Waterloo Earth Scientist travels to NW China to study fast and deadly loess landslides

Tuesday, November 28, 2017

Working with researchers from Chengdu University of Technology and the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (SKLGP), Professor Stephen Evans of the Department of Earth and Environmental Sciences is studying catastrophic landslides in China.

In October, he carried out field work in the Loess Plateau of Gansu and Ningxia Provinces, captured in these dramatic photographs.

Loess is a wind-blown silt-fine sand that mantles hillslopes and fills deep river valleys in a vast region of northwest China covering 640,000 km2. Once the cradle of Chinese civilization, the region is now known for having some of the world’s highest soil erosion rates.

In addition to soil erosion, loess is particularly susceptible to seismic shaking and its structure collapses during strong earthquakes. In 1920, the region was struck by a powerful earthquake which triggered thousands of loess landslides, many of which dammed rivers to form landslide-dammed lakes. It is estimated that some 235,000 people were killed in the earthquake as a result of the combined effect of building collapse and co-seismic loess landslides.

Evans is the Director of Geological Engineering at the University of Waterloo. He specializes in the behaviour and risk assessment of natural hazards, including landslides, landslide dams, glacial hazards, and tsunamis.