Significance of the spatial resolution of DEM in regional slope stability analysis Enguri Dam, Republic of Georgia

Document Type

Book Chapter

Publication Date

1-7-2021

Department

Department of Geological and Mining Engineering and Sciences

Abstract

Landslides are the most common natural hazard in mountainous terrains and have a high potential to disrupt human activities and damage infrastructure when they occur in populated areas. The study area encompasses a portion of the Enguri Hydroelectric Dam (and reservoir), along with the steep, clay-rich slopes directly to the east of the reservoir. A large landslide in this area would have far-reaching negative consequences, as the Enguri Hydroelectric facility provides 50% of domestic energy production and serves as an anchor for socio-economic stability in the region. In order to reduce the risks associated with these slope failures, it is essential to improve our ability to forecast future landslides and determine which slope areas should be targeted for mitigation practices. This study will view the significance of input Digital Elevation Model (DEM) spatial resolution (30 m vs. 12 m) within a physics-based numerical model for regional slope stability analysis. Unlike the previous researches that have viewed the significance of input DEM spatial resolution within statistical slope stability models, we found that there is considerable improvement in the quality of output landslide susceptibility maps when utilizing DEMs with a higher spatial resolution. At 12 m spatial resolution, there is more distinct delineation of the reservoir boundary adjacent to the base of the hazardous slope. More importantly, the trials utilizing the 12 m DEM accounted for 0.22 km2 of the new slope area that is considered “unstable” (FS < 1.25). These important details were completely missed at a spatial resolution of 30 m. The findings from this study highlight the advantages of utilizing high spatial resolution DEMs when using a physics-based numerical model for a regional slope stability analysis. Landslide susceptibility maps with higher spatial resolution reveal important slope details that could drastically improve the efficiency of landslide mitigation practices, and aid in the forecasting of potentially catastrophic slope failures.

Publisher's Statement

© Springer Nature B.V. 2021. Publisher’s version of record: https://doi.org/10.1007/978-94-024-2046-3_15

Publication Title

NATO Science for Peace and Security Series C: Environmental Security

ISBN

978-94-024-2045-6

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