Regarding the study of (Singeisen, et al.
, 2024), in regions prone to seismic activity, steep slopes
within fault damage zones are identified as highly vulnerable to coseismic landslides, resulting from a
combination of intense ground motion and weakened rock mass strength. The amplification of seismic
shaking, caused by topographic effects and impedance contrasts, further exacerbates the susceptibility
to landslides. Understanding these factors is crucial for effective risk management, given the widespread
damage to infrastructure and loss of life caused by coseismic landslides, making them one of the most
hazardous secondary effects of earthquakes. In the same way, The Egyptian Red Sea coast, a
mountainous coastal region periodically exposed to landslides causing severe human and economic
losses due to its geological, hydrogeomorphological, and seismological nature, highlights the importance
of assessing contributing parameters such as slopes, elevation, active faults, earthquakes, rainfall, rock
unit characteristics, and lineaments, linear surface features indicating faults or fractures, for
comprehensive risk assessment and mitigation of these natural disasters leading to socio-economic
crises (Rashwan, 2024).
On the other hand, seismic fragility analysis, a fundamental component of landslide hazard risk
assessment, establishes the correlation between the probability of unsatisfactory performance of slopes
and the escalating intensity of ground motions. This analysis is particularly crucial given the significant
damage earthquakes have inflicted on various slope-related engineering structures in recent decades,
including natural slopes, slope retaining structures, subgrade slopes, and embankment slopes, as
evidenced by numerous reports of earthquake-induced slope-related geological disasters resulting in
substantial loss of life and property (Hu, 2024). Therefore, to mitigate the risk of ground movement, one
strategy involves the thorough identification of the characteristics associated with areas prone to
landslides. This approach encompasses conducting comprehensive geophysical analyses across various
study sites to assess the underlying geological conditions. Through such analyses, it has been revealed
that the soil in these areas contains a slipping surface, which significantly increases the susceptibility of
the land to landslides. This slipping surface is believed to have been formed as a result of disparities in
rock types between the surface and deeper layers, highlighting the complex geological dynamics at play.
Understanding these geological intricacies is crucial for effectively assessing and managing landslide risks
in these areas (Zairina, et al., 2024).
In the study of (Wang, et al., 2024), the classification of soil is essential for comprehending how
landslides occur and evolve, particularly regarding the uncertainties surrounding soil strength and its
spatial variability. A study examining the influence of spatial variability in soil strength on landslides
found that acknowledging soil heterogeneity results in a 12% increase in the distance covered by
landslides compared to analyses that assume soil uniformity. This emphasizes the necessity of
considering soil spatial variability in classification to prevent underestimating landslide distances and to
enhance understanding of how landslides occur and develop over time. Likewise, in Greece, given its
complex geological structure and significant tectonic stress, remains highly vulnerable to such
calamitous occurrences. Additionally, it is essential to highlight the pivotal role of numerical simulations
in comprehending the intricate dynamics of natural disasters, especially in assessing how the spatial
variability in soil properties affects the permanent displacement of earth slopes under different
earthquake scenarios. These simulations provide invaluable insights into the intricate interplay between
soil characteristics and seismic forces, elucidating how variations in soil properties impact slope stability
and behavior before and after seismic events (Alamanis, et al., 2023).
Moreover, Soil properties dictate slope failure modes, evident in varied outcomes under rainfall
alone versus rainfall followed by earthquakes. The distribution of water content and pore water
pressure, influenced by soil permeability, plays a crucial role in slope failure mechanisms. Additionally,
soil type significantly impacts peak acceleration during slope failure, with coarse-grained soil exhibiting
higher critical acceleration than fine-grained soil, highlighting the importance of soil properties in slope
stability (Yang, et al.,2023). Similarly, the link between rainfall-induced widespread shallow landslides in
cohesive soils and changes in pore water pressure, aiming to fill knowledge gaps. In-situ slope
experiments were conducted with pre-designed vertical profiles at the slope toe, utilizing sensors to
monitor soil properties during failure. Results indicate that failure initiates where internal material is
constantly removed from the slope, even before reaching maximum static pore water pressure. Stability
persists until pore water pressure near the failure surface reaches the maximum provided by rainfall
(Zeng, et al., 2023).
References
Anisa Zairina, S. S. (2024). Geophysical, geotechnical, and vegetation characteristics in landslide areas in
Pujon and Ngantang, Malang Regency, East Java. Journal of Degraded and Mining Lands
Management.
Bing Yang, J.-r. H.-h.-c. (2023). Influence of different soil properties on the failure behavior of deposit
slope under earthquake after rainfall. Journal of Mountain Science.
Hongqiang Hu, Y. B. (2024). Seismic fragility functions for earthquake-induced landslide risk assessment
using identified optimal earthquake intensity measures. CATENA.
Mohamed Rashwan, L. M. (2024). Landslide susceptibility assessment along the Red Sea Coast in Egypt,
based on multi-criteria spatial analysis and GIS techniques. Scientific African.
Nikolaos Alamanis, a. P. (2023). Impact of Soil Properties’ Spatial Correlation Lengths and Inclination on
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Runqiang Zeng, Z. Z. (2023). Effects of changes in soil properties caused by progressive infiltration of
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