1. Bodemdaling
Gilles Erkens
&
de taskforce bodemdaling

2. Land subsidence: why bother?
17 juni 2014

3. 17 juni 2014
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 buildings, structures
Why discriminating between human-induced and natural processes?
 Magnitude
 Cooping strategy (mitigation versus adaptation)
9 m
land
subsidence
between
1925-1977
(52 years)
~ 17.3 cm/y

4. Impacts of land subsidence
17 juni 2014
1) Flooding 2) Damage to structures

5. Media
Aandacht!

6. Problematiek: GW onttrekking
Groundwater extraction leads to subsidence
Subsidence map of Jakarta 1974-2010:
-4,1 meter
-2,1 meter
-1,4 meter
-0,7 meter
-0.25 meter
Extensometer at Jalan Tongkol
4,5 cm
1997
2007
3 cm
2009
2010
41 cmJan84 Jan86 Jan88 Jan90 Jan92 Jan94 Jan96
-35
-30
-25
-20
-15
Date
Pz.Head(m)
d:JakartaMaathuis_dataCKG-PDK2.xls
Jan84 Jan86 Jan88 Jan90 Jan92 Jan94 Jan96
-40
-38
-36
-34
-32
-30
Date
Pz.Head(m)
d:JakartaMaathuis_dataCKG-PDK3.xls
Jan84 Jan86 Jan88 Jan90 Jan92 Jan94
-20
-15
-10
-5
0
Date
Pz.Head(m)
d:JakartaMaathuis_dataCKG-PDK4.xls
Subsiding cities:
• Jakarta
• HCMC
• Bangkok
• Manila
• Dhaka
• New Orleans
• Singapore
• Hanoi
• Richmond
• Shanghai
• Venice
• Lorca
• Mexico City
• and many more

7. Land subsidence vs absolute sea-level rise
17 juni 2014

8. The sinking cities assessment
17 juni 2014
1. How much subsidence is there?
2. What is causing subsidence?
A quick subsidence assessment for mega-cities:
Jakarta, Ho-Chi-Minh City, Dhaka, New Orleans, Bangkok
3. How much subsidence is predicted?
4. What impact has subsidence?
5. Who is responsible?
6. What are solutions?
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
NEW ORLEANS
JAKARTA
TOKYO
DHAKA
HCMC
BANGKOK

9. De bijdrage van Deltares
17 juni 2014
We willen:
- De oorzaak begrijpen
- Een voorspelling kunnen maken
- Oplossingen kunnen aandragen
-4,1 meter
-1,4 meter
-2,1 meter
-0,7 meter
-0.25 meter
-4,1 meter
-2,1 meter
-1,4 meter
-0,7 meter
-0.25 meter
New Orleans, USA
Jakarta, Indonesia

10. Methodologie: Integratie van monitoring en
modellering
Geological model
of the subsurface
Geomechanical
modelling
Forecasted
ground-motion
Ground-motion
monitoring data
Validation&Improvement
Comparison &
inverse modelling
Risk analysis &
Decision making
Specific requirements to satellite data
Geological model
of the subsurface
Geomechanical
modelling
Forecasted
ground-motion
Ground-motion
monitoring data
Validation&Improvement
Comparison &
inverse modelling
Risk analysis &
Decision making
Specific requirements to satellite data
Geo(hydro)logical
modelling
iMOD SUB-CR

11. Meerwaarde van iMOD
• Directe koppeling met het grondwatermodel
• Dezelfde schematisatie van de ondergrond,
• Snel doorrekenen van effect grondwaterstandsverlagingen,
• Inbrengen van grondwaterpompen
• Goed medium om ondergronddata te visualiseren
• Mogelijkheden tot 3D bekijken data
• Mogelijkheden tot het tekenen van profielen

12. Geologisch + geohydrologisch model
Droombeeld
17 juni 2014
Voorbeeld Ho Chi Minh City, Ngo Duc Chan 2008
Input View
Layers
8. Aquifer 1
7. Aquitard 1
6. Aquifer 2
5. Aquitard 2
4. Aquifer 3
3. Aquitard 3
2. Aquifer 4
1. Aquitard 4
0.000 10.000
1
2
3
4
5
6
7
8
1 2
1
-4
-59
-69
-119
-129
-169
-179
-249
1
-4
-59
-69
-119
-129
-169
-179
-249
Level (m)
Realiteit

13. Is gekoppelde modellering mogelijk?
2000: USGS Modflow SUB package
2005: USGS Modflow SUB-WT
2012: Deltares SUB-CR
2013: Deltares iMOD SUB-CR
•Interbeds: lenzen van lutumhoudende
fijnzandige grondlagen in aquifers
•Aquitards: uitgestrekte lutumhoudende
fijnzandige geologische afzettingen.

14. Kenmerken van het SUB-CR model
–Is een gekoppeld bodemdaling-
grondwatermodel (geen fysisch
ondergrondmodel)
–Maakt betere bodemdalingvoorspellingen door
meenemen van kruip (secondary settlement)
Gekoppeld aan iMOD
–3D-berekeningen
–Werkt op grote schaal (>1 km2): megasteden,
hele delta’s

15. Resultaten uit Jakarta

16. Evaluatie bodemdaling voor scenario’s onttrekkingen
2) Extrapolatie huidige situatie 3) Herstel naar situatie 1995
Z2100 = - 3.88 m Z2100 = - 3.11 m
1) Toenemende verlaging 1m/jr 4) Snel herstel situatie 1995
Z2100 = - 5.69 m Z2100 = - 2.77 m
17 juni 2014
Vertical 1 (X = 0.000 m; Z = 0.000 m)
Method = NEN - Bjerrum with Terzaghi (Linear strain)
Fit factors used
Coefficient of determination = 0.902
Depth = 1.000 [m]
Settlement after 49275 days = 3.879 [m]
0 10000 20000 30000 40000
4.000000
3.000000
2.000000
1.000000
0.000000
Settlement[m]
Measurement
0 10000 20000 30000 40000
Time [days]
-0.000010
-0.000005
0.000000
0.000005Loading[kPa]
1960 1980 2000 2020 2040 2060 2080 2100
Year
Time (days)
Vertical 1 (X = 0.000 m; Z = 0.000 m)
Method = NEN - Bjerrum with Terzaghi (Linear strain)
Fit factors used
Coefficient of determination = 0.902
Depth = 1.000 [m]
Settlement after 49275 days = 3.879 [m]
0 10000 20000 30000 40000
4.000000
3.000000
2.000000
1.000000
0.000000
Settlement[m]
Measurement
0 10000 20000 30000 40000
Time [days]
-0.000010
-0.000005
0.000000
0.000005Loading[kPa]
1960 1980 2000 2020 2040 2060 2080 2100
Year
Time (days)
1960 1980 2000 2020 2040 2060 2080 2100
Time-History
Vertical 1 (X = 0.000 m; Z = 0.000 m)
Method = NEN - Bjerrum with Terzaghi (Linear strain)
Depth = 1.000 [m]
Settlement after 49275 days = 5.693 [m]
0 10000 20000 30000 40000
4.000000
2.000000
0.000000
Settlement[m]
0 10000 20000 30000 40000
Time [days]
-0.000010
-0.000005
0.000000
0.000005
0.000010
Loading[kPa]
Year
Time (days)
1960 1980 2000 2020 2040 2060 2080 2100
Time-History
Vertical 1 (X = 0.000 m; Z = 0.000 m)
Method = NEN - Bjerrum with Terzaghi (Linear strain)
Depth = 1.000 [m]
Settlement after 49275 days = 5.693 [m]
0 10000 20000 30000 40000
4.000000
2.000000
0.000000
Settlement[m]
0 10000 20000 30000 40000
Time [days]
-0.000010
-0.000005
0.000000
0.000005
0.000010
Loading[kPa]
Year
Time (days)
MSettle7.3:jwrmsFit2recover.sli
<NotRegistered>
<NotRegistered><NotRegistered>
Phone<NotRegistered>
Fax<NotRegistered>
date
Registered>
Registered>18/03/2011
Annex
Vertical 1 (X = 0.000 m; Z = 0.000 m)
Method = NEN - Bjerrum w ith Terzaghi (Linear strain)
Depth = 1.000 [m]
Settlement after 49275 days = 3.111 [m]
0 10000 20000 30000 40000
4.000000
3.000000
2.000000
1.000000
0.000000
Settlement[m]
0 10000 20000 30000 40000
Time [days]
-0.000010
-0.000005
0.000000
0.000005
Loading[kPa]
MSettle7.3:jwrmsFit2recover.sli
<NotRegistered>
<NotRegistered><NotRegistered>
Phone<NotRegistered>
Fax<NotRegistered>
date
<NotRegistered>
<NotRegistered>18/03/2011
Annex
Time-History
Vertical 1 (X = 0.000 m; Z = 0.000 m)
Method = NEN - Bjerrum w ith Terzaghi (Linear strain)
Depth = 1.000 [m]
Settlement after 49275 days = 2.765 [m]
0 10000 20000 30000 40000
4.000000
3.000000
2.000000
1.000000
0.000000
Settlement[m]
0 10000 20000 30000 40000
Time [days]
-0.000010
-0.000005
0.000000
0.000005
0.000010
Loading[kPa]

17. Toekomstige ontwikkelingen
iMOD SUB-CR
 Inzetten in nieuwe case studie gebieden: New Orleans, Jakarta
 Gebruik voor opbouw van ondergrondmodellen en
informatiesystemen van delta steden
 Gebruikmaken van bestaande Modflow-modellen voor floodrisk
studies
 Koppeling met beleidsbeslissingsmodellen en kostenmodules
uit het schade-onderzoek
17 juni 2014

18. 4D: Jurong Island
17 juni 2014

19. Thank you