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1. Dr. K Abdulrahman Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 5( Version 1), May 2014, pp.109-116
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Case Study of the Chaq-Chaq Dam Failure: Parameter
Estimation and Evaluation of Dam Breach Prediction Models
Dr. KawaZedanAbdulrahman
Abstract
On 4th
of February, 2006 at about 10:00 pm.Chaq-Chaq dam failed due to overtopping. The fall of 131.2 mm of
rain over a 24-hour period was recorded at Sulaimani metrological gage station, which is located about
7.5Kmsouth-east of the dam. As a result, the reservoir level rose, the dam has been overtopped and finally
breached near the spillway at the right abutment. Fortunately no human lives loss nor important structure
destruction were reporteddue to the dam failure. The aim of this paper is to estimate the flood hydrograph
passing through Chaq-Chaq dam breach using measured breach geometry as input to unsteady option of HEC
RAS 4.1.0 and calibrating the breach formation time to obtain the measured maximum water surface at Chaq-
Chaq Bridge (1.36 km downstream of dam axis). In addition the recent breach prediction models were evaluated
to check their accuracy in predicting the breach geometry, breach formation time and peak breach discharge.
I. Introduction
Chaq-Chaq dam is located about 2 km NE of
Sulaimani city (Iraq). Fig. 1 shows a satellite image
of the area between Chaq-Chaq dam and Chaq-Chaq
Bridge.Chaq-Chaq dam is a zoned earth dam of
central clay core and gravelly shell as shown in Fig.2.
Chaq-Chaq dam was designed and built by engineers
of little experience in the field of dam design and
construction. As a recognized design problem,one of
the major mistakes was the building of the spillway
beside the dam in the same valley not as a separate
structure. The spillway wall has been made vertical.
Compaction of an embankment near a vertical wall is
notrecommended in constructing embankmentdams
because this procedure will produce a weak bond at
the interface of the wall and the embankment(FEMA,
2005).In addition; the required compaction for the
materials close to the vertical wall will not be gained.
This weak-compacted portion will be weaker
compare to the other well-compacted portions of the
dam. Therefore, the dam breached close to the
spillway rather than other locations.
In order to check the accuracy of existing
breach prediction models in predicting the breach
geometry, breach formation time and peak breach
discharge; a bathymetric survey after the dam failure
has been carried out to obtain the breach geometry.
Extensive interviews with the surrounding habitants,
owners of the tourism cabinets, and directorate of
security have been done to gather information about
the breach formation time and the highest water level
at Chaq-Chaq Bridge.The breach formation time and
the highest water level at Chaq-Chaq Bridge is used
as input to calibrate the HEC RAS 4.1 (Brunner,
2010 a,b) to achieve the maximum flood discharge
passing through the dam breach as it will be
presented as the followings.
Figure 1: Satellite image showing the area between
Chaq-Chaq dam and Chaq-ChaqBridge.
RESEARCH ARTICLE OPEN ACCESS
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Figure 2: Photo of Chaq- Chaq dam after failure.
II. Breach GeometryData
Bathymetric survey has been carried out to obtain the breach geometries;Table 1 shows the geometry
parameters of Chaq-Chaq dam and its breach.
Table 1: Geometry parameters of Chaq-Chaq dam.
Parameter Height
of dam
H (m)
Top
width
(m)
Upstream
slope (v:h)
Downstream
slope (v:h)
Breach
Bottom
width
(m)
Breach
Average
width
(m)
Breach
Top
width
(m)
Dam
crest
level
(masl)
Value 14.5 9 1:3 1:2 29.6 38 46 780
III. Breach hydraulic data
Due to insufficient spillway capacity Chaq-
Chaq dam was overtopped and then failed. According
to a local witness (who was the formal responsible of
the dam and his house was located about 100 m far
from the dam) the maximum depth of water above
the dam crest was between 0.5 − 0.6 m. So, he was
also estimated the breach formation time to be
between 1 to 1.5 hours. In addition the maximum
water level due to the dam failure flood at Chaq-Chaq
bridge which is located about 1.36 km downstream of
the dam has been decided based on eyewitness
accounts. The maximum water level at the bridge was
around 759.4-759.5maslas corresponded to 20-30 cm
below the lower cord of the bridge. There was a
security team at the bridge to prevent peoples from
passing the bridge because there was a potential of
bridge failure due to the flood before and during the
dam failure. The flood extent at the bridge was seen
by the security team. Table 2 shows some of the
hydraulic parameters of Chaq-Chaq dam and Chaq-
Chaq Bridge.
Table 2: Hydraulic parameters of the Chaq-Chaq dam and bridge.
Para
meter
Depth
of
overt
oppin
g (m)
Breach
formati
on
time
(hr)
Reservoir
storage at
NPL El.
777.5
MCM
Reservoir
storage at
El. 780.0
MCM
Reservoir
storage at
El. 780.6
MCM
Spillway
length
(m)
Spillwa
y crest
level
(masl)
Minimum
stream bed
level at the
bridge
(masl)
High
cord
level
of the
bridge
(masl)
low
cord
level
of the
bridge
(masl)
Maxim
um
water
level
at the
bridge
(masl)
Value 0.6 1-1.5 1.4 2.344 2.55 15 777.5 754.4 761 759.7 759.6
Flow
Direction
Spillway Dam BodyCore
Shell
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IV. Upstream and downstream cross
sections data
One-dimensional dam breach hydraulic
modelof HEC-RAS is used frequentlyto predict the
flood inundation area due to a dam breachflood
through the downstream valley. It was found
thatHEC-RAS performed well, with relatively good
agreement between predicted and measured water
levels(Yochum etal.,2008) and(Gee, 2010).
HEC-RAS modeling system is a public
domain model developed by the US Army Corp of
Engineers (Brunner, 2010 a,b). It performs one-
dimensional (1D) steady and unsteady flow
simulations on a full network of natural or man-made
open channels. Additionally, it has the ability to
model storage areas and dam break problems as well
as bridges and culverts hydraulics.
In order to model the flooding in the stream
valley using HEC‐RAS; cross sections data are
required. In this study a topographic map of 1m
interval is obtained in AutoCAD format from the
municipality of Sulaimanya.Then, the river reach in
the Chaq-Chaq system extending over a length of
4.15 km from upstream end of the reservoir to the
downstream portion of the damis considered for
analysis.
The cross sections data of the river reach
aredeveloped by AutoCAD Civil 3D 2013, by using
this software the main channel as well as right and
left overbank have beennoted and coded in the
hydraulic model. A number of 21 cross sections at
the upstream of the dam are used to model the
reservoir area and19 cross sections were developed at
the downstream portion. Extra cross sections were
added by interpolation at a maximum distance of 75
m.
The values of Manning’s roughness
coefficient were entered directly into the cross
section editor to describe the channel and overbanks.
These values were determined by visual inspection
and satellite imagesbased on guidance fromChow
(1959). The Manning’s roughness coefficient values
were set at 0.028 for main channel and the two
overbanks. These values have been assumed because
the stream reach under study is clean with stones and
high flow stages are expected during the dam break
analysis (Parhi etal, 2012).
V. HEC-RAS Model
The unsteady option of HEC-RASrequires
the breach geometry and breach formation time as
input in order to model a dam breach flood.The
breach geometry is readily available from the
bathymetric survey but breach formation time is still
a matter of uncertainty (1-1.5 hrs).
Breach formation time is the most sensitive
parameter in developing a hydraulic model for dam
break problems and breach hydrograph development.
Therefore, in this study it is attempted to calibrate the
breach formation time through simulation of breach
flood using HEC-RAS 4.1 unsteady model. For
calibration of Breach formation time value; the
observedWSE at the downstream bridge has been
considered.
A weir coefficient of 1.1 was used in this
analysis; the trigger time of breach is set such that it
corresponds to the time of peak of a developed inflow
hydrograph as it will be explained in the next
paragraph. At that time the water surface elevation
was equal to 780.57 m which is close to the observed
water surface elevation ( 780.5 − 780.6 m). This
equality in the simulated and the observed WSE
proves that the developed inflow hydrograph is
accurate and that there was under-estimate for the
inflow hydrograph in the design of Chaq-Chaq Dam.
VI. Boundary conditions
The upstream boundary condition is
modeled using the flood hydrograph corresponding to
the measured 131.2 mm rainfall depth during 24 hrs
on a 151 𝑘𝑚2
of catchment area. The flood
hydrograph is developed from contributing
catchments using NRCSunit hydrograph (UH)
method. The NRCS dimensionless UH is a synthetic
unit hydrograph in which the discharge is expressed
by the ratio of discharge to peak discharge and the
time by the ratio of time to the time of rise of the unit
hydrograph(Chow etal., 1988). Fig.3 shows the
developed inflow flood hydrograph. Details on how
to develop flood hydrograph using NRCS UH can be
found in McCuin (2005).
The downstream boundary condition is set
to normal depth and an approximate water surface
slope is assumed for the friction slope.
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Figure 3: Inflow flood hydrograph.
VII. Initial conditions
The WSE upstream of the dam is set to 780
m which is the crest elevation of the dam; while WSE
at the downstream reach is set such that 2 m depth of
water is existing.
VIII. Hydraulic model result
Using of surveyed dam breach geometry
combined with standard approaches for developing
the upstream hydrograph boundary conditiona HEC
RAS model was developed to generate different
breach hydrograph corresponding to different breach
formation times, namely 1.25 hrs, 1.50hrsand
1.60hrs.Fig. 4 provides a plot of modeled water
surface profiles at different times of the simulation
and Fig. 5 shows the outflow flood hydrograph
through the dam breach.
Each hydrograph was routed through the
downstream reach to produce different water surface
elevations at the downstream bridge; the results of
the model at the bridge location are shown in Table 3.
The percentage of errorsbetween the predicted water
surface elevation and theobservedwater surface
elevation at the downstream bridge are depicted in
the Table 4.
Figure 4: water surface profiles at different times of simulation corresponding to 1.6 hrsof breach formation
time.
0.00
20.00
40.00
60.00
80.00
100.00
120.00
140.00
160.00
180.00
200.00
0 10 20 30 40 50 60 70 80 90
Flood(m3/sec)
Time (hrs)
0 1000 2000 3000 4000
750
760
770
780
Main Channel Distance (m)
Elevation(m)
Legend
WS 04FEB2006 2340
WS 04FEB2006 2200
Ground
Bridgesection
DamAxis
FirstSectionatupstream
Chaq Chaq Ch1
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Figure 5: Outflow flood hydrograph due to Chaq-Chaq dam breach.
Table 3: Results of the model at the bridge location at different breach formation time.
Breach
formati
on time
(hr)
River
Sta
Time
of peak
(hrs)
Q
Total
(𝒎 𝟑
/s
)
Min
Ch
El
(m)
W.S.
Elev
(m)
Crit
W.S.
(m)
E.G.
Elev
(m)
E.G.
Slope
(m)
VelC
hnl.
(m/s)
Flow
Area
(𝒎 𝟐
)
Top
Width
(m)
Froud
e #
Chl
1.25
Just
upstrea
m of
bridge
4FEB200
62325
929.5 754.4 760.60 758.4 760.8
0.0005
17
2.37 492.4 287.2 0.32
1.5
Just
upstrea
m of
bridge
04FEB20
06 2335
919.1 754.4 759.92 758.4 760.2
0.0009
71
2.94 392.1 208.1 0.43
1.6
Just
upstrea
m of
bridge
04FEB20
06 2340
915 754.4 759.55 758.4 760
0.0012
81
3.24 352.9 165.3 0.48
Table 4: Departures of estimated and observed water surface elevations at Chaq-Chaq Bridge corresponding to
different BFT.
Breach formation time
(hr)
Estimated WSE at
Chaq-Chaq bridge
using HEC RAS (m)
ObservedWSE at Chaq-
Chaq bridge (m)
Difference between
estimated and measured
WSE (m)
1.25 760.60 759.50 1.10
1.5 759.92 759.50 0.42
1.6 759.55 759.50 0.05
A comparison of the predictedWSE with the
observed WSE at the bridge indicates that a breach
formation time of 1.60 hrs may be considered the
most accurate value, with a differenceof 0.05 m in
WSE.The modeling indicates a peak breach flood
discharge of979.2 m3
s and this value attenuates at
the bridge to 915.4 m3
s.
IX. Existing Empirical Breach Prediction
Models
Simulation of dam breach floods is essential
to characterize and identify hazards due to
hypothetical dam failures. Hydraulic modelssuch as
HEC-RASare often used for the analysis of
downstream impacts resulting from potential
damfailures. Estimation of the dam breach
parameters, such as formation time, width and side
slopes,has usually done external to the hydraulic
model. If input breach parameters cannot be
predicted with sufficient accuracy, more conservative
parameters and associated increased costs may be
1200 1800 2400 0600
04Feb2006 05Feb2006
0
200
400
600
800
1000
1200
Plan: 1.1 weir 1.5 River: Chaq Chaq Reach: Ch1 RS: 19.5
Time
Flow(m3/s)
Legend
Flow
Beginning of
dam failure
@time of 2200
Peak outflow@
time of 2340
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required (Wahl, 1997).This paper aims to check the
reliability of the existing breach prediction
methodologies in estimating the breach parameters of
Chaq-Chaq dam.
Four important breach parameters
namelytop width, average width, breach formation
time and peak discharge pass through the beach are
estimated by thefollowing breach prediction models
Froehlich (1995, 2008), Xu and Zhang (2009) and
Pierce etal. (2010)and the results are compared to the
measured values (breach geometries) and HEC-RAS
output values (breach formation time and peak
discharge).
Froehlich (1995) model was selected based
on the results obtained by(Wahl, 2004) which
showed that this model is more accurate than other
existing prediction models up to the time the paper
was published.Froehlich (1995) as cited in (Wahl,
2004), developed the following formulas based on
75, 34 and 31 case studies for Bavg , Tf and Qp ;
respectively:
Bavg =0.1803× ko × Vw
0.32
× Hb
0.19
… … … … … … … … … … . . … … … … … … … (1)
Tf = 0.00254 × Vw
0.53
× Hb
−0.9
… … … … … … … … … … . . … … … … … … … … … (2)
Qp = 0.607Vw
0.295
Hw
1.24
… … … … … … … … … … … . … … … … … … … … … … . . (3)
Where Ko = constant = 1.4 if there is overtopping and 1.0 if else, Z=1.4 if there is overtopping, otherwise
Z=1.0, Vw = volume of reservoir at the time of failure, hb =height of breach, Bavg = average width, Tf =
breach formation time and Qp = peak discharge.
Froehlich (2008) developed the following formulas based on 74, 23 case studies for Bavg , and tf; respectively:
Bavg = 0.27Ko Vw
0.32
Hb
0.04
… … … … … . . … … … … … … . … … … . . … … … … . . (4)
Tf = 0.0175
Vw
gHb
2 … … … … … … … … … … … … … … … . … … … … … … … … . (5)
Where Ko = constant = 1.3 if there is overtopping and 1.0 if else, Z=1.0 if there is overtopping, if not Z=0.7.
Xu and Zhang (2009) proved that his model is more accurate than other models. This model was developed
using 182 case studies to estimateBt,Bavg , Tf and Qp; respectively:
Bt
Hb
= 1.062
Hd
Hr
0.092
Vw
1
3
Hw
0.508
eB1 … … … … … … … … … … … … … … … … . (6)
With Bt = top width of the breach, Hd = dam height, Hr = 15m , Hw = height of water at the time of
failure,B1 = b3 + b4 + b5, in which b3 = 0.061, 0.088, and −0.089 for dams with core-walls, concrete faced
dams, and homogeneous or zoned-fill dams, b4 = 0.299 and −0.239 for overtopping and seepage erosion or
piping, b5 = 0.411, −0.062, and−0.289 for high, medium, and low dam erodibility
Bave
Hb
= 0.787
Hd
Hr
0.133
Vw
1
3
Hw
0.652
eB2 … … … … … . … … … … … … … … … . (7)
with B2 = b3 + b4 + b5, in which b3 = −0.041, 0.026, and − 0.226 for dams with core-walls, concrete faced
dams, and homogeneous or zoned-fill dams, respectively, 𝑏4 = 0.149 𝑎𝑛𝑑 − 0.389 for overtopping and seepage
erosion/piping, respectively, 𝑏5 = 0.291, −0.14, and − 0.391 for high, medium, and low dam erodibility,
respectively
Tf
Tr
= 0.304
Hd
Hr
0.707
Vw
1
3
Hw
1.228
eB3 … … … … … … … … … … … … . … … … . (8)
withTr = 1 hr., B3 = b3 + b4 + b5 , in which b3 = −0.327, −0.674, and − 0.189 for dams with core-walls,
concrete faced dams, and homogeneous/ zoned-fill dams, respectively, b4 = −0.579 and − 0.611 for
overtopping and seepage erosion/piping, respectively, b5=−1.205, −0.564, and 0.579 for high, medium, and low
dam erodibility, respectively.
Qp
gVw
5/3
= 0.175
Hd
Hr
0.199
Vw
1
3
Hw
−1.274
eB4 … … … … . … … … … … . … … … (9)
withB4 = b3 + b4 + b5, in which b3 = −0.503, −0.591, and − 0.649 for dams with core-walls, concrete faced
dams, and homogeneous or zoned-fill dams, respectively, b4 = −0.705 and − 1.039 for overtopping and
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seepage erosion/piping, respectively, b5 = −0.007, −0.375, and − 1.362 for high, medium, and low dam
erodibility, respectively.
Pierce (2010) showed that his developed multiple-regression model using 87 case studies is more accurate than
the Froehlich (1995) in predicting peak-discharge through an embankment dam breach.
Qp = 0.038Vw
0.475
Hd
1.09
… … … … … … … … … … … … … … … . . . … … … … … (10)
X. Comparison with considered empirical breach prediction models
Applying the above equations to Chaq-Chaq dam failure yields the results shown in Table 5.
Table 5: Results of empirical models applied to Chaq-Chaq dam failure.
Breach
parameter
Observed
value
HEC RAS
Prediction
Froehlich
(1995)
Prediction
Froehlich
(2008)
Prediction
Xu and
Zhang(2009)
𝐏𝐫𝐞𝐝𝐢𝐜𝐭𝐢𝐨𝐧 𝐛
Pierce
(2010)
𝑩𝒕 (m) 46 N.A. 57.25 𝑎
51 𝑎 54.5 N.A.
𝑩 𝒂𝒗𝒆 (m) 38 N.A. 47.1 43.8 38.4 N.A.
𝑻 𝒇 (hr) 1-1.5 1.6 0.57 0.62 1.17 N.A.
𝑸 𝒑 (
𝒎 𝟑
𝑺
) N.A. 979.2 1364 N.A. 1274 809
Side slope
Z
1.13 N.A. 1.4 1 N.A. N.A.
a. Obtained by using values of Z and 𝐵𝑎𝑣𝑒
b. Medium dam erodibility is assumed.
Table 6: Percentage of errors between predicted and measured values.
Breach
parameter
Froehlich
(1995)
Prediction
Froehlich (2008)
Prediction
Xu and Zhang
(2009)
Prediction
Pierce
(2010)
Prediction
𝑩𝒕 (m) 24 10.8 18.5 N.A.
𝑩 𝒂𝒗𝒆 (m) 23.9 15.2 1.0 N.A.
𝑻 𝒇 (hr)* -64.4 -61.2 -26.8 N.A.
𝑸 𝒑 (
𝒎 𝟑
𝑺
)* 39.2 N.A. 30.1 -17.3
*HEC RAS results are considered as measured values
Generally, all the models over-predict the
breach top width andthe averagewidth.This trend of
the models to over-predict the breach size may be
attributed to the fact that they are developed based on
the assumption of breach forms in a shape of
trapezoid, while Chaq-Chaq breach has a vertical side
near the spillway which may be considered as an odd
case. However,Xu and Zhang (2009) predicts the
average breach width more accurate than others,
where the percentage of the error between the
predicted and the measured values is 1% as shown in
table (6). While the predicted breach top width using
Froehlich (2008) appears to be better than others with
an error of 10.8% and Xu and Zhang comes in the
second order with an error of 18.5%.
All the used models under-predict the breach
formation time, includingXu and Zhang (2009) who
was the best where it gives an error of -26.8%.
Froehlich (1995 and 2008) errors are -65.4% and -
62.4%; respectively.
The predictedpeak flood discharge using the
considered empirical models shows that most of these
equations tend to over-predictthe value of this
parameter; except Pierce (2010) which yields a value
lower than that indicated by HEC RAS model. Pierce
(2010)yieldsapeak flood discharge with an error of -
17.3%, Xu and Zhang (2009)estimates the peak
discharge with an error of 30.1% andFroehlich
(1995)estimates the peak discharge with an error of
39.2%.
XI. Conclusions
Simulation of dam breach floods is essential
to characterize and identify hazards due to
hypothetical dam failures. Hydraulic models such as
HEC-RAS are often used for the analysis of
downstream impacts resulting from potential dam
failures. Estimation of the dam breach parameters,
such as formation time, width and side slopes, has
usually done external to the hydraulic model.
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Due to uncertainty in determining the exact
value of the breach formation time; different values
of breach formation time have been coded into the
HEC RAS 4.1 to calibrate its valueby using the
observed highest water level at Chaq-Chaq Bridge.In
this context a breach formation time of 1.6 hrs was
achieved. Themaximum flood discharge passing
through the dam breach for the corresponding breach
formation time was 979.2 𝑚3
𝑠for the corresponding
breach formation times.
The most competitive and recent breach
prediction models were examined to determine the
most accurate onein predicting the breach
parameters.In this context; Xu and Zhang (2009)
performs better than other in predicting the average
breach width and the breach formation time.
Froehlich (2008) predicts the top breach width more
accurate than other models andXu and Zhang(2009)
is in the second order. The peak flood discharge
passing the breach of the dam is under-estimated by
pierce (2010) with an error of 17.3%, while Xu and
Zhang (2009) over-estimates the peak discharge with
an error of 30.1%.
As a conclusion Xu and Zhang (2009) can
be considered as the most accurate breach prediction
model because it was the best in predicting the breach
width and the breach formation time.
XII. Acknowledgments
The writer acknowledges the support from
the municipality of Sulaimani especially the GIS
department (Shahlaa A. F., Azad A. H., and
Mohammed H.). Thanks also go to Dr. RizgarS. and
Dr. NihadB.for their valuable notations.
Bibliography
[1] Pierce M. W.; Thornton C. I.; Abt S. R.
(2010). Predicting Peak Outflow from
Breached Embankment Dams. Journal of
Hydrologic Engineering, 15(5), 339-349.
[2] Atallah, T. A. (2002). A review on dams and
breach parameters estimation. Virginia:
MSc. Thesis .
[3] Brunner, G. W. (2010 a). HEC-RAS river
analysis system. User’s Manual, version4.1,
Hydrologic Engineering Center. Institute for
Water Resources, U. S. Army Corps of
Engineers, Davis, Calif.
[4] Brunner, G. W. (2010 b). HEC-RAS river
analysis system. Hydraulic Refference
Manual version 4.1, Hydrologic Engineering
Center. Institute for Water Resources, U.S.
Army Corps of Engineers, Davis, Calif.
[5] Chow, V. T. (1959). Open channel
hydraulics. New York: McGraw-Hill Book
Company.
[6] Chow, V. T., Maidment, D. R., Mays, L. W.
(1988). Applied hydrology. McGRAW-
HILL.
[7] FEMA. (2005). Conduits through
embankment dams. Federal Emergency
Management Agency.
[8] Froehlich, D. C. (2008). Embankment dam
breach parameters and their uncertainties.
Journal of Hydraulic Engineering, 134(12),
1708-1721.
[9] Gee, D. M. (2010). Dam breach modeling
with HEC-RAS using embankment erosion
process models. World Environmental and
Water Resources Congress (pp. 1347-1356).
Davis: ASCE.
[10] McCuin, R. H. (2005). Hydrologic analysis
and design. New Jersey: Pearson.
[11] Parhi, P. K., Sankhua, R. N., Roy, G. P.
(2012). Calibration of Channel Roughness
for Mahanadi River, (India) Using HEC-
RAS Model. Journal of Water Resource and
Protection, 4, 847-850.
[12] Wahl, T. L. (2004). Uncertainty of
predictions of embankment dam. Journal of
Hydraulic Engineering, 130(5), 389-397.
[13] Xu, Y., Zhang, L. M. . (2009). Breaching
parameters for earth and rockfill dams.
Journal of Geotechnical and
Geoenvironmental Engineering, 135(12),
1957-1970.
[14] Yochum, S. E., Goertz L. A., Jones, P. H.
(2008). Case study of the Big Bay dam
failure: accuracy and comparison of breach
predictions. Journal of Hydraulic
Engineering, 134(9), 1285-1293.