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 theInternational 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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