Cascading and Multi-Geohazard Risk Reduction: From Scour and Erosion To Landslides and Tsunamis

Abstract

I present here some recent advances in understanding and reducing cascading and multi-geohazard risks, ranging from scour and erosion to landslides and tsunamis. Both represent the earth surface mass movements of multi-disciplinary nature that bring about significant consequences on human lives and critical infrastructures. The landslides that trigger tsunamis represent coastal and submarine landslides, river landslides, reservoir landslides, lake landslides, as well as fjord landslides, where the origins range widely from earthquakes to volcanoes, rainfalls, and rising water levels. The crucial role of liquefied gravity flows in large-scale mass movements and their devastating impacts will be highlighted, together with the mitigation strategies. Some recent advances in the mechanics and countermeasures in a broad range of scour and erosion across America, Europe, Asia and Oceania demonstrate the critical importance of integrating hydraulics and geotechnics. Relevant topics include the wave-seabed-structure interaction, liquefaction and scour protection, role of suction dynamics in the earth surface porosity evolution, erosion and morphodynamic stability, and internal erosion with sustainable hydro-geoengineering solutions against high waves, tides, storm surges, seepage flow, earthquakes, overtopping, and rainfalls under changing climate. A global disaster risk reduction platform may facilitate the global promotion of understanding and reducing such cascading multi-geohazard risks for a better, more sustainable world.

Bio

Shinji Sassa is Head of Soil Dynamics Group and Research Director of International Research Center for Coastal Disasters, Port and Airport Research Institute, National Institute of Maritime, Port and Aviation Technology, Japan. His expertise includes Scour and Erosion, Landslides and Tsunamis as Multi-Geohazards. He is the recipient of numerous distinguished awards, including the Prime Minister’s Commendations for Disaster Prevention Merit, Outstanding Research Accomplishment Award, National Land Technology Development Award, and several Editor Awards for leading international journals. His Liquefaction Prediction and Assessment Paper was Top-Read Paper in ASCE Most Read Articles 2017-2021, and his Landslide-induced Tsunami paper is the most cited paper on Landslides and Tsunamis in Journal Landslides. He is currently Principal Coordinator of the International Union of Geological Sciences (IUGS) Task Group on Submarine Geohazards, Acting Executive Director of the International Consortium on Landslides (ICL), Chair of the International Consortium on Landslides (ICL) Network Committee, and Chair of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE) Technical Committee on Scour and Erosion.