Importance of Multi-Dimensional Morphodynamics for Habitat Evolution in the Austrian Danube River 1715-1821

University of Natural Resources &
Life Sciences Vienna
Department of Water, Atmosphere & Environment I Institute of Hydrobiology & Aquatic Ecosystem Management I DI Dr. Severin Hohensinner30.07.2013 1
Importance of multi-dimensional
morphodynamics for habitat evolution:
Austrian Danube River 1715 – 1821
Severin Hohensinner & Mathias Jungwirth
World‘s Large Rivers Conference
Vienna, 11th April 2011
Institute of Hydrobiology & Aquatic Ecosystem Management
Department of Water, Atmosphere, Environment
University of Natural Resources & Life Sciences Vienna (BOKU)

Focus and topics
 Historical development of the Danube floodplain
in the Machland 1715 – 1812
 Short-term morphodynamics 1812 – 1817
 Consequences for floodplain habitats
(intensity of hydrological connectivity)
 General considerations regarding
trajectories of habitat development
 Conclusions

Danube
Austrian Danube River
80 % impounded
20 % free-flowing
National Park
Danube River in the
MACHLAND floodplain
Machland

Machland: current situation
2006Inst. of Hydrobiology & Aquatic Ecosystem Mgmt.
Univ. of Natural Resources & Life Sciences Vienna

Inst. of Hydrobiology & Aquatic Ecosystem Mgmt.

Hütting
Franzenau

216
218
220
222
224
226
228
230
232
234
m
ü
A
River length - station (m)
Longitudinal profile 1812 - Northern main arm
bifurcation
of main arms
confluence
of main arms
river bottom
low water
mean water
ca. 3-5-year flood
Longitudinal profile 1812
Northern main channel arm
backwater
effect

erosion:
15 Mio. m³
aggradation: 13 Mio. m³
cut-off
avulsion
Spatial morphological turnover
1812 – 1817
=> changes in 35 % of the recent
river-floodplain system

Transect through river-floodplain system
1812 – 1817

avulsions
cut-off

Changes of water/groundwater level
1812 – 1817
total floodplain:
net change of water/
groundwater level
< 10 cm
=> short-term
„quasi-equilibrium“ ?
Hohensinner et al. (2008)
in CATENA
-40
-30
-20
-10
0
10
20
30
40
50
-1.1 - -1.0
-1.0 - -0.5 -0.5 - 0.0 0.0 - 0.5 0.5 - 1.0 1.0 - 1.1
Lowering/uplift of water/groundwater surface (m)
Areasharesofactivezone(%)
lowering
uplift

Department of Water, Atmosphere & Environment I Institute of Hydrobiology & Aquatic Ecosystem Management I DI Dr. Severin Hohensinner
0
10
20
30
40
50
60
70
80
90
100
Cumulativeareasharesofdepthsofthe
groundwaterlevelsinthefloodplain(%)
Depth of groundwater table at MW (m)
Machland 1812
Machland 1817
Machland 1991
Vienna/Lobau 2003
30.07.2013 15
Hydrological subsurface connectivity
Depths of groundwater table in the floodplain
Hohensinner et al. (2008)
in CATENA

Intensityofhydrologicalconnectivity
Time
high
low
terrestrialization
Trajectory of floodplain habitat development:
gradual change of hydrological connectivity
gradual main channel incision
gradual main channel aggradation

Time
high
low
terrestrialization of floodplain habitat
gradual main channel incision
gradual main channel aggradation
Avulsion
reduced connectivity due to avulsion
sudden change due to avulsion

Time
high
low
Avulsion
one habitat with avulsion

Time
high
low
Avulsion
intensified connectivity due to avulsion
intermediate connectivity
several habitats with avulsion

Shifting of navigable river arms 1700 – 1859

Time
high
low
Avulsion Avulsion
several habitats with several avulsions

Habitat dynamics
prior to chanelization 1812 – 1821
(main changes)
Eupotamon A
15 yrs
Eu B
6 yrs
Para A
5 yrs
Para B
5 yrs
Plesio
13 yrs
VABB
5 yrs
36 yrs
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85
Intensityofhydrologicalsurfaceconnectivity
Median-age (50%-age) of the habitat type area (years)
min
max
1.5 %
0.8 %
1.4 %
2.1 % 3.5
0.3 %2.8 %
2.6 %
5.7 %
7.4 %
2.1 %
3.9 %
2.2 %
2.1 %
1.6 %
1.8 %
1.6 %
EFA - elevated floodplain area
30.07.2013 22

0
10
20
30
40
50
60
70
80
90
100
1715 - 1821
natural
1829 - 1838
initial channelization
1859 - 1991
end of/after
channelization
Meandeviation(%)
1: total water body area at SMW (% of study site)
2: total habitat shares at SMW (% of study site)
3: aquatic habitat shares at SMW (% of total water bodies)
4: aquatic habitat shares at LW (% of total water bodies)
5: expansions of aquatic habitatsLW - SMW (% of study site)
6: median habitat ages / 50%-ages in active zone (years)
7: Connectivity-Index of active zone (CI)
1
6
5
43
2
7
1
7
5
4
3
2
1
65432
599
699
248
315
6
7
30.07.2013 23
pre-channelization
pre-channelization
1715 - 1821:
variation of
most habitat
parameters < 10 %
=> long-term
„quasi-equilibrium“ ?
Variability of habitat characteristics of the
river-floodplain system 1715 – 1991Meanvariation(%)

Eupotamon A
157 yrs
Eu B
60 yrs
Para A
33 yrs
Para B
23 yrs
Plesio
26 yrs
VABB
125 yrs
elevated floodplain area
160 yrs
0 50 100 150 200 250 300 350 400 450 500 550 600
Intensityofhydrologicalsurfaceconnectivity
Median-age (50%-age) of the habitat type area (years)
min
max
0.02 %
0.01 %
0.03 %
0.76 %
0.54 %
0.53 %
0.42 %
0.66 %
0.31 %
0.72 %
0.56 %
0.14
%
0.17 %
0.15 %
0.25 %
0.05 %
0.04 %
0.14 %
30.07.2013 33
Habitat dynamics
after chanelization 1859 – 1991
(main changes)

on a broader spatial scale, morphodynamic processes can
effect counteracting habitat developments leading to a
„quasi“-stable habitat composition („shifting habitat mosaic“)
Conclusions
the spatio-temporal pattern of diverse morphodynamic
processes is reflected by a complex mosaic of differently
developed habitat patches
the development of riverine habitats
(besides hydrology) depends on gradually occurring
morphological changes (channel migration, terrestrialization)
and on sudden processes (avulsions, cut-offs)

Severin Hohensinner & Mathias Jungwirth
Institute of Hydrobiology & Aquatic Ecosystem Management
Department of Water, Atmosphere, Environment
University of Natural Resources &Life Sciences Vienna (BOKU)
Austrian Science Fund

Importance of Multi-Dimensional Morphodynamics for Habitat Evolution in the Austrian Danube River 1715-1821

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Importance of Multi-Dimensional Morphodynamics for Habitat Evolution in the Austrian Danube River 1715-1821

Similar to Importance of Multi-Dimensional Morphodynamics for Habitat Evolution in the Austrian Danube River 1715-1821 (20)

Recently uploaded

Recently uploaded (20)

Importance of Multi-Dimensional Morphodynamics for Habitat Evolution in the Austrian Danube River 1715-1821