Flood protection, Natura 2000 and navigation in the ... · Prof. dr. Patrick Meire Ecosystem...
Transcript of Flood protection, Natura 2000 and navigation in the ... · Prof. dr. Patrick Meire Ecosystem...
Flood protection, Natura 2000 and navigation in the Scheldt estuary: how to combine conflicting interest into a mutual successful management
Prof. dr. Patrick Meire
Ecosystem Management Group
University of Antwerp
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AntwerpenSchelde river350 km longestuarymacrotidal160 km long
Netherlands
Belgium
France
Change in geomoprhology: embankments
From 1000 BP onwards:
150.000 ha embanked
1000 ad
1750 ad
Green: tidal marshes
Yellow: tidal flats
Dark yellow: dunes
Redbrown: Holoceen sands;
brown: coastal peat areas;
Pink: embankments
Antwerpen
Gent
Vlissingen
BELGIUM
THE NETHERLANDS
WESTERSCHELDE
ZEESCHELDE
Changing geomoprhology: deepening
But: an estuary is a system
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agriculture
industry
Morphologyshipping
Channel depth
surfaceHydrodynamics
Sea level rise in combination with morphological changes in the estuary resulted in an amplification of the tides!
Concerns about tidal amplification
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Concerns about increased flood risks
But: an estuary is a system
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agriculture
industry
Morphologyshipping
Channel depth
surface
Hydrodynamics
Concerns about erosion, morphological changes
Tidal marsh of Waarde
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Cox et al. 2003, Continental Shelf Research
But: an estuary is a system
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agriculture
industry
Morphologyshipping
Channel depth
surface
Water quality
householdsBiodiversity andEcological functioning
Hydrodynamics
But: an estuary is a system
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agriculture
industry
Morphologyshipping
Channel depth
surface
Water quality
householdsBiodiversity andEcological functioning
Hydrodynamics
Fresh Brackish Marine
Expected number of species
Concerns about biodiversity
How did we cope with these problems?
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Floods: More infrastructure: SIGMAPLAN
Heigher and stronger dikes
Flood Control Area (FCA)
Floods: More infrastructure: SIGMAPLAN
Floods: More infrastructure: SIGMAPLAN
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SAFETYDuring a storm(6-12-2013)
Overflow dike
FCA –CRT Bergenmeersen
Floods: More infrastructure: SIGMAPLAN
Floods: More infrastructure: SIGMAPLAN
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Model simulation of 100-yr storm surge (Meire et al. 2014 ECSA Bull.)
60 cm80 cm
After all FCA (by 2030)
Sto
rm s
urg
e w
ate
r le
ve
l (m
TA
W)
Distance to estuary mouth (km)
Impact of FCA on high water levels
Floods: More infrastructure: SIGMAPLAN
• Sigmaplan protects agains floods
• BUT
• Does not tackle the cause of increasing flood risk
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Water quality: waste water treatment
Water quality: waste water treatment
Notwithstanding major improvement,
➔ Water quality objectives not reached
➔ Does not take into account the interaction betweenwater column and river bed (historic pollution is notremoved)
➔ Does not take into account nutrient ratio’s whichimpacts algal growth
➔ Does not take into account the biogeochemicalfunctioning of the ecosystem
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Biodiversity protection driven by legislation
EU habitat directive requires compensation of habitat lossin Natura 2000 areas
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Biodiversity protection driven by legislation
• Loss of a tidal marshes for a container terminal is compensated by restoring a former marsh
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Biodiversity protection driven by legislation
It can prevent overall loss of habitat
• Is mainly based on structural aspects
• To maintain the surface of specific habitat types
• To maintain a certain population of specific species
• Mentioned in the appendices of the directives
BUT
• Is the restoration succesful?
• Does it impact estuarine problems?
• ➔ does it lead to desirable futures?
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Biodiversity: designation and management of reserves
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Use of rip-rap
Paul Holmes Strays, Humber estuary
Key message
• Present management is an endless vortex leading tofurther tidal amplification, geomorphological changes and loss of biodiversity and will require more and more management measures to garantuee safety againstfloods and access to the harbour of Antwerp
• A good understanding of the functioning of the system and a “systems diagnosis” is a crucial step to go from a sectorial approach to an integrated approach!
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Key message
A fundamental paradigmashift is necessary. The crucialquestion is no longer, do have human interventions have aneffect on biodiversity, but has loss of habitat andbiodiversity an effect on
▪ The economy
▪ Human welbeing
Nature is not part of the probleem, but part of thesolution!
Restoration driven by functional approach
➔ Requires a different more integrated approach
A move from a structural towards a functional approach, where habitat are designed in such a way that they improvethe overall functioning of the estuary tackling the major estuarine processes
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Bringing things together: towards anintegrated approach
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Towards an integrated approach
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ECOSYSTEM
Properties Functions
SOCIETY
Benefits values
ECOSYSTEM SERVICES
SUPPLY DEMAND
Ecosystem services as a unifying concept requires:
• Quantification of ES == supply of ES
• Understanding the demand of ecosystem services
Bio-physical system
Limitations and opportunities
Supply of ES
What are the Service providing units (SPU)/ Ecosystem service provider (ESP)?
Which and how much Ecosystem Services are delivered by what?
Ecosystem services?
Quantification of the demand for ES
The need for ES is very often not obvious as the link between problems experienced by people and the underlying loss of ES delivered by ecosystems causing the problem is very often not understood!
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Geo-physical system
Demand for
ESS
Limitations and opportunities
Socio-economic system
Supply of ESS
How much of an ES do we need?
Formulating objectives
▪ Safety ➔ floodrisk should be less than 1/4000
▪ Tidal dissipation ➔ tidal amplification should stop
▪ Nutrient removal ➔ load to North Sea must drop
▪ Si delivary➔ should be high enough to prevent Si limitation
▪ Primary production➔ should sustain fisheries
Formulating objectives
▪ maintaining hydromorphology➔minimize dredgingcosts
▪ resilient ecosystem ➔maintain water quality, productivity, recreation, EU conservation objectives
▪ ….
▪➔MUST BE DETERMINED IN A QUANTITATIVE WAY
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Bio-physical system
Demand for
ESS
Limitations and opportunities
Socio-economic system
Supply of ESS
Mismatch?
Where to look?
Where are the bio-physical opportunities
and limitations situated?
Final CO: ➔ Max (surface S1,..Sn; F1,…,Fm)
➔ Habitat quality
H
a
b
i
t
a
t
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Conservation Objectives (CO)
Species 1
populationSurface S1
habitat quality
density
Function 1
habitat quality
volume
Surface F1unit
Updated SIGMAPLAN
Intertidal marsh creation to solve estuarine problems
Marshes in 1200: ~100 000 ha
Marshes now: ~3260 ha
Marshes by 2030: + 1500 ha
Maintenance
Ketenisse
Marsh restoration
Develop new techniquesFlood Control Area (FCA)
Combining ES
▪ Flood control ➔ water quantity
▪ Biogeochemical functioning➔ water quality
Looking for bundles of ES and new concepts andmanagement measures!
Pilot project Lippenbroek
10 ha of tidal nature developping: May 2008
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1
2
3
4
5
6
7
7/04 12/04 17/04 22/04 27/04 2/05 7/05
date
level
(m T
AW
)
Schelde (De Plaat)
Lippenbroek
0
1
2
3
4
5
6
7
7/04 12/04 17/04 22/04 27/04 2/05 7/05
date
level
(m T
AW
)
Lippenbroek
Schelde (De Plaat)
0
1
2
3
4
5
6
7
7/04 12/04 17/04 22/04 27/04 2/05 7/05
date
level
(m T
AW
)
Lippenbroek
Schelde (De Plaat)
❖ reduction of tides with 3 meter
❖ No reduction of spring-neap tide variation
Results: tidal range
Water quality regulation
Lippenbroek 16-05-06
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25
50
75
100
125
150
175
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
time (hour)
oxyg
en
(% s
at)
INFLOW OUTFLOW
Water quality regulation: oxygen delivery
Water quality regulation: Silica delivery
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0
2
4
6
8
10
9 10 11 12 13 14 15 16 17 18 19 20 21 22
time (hrs)
DS
i (m
g/l
SiO
2)
Lippenbroek estuary
Inflow Outflow
DSi (mg/l) 3/7/2006
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Water quality regulation: Silica delivery
Water quality regulation: nitrogen retention
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Yearretention of TDIN: averge 5 kg per tide!
Distance from creek edge (m)
Gro
undw
ater
leve
l (m
TA
W)
Benthic processes
Water quality regulation: nitrogen retentionmechanism
restored marsh | spring tide
Gro
undw
ater
leve
l (m
TA
W)
Distance from creek edge (m)
Water quality regulation: nitrogen retentionmechanism
Natural marsh Restored marsh
Tidally deposited sediment
Historically compacted subsoilTidally deposited sedimentcree
k
sediment
organic matter macropores
high-resolution X-ray CT scanning
Natural marsh Restored marsh
Tidally deposited sediment
Historically compacted subsoilTidally deposited sediment
sediment
organic matter macropores
cree
k
Natural marsh Restored marsh
Tidally deposited sediment
Historically compacted subsoilTidally deposited sediment
sediment
organic matter macropores
cree
k
Bergenmeersen
Polders van kruibeke
FCA Polder van Kruibeke
Inauguration of the “Polders van Kruibeke” June24th 2017
https://vimeo.com/226267624
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Managed realignment
1990 1998
Managed retreat of potpolder Lillo
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Managed retreat Wijmeers
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Is this restoration economically viable?
Polders of Kruibeke
Sigmaplane.g. Polders of Kruibeke
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Polders of Kruibeke
Step 1: What are the effects of the project
100 M€ (600 ha) (until 2100 ) 237 ha - 600 ha
640 m³/y (annual productivity)
N burial: 7.8 tonN/y
Denitrification: 32 tonN/y
5,000 tonCO2/yP burial:
0.5 tonP/y
21 tonPM10/y
FLOOD PROTECTION FOOD PRODUCTION: LIVESTOCK FOOD PRODUCTION: CROPS
WOOD PRODUCTION AIR QUALITY REGULATION: FINE DUST CAPTURE
WATER QUALITY REGULATION CLIMTE REGULATION: CO2 SEQ.
Boerema et al. 2015, Terra et Aqua nr. 41Project for the International Association for Dredging Companies (IADC)
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Polders of KruibekePolders of Kruibeke
Step 2: Cost-efficient project (benefits>costs)?
Without ES benefits
€
-200.000.000
-100.000.000
0
100.000.000
200.000.000
Costs Benefits Sum Costs Benefits Sum
Without project With project
Investment
Maintenance (100y)
Food (100y)
Flood (100y)
Sum
+additionalES benefits
€
-200.000.000
-100.000.000
0
100.000.000
200.000.000
Costs Benefits Sum Costs Benefits Sum
Without project With project
Investment
Maintenance (100y)
Food (100y)
Flood (100y)
Additional ES benefits (100y)
Sum
Food
Floodsafety
Boerema et al. 2015, Terra et Aqua nr. 41Project for the International Association for Dredging Companies (IADC)
INTEGRATE THE PEOPLE
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Key message
• Estuarine restoration is much more than just making a new habitat.
• The integrated approach requires the understanding of the whole system functioning and insight into the trends of the major driving forces.
• Hydrodynamics, morphology and ecology are closely linked and
• Objectives should be formulated in a more integrated way (not just biodiversity)
• Move towards a process based restoration! Not for the ecologist but for the ecology
Conclusion
• For the Schelde case, the concept of ES has
• Facilitated the communication between different stakeholders
• Allowed a more integrated approach
• To formulate ES objectives for different parts of the system and different users
• ➔ the concept has impacted the outcome of the project!
Communication as a crucial issue
• The benefits and added value of the project should becommunicated to the stakeholders
• ES makes communication about ecosystem basedadapation much easier than biodiversity as such
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Please come and visit the Scheldeit would be a great pleasure to guide you around
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FOR MORE INFO: WWW.SIGMAPLAN.BE
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Thanks for your attention