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Development of a Seismically Induced Landslide Susceptibility Scale for Greece for Addressing Data Imbalance

Description: 

The persistent conundrum of data imbalances in landslide susceptibility zonation (LSZ) practices leads us to develop a data driven heuristic scale of LSZ which is used to integrate landslide and seismic hazards for Greece. Three landslide controlling parameters viz. slope angle, slope roughness and friction angle are integrated with one seismic parameter: Peak Ground Acceleration (PGA) to generate the seismically induced LSZ map of Greece. The landslide database is prepared using the USGS ScienceBase-Catalog for Lefkada Earthquake, 2003. As only 274 landslide events are available for this earthquake, there is an accentuating problem of data/inventory imbalance which results in overfitting/underfitting of weights. Application of traditional LSZ models with such limited dataset generally shows exacerbated effects of one landslide controlling parameter and often neglects the impact of others. This might produce an LSZ map which is heavily skewed towards the overfitted controlling parameter. To address this issue, we develop a LSZ scale using Frequency Ratio, Information Value and Fuzzy Cosine Amplitude methods where concurrency of weights for each thematic layer of landslide controlling parameters are established. In the next phase, a scale of 1 to 9 is derived based on the established concurrency, and the consistency of the decision is further checked using a multi-criteria structured technique: Analytical Hierarchy Process (AHP). If the consistency ratio (CR) for each decision is less than 10%, it is accepted, else the process is revised. Once all the weights (now in the range of 1 to 9) are calculated, they are overlaid arithmetically in a GIS environment to produce the final seismically induced LSZ map of Greece. The resultant LSZ map demarcates the study area into five distinct zones of landslide susceptibility with 77% predictive accuracy. The study demonstrates the applicability of the proposed LSZ scale for areas with problems of data/inventory imbalances.

Session: Regional-Scale Hazard, Risk and Loss Assessments [Poster Session]

Type: Poster

Date: 5/3/2024

Presentation Time: 08:00 AM (local time)

Presenting Author: Devjyoti

Student Presenter: No

Invited Presentation: 

Authors