Legacy of Pre-Phase Landslides: Impact on Post-Seismic Landslide Susceptibility
Oct 24, 2023
A new study delves into the long-lasting effects of pre-phase landslides on future landslide occurrences and evaluates the susceptibility of regions prone to seismic events. The study was conducted by a research team from the Aerospace Information Research Institute (AIR), Chinese Academy of Sciences, with the research results published in the International Journal of Digital Earth on Oct. 18, aiming to establish a robust post-seismic landslide susceptibility model and unravel the spatio-temporal dynamics of landslide vulnerability.
With a focus on the magnitude-7.0 earthquake-stricken Jiuzhaigou World Heritage Site in southwest China’s Sichuan Province, the study adopts an integrated space-to-ground monitoring technology to build a multi-temporal post-seismic landslide dataset. This dataset serves as a fundamental component for assessing the post-seismic landslide susceptibility.
The research employs the buffer analysis method to document the spatio-temporal characteristics of post-seismic landslides. By doing so, the study gains insights into how the location and timing of landslides are influenced by previous seismic events.
Distance emerges as a pivotal factor in quantifying the legacy effect of pre-phase landslides on future landslide occurrences. Using this information, an improved time-variant model is formulated to evaluate post-seismic landslide susceptibility accurately.
The research findings reveal that post-seismic landslides tend to gradually occur in closer proximity to pre-phase landslide locations over time. The distance from the initial landslides emerges as a critical indicator, significantly enhancing the precision of post-seismic landslide susceptibility models. Notably, the correlation between landslide susceptibility and seismic activity weakens after a significant seismic event.
In light of these findings, the study suggests that post-seismic landslide prevention efforts should prioritize addressing pre-phase landslide expansion triggered by rainfall. Timely removal of landslide deposits and effective management of debris flows are crucial for averting secondary geological disasters in earthquake-affected regions.
This research underscores the importance of understanding the enduring impact of pre-phase landslides on future landslide susceptibility, therefore contributing to more effective disaster management and mitigation strategies in seismically active regions.
Contact: luyq@aircas.ac.cn
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