Using SUB model to predict long-term land subsidence in Yunlin and Chiayi areas
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1 Using SUB model to predict long-term land subsidence in Yunlin and Chiayi areas Presenter : Chiou-Shiang Hung Adviser : Chuen-Fa Ni Date : 2010/10/07
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Using SUB model to predict long-term land subsidence in Yunlin and Chiayi areas. Presenter : Chiou-Shiang Hung Adviser : Chuen-Fa Ni Date : 2010/10/07. Outline. Literature review Motivation Methodology Results Future work. Literature review. - PowerPoint PPT Presentation
Transcript of Using SUB model to predict long-term land subsidence in Yunlin and Chiayi areas
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Using SUB model to predict long-term land
subsidence in Yunlin and Chiayi areas
Presenter : Chiou-Shiang Hung Adviser : Chuen-Fa Ni Date : 2010/10/07
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• Literature review
• Motivation
• Methodology
• Results
• Future work
Outline
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Literature review
• Steep declines in water level were accompanied
by high rates of land subsidence.
(A.M. Wilson, S. Gorelick. 1996)
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Motivation
• The Choshui River alluvial fan consists
of sand, silt and clay.
(Hung Wei Jia et al. 2009)
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Model
• MODFLOW-2000 (Version 1.19.01, March
25 2010)
• SUB (Subsidence and Aquifer-System
Compaction) Package
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Governing equation
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Governing equation
Kv is the vertical hydraulic conductivity.
h is the hydraulic head.
Ssk is the specific storage.
t is time
△b is the change in thickness.
Sskv is the inelastic specific storage.
Sske is the elastic specific storage.
bo is the initial thickness.
△h is the change in hydraulic head.
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Layers 1, 2 and 3Initial Head = 0
1000
2000
STORAGE COEFFICIENT=0.1
STORAGE COEFFICIENT=6.56x10–5
STORAGE COEFFICIENT=2.62x10–4
Column
Row
1 2 3 4 5 6 7 8 9 1010
98
76
54
32
10
-100
-150
-350
K = 20 [m/day]
Vertical leakance value = 3x10–6/m
T = 1000, 0.5 [m2/day]
Vertical leakance value = 3x10–6/m
T = 1000 [m2/day]
100
50
200
Layer 1
Layer 2
Layer 3
Conceptual model
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T(transmissivity)=1000 [m2/day]
Conceptual model (Layer 2)
T(transmissivity)=0.5 [m2/day]
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1 2 3 4 5 6 7 8 9 10
1
2
3
4
5
6
7
8
9
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Discharge area (Layer 1)
Recharge area (Layer 1)
0 2 KILOMETERS
Pumping well (Layer 3)
Conceptual model
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Results (Head)
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
Initial
Layer 1
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
1 year
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
10 years
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
30 years
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Layer 2
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
Initial
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
1 year
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
10 years
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
30 years
Results (Head)
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Layer 3
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
Initial
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
1 year
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
10 years
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
30 years
Results (Head)
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X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
5 years
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
10 years
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
20 years
X (m)
Y(m
)
0 3000 6000 90000
6000
12000
18000
30 years
Results
Subsidence
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Future work
• Data collection
• Model calibration and verification
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Thanks for your attention
