 3D electrical resistivity tomography (ERT-3D and consolidation injections. To determine its usefulness, the method has been applied in a case located in Estepona (southern Spain). The chosen tomography model is the dipole–dipole configuration, with an optimized distance between electrodes of 0.80 m for a better visualization of the foundation subsoil; with this parameterization, a total of 72 electrodes were installed in the analyzed case. In this work, the depth of the anomaly in the building’s supporting subsoil was detected ranging from 2.00 m to 3.90 m deep. The study also delineates areas of high resistivity variations (50–1000 Ω m) in the middle and eastern end of the field. These data have been validated and corroborated with a field campaign. The results of the ERT-3D monitoring are presented, once the investment data has been processed with the RES3DINV software, from the beginning to the end of the stabilization intervention. The novelty occurs with the interaction between the tomography and the foundation consolidation injections, until the final stabilization. This is a very useful methodology in case of emergency consolidation, where there is a need to minimize damage to the building. Thus, people using this combined system will be able to practically solve the initial anomalies of the subsoil that caused the damages, in a non-invasive way, considerably lowering the value of the resistivities. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

23 pages, 4709 KiB

Open AccessFeature PaperArticle

Marine Gas Hydrate Geohazard Assessment on the European Continental Margins. The Impact of Critical Knowledge Gaps

by Ricardo León, Miguel Llorente and Carmen Julia Giménez-Moreno

Appl. Sci. 2021, 11(6), 2865; https://doi.org/10.3390/app11062865 - 23 Mar 2021

Cited by 5 | Viewed by 3301

Abstract

This paper presents a geohazard assessment along the European continental margins and adjacent areas. This assessment is understood in the framework of the seafloor’s susceptibility to (i.e., likelihood of) being affected by the presence of hydrate deposits and the subsequent hazardous dissociation processes [...] Read more.

This paper presents a geohazard assessment along the European continental margins and adjacent areas. This assessment is understood in the framework of the seafloor’s susceptibility to (i.e., likelihood of) being affected by the presence of hydrate deposits and the subsequent hazardous dissociation processes (liquefaction, explosion, collapse, crater-like depressions or submarine landslides). Geological and geophysical evidence and indicators of marine gas hydrates in the theoretical gas hydrate stability zone (GHSZ) were taken into account as the main factors controlling the susceptibility calculation. Svalbald, the Barents Sea, the mid-Norwegian margin-northwest British Islands, the Gulf of Cádiz, the eastern Mediterranean and the Black Sea have the highest susceptibility. Seafloor areas outside the theoretical GHSZ were excluded from this geohazard assessment. The uncertainty analysis of the susceptibility inference shows extensive seafloor areas with no data and a very low density of data that are defined as critical knowledge gaps. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

19 pages, 3662 KiB

Open AccessArticle

Debris Flow Characteristics in Flume Experiments Considering Berm Installation

by Hyungjoon Chang, Kukhyun Ryou and Hojin Lee

Appl. Sci. 2021, 11(5), 2336; https://doi.org/10.3390/app11052336 - 6 Mar 2021

Cited by 4 | Viewed by 3149

Abstract

This study was conducted to identify the characteristics and mobility of debris flows and analyze the performance of a berm as a debris flow mitigation measure. The debris flow velocity, flow depth, Froude number, flow resistance coefficients, and mobility ratio were accordingly determined [...] Read more.

This study was conducted to identify the characteristics and mobility of debris flows and analyze the performance of a berm as a debris flow mitigation measure. The debris flow velocity, flow depth, Froude number, flow resistance coefficients, and mobility ratio were accordingly determined using the results of flume tests. To analyze the influence of the berm, the results for a straight channel test without a berm were compared with those for a single-berm channel test. The debris flow velocity was observed to increase with increasing channel slope and decreasing volumetric concentration of sediment, whereas the mobility ratio was observed to increase with increasing channel slope and volumetric concentration of sediment. In addition, it was confirmed that the installation of a berm significantly decreased the debris flow velocity and mobility ratio. This indicates that a berm is an effective method for reducing damage to areas downstream of a debris flow by decreasing its potential mobility. By identifying the effects of berms on debris flow characteristics according to the channel slope and volumetric concentration of sediment, this study supports the development of berms to serve as debris flow damage mitigation measures. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

Review

Jump to: Research, Other

28 pages, 1291 KiB

Open AccessReview

Recent Advancement in Assessment and Control of Structures under Multi-Hazard

by Matin Jami, Rajesh Rupakhety, Said Elias, Bjarni Bessason and Jonas Th. Snæbjörnsson

Appl. Sci. 2022, 12(10), 5118; https://doi.org/10.3390/app12105118 - 19 May 2022

Cited by 8 | Viewed by 3371

Abstract

This review presents an up-to-date account of research in multi-hazard assessment and vibration control of engineering structures. A general discussion of the importance of multi-hazard consideration in structural engineering, as well as recent advances in this area, is presented as a background. In [...] Read more.

This review presents an up-to-date account of research in multi-hazard assessment and vibration control of engineering structures. A general discussion of the importance of multi-hazard consideration in structural engineering, as well as recent advances in this area, is presented as a background. In terms of performance assessment and vibration control, various hazards are considered with an emphasis on seismic and wind loads. Although multi-hazard problems in civil engineering structures are generally discussed to some extent, the emphasis is placed on buildings, bridges, and wind turbine towers. The scientific literature in this area is vast with rapidly growing innovations. The literature is, therefore, classified by the structure type, and then, subsequently, by the hazard. Main contributions and conclusions from the reported studies are presented in summarized tables intended to provide readers with a quick reference and convenient navigation to related publications for further research. Finally, a summary of the literature review is provided with some insights on knowledge gaps and research needs. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

Other

Jump to: Research, Review

22 pages, 23198 KiB

Open AccessTechnical Note

Debris Flow Classification and Risk Assessment Based on Combination Weighting Method and Cluster Analysis: A Case Study of Debris Flow Clusters in Longmenshan Town, Pengzhou, China

by Yuanzheng Li, Junhui Shen, Meng Huang and Zhanghai Peng

Appl. Sci. 2023, 13(13), 7551; https://doi.org/10.3390/app13137551 - 26 Jun 2023

Cited by 7 | Viewed by 1916

Abstract

Debris flows can damage infrastructure and threaten human life and property safety, especially in tourist attractions. Therefore, it is crucial to classify and evaluate the risk of debris flows. This article takes 14 debris flows in Longmenshan Town, Pengzhou, Sichuan, China, as the [...] Read more.

Debris flows can damage infrastructure and threaten human life and property safety, especially in tourist attractions. Therefore, it is crucial to classify and evaluate the risk of debris flows. This article takes 14 debris flows in Longmenshan Town, Pengzhou, Sichuan, China, as the research object. Based on on-site geological surveys, combined with drone images and multiple remote sensing images, the essential characteristics of each debris flow are comprehensively determined. A total of nine factors are used as the primary indicators affecting the risk of debris flow: drainage density, roundness, the average gradient of the main channel, maximum elevation difference, bending coefficient of the main channel, the loose-material supply length ratio, vegetation area ratio, population density, and loose-material volume of unit area. The subjective weights of each indicator are obtained using the Analytic Hierarchy Process, while the objective weights are obtained using the CRITIC method. Based on this, the distance function is introduced to couple the subjective and objective weights, determine each indicator’s combined weights, and obtain the integrated evaluation score values of different debris flow hazards. Considering the integrated evaluation score of debris flow, cluster analysis was used to classify 14 debris flows and cluster effectiveness indicators were introduced to determine the effectiveness of debris flow classification. A quantitative standard for the risk of debris flow within the study area was proposed, and finally, a risk assessment of debris flow in the study area was made. Comparing the results of this paper with the gray correlation method, the coupled synergistic method, and the geological field survey results, proves that the proposed method is feasible and provides a reasonable scientific basis for the study of the hazard assessment of regional debris flow clusters and other related issues within the scope of the Jianjiang River basin and other areas. Full article

(This article belongs to the Special Issue Geohazards: Risk Assessment, Mitigation and Prevention)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Geohazards: Risk Assessment, Mitigation and Prevention

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (31 papers)

Research

Review

Other

Further Information

Guidelines

MDPI Initiatives

Follow MDPI