Onderzoek naar Bodemdaling

Transcriptie

1 Onderzoek naar Bodemdaling - Internationale context - Kennisvragen - Samenwerking Gilles Erkens, Roelof Stuurman e.a.

2 Bodemdaling: een serieus probleem 14 oktober 2015

3 What causes the land to subside? Natural causes (geological processes): Loading of the earth s crust by ice sheets, sediment (delta s), the ocean/sea Compaction of older sediments after sedimentation Anthropogenic causes (human-induced processes): Oil/gas extraction (usually relatively deep) Groundwater extraction (usually moderately deep) Drainage of soils oxidation of peat, soil compaction Loading of soft soils 9 m land subsidence between (52 years) ~ 17.3 cm/y Why discriminate between human-induced and natural processes? Magnitude Cooping strategy (mitigation versus adaptation) 14 oktober 2015

4 Bodemdaling vs absolute zeespiegelstijging 14 oktober 2015

5 Impacts of land subsidence: flooding Relative sea level higher due to land subsidence Damage to flood protection structures Different flood inundation maps (land subsidence is spatially distributed) 14 oktober 2015 JAKARTA

6 Predicting subsidence: the Jakarta case Bodemdaling in Jakarta Subsidence map of Jakarta : Total subsidence -25 up to -400 cm ; rate -0.5 up to -17 cm/year -4,1 meter -2,1 meter -0,7 meter -1,4 meter meter Pluit Total 14 oktober Sea level rise Minimum Subsidence 4-6 cm cm 4-6cm cm 8-12 cm cm

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8 The sinking cities assessment A quick subsidence assessment for mega-cities: Jakarta, Ho-Chi-Minh City, Dhaka, New Orleans, Bangkok 1. How much subsidence is there? DHAKA 2. What is causing subsidence? NEW ORLEANS 3. How much subsidence is predicted? JAKARTA 4. What impact has subsidence? HCMC 5. Who is responsible? BANGKOK 6. What are solutions? TOKYO 14 oktober 2015 The assessment aimed to: Get insight in the processes To obtain a research agenda for this topic To list best practice cases for others to learn

9 Kennisvragen 1. Hoe Meten we bodemdaling? 2. Het ontrafelen van het meetsignaal (Matching): wat zijn de oorzaken van bodemdaling? 3. Hoe voorspellen we bodemdaling met Modellen? 4. Wat is de schade en wat zijn vermijdbare kosten (MKBA s) 5. Wat zijn mogelijke oplossingsrichtingen voor bodemdaling (Maatregelen)?

10 New Orleans, USA

11 Hoogtebestand van New Orleans 14 oktober 2015

12 Impacts of land subsidence: damage Differential subsidence causes: Damage to buildings, structures Infrastructure Sewage/gas pipes, electricity cables (connections) 14 oktober 2015 NEW ORLEANS

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15 14 oktober 2015 InSAR measurements

16 BodemdalingMetingen in Nederland (TUDelft) 14 oktober 2015

17 Noodzakelijke stap: in-situ metingen! 14 oktober 2015

18 Subsidence components Courtesy Tulane University, New Orleans Total subsidence in NO = ~6 mm/yr ~ 1.6 mm/yr ~ mm/yr???? ~0.15 mm/yr ~0.45 mm/yr 14 oktober 2015

19 Subsidence by groundwater extraction? 14 oktober 2015

20 Urban Fieldwork in New Orleans

21 Predicting subsidence in New Orleans 14 oktober 2015

22 Strat NL-3D Lithologie NL-3D Strat GeoTOP Lithologie GeoTOP Lithologie Randstadrail 14 oktober 2015

23 Urban Fieldwork in Kanis, Woerden

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25 Predicting subsidence in New Orleans 14 oktober 2015

26 Settlement [m] Settlement [m] Loading [kpa] Loading [kpa] Settlement [m] Settlement [m] Loading [kpa] Loading [kpa] Year Time [days] Measurement Vertical 1 (X = m; Z = m) Method = NEN - Bjerrum with Terzaghi (Linear strain) Time-History Time (days) Fit factors used Coefficient of determination = Depth = [m] Settlement after days = [m] 2) Business as usual 3) Recovery to 1995 situation Z 2100 = m Z 2100 = m Year Time [days] Vertical 1 (X = m; Z = m) Method = NEN - Bjerrum with Terzaghi (Linear strain) Time (days) Annex date <Not Registered> Phone <Not Registered> <Not Registered> <Not Registered> <Not Registered> Fax <Not Registered> <Not Registered> 18/03/ Modelleren en voorspellen Annex date <Not Registered> Phone <Not Registered> <Not Registered> <Not Registered> <Not Registered> Fax <Not Registered> <Not Registered> 18/03/2011 Depth = [m] Settlement after days = [m] MSettle 7.3 : jwrmsfit2recover.sli MSettle 7.3 : jwrmsfit2recover.sli Vertical 1 (X = m; Z = m) Method = NEN - Bjerrum with Terzaghi (Linear strain) 1) Increased GW pumping 1m/yr 4) Rapid recovery to 1995 situation Z 2100 = m Z 2100 = m 14 oktober Vertical 1 (X = m; Z = m) Method = NEN - Bjerrum with Terzaghi (Linear strain) Time [days] Time-History Time [days] Depth = [m] Settlement after days = [m] Depth = [m] Settlement after days = [m]

27 Settlement [mm] Zettingsmodellen betrouwbaarheid Vergelijking van drie verschillende zettingsmodellen in lange duur proef Time [days] Klei Oedometer test abc Isotachen Koppejan NEN-Bjerrum Isotachen oktober 2015

28 Subsidence , at a constant drainage depth Legend ahnminstep5.img (m) CLIMATE CHANGE SCENARIO Legend dh014600dmosaicv2.img (m) oktober

29 Schattingen schade bedragen Funderingsschade (bodembewegingen en gerelateerde grondwateronderlast): meer dan 5 miljard Euro aan panden tot nu toe door, circa 40 miljard Euro tot 2050 (theoretisch maximum). Deltares 2012 Gemeentelijke infrastructuur: op landelijke schaal liggen de meerkosten voor gemeenten door slappe grond in de ordegrootte 0,25 miljard euro per jaar (0,17 miljard voor wegen en water plus 0,08 miljard voor riolering). Kennisleemte: Schadeschattingen, regionaal

30 Maatregelen? There are two strategies to deal with subsidence: Mitigation Works for human-induced land subsidence Technical: Diminish pumping, aquifer storage recovery, using lighter building materials Adaptation Works for natural and remaining humaninduced land subsidence Technical: reintroducing sediment, build higher levees Non-technical: better spatial planning, governmental embedding 14 oktober 2015

31 Mitigerende maatregelen Kennisleemte: Monitoringsprogramma s pilotlocaties technische oplossingen

32 Adaptieve maatregelen Kennisleemte: MKBA s (van mm/jaar naar /jaar) Handelingsperspectief

33 Nationaal Informatievoorziening Bodembeweging

34 Bodemdalingsonderzoek in Nederland: The Big Five The Telescope News

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37 Thank you

38 En salinization, Wat meer?