Welcome
Welcome to my website! My name is Lisanne Braat, I am a planetary geomorphologist focussing on fluvial and coastal processes on Earth and Mars.
On this website I like to share my research and related activities. I hope to give some insight into the research that I do, and into my life as a scientist. I get to visit great places around the world to present, collaborate and do fieldwork. Besides these great adventures, I spend the majority of my time behind a computer and in the lab.
One of my hobbies is video editing. Therefore, you can find many videos on my website about different topics. You can see two examples on the right. Furhtermore, I sporadically write blog posts about my research highlights!
As a fluvial and coastal geomorphologist I study landscapes and landforms that develop when water flows over the surface and enters the sea. Transport of water moves sediment and creates morphological change. I study these sediment transport processes and how the landscape changes over time. My typical study areas are rivers, estuaries and deltas.
Deltas as a record of ancient hydrological conditions on Mars
Currently, I work as a postdoctoral research fellow at Utrecht University. Here, I study river deltas on Mars. Mars is currently a very cold and dry place, however, early-Mars was a water-rich planet with rivers, lakes, and possibly an ocean. By using numerical hydro-morphological modelling and physical experiments to reconstruct deltas, I aim to learn more about the hydro-morphological processes that shaped the surface of Mars. For example, how long dit it take to form the deltas? how much water was required? and how long was there fluvial activity? Answers to these question help to better determine past climate on Mars, habitability and the potential for life.
Comparing deltas on Earth and Mars
My current work is a continuation of my previous postdoc research at the European Space Agency (ESA) and the California Institute of Technology (Caltech). I spent 3 years at ESA with an internal research fellowship focussing on the effect of gravity on delta morphology. My research showed that Martian deltas grow much quicker than terrestrial deltas and typically carry more suspended sediment, which affects the morphology.
Before ESA, I spent 1 year at Caltech supported by a Rubicon grant from the Dutch Research Coucil (NWO). At Caltech I ammended the sorfware package Delft3D, so far only applied to Earth, to work on Mars and investigated the effect of gravity on sediment transport. My research showed that bigger grains are transported on Mars, more sediment is suspended and the sediment flux is larger when comparing the same river discharge and channel morphology on Earth and Mars.
Morphodynamics and sedimentology of estuaries with sand and mud
I obtained my PhD on the 10th of May 2019 at the Department of Physical Geography (Faculty of Geosciences, Utrecht University, the Netherlands). My PhD topic was the sedimentology and morphodynamics of estuaries with sand and mud and was part of the NWO Vici project "Turning the Tide". The different sediment characteristics of mud and sand have implications for the large-scale shape and dynamics of estuaries. During my PhD I studied these effects. For part of my research I conducted scaled, physical (flume) experiments in the Metronome tidal facility, where we used periodic tilting of the flume to simulate ebb and flood currents. Furthermore, I used fieldwork and numerical modeling (Delft3D) to study the effect of mud supply on the morphodynamics. For a summary of my PhD, you can view the video on the right.
If you have questions about my research or making science movies, do not hesitate to contact me!