Transcript No Slide Title

MODELING FOR THE CASE STUDY OF THE MEUSE
IN LIMBURG
Traditional river management
World view
•The river can be controlled
•Living in the flood plain is safe as long as the proper
measures are taken  Confidence in the water authorities
Management style
•Goals: safety and navigation
•Canalization
•Widening
•Building dikes
•Water level control through sluices
New perspective on river management
World view
•Changing risk perception
•Probability of higher discharges due to climate change,
landuse change ..
Management style
•Policy line “Room for rivers”
•Water management 21st century
•Water as a guiding principle
•Integrated river management, but …….safety first !
•River widening for summer bed and floodplain
De Maaswerken
Visie Maasdal:
•Room for the Meuse  safety to a level
of 1:250 for all
•High quality shipping route
•Nature a prominent role
At the cost of:
•No new housing
•Reduction of the agricultural sector
Current state of the Maaswerken project
Limiting factors:
•finances
•morphology
Negative “side” effects:
•drought related damage
•polluted sediments
 conflicting goals
Research questions
•Is the vision of the Maaswerken a good one?
•Is it realistic?
•Don’t the negative side-effects outweigh the goals that
have been set?
•Is the approach sufficiently far sighted?
•How do the proposed measures impact on the interests
of stakeholders?
•How might they interact on the basis of these
measures and how might this influence the project?
•How may changing insights affect stakeholder
behaviour?
•Is Maaswerken on the right track ?
Conceptual model
Response-Maaswerken
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Deepening
Broadening
Dikes
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Other policy options
Lowering floodplains
Side gullies
Sluices
Exogenous Pressures (catchment)
Changing discharge
 Climate change
 Land use change
 Canalization
 Water extractions
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Auto. responses
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Housing legislation
Warning system
Retention measures
Water distribution
Flood adaptation
House prices
Shift in modal split
…
Endogenous Pressures (Limburg)
Water
pollution
Changing
discharge:
 Climate change
 Landuse change
Water demand:
 For drinking water
 For agricultural
use
 For industrial use
Water pollution:
 Sewage water
 Agricultural
pollution
 Industrial pollution
Discharge pattern / water quality at Borgharen
State
Riverbed state:
 Riverbed geometry
 Roughness
 Constructional works
Water quantity:
 Discharge pattern
 River water level
 Groundwater table
Water quality:
 River water quality
 Sediment quality
 Groundwater quality
Impacts
Central impacts:
 Safety
 Navigation
 Nature
Side impacts:
 Agriculture
 Drinking water supply
 Industry
Implementation costs:
 Financial costs
 Inconvenience
 Storage polluted silt
Impact of climate change on flood risk
Meuseflow approach
Model set up
Ten day averages of rainfal and temperature
Spatial aggregation towards a “lumped” model (min. three zones)
For each lump the water balance is described
 Output: Ten day averages of discharge at Borgharen
Climate change
Climate change simulated by:
dP = + x %, dT = + y °C
Extreme discharges
P(Qp > Qc ) is deduced using a statistical relation between the
observed ten day averages of discharge and corresponding
monthly peak values.
Impact of climate change on flood risk 2
Advantages
An ideal approach to calculate ten day averages of discharges
Can be used to estimate the impact of climate change on droughts
as well
Relatively straight forward and “well defined”
Disadvantages
Climate change only incorporated as a change in average or in ten
daily variability.
Impact of land use changes on the frequency of occurrence of
extreme events omitted from the analysis.
 Comparison to other, more detailed, approaches
Model of the Limburg Meuse
spatial aggregation
A top down approach:
•Modelling aggregated entities
•Illustrating results by modelling characteristic sites
along the river.
Model of the Limburg Meuse 2
spatial aggregation
The simplest case:
Modelling the entire PSIR chain for one arbitrary cross-section
Characterization of
the current state:
•Riverbed geometry
•Soil types
•Soil pollution
•Land use floodplain
•...
Advantage: Captures many of the relevant aspects for river management
Disadvantage: Excludes interactions with up/down stream river sections