Influence of Earthquakes on Landslide Susceptibility in a Seismic Prone Catchment in Central Asia

Abstract

Central Asia is one of the most challenged places, prone to suffering from various natural hazards, where seismically triggered landslides have caused severe secondary losses. Research on this problem is especially important in the cross-border Mailuu-Suu catchment in Kyrgyzstan, since it is burdened by radioactive legacy sites and frequently affected by earthquakes and landslides. To identify the landslide-prone areas and to quantify the volume of landslide (VOL), Scoops3D was selected to evaluate the slope stability throughout a digital landscape in the Mailuu-Suu catchment. By performing the limit equilibrium analysis, both of landslide susceptibility index (LSI) and VOL were estimated under five earthquake scenarios. The results show that the upstream areas were more seismically vulnerable than the downstream areas. The susceptibility level rose significantly with the increase in earthquake strength, whereas the VOL was significantly higher under the extreme earthquake scenario than under the other four scenarios. After splitting the environmental variables into sub-classes, the spatial variations of LSI and VOL became more clear: the LSI reduced with the increase in elevation, slope, annual precipitation, and distances to faults, roads, and streams, whereas the highest VOL was observed in the areas with moderate elevations, high precipitation, grasslands, and mosaic vegetation. The relative importance analysis indicated that the explanatory power reduced with the increase in earthquake level and it was significant higher for LSI than for VOL. Among nine environmental variables, the distance to faults, annual precipitation, slope, and elevation were identified as important triggers of landslides. By a simultaneous assessment of both LSI and VOL and the identification of important triggers, the proposed modelling approaches can support local decision-makers and householders to identify landslide-prone areas, further design proper landslide hazard and risk management plans and, consequently, contribute to the resolution of transboundary pollution conflicts.

Inclusion of Nature-Based Solution in the Evaluation of Slope Stability in Large Areas

“…In this study, the volume of soil removed by landslides was not predicted. The description of this phenomenon can be found in [8,47,53] and possible methods of its evaluation are described in [54,55].…”

“…The evaluation methods were intensively developed in the past decades. Nowadays, as mentioned in [2] and similarly in [3], they are usually divided into several classes: (1) qualitative methods that are based on expert experience, (2) semi-quantitative methods that are supplemented with scores/weights assigned to particularly assessed landslide susceptibility triggering aspects and (3) quantitative methods that can be further divided into geotechnical methods (physically based slope stability evaluation) [4][5][6][7][8], statistical analysis [2,9], neural network methods [10,11] or neuro-fuzzy logic methods [12,13].…”

Drone-based investigations of uranium mining legacies: an airborne gamma spectrometry method to support, inspect, and monitor mine closure processes

“…The ULS are mainly located in mountainous regions (Figure 1). Due to geo-risks such as landslides, which can be triggered by seismic or heavy rainfall events, there is a permanent risk of displacement of radioactive and toxic material from the waste dumps and tailings (Li et al 2021a). A particular hazard in the Ferghana Valley is the risk of radioactively contaminated material entering from the ULS located in Charkasar, Yangiabad, Shekafter, Mailuu Suu and Min-Kush.…”

Instability Induced by Random Background Noise in a Delay Model of Landslide Dynamics

“…Landslides induced by external dynamical effects are common natural phenomena: there are many contemporary examples of massive landslides triggered by earthquakes [1][2][3], volcanic activity [4], or artificial vibrations [5,6]. The mechanism of the dynamically triggered events is obvious: if the impact is strong, then the intensity of the vibrations themselves is causing the soil failure.…”