Comparative research of groundwater management in the coastal areas in Southeast Asia
Land Subsidence Monitoring
g in China
HE Qingcheng
CCOP Technical Secretariat,
Bangkok, Thailand
E-mail: [email protected]
heqc@ccop or th
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
Outline
 Land
subsidence in China
 Land subsidence monitoring in China
 Case study
---Shanghai
---Tianjin
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
Distribution of Land Subsidence in China
Tianjin
North China Plain
Fen-Wei
Faulted basin
Shanghai
XI’AN
Yangtze River Delta
Three major subsidence regions in China
North China Plain,
Plain Yangtze River Delta,
Delta Fen-Wei
Fen Wei Faulted Basin
Tianjin,
Shanghai
andforXi’an
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Distribution of Land Subsidence in China
There are more than 50 subsidence cities mainlyy in the three regions
g
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As large as 79,000
79 000 square
kilometers of land has
dropped more than 200
millimeters
illi t andd about
b t 50
cities have wide-spread land
subsidence.
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Land subsidence in China
In the Yangtze River Delta
About 10,000 square
kilometers of land has
dropped more than 200
mm.
The accumulative
subsidence of Shanghai
and Wuxi are 2980mm and
2800mm, respectively.
Accumulative subsidence contour
in the Yangtze Delta(until 2010）
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-2800
-2980
-1200
Land subsidence in China
L d subsidence
b id
iin th
t
Land
the Y
Yangtze
River Delta
Delta---Shanghai
Shanghai Region
Between 2002 and 2006, the

land subsidence in the whole
city was controlled to a certain
extent,
and
the
average
sinking rate was 12.7mm/a.
Between 2006 and 2010, the

cumulative
subsidence
amount of most areas was
relatively small, between 025mm.
The
area
accumulative
of
subsidence
greater than 50mm
0
amounted
Coordinating Committee for Geoscience
Programmes
East and
Southeast
Asia (CCOP)
Accumulative
subsidenceincontour
in Shanghai
（2006-2010）
to 162km2 .
Land subsidence in China
Land subsidence in the Yangtze
River Delta
--Su
-Su--XiXi-Chang Region
In
Su-Xi-Chang region
g province:
p
Jiangsu
of

Land subsidence originally
appeared in 1955, and three
regional
subsiding
cones
formed in Suzhou, Wuxi and
Ch
Changzhou
h
city.
i

In
recent
subsiding
ten
years,
rate
has
decreased greatly due to
prohibition and limitation of
p
groundwater
Now
Expension tendency of subsiding aera in Su-Xi-Chang
Coordinating Committee for Geoscience
Region
in different
period（1986,1991,2002）
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in East
and Southeast Asia (CCOP)
withdrawal.
the area of subsiding
rate greater than 10mm/a is
about 500km2 .
Land subsidence in China
In Hang-Jia-Hu plain of Zhejiang
p
province:

Land subsidence originated in
about 1964, In late 1970s-early
1980
l d
b id
1980s,
land
subsidence
developed rapidly;

Since 2006, land subsidence
was efficiently controlled by
prohibiting
and
limiting
groundwater
d t
withdrawal.
ithd
l Until
U til
2010, the areas of subsiding rate
greater than 10mm/a were about
g
195km2, decreasing 92% as
compared to 2005.
Land subsidence in the
Yangtze River Delta
--Hang
-Hang--Jia
Jia--Hu Region
Accumulative subsidence contour
Coordinating Committee for Geoscience
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in Hang-Jia-Hu plain （1964-2010）
Land subsidence in China
Sketch map of Land subsidence in the North China Plain
Ti ji
Tianjin
Beijing
The Bohai Sea
The East China Sea
Cangzhou
The maximum accumulative subsidence was 3300mm in Tanggu area of Tianjin.
In 2009
2009, the area of subsiding rate in Tianjin region greater than 10mm/a and
50mm/a was 6800 km2 and 1300 km2 ,respectively.
Coordinating Committee for Geoscience
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Land subsidence in China
Factors for land subsidence
 Geological
conditions:
g
thick soft sediments with high compressibility
 Dynamic conditions:
(1) groundwater overdraft;
(2) engineering construction
Rapid expansion and development of industrialization and
urbanization are also most important factors for land subsidence.
Coordinating Committee for Geoscience
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Land subsidence in China
A water tower in Tianjin was cracked due to land subsidence
Coordinating Committee for Geoscience
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Land subsidence in China
The walls of houses was cracked due to land subsidence.
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Land subsidence in China
The mouth of wells disjointed from ground
Coordinating Committee for Geoscience
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Land subsidence in China
The navigation capacity of bridges were greatly decreased.
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Land subsidence in China
Floods and storm tides occurred frequently in the coastal cities
(Tianjin,October 11, 2003)
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Land subsidence in China
The tidal dike has been reinforced for several times in many coastal cities
Coordinating Committee for Geoscience
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Land subsidence in China
Economic loss due to land subsidence
st ate o
o c loss
oss due to land
a d:
Estimate
of tota
total eco
economic
 Shanghai is ¥13 billion yuan (2001-2010), or ¥ 300
yuan ((1921-2010).
billion y
)
 Su-Xi-Chang region is ¥17 billion yuan until 2000.
 Hang-Jia-Hu
g
region
g
is ¥56 billion y
yuan ((1964-2004).
)
 Tianjin city is about ¥120 billion yuan until 2003.
g total loss is ¥9-10 billion/a
the average
the annual direct loss is ¥0.8-1.0 billion yuan
The total economic loss consists of direct and indirect
loss, and indirect loss accounts for 80-90% of the total
economic loss.
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
Land subsidence monitoring in China
Since 1999, China Geological Survey (CGS) started the National
Program on Investigation and Monitoring of Land Subsidence.
Borehole extensometers and automatic monitoring system;
Global positioning systems(GPS);
InSAR(Interferometric Synthetic Aperture Radar);
Levelingg measurements;
Automatic monitoring system for groundwater levels.
Coordinating Committee for Geoscience
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Land subsidence monitoring in China
Groundwater monitoring:
Groundwater level:625 wells;
Groundwater quality: 285wells;
Automatic monitoring points: 72
points.
Land subsidence monitoring:
Benchmark on bedrock: 72 points;
Borehole extensometer: 83 points;
Ground crack monitoring: 8 points.
GPS roving stations: 554 points.
t ki stations:
t ti
GPS permanentt tracking
12 points.
Automatic monitoring points: 72
points.
Investigation and monitoring works
i th
in
the Y
Yangtze
t river
i
d
delta
lt
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
Borehole
Extensometer
GPS
Land subsidence monitoring in China
InSAR (Interferometric
Synthetic Aperture Radar):
covering 67000 km2.
Investigation
and monitoring
works in the
Yangtze river
delta
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
Land subsidence monitoring in China
Shanghai deployed facilities like leveling nodes, borehole extensometers
and bedrock bench marks in different geological formation areas along
project lines, and had formed a land subsidence backbone network that is
independent but still tightly associated with the leveling network of the
central
t l city.
it
Engineering Land Subsidence
Monitoring Network in Urban
Areas of Shanghai city
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
Land subsidence monitoring in China
Groundwater monitoring:
GPS
G
Groundwater
d t level:436
l l 436 wells;
ll
Land subsidence monitoring:
Benchmark on bedrock: 2 points;
Borehole extensometer: 17 points;
GPS roving stations: 45 points;
L li nodes:
d 1742 points.
i t
Leveling
Investigation and monitoring
works in Tianjin Region
Coordinating Committee for Geoscience
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Land subsidence in China
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
Shanghai City
Major
cities & regions with land
Coordinating Committee for Geoscience
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subsidence
in Eastern China
Land subsidence induced by the exploitation of
ground water
This picture shows the bund
before 100 yeas. The embankment
did not exist at that time.
time
This picture presents the current
bund, the embankment have been
rise several times since it was
built
built.
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
Coordinating Committee for Geoscience
in East
Southeast
TheProgrammes
monitor net
ofand
water
tableAsia
in (CCOP)
Shanghai
地下水
水位标高（m）
The water table of the 4th confined
aquifer in Shanghai in 2007
-5
-10
-15
-20
-25
-30
-35
35
-40
-45
宝山大场地区（宝001-01S)
浦东高桥地区（浦077-01)
-50
金山枫泾地区(金247-01C)
青浦白鹤地区(青030-02W)
-55
1961 1966 1971 1976 1981 1986 1991 1996 2001 2006
年
The change feature of water table of the
4th confined aquifer since 1961
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
Na ion
Mineralization
Cl ion
Committee for Geoscience
TheCoordinating
monitor net of
groundwater quality in Shanghai area
Based on the longlong-term monitor of
ground water, the chemical component
off ground
d water
t iin Sh
Shanghai
h i area was
stable.
Programmes in East and Southeast Asia (CCOP)
The monitor of land subsidence
Coordinating Committee for Geoscience
The monitor net of land subsidence
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The monitor station for land subsidence
Coordinating Committee for Geoscience
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The benchmark net used for monitoring land subsidence
in the central city
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Precise levelingg
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
SITUATION OF SHANGHAI LAND SUBSIDENCE

Structure
St
t
and
d variety
i t off groundwater
d t mining
i i and
d
artificial recharge
Huangpu River
Yangtz River
There are total five confined aquifers.
 The 4th aquifer is the main exploitation layer.
Before 1964, groundwater was excessly mined,
which resulted in serious land subsidence.
Groundwater mining have been restricted since
1964, artificial recharge have been utilized.
Now, through adjusting mining plan, the quantity
of mining is gradually decreasing.
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The changes
of pumping groundwater and artificial
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recharge

General situation of land subsidence
Through leveling survey, the landmark which lies to Shanghai Ningbo road has
reflected the land subsidence at that time between 1910 and 1919
From 1921 to 1948, land subsidence is more visible than before.
Between 1949 and 1965, land subsidence is serious, especially between 1957
and 1961.
From 1966 to now, land subsidence has been controlled through decreasing
exploitation.
Coordinating Committee for Geoscience
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Land subsidence
volume (mm)
Land subsidence
isoline between 1980
and 1995 of the whole
city
1980-1995
Land subsidence isoline
between 1995and 2001
of the whole city
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1995-2001
Land subsidence isoline
between 2001and 2006
of the whole city
2001-2006
With the rate
increasing, the
diversity of
Shanghai land
subsidence is
visible
i ibl in
i
space.The data of
subsidence
separated from
each other
seriously,
y, what
indicated the
difference for
sedimentation.
sedimentation
That has impact
on municipal
infrastructure
infrastructure.
Coordinating Committee for Geoscience
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ANAYLSIS OF INFLUENCED FACTORS OF
SHANGHAI LAND SUBSIDENCE
larger-scale
construction, subsidence
accelerated
excess exploitation
in the early period
exploitation was strictly
controlled and land
subsidence became stable
 Before 1966, groundwater mining is primary factor of land subsidence, which resulted in serious
land subsidence.
 From 1966 to 1990, government have adopted prevention and cure measures to control land
subsidence ,the
the setting velocity has been kept within the minimum range.
range
 Since 1990, large-scale construction is another main factor, which accelerated land subsidence.
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)

Groundwater mining is remain the primary
factor of Shanghai land subsidence
Com
mpression(mm)
deformation
water level
time(
Groundwater level(m)
Historically, excess groundwater mining
has resulted in groundwater level
decreasing, and groundwater level descent
funnel is formed
formed, which will induce serious
land subsidence.
Cay layers is non-elastic , the
compression of which has the character of
hysteresis.
So,Committee
when groundwater
level
Coordinating
for Geoscience
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ascends, land subsidence still continue.
LAND SUBSIDENCE MONITORING
Shanghai has established monitoring network of land
subsidence, including land subsidence monitoring station,
groundwater level monitoring well
well, extensometer
extensometer, GPS
GPS, and
others.
Generally, leveling is the primary method to master the state
of Shanghai land subsidence,
subsidence also GPS and INSAR technique
are used every to monitor the land subsidence.
INSar
Land
subsidence
monitoring
station
GPS
leveling
extensometer
Groundwater
recharging
g g
well
Groundwater
level
monitoring
well
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
Monitoring station
off land
l d
subsidence
Coordinating Committee for Geoscience
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Distribution of GPS monitoring point
Coordinating Committee for Geoscience
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Distribution of groundwater
level
monitoring
well
Coordinating
Committee for
Geoscience
Programmes in East and Southeast Asia (CCOP)
Control of land subsidence in Shanghai
By control of exploitation, recharging of groundwater,
j
g the level of g
groundwater exploitation,
p
, etc.,,
adjusting
land subsidence was controlled well.
Recharging
g g well ((deep
p aquifer)
q
) Recharging
g g well ((shallow aquifer)
q
)
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
Land subsidence in Tianjin
Tianjin
is a coastal
cityforand
a major economic centre in the north of China
Coordinating
Committee
Geoscience
2 with
Programmes
in Eastof
and
Southeast Asia
(CCOP)about 10 million people.
It covers
an area
11000Km
Distribution of Land subsidence
Tianjin accumulative
land subsidence
from 1967 to 2009
Accumulative land
subsidence in Tanggu
district of Tianjin reached
3.3m.
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
Distribution of Land Subsidence
The land subsidence
has exceeded 8000
K 2 and
Km
d th
the severall
cones of depression
occurred
occurred.
The maximum
accumulative subsidence
is over 3.3m at present.
In recent years, with
development of
economy, severall
new centers of land
subsidence
appeared.
And the rates of these
area were more than
40mm/a.
Coordinating Committee for Geoscience
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Land subsidence history
Tianjin began to utilize groundwater resources
in1923. According to historical leveling points, land
subsidence happened, along with the development of
groundwater.
d t
4
Q(m 10 /a)
10000
Serious period
100Mm3/a
80-100mm/a
8000
S(mm/a)
110
6000
100
90
80
4000
70
60
50
40
2000
Controlled
period
20Mm3/a
10-20mm/a
Growth
G
h period
i d
3
12-100Mm /a
10-100mm/a
30
Initial period
12Mm3/a
10-20mm/a
20
10
0
Coordinating Committee for Geoscience
1920
1930
1940
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in East and
Southeast 1950
Asia (CCOP) 1960
1970
1980
1990
2000
losses due to storm tide increased
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Programmes in East and Southeast Asia (CCOP)
Characteristics of land subsidence in Tianjin
–
The Quaternary and Neogene deposits have a
thickness exceeding 1000m.
–
It’s difficult to provide enough water to meet the
growing demands.
–
The causes of land subsidence are complex and
varied .
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
Unconsolidated soil
nature consolidation
Natural factors
Neotectonic movement
S llevell rising
ii
Sea
Coordinating Committee for Geoscience
Programmes
East
and Southeast
Asia (CCOP)
the
causesinof
land
subsidence
can be divided into two kinds
Artificial factors
Petroleum production
geothermal development
Gas production
groundwater over-exploitation
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)
the causes of land subsidence can be divided into two types
Artificial factors
Load of high buildings
Coordinating Committee for Geoscience
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Artificial factors
Dewatering
Coordinating Committee for Geoscience
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Thank you
ou for
your
attention!!
Coordinating Committee for Geoscience
Programmes in East and Southeast Asia (CCOP)