restoring ecosystem functions in a heavily disturbed estuary n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
RESTORING ECOSYSTEM FUNCTIONS IN A HEAVILY DISTURBED ESTUARY PowerPoint Presentation
Download Presentation
RESTORING ECOSYSTEM FUNCTIONS IN A HEAVILY DISTURBED ESTUARY

Loading in 2 Seconds...

play fullscreen
1 / 28

RESTORING ECOSYSTEM FUNCTIONS IN A HEAVILY DISTURBED ESTUARY - PowerPoint PPT Presentation


  • 69 Views
  • Uploaded on

RESTORING ECOSYSTEM FUNCTIONS IN A HEAVILY DISTURBED ESTUARY. Tom Maris, Stijn Temmerman & Patrick Meire. Schelde: disturbed estuary. Function. Structure. Driving forces: - Dredging & embankments Pollution Climate change. loss of ecosystem functions Impact on: safety economy

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'RESTORING ECOSYSTEM FUNCTIONS IN A HEAVILY DISTURBED ESTUARY' - merrill-evans


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
restoring ecosystem functions in a heavily disturbed estuary
RESTORING ECOSYSTEM FUNCTIONS IN A HEAVILY DISTURBED ESTUARY

Tom Maris, Stijn Temmerman & Patrick Meire

slide2

Schelde: disturbed estuary

Function

Structure

  • Driving forces:
  • - Dredging & embankments
  • Pollution
  • Climate change
  • loss of
  • ecosystem functions
  • Impact on:
  • safety
  • economy
  • ecology
slide3

Schelde: disturbed estuary

44000

30

28,4

42000

25

42341

20,3

40000

20

38000

15

Surface (ha)

% intertidal area

36000

10

35853

34000

5

32000

0

1900

1990

total surface

% intertidal

Loss of intertidal habitat loss of goods and services

slide4

Schelde: disturbed estuary

Increasing tides: risk for floodings

slide5

Schelde: disturbed estuary

slope , current speed   marsh erosion 

Increasing tides: habitat loss

slide6

Schelde: solutions?

Function

Structure

Sustainable solutions:

Restoring functions

Managed realignment?

- Elevation often not suitable

- Not always compatible with

safetyplan

Return to pristine situation

is impossible.

Flood control area:

restoring safety

Controlled reduced tide:

restoring ecology

pilot study lippenbroek
Pilot studyLippenbroek

How to restore estuarine nature

in an area far below MHW?

concept fca crt safety ecology and a new ecosystem

estuary

FCA

polder

Outlet

estuary

CRT

Ring Dike

Lowered FCA dike

polder

Inlet

Outlet

Ring Dike

Lowered FCA dike

Concept FCA – CRT safety, ecology and a new ecosystem
  • Safety: FCA
  • - Lowered dike stretch
  • Critical tides: whole storage capacity
  • Only few times/year!
  • Ecology: CRT
  • - Introducing estuarine ecosystem
  • Tidal regime in area
  • Two times a day!
slide9

Pilot project Lippenbroek

Management scenario Lippenbroek

Lippenbroek

1: Ring Dike

2: FCA dike

3: Inlet sluice

4: Outlet sluice

4

3

2

1

1

1

1

10 ha of tidal nature developping since March 2006

slide10

Pilot project Lippenbroek

10 ha of tidal nature developping: May 2008

slide11

Introducing macrotidal regime

  • Reduction of high water level by 3 meter
  • No reduction of spring – neap variation
slide12

Introducing macrotidal regime

Intertidal habitat development

slide14

Tide - Sedimentation

Tidal marsh

?

?

?

Tidal flat

slide16

Spring 2006

Winter 2008

Spring 2006

Winter 2008

High

Mean

Low

spring 2006

Winter 2008

Zoobenthos

Low

Terrestric species

+ Insects+ others

Mean

Max density

in fine sediments

200000 / m²

Aquatic species + insects

High

Aquatic species

+ insects

Sediment

(cm)

slide17

Phragmites australis

Ranunculus repens

Salix sp.

Typha latifolia

Lythrum salicaria

Iris pseudacorus

Callitriche sp.

Veronica beccabunga

Alisma plantago-aquatica

Vegetation: colonisation of bare sites

  • Colonising species (40)
  • Low inundation frequency:
  • 30 species
  • Wetland + ruderal species
  • Salix and Phragmites potentially dominant
  • Averaged inundation frequency:
  • 27 species
  • Ruderal + wetland species
  • Salix, Phragmites, Typha: pot. dominant
  • High inundation frequency:
  • 10 species
  • typical wetland species
  • Typha potentially dominant
slide20

Water quality: Silica

DSi delivery on 3/7/2006

slide21

Delivery when DSi is limiting

Water quality: Silica

slide22

Water quality: Nitrogen

On average 1 kg N retention per ha per tide

slide23

FCA-CRT: sustainable?

Ring dike

Overflow dike

???

CRT

slide24

???

future

Sedimentation

Elevation (m TAW)

date

Flattening of the area

Changing inundation frequencies: decrease of accretion?

slide26

Lippenbroek conclusion

  • Tidal marsh restoration in area below MHW is possible
  • Tidal regime and sedimentation can be tuned
  • Sedimentation rate can be reduced to preserve storage capacity
  • Sedimentation rate can be maximased to prepare a low site for succesful managed realignment
  • Tidal marsh restoration in area below MHW is possible
  • Tidal regime and sedimentation can be tuned
  • Tidal marsh restoration in area below MHW is possible
  • Tidal regime and sedimentation can be tuned
  • Sedimentation rate can be reduced to preserve storage capacity
  • Tidal marsh restoration in area below MHW is possible
  • Tidal regime and sedimentation can be tuned
  • Sedimentation rate can be reduced to preserve storage capacity
slide28

Introducing macrotidal regime

HW

Maximum inflow

Start inflow

Stop inflow

Start outflow

stagnant

6.0

Estuary

5.0

sluice 4.7

4.0

Water level (m TAW)

3.0

2.0

Polder

1.0

0.0

0

2

4

6

8

10

12

Time (hour)