“Studying landslides not only helps us to mitigate hazards on Earth, but also helps reconstruct the present and past environmental conditions on planets and moons”
Research focus: mountain geomorphology on Earth and beyond
Profile: Tjalling de Haas is a geomorphologist dedicated to understanding and explaining surface processes on Earth and beyond, with a particular focus on fast-moving landslides such as debris flows. He leads an interdisciplinary research program that examines surface processes on Earth, Mars, and other planets and comets. His work combines two unique research lines that use analogue experiments, fieldwork, modelling, and remote sensing:
- Understanding the dynamics, erosion processes, and morphology of debris flows and their hazardous impact;
- Deciphering the formative processes of extra-terrestrial landslides to reconstruct past environmental conditions and availability of volatiles (e.g., H2O).
Recognition: For this research he has received multiple prizes, such as EGU’s Arne Richter Award and NWO’s Vening Meineszprijs. In addition, he has been awarded several prestigious personal grants: NWO-Rubicon (2016), NWO-Veni (2018), NWO-Vidi (2025).
Experimental setups: Tjalling and his team have developed multiple novel experimental setups to simulate landslides and their impact on Earth as well as under extraterrestrial conditions, such as under low-gravity and thin atmospheres. Here some highlights:
The debris-flow flume in the Earth Simulations Lab at Utrecht University, used for experiments on flow dynamics, bed erosion, bank erosion, and effects of vegetation on hazard impact reduction: www.uu.nl/debrisflowflume.
A rotating drum for studying landslide dynamics and mobility under micro- and hypergravity during parabolic flights. See these clips from NTR Wetenschap for an impression:
https://www.youtube.com/shorts/ZjVqPT2bwvs
- A flume to simulate landslides driven by sublimating volatiles (e.g., CO2, H2O) under thin atmospheres of planets and moon, performed in large vacuum chambers at the Open University in the UK and Aarhus University in Denmark. See these clip for some examples:
Field sites: Tjalling has studied landslides and debris flows on many locations on Earth, including Svalbard, the Atacama Desert, Owens Valley (USA), Death Valley (USA), and the European Alps. His current fieldwork predominantly focusses on the Illgraben (CH), the most active debris-flow torrent in Europe, typically experiencing 5-10 debris flows per year. See the clips below for more details on the drone measurements performed at the Illgraben.