Tjalling is an assistant professor in Natural Hazards and Geomorphology. His research has focused on the full sediment source-to-sink chain, from bedrock weathering, to debris flows, rivers and estuaries on Earth and Mars. Current research by Tjalling focuses on debris-flow entrainment, debris-flow fan evolution through avulsions, and understanding the spatio-temporal evolution of Martian gullies.

His ongoing NWO-VENI project is on unraveling debris-flow entrainment, through a combination of fieldwork in the European Alps (Illgraben, Switzerland and Lattenbach, Austria) and physical modelling in the new Earth Science Simulation laboratory at Utrecht University. Every year debris flows cause many fatalities and damage in mountainous areas, and his work on debris-flow entrainment will lead to more accurate debris-flow volume estimation, which enables better hazard prediction and mitigation. 

The ongoing DFG funded project of Dr. Shiva Pudasaini (University of Bonn, Germany) and Dr. Tjalling de Haas focuses on landslide-tsunami interactions. The project aims to develop tools to predict and mitigate tsunami hazards worldwide, through a combination of physical modelling at Utrecht University and numerical model development (r.Avaflow) at the University of Bonn.

Tjalling is the chair of the Planetary Geomorphology working group of the International Association of Geomorphologist (IAG). He publishes the "Planetary Geomorphology Image of the Month":

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