Elfeki, A. M. and Dekking F. M. (2005). Modeling Subsurface Heterogeneity by Coupled Markov Chains: Directional Dependency, Walther’s Law and Entropy. Journal of Geotechnical and Geological Engineering, Vol. 23: pp.721-756.
★ CALL US 9953330565 ( HOT Young Call Girls In Badarpur delhi NCR
Modeling Subsurface Heterogeneity by Coupled Markov Chains: Directional Dependency, Walther’s Law and Entropy.
1.
2. Theory of Forward MC: FMC
-1 -2 -3 0
-1
Pr( | , , ,..., )
Pr( | ) : ,
i i i ik l n ar
i ik l lk
SS S S SZ Z Z Z Z
pS SZ Z
SS S
i0 1 i+1i-1 N2
l k qdSSa
N-1
SrSb
3. Theory of Backward MC: BMC
1Pr( | ).i il k
kl
S SZ Zp
lkp
klp
SS S
i0 1 i+1i-1 N2
l k qdSSa
N-1
SrSb
4. Conditioning FMC (Elfeki and
Dekking 2001)
( 1)
1 0 ( )
: Pr ( ) ,
N
ab bq
Nb a qab q N
aq
p p
p | ,S S SZ Z Z
p
SS S
i0 1 i+1i-1 N2
l k qdSSa
N-1
SrSb
5. Conditioning BMC
1 0Pr ( ).N Nr q a
qr a
| , SS SZ Z Zp
1 0
1 0
0
Pr( , )
Pr ( ) .
Pr ( )
N Nr q a
N Nr q a
qr a
N q a
, SS SZ Z Z
| , SS SZ Z Zp , SSZ Z
1 0
1 0 1 0 0
0 0
Pr ( )
Pr ( ).Pr ( ).Pr( )
.
Pr ( ).Pr( )
N Nr q a
qr a
N N Nq r ra a a
N q a a
| , SS SZ Z Zp
| , S | S SS S SZ Z Z Z Z Z
| S SSZ Z Z
SS S
i0 1 i+1i-1 N2
l k qdSSa
N-1
SrSb
6. Conditioning BMC (cont.)
1 0
( 1)
1 1 0
( )
0
Pr ( )
Pr ( ).Pr ( )
,
Pr ( )
N Nr q a
qr a
N
N N Nq r r rq ara
N
N q a aq
| , SS SZ Z Zp
p p| | SS S SZ Z Z Z
| S pSZ Z
SS S
i0 1 i+1i-1 N2
l k qdSSa
N-1
SrSb
9. , 1, , 1 0,,
( )
( )
: Pr( | , , )
, 1,..., .
i j k i j d i j m j adm k a
h h i v
kd ak mk
h h i v
fd of mf
f
p Z S Z S Z S Z S
. .p p p
k n
. .p p p
Coupled Markov Chain for Backward Conditioning on the Left Boundary.
i+1,ji,j
i,j-1
1,1
Nx,Ny
Nx,1
1,Ny
Nx,j
Coupled Markov Chain for Forward Conditioning on the Right Boundary.
i-1,j i,j
i,j-1
1,1
Nx,Ny
Nx,1
1,Ny
Nx,j1,j
1,j
------------------>
------------------<
10. Methods of Implementation FCMC,
BCMC and FBCMC
? >? >
?< ?<
? > ?<
Forward Markov Chain Model (two forward steps)
Backward Markov Chain Model (two backward steps)
Forward-Backward Markov Chain Model (one forward step and one backward step)
Well (1) Well (2) Well (1) Well (2)
11. Procedure for Extracting a Final
Geological Image
.0
1
)(
otherwise
SZif
ZI
kij
ijk
MC
R
R
k
k
R
k
ij ji
ji
ZI
MCMC
SZ
1
)(
)(
,
, 1}{#
}...,,max{ 21 n
ijijij
l
ij
Let the realizations be numbered 1,…, MC, and let Zij
(R) be the
lithology of cell (i,j) in the Rth realization. The empirical relative
frequency of lithology Sk at cell (i,j) is:
In the final image Z* the lithology at cell (i, j) will be the lithology
which occurs most frequently in the MC realizations. So, if Sl is such
that
Zij
*= Sl.
12. Sensitivity Analysis
• Various sampling intervals.
• Various horizontal transition probability matrices.
• Various degrees of diagonal dominancy of the horizontal transition
matrix.
• Use of Walther’s law to account for horizontal variability.
• Effect of conditioning on the model performance.
• Sensitivity of the Monte Carlo realizations.
• Various implementation strategies: forward, backward and
forward-backward methods.
• Use of cross validation to evaluate the model performance.
13. Case Studies
• Case study no. 1 (Afsluitdijk-Lemmer), NL
• Case study no. 2 (Casparde Roblesdijk part
of Waddenzeedijken,), NL
• Case study no. 3 (The Delaware river and
its underlying aquifer system in the vicinity
of the Camden metroplitan area, New
Jersey)
44. 0 4000 8000 12000 16000
Overall Horizontal Field Scale (meters)
0
0.01
0.02
0.03
0.04
dy/dx
Afsluitdijk- Lemmer (Netherlands)
Afsluitdijk Caspar de Roblesdijk (Netherlands)
Delaware River Aquifer (Longitudinal-Section), USA
Delaware River Aquifer (Cross-Section),USA
MADE site at Columbus, Mississippi [Elfeki and Rajabiani, 2002]