Geologically complex regions more prone to landslides, study suggests

We know that steep slopes and heavy rain help to trigger landslides, but are some types of landscape more susceptible than others? A study suggests that geologically complex regions are more likely to produce landslides.

Yifan Zhang, from the Institute of Mountain Hazards and Environment in Chengdu, China, and colleagues developed an index of geological complexity that combines four different geological components: lithologic complexity (number of different rock types per unit area); tectonic complexity (density of faults); seismicity (probability of earthquake activity); and structural complexity (how disordered the rock structures are).

Applying their model of geological complexity to an area of the eastern Himalayas in Tibet, they report in the Bulletin of Engineering Geology and the Environment that the regions with the highest geological complexity index produced the most landslides.

Whether the model will still apply in less seismically active regions of Earth remains to be seen, but it provides a fresh approach to reading our landscape and demonstrates that multiple geological factors feed into a region’s predisposition to landslides.

Combine the geological factors with other variables such as climate, human activity and topography, and we might gain a clearer picture of where landslides are most likely to occur, helping to inform planning guidelines, for example.