Delta’s on the Delta’s on the move…move…

How to respond to How to respond to climate change?climate change?

22

Global Air Temperature Change 1856-2001

Warmest Year 19982nd Warmest Year 2001

8 Warmest Years

Trend = 0.6 + 0.2oC.

(CRU, 2002)

Global Impacts

Sea level rise will have significant impacts on low-lying coastal areas and small islands...

RIKZ-study;

SimDelta = Morphological Simulation Model

Conclusion: because of the dikes and the dams sediment input from the sea was stopped. Subsidence of the polders was accelerated by drainage of the reclamated land.

Comcoast project Perk polder Comcoast project Perk polder (Province (Province of Zealand)of Zealand)

Comcoast project Perk polder Comcoast project Perk polder (decided (decided 2009)2009)

http://www.hvanzijl.nl/images/1420a.gif

Coastal erosionCoastal erosion((Hondsbossche Hondsbossche

Zeewering)Zeewering)

The Hondsbossche sea wall along the Dutch coast. By breaking The Hondsbossche sea wall along the Dutch coast. By breaking through the sea wall, part of the land behind it will flood with the through the sea wall, part of the land behind it will flood with the tides.tides.The silt caught up in the vegetation ensures that the land gradually The silt caught up in the vegetation ensures that the land gradually increases in height in line with or even above sea level . Realised in increases in height in line with or even above sea level . Realised in 1997.1997.

Hollandsch Diep

Haringvliet

VZM

Maas

Bo. Merwede

Lek

Oude Maas

Nieuwe MaasNieuwe Waterweg

880

150

730160

460750

310

1520

330

550

990

440Dordtse Kil Nwe Merwede

770

Be. Merwede620 1610

5

Westerschelde

Grevelingen100

Oosterschelde

Veerse meer

w:40

z:25

9

440

880

Average flows (m3/s)Average flows (m3/s)

The average freshwater supply of Rhine and Meuse to the west part of the Netherlands is ca. 2350 m3/s, while the need for agriculture, industry and tapwater does not exceed 25 - 75 m3/s

Most of the freshwater is used to rinse incoming salt water Ies de Vries, RIKZ

Shift freshwater inlet points to the Shift freshwater inlet points to the east and restore the marine east and restore the marine

character of the estuarycharacter of the estuary

Freshwater

Salt water

Brackish

Tidal area

Dams

0123456789

10

<1 5 10 15 20 25 30 35 40Electrical conductivity (mS/cm)

To

tal

bio

ma

ss

(g

)

A O3 U

Salt tolerant crop Quinoa (Chenopodium quinoa)

Amaranth: a salt sensitive crop

Adaptation of agriculture in saline areas

Increasing salinity

Adaptation of agriculture in Adaptation of agriculture in response to salt intrusionresponse to salt intrusion

Return of reclaimed land to Return of reclaimed land to the sea because of high the sea because of high

maintenance costsmaintenance costs

Future vision..Netherlands Future vision..Netherlands embracing the sea ...embracing the sea ...

Cancer inhibitors produced by marine sponges.

Marine algae producing substances of economic value

The “Seawing” a self-The “Seawing” a self-supplying floating supplying floating aquaculture labaquaculture lab

Cultivation of marine algae Cultivation of marine algae for fish breedingfor fish breeding

Sunlight distributed homogenously by glass fibers in algae culture

Fish containersAlgae production used for

fish food

Plan Lely (1918) designed Plan Lely (1918) designed for land reclamationfor land reclamation

Clay

Sand

Brackish water; Lely lagoon

Marsh lands

Sluice and tidal power unit

Wadden sea Outlet

Outlet

Reed marshes

Inlet

IJssel lake

Boats

Draft plan “Water lily” after Kees Hulsbergen H2ID

The Lily lagoon anno The Lily lagoon anno 21002100

Tekening Maarten Groot

OceanLab

Schematic model of a delta with traditional Schematic model of a delta with traditional management measures (left side picture) and modern management measures (left side picture) and modern management measures which should overcome the management measures which should overcome the disadvantages of traditional measures (right side). disadvantages of traditional measures (right side).

Ecosystem based approach to river basin Ecosystem based approach to river basin management:management:

Is an “opportunity driven” type of Is an “opportunity driven” type of management (“joy” or “Freude-aspect”) management (“joy” or “Freude-aspect”) rather than a “fear driven” type of rather than a “fear driven” type of management.management.

Ecological Ecological andand economical goals can be economical goals can be combined.combined.

It is a generic concept.It is a generic concept. Stimulates technical and non-technical Stimulates technical and non-technical

innovations.innovations. Needs interaction between society and Needs interaction between society and

science. science.

Conclusions