Ecogeomorphic analysis of badlands
in sub-humid climates
Vegetation – erosion – weathering interactions
Dr. Eva Nora Müller
Earth and Environmental Sciences, University of Potsdam
visiting Land surface dynamics group, University of Edinburgh
Problem: Sedimentation of Reservoirs
→ Reduced water availability: drinking water supply & irrigation
→ Problems for hydro-power stations
Connectivity of hydrological systems
DFG - SESAM II Project (2010-14)
Bronstert, Güntner, Batalla, de Araujo, Förster, Müller, Francke,
Brosinsky, Werb
Hotspot dynamics of badlands
Study site: Upper Ebro, Spain
Francke, 2009
Study site: Upper Ebro, Spain
Francke, 2009
Distribution of badlands
Geologic map of the Isabena Catchment
Objectives
1) Bridging the gap between short- and medium-term
erosion rates event – 150 years
2) Evolution of humid badlands as a function of
vegetation dynamics ecohydro – ecogeomorphic system‘s approach
3) Assessment of tipping points climatic, land-use, geological
Approach
a) Event-based soil erosion modelling MAHLERAN1
b) Model coupling I: soil-moisture dynamics HydroVeg2
c) Model coupling II: vegetation dynamics EcoHyD3
d) Model coupling III: geomorphic processes PDZ-CAZ4
1 Wainwright
2,3 Tietjen
4 Yoo
et al. 2008
et al. 2009, 2010
and Mudd 2008
The Mahleran Model
Model for Assessing Hillslope to Landscape Runoff, Erosion and Nutrients
Event-based, process-based soil erosion model
Picture by J. Wainwright et al.
Flow chart for Mahleran Model
Spatial resolution: grid with 0.5-2 m cell size
Temporal resolution: 1 sec – 1 min
Flow chart for Mahleran Model
Spatial resolution: grid with 1m cell size
Temporal resolution: 1 sec – 1 min
Flow chart for Mahleran Model
Spatial resolution: grid with 1m cell size
Temporal resolution: 1 sec – 1 min
Flow chart for Mahleran Model
Spatial resolution: grid with 1.5 m cell size
Temporal resolution: 1 sec – 1 min
Badlands in Villacarli valley
Badlands in Villacarli valley
Badlands in Villacarli valley
High-resolution DEM: 1.5 metres (LIDAR data)
Testing data for individual storms
Runoff event on 23.09.2006
0.140
Discharge (m3/s)
0.120
0.100
0.080
0.060
0.040
0.020
0.000
0:00
4:48
9:36
14:24
Time (h:min)
Field campaign by Francke et al., 2008 &
SESAM Project (2004-2008):
• 1-sec rainfall data
• 2-min discharge data
• 10-min sediment data
19:12
0:00
Model coupling II: vegetation dynamics
EcoHyD
HydroVeg*
Mahleran
Peter Biro‘s project work
* Britta Tietjen et al. (2009) WRR 45, W01418
Model coupling II: vegetation dynamics
EcoHyD
Mahleran
HydroVeg*
EcoHyD*
Peter / my current task
*Britta Tietjen et al. (2009) WRR 45, W01418 and (2010) Ecohydrology 3, 226-237
Model coupling III: geomorphic processes
PDZ-CAZ
Yoo and Mudd
*Yoo and Mudd (2008) Toward process-based moeling of geochemical soil
formation across diverse landforms: A new mathematical framework. Geoderma
46(1-2): 248-260
Bridging the gap: event-based versus
medium-term soil erosion
Scenario calculations:
– Water and soil budgets for 100 years
– Seasonal variations
– Dominant processes
Relate to:
Sedimentation cores of Barasona Reservoir
Analysis of old air photos (1950s, 1920s)
Badlands and Land-use
Badlands in 1953
Badlands in 2010
Analysis of vegetation dynamics
Analysis of vegetation dynamics
When do the boundaries become unstable?
Analysis of vegetation dynamics
When do the boundaries become unstable?
Analysis of vegetation dynamics
When do the boundaries become unstable?
Assessment of tipping points
Ecogeomorphological system analysis:
• Alterations in climate increased droughts, storms, temperature
• Alterations in land-use cropping, land abandonment, afforestation
• Geomorphic long-term developments
Bioengineering application
How to stabilise the badlands?
Vegetation!
Endurers:
Builders:
perennial, able to survive on moving substrate,
very low densities, no effects on soil evolution
and sediment deposition
can only be established in fairly stable
substrates, high density that helps sediment
deposition and soil evolution
Studies on plant function traits required
e.g. Guerrero-Campo et al. (2008) Plant traits
enabling survival in Mediterranean badlands in
northeastern Spain suffering from soil erosion. J
Vegetation Science 19: 457-464