Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
Bas Arens, Bureau for Beach and Dune Research
Amsterdam
Dynamic foredune
management in the
Netherlands
Change in policy
= change in foredune development
• From defensive to offensive
• Coastline retreat was stopped
• Sand sup...
0
20
40
60
80
100
120
1100
1150
1200
1250
1300
1350
1400
1965 1975 1985 1995 2005
nourishedvolume(m3/m)
volumeforedunes(m3...
0
10
20
30
40
50
60
S R P
percentageofcrosssections(%)
Foredune type
Dutch Coast
1966-1988 1988-2008
foredune
2130 Grey dunes
2120 White dunes
2110 Embryonic dunes
beach
wind
salt
sand (from beach)
Short gradient – no sand ...
Foredune
development
Schouwen
1997-2012
© RWS www.kustfoto.nl
Response: sand sharing system
foredune
2130 Grey dunes
2120 White dunes
beach
wind
salt
sand (from beach and foredune)
beach (wave erosion)
zand (wind e...
1
10
100
1000
10000
100000
0 200 400 600 800
trappedweight(gr)
distance from dunefoot (m)
0
10
20
30
40
50
60
70
80
Delta Holland Wadden NL
percentageoftotal(%)
stable, no dynamic processes moderate sand exchange...
“Dynamic” projects
• Sand engine
– Offensive strategy
• Noordwestkern
– Foredune remobilisation
©: Rijkswaterstaat/Joop van Houdt
Sand catchers Sand engine (Zandmotor)
Changes in height 2013-2014
Sand catchers Noordwestkern
Conclusions
• Dynamic foredunes preferable?
– Long transport gradient
– White dunes need sand
– Grey dunes need (a little)...
Dynamic frontdune management in the Netherlands
Dynamic frontdune management in the Netherlands
Dynamic frontdune management in the Netherlands
Upcoming SlideShare
Loading in …5
×

Dynamic frontdune management in the Netherlands

510 views

Published on

Dynamic Dune Congress 2015
Keynote: Bas Arens - Dynamic frontdune management in the Netherlands

Published in: Environment
  • Be the first to comment

Dynamic frontdune management in the Netherlands

  1. 1. Bas Arens, Bureau for Beach and Dune Research Amsterdam Dynamic foredune management in the Netherlands
  2. 2. Change in policy = change in foredune development • From defensive to offensive • Coastline retreat was stopped • Sand supply to (fore)dunes
  3. 3. 0 20 40 60 80 100 120 1100 1150 1200 1250 1300 1350 1400 1965 1975 1985 1995 2005 nourishedvolume(m3/m) volumeforedunes(m3/m) volume foredunes beach nourishment shoreface nourishment
  4. 4. 0 10 20 30 40 50 60 S R P percentageofcrosssections(%) Foredune type Dutch Coast 1966-1988 1988-2008
  5. 5. foredune 2130 Grey dunes 2120 White dunes 2110 Embryonic dunes beach wind salt sand (from beach) Short gradient – no sand sharing
  6. 6. Foredune development Schouwen 1997-2012
  7. 7. © RWS www.kustfoto.nl Response: sand sharing system
  8. 8. foredune 2130 Grey dunes 2120 White dunes beach wind salt sand (from beach and foredune) beach (wave erosion) zand (wind erosion) Long gradient – transfer zone
  9. 9. 1 10 100 1000 10000 100000 0 200 400 600 800 trappedweight(gr) distance from dunefoot (m)
  10. 10. 0 10 20 30 40 50 60 70 80 Delta Holland Wadden NL percentageoftotal(%) stable, no dynamic processes moderate sand exchange intensive sand exchange
  11. 11. “Dynamic” projects • Sand engine – Offensive strategy • Noordwestkern – Foredune remobilisation
  12. 12. ©: Rijkswaterstaat/Joop van Houdt
  13. 13. Sand catchers Sand engine (Zandmotor)
  14. 14. Changes in height 2013-2014
  15. 15. Sand catchers Noordwestkern
  16. 16. Conclusions • Dynamic foredunes preferable? – Long transport gradient – White dunes need sand – Grey dunes need (a little) sand – Stop acidification of soils – Dunes can grow with sea level rise • Offensive strategy – Risk for block in sand transfer – Long term effects on dunes unclear

×