Impact Of Landslides Research Articles

Исследование многолетних изменений прибрежных территорий Азовского моря на основе данных спутниковой съемки методами классификации изображений ArcGIS Pro

With the advent of new methods for tracking the Earth’s surface, the priority of the data source for environmental monitoring has shifted in favor of remote sensing (RS) data. The processing of remote sensing data of the territory is the possibility of modern tracking and control of hazardous processes. During the study, by comparing satellite images for different years using various methods of the ArcGIS Pro geoinformation environment, an analysis was made of changes in the coastal zone of the Sea of Azov. Three methods for finding changes in the coastal zone associated with dangerous landslide-abrasion processes were evaluated: detection of changes in the coastal zone by replacing the red channel in an earlier image with the red channel of a later image (Composite Bands method); deep Learning method; compute Change method. The study showed the advantage of the Compute Change method on this sample of first data, which made it possible to assess the impact of landslide and abrasion processes on the coastal zone of the Sea of Azov. The results obtained are consistent with the data of field studies of the coastal zone of the Sea of Azov and the data of environmental control of the Krasnodar territory.

Floods, landslides and COVID-19 in the Uttarakhand State, India: Impact of Ongoing Crises on Public Health.

The Uttarakhand State, known for its Himalayan Mountains, is a territory in Northern India that is extremely vulnerable to earthquakes, landslides, and floods. Currently, due to the COVID-19 outbreak, India is facing the dual challenge of containing a pandemic and responding to natural disasters. This situation can have a negative impact on the health and the economic development of the region, leading to a long-lasting humanitarian crisis that can disrupt even more, the already overburdened health service. In addition, it can pose serious threats to the wellbeing of the population as it complicates physical distancing and other COVID-19 prevention measures. It is of utmost importance to analyse the impact of floods, landslides, and COVID-19 pandemic on the health system of the Uttarakhand State, and how these crises interact with each other.

Using dimpled-pipe surface to reduce submarine landslide impact forces on pipelines at different span heights

The interaction between submarine landslides and pipelines has attracted widespread attention. For a pipeline designer, generalizing practical analysis models, obtaining accurate dynamic forces (i.e., the drag force and lift force), and proposing effective pipeline protection measures are prerequisites for ensuring their safe operation. In this paper, a computational fluid dynamics approach is employed to investigate if a golfball-type dimpled pipeline surface reduces impact forces induced by submarine landslides. Considering technology suspension, geomorphology suspension, environmental erosion suspension and acquired suspension, numerical models are generalized to allow prescribing different pipeline span heights, and are impacted by fluidized homogeneous submarine landslides. For the given Reynolds numbers and span heights, golfball-type dimpled pipelines experience a reduced peak drag force than standard circular pipelines. In addition, the pipeline dimple suppresses the lift force variation and greatly reduces the force amplitude. As a result, pipeline damage could be lessened or even avoided. Also, a methodology for predicting the drag reduction of dimple-surfaced pipelines under various conditions is provided, and the two necessary conditions for the periodic vibration of the lift force are proposed. Finally, the full life cycle of vortices shed from the pipeline and the hydrodynamics during landslides impact on pipelines are revealed providing the needed insights to prevent future submarine pipeline failures.

Integration of Vulnerability and Hazard Factors for Landslide Risk Assessment.

Among the numerous natural hazards, landslides are one of the greatest, as they can cause enormous loss of life and property, and affect the natural ecosystem and their services. Landslides are disasters that cause damage to anthropic activities and innumerable loss of human life, globally. The landslide risk assessed by the integration of susceptibility and vulnerability maps has recently become a manner of studying sites prone to landslide events and managing these regions well. Developing countries, where the impact of landslides is frequent, need risk assessment tools that enable them to address these disasters, starting with their prevention, with free spatial data and appropriate models. Our study shows a heuristic risk model by integrating a susceptibility map made by AutoML and a vulnerability one that is made considering ecological vulnerability and socio-economic vulnerability. The input data used in the State of Guerrero (México) approach uses spatial data, such as remote sensing, or official Mexican databases. This aspect makes this work adaptable to other parts of the world because the cost is low, and the frequency adaptation is high. Our results show a great difference between the distribution of vulnerability and susceptibility zones in the study area, and even between the socio-economic and ecological vulnerabilities. For instance, the highest ecological vulnerability is in the mountainous zone in Guerrero, and the highest socio-economic vulnerability values are found around settlements and roads. Therefore, the final risk assessment map is an integrated index that considers susceptibility and vulnerability and would be a good first attempt to challenge landslide disasters.

The analysis of landslide vulnerability level distribution in the Labuhanbatu Utara Regency, North Sumatera Province, Indonesia

Forest degradation can increase the level of disaster risk, particularly landslides. The impact of landslides, especially in Labuhanbatu Utara Regency, North Sumatera Province, socio-economic, physical and environmental losses that are directly perceived by the community in the disaster site. The study objective was to analyze the distribution of landslide vulnerability levels in the Labuhanbatu Utara Regency. The spatial distribution of landslide vulnerability level used spatial modeling with the Storie Index method with four variables, including rainfall, slope, soil type, and land cover type. The spatial distribution of landslide vulnerability level was mostly at a very low – low level with a percentage of 57.6% of the area of Labuhanbatu Utara Regency. Areas that occupied high – very high of landslide vulnerability level with the largest area were in three districts, including Na IX-X, Aek Natas, and Kualuh Selatan. Landslide prone areas are generally located on plantation and agricultural land use and also distribute on steep slopes. Various parties need to reorganize community activities in areas of high – very high landslide vulnerability to reduce disaster risk.

METHODS OF CONSTRUCTION OF FOUNDATIONS ON COMPLEX RELIEF

The article considers the preconditions and presents the results of substantiation and development of rational methods of construction of foundations on a complex relief in the conditions of reconstruction of urban development by the method of its compaction and rationalization. The developed methods are used for the conditions of restoration of architectural monuments and their complexes, as well as in general allow to provide comprehensive protection of adjacent urban areas from adverse factors of construction production. Comprehensive solution of problems of increasing the efficiency of construction processes and ensuring the stability of slopes in the construction of high-rise buildings with a developed underground part, as well as reducing the impact of dangerous landslides on adjacent areas and buildings, reducing noise and vibration on cultural heritage sites and natural complexes , accepted in the article as the main prerequisites for the justification and development of new technologies. Substantiation and development of methods of construction of foundations on difficult relief is performed on the basis of the results of statistical processing of actual data on the level of productivity of drilling equipment on the elements of slopes - top, middle part and foot of the slope.

GIS-Based Three-Dimensional SPH Simulation for the 11 April 2018 Yabakei Landslide at Oita Nakatsu, Japan

Landslides are usually triggered by strong earthquakes, heavy rainfalls, or intensive human activities in common wisdom. However, an unexpected landslide occurred in the Yabakei area, Nakatsu, Oita, Japan, at the pre-dawn hour 3:50 a.m. on 11 April 2018, without any accompanying rainfall and earthquake records during the event. This catastrophic landslide was 200 m in width, 110 m in height, and 60,000 m3 in mass volume, damaging four residential buildings with fatalities of six residents at the landslide toe. Field investigation was conducted immediately to identify geological setting, hydrological condition, and landslide geomorphological characteristics. Key findings speculate that infiltration of groundwater stored in the internal fractures led to the swelling and breaking of illite and askanite in the weathered sediment rocks, resulting in the failure of the Yabakei landslide. To reproduce and explore the dynamic process of this landslide event, based on spatial GIS data, we applied the proposed three-dimensional, Herschel-Bulkley-Papanastasiou rheology model-based smooth particle hydrodynamics (HBP-SPH) method to simulate the landslide dynamic process. Buildings in the landslide area are covered by a set of surfaced cells (SC) to analyze the mass impact on the residential buildings. Results showed good accordance between observation and simulation by the proposed SC-HBP-SPH method. The landslide impact force to the residential buildings could be up to 4224.89 kN, as indicated by the simulation.

Investigation on responses and capacity of offshore pipelines subjected to submarine landslides

Offshore pipelines are the main means for transmitting marine oil and gas resources, and they are usually threatened by various geohazards, typically by submarine landslides. However, systematical analyses and solutions for pipeline capacity to resist submarine landslides have been rarely reported. This paper aims to carry out a series of numerical simulations to investigate the responses and capacity of offshore pipelines subjected to submarine landslides. First, a finite element model is developed and validated, in which the pipeline is modeled using beam elements and pipe-soil interaction is modeled using the axial and lateral soil springs with different force-displacement relationships. To further accurately and efficiently assess pipeline performance under the impact of submarine landslides, equivalent boundary conditions are proposed based on the analytical solution. After validation of the equivalent boundary conditions, a series of parametric studies is performed to investigate the capacity of offshore pipelines under the impact of submarine landslides (i.e., critical impact force). Various ranges of soil properties, pipeline burial depths, diameters, steel grades and landslide widths are included in the parametric study. Then through regression and dimensional analysis, the normalized critical impact force is reasonably formulated using the normalized landslide width, normalized axial and lateral soil resistances. Moreover, scour effect induced by seabed currents on the critical impact force is also investigated. Finally, the design charts are achieved and are directly used to predict the critical impact force and evaluate the pipeline safety under the impact of submarine landslides.

Physical model experiment on the influence of water depth on the underwater pipeline surface impacted by landslide surge

A physical model experiment of flume block landslide was used to study the influence of landslide surge impact on underwater pipeline surface under different water depths. The influence of surge impact pressure on pipelines with different water depths and the impact pressure of surge at different angles of underwater pipelines wall were analyzed. And the relationship between the maximum impact pressure of underwater pipelines and the depth of water was obtained. The results indicated that with the decrease of the water depths, the maximum impact pressure at the wall of the underwater pipeline increases approximately linearly, and the slider is easier to form higher first wave height. The maximum impact pressure of the upper surface of the pipeline wall is greater than that of the lower surface of the pipeline wall under the same working conditions. It is also found that the smaller the depth of water, the larger the maximum pressure and average pressure at the measuring point would be and the greater the pressure fluctuation becomes when slider volume and landslide water inlet angle and speed remain the same.

A review of recent studies on landslide hazard in Latin America

ABSTRACT Over the last few decades, the impact of landslides has increased in Latin America. However, there is a deficiency in the region of diagnostic studies on landslide hazards. This review analyzes the state of the art of studies on landslide hazard occurred in Latin America. A search for articles published from 2000 to 2019 was carried out in Scopus, WoS, SciELO, REDIB, and Redalyc. The search yielded 1,365 publications, which were purged obtaining 283 articles, analyzed through a database organized in four categories: general information, study area, research objectives, and methodology. We identified an increase in the number of publications from the year 2011. Seventy-five percent of the 20 countries in the region published papers on landslides that had occurred in these countries, mainly research focus on susceptibility and characterization, and a reduced number, on hazardousness, inventories, trigger factors and conditioning factors. The results suggest the opportunity to incorporate novel methods, tools, techniques, and inputs into research of landslides in Latin America. This review constitutes an analytical and critical contribution to the study of landslide hazards in the region and indicates the studies that are urgent to enforce its integral management in the region and in other intertropical zones.

Historical dynamics of landslide risk from population and forest-cover changes in the Kivu Rift

Human activity influences both the occurrence and impact of landslides in mountainous environments. Population pressure and the associated land-use changes are assumed to exacerbate landslide risk, yet there is a lack of statistical evidence to support this claim, especially in the Global South where historical records are scarce. In this work, we explore the interactions between population, deforestation and landslide risk in the Kivu Rift in Africa. To do so, we develop a holistic landslide risk model that evaluates 58 years of population and forest-cover trends. We show that the current landslide risk in the eastern Democratic Republic of the Congo (DRC) is twice as high as in neighbouring Rwanda and Burundi. Congolese households, on average, populate more hazardous terrain, probably as a result of conflicts and economic pull factors such as mining. Moreover, the recent large-scale deforestation of primary rainforest in the DRC has considerably exacerbated the landslide risk. Our analysis demonstrates how the legacy of deforestation, conflicts and population dynamics is reflected in the landslide risk in the Kivu Rift. A mapping study covering over 50 years finds that landslide risk is much higher in the Democratic Republic of the Congo, due to more recent deforestation and more people living in more susceptible areas, than in similar landscapes in neighbouring countries.

Characteristics and Dynamic Process Modeling of the Rainfall-Induced Landslide on August 21, 2020 in Hanyuan County, China

On August 21, 2020, a landslide occurred in Zhonghai village of Hanyuan County, Sichuan Province, China. The landslide is triggered by two successive rounds of heavy rainfall. This landslide can be clearly divided into an initial landslide and a main landslide. The main landslide is activated by the intense impact and overloading of the initial landslide. The depth-integrated continuum method is adopted to simulate the dynamic process. Due to the complicated failure process, it is found that there is no proper unified parameters in Coulomb model which could well reproduce the two successive landslides. It implies that the dynamic process of landslides is highly associated with the characteristics of sliding bodies. Here, an implement of variable frictional coefficients for different parts is proposed and the parameters are calibrated. It is demonstrated that results from numerical modeling match well with the field investigation. The complicated landslides in two different stage can both be efficiently revealed by depth-integrated continuum modeling.

A two-layer model for landslide generated impulse wave: Simulation of the 1958 Lituya bay landslide impact wave from generation to long–duration transport

An updated one-dimensional two-layer coupled mathematical model is developed for landslide generated impulse wave (LGIW) from wave formation to long-duration travel. The coupled model is composed of a landslide model in a bed-fitted coordinate system and a shallow-water wave model in a global coordinate system. The coupling is realized through a reconstruction and interpolation algorithm. We successfully reproduced the experimental reproduction of 1958 Lituya LGIW for a total duration of 250 s at prototype scale, and well captured the three runups on the right bank and three runups on the left bank, together with the six wave crests and troughs in the channel. This seems to be the first reproduction of the Lituya LGIW for such a long duration. The predicted free surface elevation and runups are comparable with experimental results though with some deviations. However, the level of reproduction of the Lituya LGIW from wave formation to long-duration traveling achieved by numerical simulation is greatly enhanced as compared with the existing interface-capture models and mesh-free/particle-based models. This proposed one-dimensional two-layer coupled model could provide a unified framework for LGIWs from generation to long-duration propagation.

Diversity and association of arbuscular mycorrhizae fungi (AMF) in landslide-impacted area

The lack of nutrient availability, organic matter, infiltration capacity, water holding capacity, and the increasing soil density are characteristics of a landslide-impacted area. Potential soil microbes such as indigenous Arbuscular Mycorrhizae Fungi (AMF) should be used to rehabilitate the area. Therefore, diversity of AMF and its association with plant roots that colonize the land should be determined. The research location was in a landslide-impacted area of Mount Bawakaraeng, South Sulawesi, Indonesia. Soil and plant root samples were collected from 2 types areas, namely (1) upstream (Lengkese village) and (2) downstream (Spoilbank of Bili-Bili dam). The results found 15 morphotypes of AMF spores including genus Acaulospora, Gigaspora, Scutellospora and Glomus. The spore density of AMF was low, i.e 837 and 1,495 in upstream and downstream areas respectively. Most of the pioneer plants that invaded the area were associated with AMF, indicated by 19.44 – 95.48% colonization level. The low density of spores proves that the impact of landslides has resulted in decreased soil biological properties. Meanwhile, the AMF colonization in pioneer roots indicated the association of mycorrhizal fungi is needed to help plant survival and improve the soil properties. Furthermore, landslide-impacted areas can be restored and used as agriculture areas.

Consideration of submarine landslide induced by 2018 Sulawesi earthquake and tsunami within Palu Bay

ABSTRACT On September 28 2018, an Mw 7.5 strike-slip earthquake occurred to the north of Palu Bay on the Sulawesi Island, Indonesia. This triggered a destructive tsunami within the bay, which reached Palu city. Simulation have been conducted to investigate the landslide source. However, the tsunami should be investigated considering a physical model in the area where detailed bathymetric survey had not been conducted. In this study, we investigated the impact of coastal landslides on the southern part of the bay using a two-layer model. Owing to the increasing collapse volume, the southern west coastal landslide could approximately explain the observations in Palu city. However, the calculated mass volume of the source largely overestimated the bathymetric survey data. Hence, we considered the possibility of submarine landslide in the southern part of the bay and the simulation results could approximately explain the maximum tsunami heights in the southern part of the bay. These results suggest that more detailed multibeam data will be required to investigate the possible submarine landslide in the southern area which could induce a destructive tsunami reaching Palu city within a few minutes after the collapse.

The preliminary inventory of coseismic ground failures related to December 2020 – January 2021 Petrinja earthquake series

The most recent major earthquake series struck near Petrinja (December 29th 2020 M 6.2), and triggered extensive ground failures in the wider area of Petrinja, Sisak and Glina. Coseismic ground failures including subsidence dolines, liquefaction and landslides have been documented over a large area by various experts and teams. These data are stored in the newly created inventory, which is openly presented in this paper. This inventory is administered and updated by the Croatian Geological Survey, and will be available online via a Web Map Service (WMS) (www.hgi-cgs.hr). The aim of the inventory is to not only provide data for the development of susceptibility maps and more detailed exploration for possible remediation measures, but also to define the priorities for immediate action. The earthquake triggered the rapid development of dropout dolines which endanger the local populations of the villages of Mečenčani and Borojevići. This is still an ongoing process in the vicinity of the houses and therefore in-situ exploration started immediately. Liquefaction related to alluvial sediments of the Sava, Kupa and Glina rivers occurred almost exclusively in loose and pure sands, and was accompanied by sand boils, subsidence and lateral spreading. Liquefaction also presents a greater hazard because settlement of houses and river embankments occurred. Lateral spreading caused failures of river flood embankments and natural river banks. According to the data known to date, the majority of the coseismic landslides were reactivated with minor displacements. Despite that, it has been recognised that houses at the edge, or in landslide colluvium suffered greater damage than other houses located outside the landslide impact zone.

Numerical Experiments on Effect of Topographical Slope Changes in the Dynamics of Landslide Generated Water Waves and Submarine Mass Flows

When gravitational mass flows hit water bodies, they create water waves, called tsunami. The slopes of the mountain flanks surrounding a glacial lake or the slopes of the side walls of artificially constructed reservoirs play important roles in the intensity of splash on landslide impact, amplitudes and propagation speeds of the resulting water waves and possible dam breaching or overspilling of water. The proper analyses of such dynamics are useful for the possible mitigation measures. Here, we apply a general two-phase mass flow model to perform several numerical experiments and present geometrically three-dimensional, high-resolution simulation results for rapidly moving two-phase landslide/debris flow down a plane with varying slopes at its different parts, impacting a fluid reservoir. First, the upstream slope is kept constant; later to make it closer to reality, sudden changes in slopes are imposed one after another at different parts of the topography. The results focus on the effects of the sudden slope changes in the formation and propagation of dynamically different solid- and fluid wave-structures in the reservoir. Results show that steeper upper part of the topography produces more highly intensified tsunami that propagates more longitudinally than the steeper lower part. Thus, steeper upper parts need stronger right coast and steeper lower parts demand stronger side walls in mountain reservoirs to withstand the wave impacts. The results may help for the proper modeling of landslide and debris induced mountain tsunamis in rapidly changing slopes, the dynamics of turbidity currents and sediment transports in fluid reservoirs in high mountain slopes.

Topographic stress control on bedrock landslide size

Landslides are a major natural hazard and act as a primary driver of erosion, chemical weathering and organic carbon transfer in mountain ranges. Evaluating the impact of landslides on Earth systems requires knowledge about the controls on their size, which are not well understood. Here we show that topographic stress, resulting from the interaction between tectonic stress and topography, influences bedrock landslide size at landscape scales by modulating the subsurface material strength through fracturing and weathering. Using a three-dimensional topographic stress model, we characterize the spatial pattern of subsurface open-fracture zones in a crystalline-rock terrain of the eastern Tibetan mountains. Then, we compare the predicted open-fracture zones with 982 mapped bedrock landslides. The results show that areas with deeper subsurface open-fracture zones tend to accommodate larger landslides. This is probably due to the influences of topographically induced fractures on the material strength and groundwater flow paths and rates. We conclude that the extent of hillslope failure depends on both distant tectonic forces and local topography, which has implications for hazard mitigation, landscape evolution and the global carbon cycle. Stress from tectonics and topography may be the primary control on the size of bedrock landslides, according to a comparison of a stress model with landslide inventories for a mountainous area in eastern Tibet.

Global connections between El Nino and landslide impacts

El Nino is a critical part of global inter-annual climate variability, and the intensity of El Nino has major implications for rainfall-induced natural hazards in many vulnerable countries. The impact of landslides triggered by rainfall is likely to be modulated by the strength of El Nino, but the nature of this connection and the places where it is most relevant remains unconstrained. Here we combine new satellite rainfall data with a global landslide exposure model to show that El Nino has far-reaching effects on landslide impacts to people and infrastructure. We find that the impact of El Nino on landslide exposure can be greater in parts of Southeast Asia and Latin America than that due to seasonal rainfall variability. These findings improve our understanding of hazard variability around the world and can assist disaster mitigation efforts on seasonal timescales.

Impact-Induced Liquefaction Mechanism of Sandy Silt at Different Saturations

Landslide-induced liquefaction has received extensive attention from scholars in recent years. In the study of loess landslides in the southern Loess Plateau of Jingyang, some scholars have noted the liquefaction of the near-saturated sandy silt layer that is caused by the impact of loess landslides on the erodible terrace. The impact-induced liquefaction triggered by landslides is probably the reason for the long-runout landslides on the near-horizontal terrace. In order to reveal the mechanism of impact-induced liquefaction, this paper investigates the development of pore pressure and the impact-induced liquefaction of sandy silt under the influence of saturation through laboratory experiments, moisture content tests, and vane shear tests. It has been found that both the total pressure and pore water pressure undergo a transient increase and decrease at the moment of impact on the soil, which takes 40–60 ms to complete and only about 20 ms to arrive at the peak. Moreover, silty sand with a saturation of more than 80° was liquefied under the impact, and the liquefaction occurred in the shallow layer of the soil body. The shear strength of the liquefied part of the soil is reduced to 1.7∼2.8 kPa. Soils with lower saturation did not liquefy. The mechanism of the impact-induced liquefaction can be described as follows: under impact, the water in the soil gradually fills the pores of the soil body as the pore size decreases, and when the contact between the soil particles is completely replaced by pore water, the soil body loses its shear strength and reaches a liquefied state. Soils in the liquefied state have a very high permeability coefficient, and the water inside the soil body migrates upward as the particles settle, resulting in high-moisture content in the upper soil.