Onderzoek naar Bodemdaling - Internationale context - Kennisvragen - Samenwerking Gilles Erkens, Roelof Stuurman e.a.
Bodemdaling: een serieus probleem
14 oktober 2015
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 Why discriminate between human-induced and natural processes? Magnitude Cooping strategy (mitigation versus adaptation)
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9m land subsidence between 1925-1977 (52 years) ~ 17.3 cm/y
Bodemdaling vs absolute zeespiegelstijging
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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)
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JAKARTA
Predicting subsidence: the Jakarta case
Bodemdaling in Jakarta
Subsidence map of Jakarta 1974-2010:
-4,1 meter -2,1 meter -1,4 meter -0,7 meter
Total subsidence -25 up to -400 cm ; rate -0.5 up to -17 cm/year
1974-1982
-0.25 meter
1982-1991
1991-2000
2000-2010
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Pluit
1989-2007
2007-2025
Total
Sea level rise
4-6 cm
4-6cm
8-12 cm
Minimum Subsidence
100-200 cm
100-200 cm
200-400 cm
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? 2. What is causing subsidence?
DHAKA 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
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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
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)?
New Orleans, USA
Hoogtebestand van New Orleans
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Impacts of land subsidence: damage Differential subsidence causes: • Damage to buildings, structures • Infrastructure • Sewage/gas pipes, electricity cables (connections)
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NEW ORLEANS
InSAR measurements
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BodemdalingMetingen in Nederland (TUDelft)
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Noodzakelijke stap: in-situ metingen!
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Subsidence components Courtesy Tulane University, New Orleans
Total subsidence in NO = ~6 mm/yr ~ 1.6 mm/yr
~ 0.034 mm/yr
?? ??
~0.15 mm/yr ~0.45 mm/yr
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Subsidence by groundwater extraction ?
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Urban Fieldwork in New Orleans
Predicting subsidence in New Orleans
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Strat NL-3D
Lithologie NL-3D Strat GeoTOP
Lithologie GeoTOP
Lithologie Randstadrail 14 oktober 2015
Urban Fieldwork in Kanis, Woerden
Predicting subsidence in New Orleans
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0.000010
40000
2060
2080
Loading [kPa]
30000
40000
30000
40000
1.000000
2.000000
3.000000
30000
40000
Time (days)
Measurement
Vertical 1 (X = 0.000 m; Z = 0.000 m) Method = NEN - Bjerrum with Terzaghi (Linear strain)
0.000005
Fit factors used Coefficient of determination = 0.902
Depth = 1.000 [m] Settlement after 49275 days = 3.879 [m]
0.000000
30000 Year 2020 Time [days] 2040
20000
2000
40000
2060
2080
Ph o n e
10000
1980
Fa x
0
1960
2) Business as usual Z2100 = - 3.88 m
• •
Time-History
4.000000 0
10000
20000
Vertical 1 (X = 0.000 m; Z = 0.000 m) 0.000010 Method = NEN - Bjerrum w ith Terzaghi (Linear strain)
Depth = 1.000 [m] Settlement after 49275 days = 3.111 [m]
0.000005
Loading [kPa]
20000
MSe ttle 7 .3 : jw rmsFit2 re co ve r.sli
10000
d a te
0
18/03/2011
Annex
4.000000
0.000000
-0.000005
-0.000010 0
3) Recovery to 1995 situation Z2100 = - 3.11 m 10000
20000
0.000000
40000
30000
40000
0.000000
30000
Time [days]
2100
1.000000
Settlement [m]
Settlement [m]
20000
0.000000
3.000000
-0.000010
10000
Time [days]
Time-History 0.000010
Loading [kPa]
0
2.000000
-0.000005
-0.000005
2100
0.000000
1.000000
0.000000
-0.000010
Settlement [m]
Year 30000 2020 Time [days] 2040
20000
2000
Ph o n e
10000
1980
Fa x
0
1960
-0.000005
-0.000010
2.000000
2.000000
3.000000
4.000000
• •
20000
30000
Time (days)
40000
0
10000
Vertical 1 (X = 0.000 m; Z = 0.000 m) Method = NEN - Bjerrum w ith Terzaghi (Linear strain)
20000
Depth = 1.000 [m] Settlement after 49275 days = 2.765 [m]
Depth = 1.000 [m] Settlement after 49275 days = 5.693 [m]
1) Increased GW pumping 1m/yr Z2100 = - 5.69 m
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MSe ttle 7 .3 : jw rmsFit2 re co ve r.sli
10000
4.000000 d a te
0
Vertical 1 (X = 0.000 m; Z = 0.000 m) Method = NEN - Bjerrum with Terzaghi (Linear strain)
18/03/2011
Annex
Settlement [m]
0.000005
Modelleren en voorspellen
0.000000
Loading [kPa]
0.000005
0.000010
4) Rapid recovery to 1995 situation Z2100 = - 2.77 m
Zettingsmodellen betrouwbaarheid Vergelijking van drie verschillende zettingsmodellen in lange duur proef 0
2
0
5
1
10
4 20
10
6 20
8
10
12
14
Time [days]
40
Klei
80
2 3
160
4
6 7 8 9 10
Settlement [mm]
5
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Oedometer test abc Isotachen Koppejan NEN-Bjerrum Isotachen
320
160
320
640
Subsidence 2000-2050, at a constant drainage depth 230000.000000
550000.000000
.000000
500000
450000.000000
.000000
80000.000000 450000
450000.000000
.000000
80000.000000
450000
500000.000000
550000
.000000
550000.000000
130000.000000
500000.000000
500000
.000000
550000
.000000
130000.000000
600000.000000
600000.000000
230000.000000
130000.000000
Legend
350000.000000
180000
.000000
180000.000000
ahnminstep5.img 130000
0 - 0.00001
80000
.000000
30000.000000
0.005 - 0.01 0.01 - 0.1
0.3 - 0.5
CLIMATE CHANGE SCENARIO
Legend dh014600dMosaicV2.img (m) 0 - 0.00001
.000000
0.00001 - 0.005
0.1 - 0.3
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30000.000000
(m)
80000.000000 30000.000000
230000.000000 400000.000000
30000.000000
180000.000000
.000000
180000
350000.000000
400000.000000
230000.000000
0.00001 - 0.005 0.005 - 0.01 0.01 - 0.1 0.1 - 0.3 0.3 - 0.5
0.5 - 1
0.5 - 1
1.000000001 - 5
1.000000001 - 5
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
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
Mitigerende maatregelen Kennisleemte: Monitoringsprogramma’s pilotlocaties technische oplossingen
Adaptieve maatregelen
Kennisleemte: • MKBA’s (van mm/jaar naar €/jaar) • Handelingsperspectief
Nationaal Informatievoorziening Bodembeweging
Bodemdalingsonderzoek in Nederland: The Big Five
The Telescope News
Thank you
• En salinization, • Wat meer?
