Adapting to climate change: examples from the Netherlands. The Netherlands 31/03/ % below sea level 65% would be flooded in absence of dikes

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1 Workshop SDTA, ICID 26 th ERC and 66 th IEC, October 11-16, 2015, Montpellier, France Adapting to climate change: examples from the Netherlands Henk Ritzema, Wageningen University, The Netherlands The Netherlands 25% below sea level 65% would be flooded in absence of dikes Combination of sea level rise and subsidence 1

2 Agricultural development water management In the past windmills were used to drain the land (left), nowadays sluices and barriers are used to protect the land against flooding (right) Water management Land use Climate change predictions: Sea-level rise Increase in river flow Increase in winter precipitation Higher risk of coastal flooding Decrease in summer precipitation Increase in temperatures 2

3 Sea level rise and subsidence: nothing new, but at a higher rate Predicted sea level rise: 2100: 0.65 and 1.3 m 2200: 2 to 4 m Predicted subsidence: 2100: m Pumping Dutch Polders to MSL -6m Waddenzee Markermeer A9 A7 Amsterdam Haarlem A6 A2 Utrecht North Sea Noordwijk A4 A12 Elevation in m+ MSL + 5m 0 m Den Haag Delft A13-5 m 3

4 Dutch Polder Landscape is inundated at MSL Waddenzee Markermeer A9 A7 Amsterdam Haarlem A6 A2 Utrecht North Sea Noordwijk A4 A12 Elevation in m+ MSL + 5m 0 m Den Haag Delft A13-5 m Pumping Dutch Polders to MSL -2m Waddenzee Markermeer A9 A7 Amsterdam Haarlem A6 A2 Utrecht North Sea Noordwijk A4 A12 Elevation in m+ MSL + 5m 0 m Den Haag Delft A13-5 m 4

5 Pumping Dutch Polders to MSL -4m Waddenzee Markermeer A9 A7 Amsterdam Haarlem A6 A2 Utrecht North Sea Noordwijk A4 A12 Elevation in m+ MSL + 5m 0 m Den Haag Delft A13-5 m Pumping Dutch Polders to MSL -6m Waddenzee Markermeer A9 A7 Amsterdam Haarlem A6 A2 Utrecht North Sea Noordwijk A4 A12 Elevation in m+ MSL + 5m 0 m Den Haag Delft A13-5 m 5

6 Climate change predictions: Sea-level rise Increase in river flow Increase in winter precipitation Higher risk of coastal flooding Netherlands = sink of the Rhine Basin 6

7 River Rhine: Peak discharge Peak discharge: Now: m 3 /s 2100: m3/s 15-25% increase Subsidence in combination with increased river flows require higher river dikes soil surface: 6m below MSL water level: 3m above MSL Water head = 9 metres 7

8 Space for the river: creation of additional storage capacity River Rhine Additional storage Flooding Risk in Dutch polder landscape Flood-prone, heavily urbanised area, valuable in terms of human settlements industry agriculture ecology 8

9 Increased risk of flooding/inundation Risk-assessment maps on internet Riskassessment maps can be consulted on the internet For each province risk-assessment maps can be consulted on the internet 9

10 Risk-assessment: public awareness Public awareness is difficult because risks are small: People do not followup Government instructions/advice Climate change predictions: Sea-level rise Increase in river flow Increase in winter precipitation Higher risk of coastal flooding 10

11 Change in rainfall: controlled Drainage Rainfall: increase in winter decrease in summer controlled drainage New paradigm: three step approach in drainage 11

12 Controlled Drainage to reduce N Loading Climate change predictions: Sea-level rise Increase in river flow Increase in winter precipitation Higher risk of coastal flooding 12

13 Damage caused by flooding and subsidence Flooding in residential areas Roads damaged by uneven subsidence Water mains and sewers damaged by uneven subsidence Smart solutions Floating houses Living with water Floating greenhouses 13

14 Consequences: development and O&M costs will increase Investment costs O & M million euros (i) clay (ii) peat (iii) peat & water (iv) peat & sand Adaptation for 3 prevailing Soil Types: Clay Sandy soils Peat Loam 3 Soil Types: Peatlands Reclaimed clay soils High sandy 4 Types of Land Use: Urban Agriculture Nature Recreation 14

15 Climate change: can we adopt ourselves? Adapting to climate change: Examples from the Netherlands Thank you for your attention 30 15