Personal profile:

Profile photo of  Dr. Jens Turowski

Dr. Jens Turowski

Section 5.1: Geomorphology

Helmholtz Centre Potsdam
GFZ German Research Centre for Geosciences

Telegrafenberg
Building F, room 428
14473 Potsdam
Phone: +49 331 288-28762
e-mail: jens.turowski(at)gfz-potsdam.de

Publications

About the person

Function and Responsibilities:

Senior research scientist.
Member of the committee for the organisation of the department seminar.
Coordinator of the physical laboratories of Section 5.1 Geomorphology.
Organisor of Section 5.1 Student Lunch.

Research Interests:

My scientific field is geomorphology, the study of landscapes, their evolution, and of the processes shaping them. My interest in general is in the interaction between climate, tectonics, and Earth surface processes. My research centers on furthering the understanding of the physical processes that shape the Earth’s surface by detailed observations, theoretical work, and analogue or numerical modelling. In my work, I collect field data with state-of-the-art instrumentation, and analyze and interpret it with statistical and theoretical methods.

In the past, my research has focused on fluvial geomorphology of mountain streams, with a particular focus on bedrock channels and step-pool systems. In addition, I am interested in the design and testing of new field instrumentation, in channel-hillslope coupling, and in the sediment cascade.

Some of my research themes are listed below. Each topic links to a recent and/or representative paper (so far as I have published on the topic).

Bedload transport

Bedrock channel dynamics

Mountain channel processes

Organic matter in stream systems

The society and the geomorphology of mountain regions

Field techniques in geomorphology

Field areas

Nepal

The April 2015 Gorkha earthquake in Nepal offers a unique opportunity to study the transient response of a landscape to a major tectonic disturbance. After large earthquakes one can observe changes in the hydrology, in the stream water chemistry, in the frequency in gravitational mass movements, and in the velocity of seismic waves traveling in shallow depths that can last for months to years after the event. All these effects can potentially be explained by the opening of cracks in the shallow subsurface, which destabilize hillslopes and provide new pathways for water and reaction surface for weathering processes. So far, observations of the transient effects of earthquakes on the landscapes were largely circumstantial, done with observations that were not optimized for the task. Shortly after the earthquake, we instrumented a small area in the Bhotekoshi catchment upstream of Barabise with seismometers, weather stations, and hydrological observatories to record all of the transient landscape effects of the earthquake in the same location with a dedicated instrument network. The project is embedded in a larger effort with European partners.

Taiwan

Taiwan provides an excellent natural laboratory for the study of Earth surface processes, and there are several reasons for this. Firstly, erosion processes happen very quickly, and are consequently easy to study. The sediment discharge from Taiwan to the ocean between 1970 and 1999 added up to 384 Mt/yr, which accounts for 1.9% of the world-wide total. This compares to a fraction of only 0.024% of the Earth’s landmass. Secondly, Taiwan provides a suitable infrastructure for access. None of the parts of the islands are too remote to get to, there are hotels and other useful infrastructure. In addition, more than 200 discharge gauging stations are operated by the Water Resources Agency, with data reaching back more than 60 years. Thirdly, there is a wealth of scientific knowledge to build upon. And fourthly, Taiwan’s climatic setting in the tropical pacific typhoon belt gives very variable weather conditions, and extreme events occur at a high frequency. This allows sampling a wide range of event magnitudes in a relatively short time frame.

An important research site in Taiwan is Lushui station in Taroko National Park. Fluvial bedrock erosion and bedrock channel morphology have been investigated there in several studies. In addition, I am involved in a monitoring project at the Daan River, where the 1999 ChiChi earthquake caused a gorge of 1km length to form in less than a decade.

European Alps

The European Alps are the closest major mountain belt, and many opportunities for scientific work arise there. I have been working in various catchments in the Swiss, Austrian, and French Alps, but most of my work was focused on four sites with exceptional data quality.

The Erlenbach is a small catchment in the Swiss pre-Alps near the town of Einsiedeln, hosting several scientific observatories focusing on hydrology, forest ecology, stream dynamics and sediment transport. The data set on bedload transport is probably the most detailed in the world, with high-quality measurements reaching back to 1982. The wealth of background information allows to study a wide range of phenomena on hydraulics, channel dynamics, bedload transport processes, and sediment routing. In addition, the Erlenbach is an important natural laboratory for testing new instruments for monitoring of bedload transport.

The Pitzbach, located near the village of Imst in Austria, hosted a unique system for measuring bedload yields continuously at high temporal resolution. The data set spans two years (1994-1995) at 15 minute intervals, and provides a rare opportunity for detailed statistical analysis of bedload discharge from a partly glaciated catchment.

The Illgraben near the town of Leuk in southern Switzerland is one of the most active debris flow channels in Europe, typically featuring 3-5 events per year. The catchment is equipped with abundant scientific instrumentation and has yielded unique insights into debris flow behavior.

The Gornera, near Zermatt and the Matterhorn, has carved a spectacular gorge into the bedrock. There, regular controlled floods allow detailed studies of the relationship between sediment transport and fluvial bedrock erosion.

Career:

Since 2013: Senior researcher at the GFZ German Centre for Geosciences, Germany

2010-2013: Research Scientist at the Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Switzerland

2007-2010: Post-doctoral researcher at the Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Switzerland

Education:

2007: Thesis: Controls on bedrock channel morphology - Experimental and theoretical investigations and comparison with natural channels

2003-2007: Doctoral thesis at the Department of Earth Sciences, University of Cambridge, UK

1999-2003: Degree studies in Experimental and Theoretical Physics, Peterhouse, University of Cambridge, UK

Projects:

We recently published the sedFlow Modell for bedload transport simulations in mountain streams. sedFlow is a flexible model environment and can be used both for scientific and operational purposes.

Publications:
Heimann et al., 2015, sedFlow - a tool for simulating fractional bedload transport and longitudinal profile evolution in mountain streams, Earth Surface Dynamics 3, 15-34, doi: 10.5194/esurf-3-15-2015
Heimann et al., 2015, Calculation of bedload transport in Swiss mountain streams using the model sedFlow - proof of concept, Earth Surface Dynamics 3, 35-54, doi: 10.5194/esurf-3-35-2015
Junker et al., 2015, Assessing the impact of climate change on brown trout (Salmo trutta fario) recruitment, Hydrobiologia 751, 1-21, doi: 10.1007/s10750-015-2223-3
Rickenmann et al., 2014, Simulation of bedload transport in the Hasliaare River with increased sediment input, River Flow 2014, Schleiss et al. (Eds.), Taylor & Francis Group, London, 2273-2281, ISBN 978-1-138-02674-2, doi: 10.1201/b17133-303

Solid matter budget of a steep mountain stream

The study focuses on the Erlenbach, which in terms of sediment transport is one of best studied catchments in the world. The aim of the project is to obtain a deeper insight into channel-hillslope coupling and solid matter transfer in steep mountain streams. This will have further implications for stream morphology and dynamics, sediment yields and routing of solid matter through the stream system.

Project members: Antonius Golly, Jens Turowski, Niels Hovius

Collaborations: Alexandre Badoux (Swiss Federal Research Institute WSL, Switzerland), Dieter Rickenmann (Swiss Federal Research Institute WSL, Switzerland), Elowyn Yager (University of Idaho, Boise, Idaho, USA)

Systematic seismic characterisation of geomorphic processes

We exploit opportunities offered by prototype-scale experiments and natural laboratories world-wide, accessed through collaborations with local researchers. High quality seismic data are collected in parallel with independent observations of surface processes to constrain the relations between these processes and their seismic records and to create a library of seismic data of well-constrained geomorphological events for benchmarking of future seismological work.

Project members: Michael Dietze, Arnaud Burtin, Jens Turowski, Niels Hovius

Field measurements of sediment-flux-driven bedrock erosion

At the Erlenbach and Gornera sites we try to better understand the relationship between bedload transport and fluvial bedrock erosion by measuring in parallel relevant parameters to high precision.

Project members: Jens Turowski

Collaborations: Alexander Beer (Swiss Federal Research Institute WSL, Switzerland), Jerôme Lavé (Université Nancy, France), James Kirchner (Swiss Federal Institute of Technology, Switzerland)

Coarse particular organic matter export from a steep mountain stream

In the Erlenbach experimental catchment, we have measured the export of coarse particular organic matter (CPOM) over several years. We use the data to study the physical process of woody debris transport, its effects on stream morphology, the relative importance of different size classes (leaves vs. logs), and the importance of CPOM for nutrient export.

Project members: Jens Turowski

Collaborations: Alexandre Badoux (Swiss Federal Research Institute WSL, Switzerland), Christian Rickli (Swiss Federal Research Institute WSL, Switzerland), Kristin Bunte (Colorado State University, Fort Collins, USA), Robert Hilton (University of Durham, UK), Markus Stoffel (University of Berne, Switzerland), Matthias Jochner (University of Berne, Switzerland)

SEDRIVER - Effects of Climate Change on Mountain Streams

The changing climate affects water resources and natural hazards in the mountainous regions of Switzerland. In this project we study how sediment transport and fish environments in alpine streams change over the next 40 years to guide the development of ecologically sound flood risk mitigation.

Project members: Jens Turowski

Collaborations: Florian Heimann (Swiss Federal Research Institute WSL, Switzerland), Alexandre Badoux (Swiss Federal Research Institute WSL, Switzerland), Dieter Rickenmann (Swiss Federal Research Institute WSL, Switzerland), Armin Peter (Swiss Federal Research Institute for Aquatic Research EAWAG, Switzerland), James Kirchner (Swiss Federal Institute of Technology ETH, Switzerland)

Sediment transport measurements with geophone sensors

In the project, we aim to identify the main factors influencing the response of the Swiss plate-type geophone sensor system for bedload monitoring, to determine which aspects of calibration can be generalized for un-calibrated field sites. Further on, the possibility to extract grain size information from the geophone measurements is explored.

Project members: Jens Turowski

Collaborations: Carlos Wyss (Swiss Federal Research Institute WSL, Switzerland), Dieter Rickenmann (Swiss Federal Research Institute WSL, Switzerland), Robert Boes (Swiss Federal Institute of Technology ETH, Switzerland), Volker Weidbrecht (Swiss Federal Institute of Technology ETH, Switzerland)

Research Boards and Committees:

Scientific societies, conferences and workshops
Since 2015: Deputy, Geomorphology Division, European Geosciences Union (EGU)
Since 2005: Session Organiser and chair, EGU General Assembly
2011-2014: Coordinator for workshops for young scientists in the Geomorphology Division at the General Assembly of the European Geosciences Union (EGU)
2013: Organising committee: International workshop of acoustic and seismic monitoring of bedload and mass movements, September 2013, Birmensdorf, Switzerland
2009-2013: Programme Committee, Geomorphology Division, European Geosciences Union (EGU)
2009-2013: Deputy, Geomorphology Division, European Geosciences Union (EGU)

Editorial work
Since 2013: Associate Editor for the journal Earth Surface Dynamics (EGU, Copernicus)
2015: Special Issue: Acoustic and seismic monitoring of bedload and mass movements, Earth Surface Dynamics
2015: Special issue: Morphodynamics of steep mountain channels, Earth Surface Processes and Landforms
2013: Special issue: Process geomorphology and ecosystems: disturbance regimes and interactions, Geomorphology
2012: Special issue: Disturbance regimes at the interface of geomorphology and ecology, Earth Surface Processes and Landforms

Awards:

2017: 2016 Editor's citation for excellence in refereeing, Geophysical Research Letters, American Geophysical Union
2016: Invited State-of-Science article on Field techniques for measuring bedrock erosion in the journal Earth Surface Processes and Landforms
2015: 2014 Editor's citation for excellence in refereeing, Water Resources Research, American Geophysical Union
2011: 2010 Editor's citation for excellence in refereeing, Journal of Geophysical Research (Earth Surface), American Geophysical Union
2010: Keynote / invited review article on semi-alluvial channels for Gravel Bed Rivers 7 (September 2010, Tadoussac, Quebec, Canada)
2003-2007: Peter Scheuer Research Student, Peterhouse, Cambridge, UK
2003-2006: NERC Blue Skies Research Studentship, UK