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Dynamic River ManagementTargets and consequences

Thinktank River Engineering TUD

June 24 2002

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Definition of Dynamic Rivermanagement (DRM)• Dynamic Rivermanagement :

River lay-out and management for functions

flood protection and navigation should offer

conditions for recovery of hydro-morphological

resilience:

System can return to original equilibrium: thus

attenuation of floodwaves, higher low water stages,

halt to bed degradation

Nature values are automatically restored !

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:Dynamic River Management: Counteracting negative effects of regulation measures

- General: small-scale measures without distant

respons (in x and t), so flexibel and reversible

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Floodplain of Rhine River near Karlsruhe

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Restoring small stream the “Sandbach” near Iffezheim

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Also in the Dutch river “Geul”

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Increasing flow conveyance :The Gameren floodplain

June 2000

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Upstream viewSouth and East channels

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Downstream viewSouth and West channels

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Secondary channels and morphology

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Consequences of “repair” measures

• Abundant vegetation in the floodplains, dynamic changes

• correction measures have to be carried out at irregular times.

• River management has to be able to track the (dynamic)

changes in the river system, forecasts the impact on different

user-interests, formulate strategies to cope with the changes

and finally (if needed) to execute short-term measures.

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Dynamic Rivermanagement System

• Elements are various quick-scan monitoring systems:

- multi-beam sounding methods

- laser-altimetry for changes in topography and vegetation patterns

- radar-reflection of waterlevels to detect changes in waterdepth (and bedlevels)

- satelite imaging

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Multibeam image of armoured layer

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Multibeam image of ds. end of armoured layer

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Relation between vegetation and hydraulic roughness

Resistance of willows

0

2

4

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0 1 2 3 4 5 6 7 8waterdepth [m]

Ché

zy c

oëffi

ciën

t

[m1/

2 /s]

wilgenstruweel

Origin of hydraulic roughness

h

Av

Vegetation type

roughness

roughness

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LANDSAT

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Remote sensing voorbeelden: CASI

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detail bushes

Height with help of

Laseraltimetry

Laseraltimetrie

•NAP – hoogte (± 5 cm)•RD – coördinaten (± 2 cm)•Intensiteit•Minimaal 4 metingen/m2

inleiding weerstand lopend onderzoek hoe verder

3D image

inleiding weerstand lopend onderzoek hoe verder

27inleiding weerstand lopend onderzoek hoe verder

Hoogte op lijn door proefgebiedje

5

10

15

20

25

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170220 170240 170260 170280 170300 170320 170340

Hoo

gte

tov

NA

P

Hoogte op lijn door proefgebiedje

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10

15

20

25

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170220 170240 170260 170280 170300 170320 170340

hoog

te t

ov N

AP

Vegetation height

Roughness mapDuursche Waarden ’97

inleiding weerstand lopend onderzoek hoe verder

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DRM: Consequences for day to day management

• Dealing with uncertainties

– more morpho-dynamics

– more interaction with terrain-owners

• Organisational modifications

• Introduction and implementation of high-tech monitoring

systems and DSS

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That’s all !