Dam Break Study-Hunza River by NESPAK
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Transcript of Dam Break Study-Hunza River by NESPAK
ATABAD LANDSLIDE
In the name of Allah the Most Gracious the Most Merciful
ATABAD LANDSLIDE
DAM BREAK STUDY OF
ATABAD LANDSLIDE
MARCH 2010
National Engineering Services Pakistan (Pvt.) Ltd.
ATABAD LANDSLIDE
THE DAM BREAK ANALYSIS HAS BEEN
CARRIED OUT BY NESPAK TO ANSWER THE
FOLLOWING QUESTIONS;
1.WHAT IS THE LOCATION & COMPOSITION OF LANDSLIDE?
2.WHAT IS THE CAPACITY OF LAKE THAT HAS BEEN FORMED?
3.WHEN THE LAKE WOULD OVERTOP THE LANDSLIDE MASS?
4.WHAT WOULD BE THE PEAK FLOOD DISCHARGE AT
VARIOUS LOCATIONS ALONG HUNZA RIVER DOWNSTREAM
OF LANDSLIDE?
5.WHAT WOULD BE THE DEPTH AND VELOCITY OF WATER AT
VARIOUS LOCATIONS?
ATABAD LANDSLIDE
THE DAM BREAK ANALYSIS HAS BEEN CARRIED
OUT BY NESPAK TO ANSWER THE FOLLOWING
QUESTIONS (CONTD….);
6. HOW MUCH IS THE WARNING TIME FOR VARIOUS
VILLAGES/GILGIT CITY ?
7. WHAT ARE THE AREAS THAT WOULD BE AFFECTED IN CASE
OF DAM FAILURE ?
8. UPTO WHICH LOCATION ON THE RIVER THE DAMBREAK
FLOOD WAVE WOULD BE HIGHLY DESTRUCTIVE?
9. WHAT ARE THE MAJOR AND IMMEDIATE STEPS/ DECISIONS
REQUIRED AT THIS STAGE?
ATABAD LANDSLIDE
THE KEY PROFESSIONALS INVOLVED IN THIS
ANALYSIS ARE;
Dr. TAHIR HAYAT VICE PRESIDENT (GT&GE)
MIRZA ASIF BAIG GENERAL MANAGER (WRD)
Dr. MANSOOR HASHMI GENERAL MANAGER (WRD)
Engr. SHAHRUKH LATIF CHIEF ENGINEER (WRD)
Engr. YASIR ABBAS SENIOR ENGINEER (WRD)
Mr. ADIL LATIF GIS/RS-ANALYST
Mr. MUHAMMAD AKRAM SURVEYOR
Mr. RAZZAQ AHMAD DRAFTSMAN
AND SUPPORTING STAFF
ATABAD LANDSLIDE
LOCATION MAP
Gilgit
ATABAD LANDSLIDE
SATELLITE MAP OF LANDSLIDE AREA
ATABAD LANDSLIDE
GEOLOGICAL MAP OF LANDSLIDE AREA
ATABAD LANDSLIDE
ATABAD LANDSLIDE
FIVE SOIL AND ONE ROCK (GRAVEL) SAMPLE WAS
COLLECTED FROM THE LANDSLIDE DAM SITE.
THREE SAMPLES OF THE DUST WERE COLLECTED AS
SAMPLE 1, 2 AND 3, WHILE TWO SAMPLES OF THE BLACK
CLAY WERE COLLECTED AND LABELED AS SAMPLE 4 AND 5.
THESE SAMPLES WERE SUBJECTED TO LABORATORY
TESTS.
THE RESULTS OF LABORATORY TESTS SHOW THAT THE
DUST SAMPLES ARE VERY FINE ROCK FLOUR AS THEY
SHOW 30% TO 80% MATERIAL PASSING NO. 200 SIEVE YET
THESE HAVE NO PLASTICITY.
SOIL AND ROCK SAMPLES
ATABAD LANDSLIDE
THUS THE VISUAL OBSERVATIONS AT THE SITE ARE
CONFIRMED THAT THE BLACK SOIL HAS ORGANIC CONTENT
AND IT IS VERY FINE AND PLASTIC. ON THE OTHER HAND THE
DUST AT SITE IS ALSO VERY FINE BUT NON-PLASTIC.
SOIL AND ROCK SAMPLES
THE BLACK SOIL SAMPLES (SAMPLE 4 AND 5) INDICATE A
VERY FINE SOIL WITH ALMOST 100% PASSING NO. 200
SIEVE IN BOTH CASES AND HAVING LL OF 28% AND PL
RANGING FROM 21% TO 22%.
THE ORGANIC MATTER CONTENT IS 0.95% AND 1.10% FOR
THE TWO BLACK CLAY SAMPLES, PEGMATITE AND
APALITE.
ATABAD LANDSLIDE
SOIL AND ROCK SAMPLES
THE GRAVEL SAMPLES COLLECTED FORM THE SITE
INDICATE THAT THESE ARE GANODIORATIC ROCKS WITH
INTRUSION OF GRANITE, PEGMATITE AND APALITE.
ATABAD LANDSLIDE
A VIEW OF SLUSH MATERIAL PRESENT IN THE UPSTREAM AREA.
ATABAD LANDSLIDE
A VIEW OF NARROW UPSTREAM VALLEY.
ATABAD LANDSLIDE
A DISTANT VIEW OF WIDE VALLEY NEAR GULMIT.
ATABAD LANDSLIDE
A VIEW OF SHISHKAT BRIDGE. NOTE THE EXPANDING LAKE WATER LEVEL TOUCHING THE FOUNDATIONS.
ATABAD LANDSLIDESOURCE INFORMATION
CONTOUR SURVEY OF LANDSLIDE MASS SPOT-5 SATELLITE IMAGERY DATA (LANDSLIDE AREA ONLY) ASTER DATA (30 M RESOLUTION) SURVEY OF PAKISTAN (SOP), G.T SHEETS
DAILY FLOW AND INSTANTANEOUS PEAK FLOW DATA AT HUNZA RIVER AT DANIYOR BRIDGE (1962-ONWARDS) GILGIT RIVER AT GILGIT (1962-ONWARDS) INDUS RIVER AT PARTAB BRIDGE (1960-ONWARDS) INDUS RIVER AT SHATIAL BRIDGE (1984-ONWARDS) INDUS RIVER AT BESHAM (1960-ONWARDS)
ATABAD LANDSLIDESOURCE INFORMATION
CROSS SECTIONAL SURVEY TOTAL = 140 CROSS SECTIONS HUNZA RIVER = 128 CROSS-SECTIONS GILGIT RIVER = 12 CROSS-SECTIONS
CROSS SECTIONS EXTRACTED FROM ASTER DATA FROM GILGIT TO BESHAM TOTAL = 90 CROSS SECTIONS AT EVERY 3 KM
ATABAD LANDSLIDE
TOPOGRAPHIC SURVEY OF LANDSLIDE
FLOW PATH
Section Across Dam
LegendL-Section
X-Section
ElevationHigh : 2500
Low : 2312
ATABAD LANDSLIDE
LONGITUDINAL SECTION OF LANDSLIDE ALONG POSSIBLE FLOW PATH
Flow Direction
ATABAD LANDSLIDE ANALYSIS OF G.T SHEET, ASTER DEM & RIVER SURVEY
ATABAD LANDSLIDE
ELEVATION CAPACITY CURVE OF LAKE
ATABAD LANDSLIDE
ELEVATION CAPACITY CURVE OF LAKE
ATABAD LANDSLIDE
ELEVATION CAPACITY CURVE OF LAKE
ATABAD LANDSLIDE
DAM-BREAK STUDIESSCENARIO ANALYSED
DAM BREAK STUDY HAS BEEN CARRIED OUT FOR TWO CONDITIONS
1. FOR 18m CUT ( ALREADY ACHIEVED)
2. FOR 30m CUT (MAY BE ACHIEVED BEFORE OVERTOPPING)
ATABAD LANDSLIDE
ESTIMATED MONTHLY AVERAGE FLOWS AT LANDSLIDE LOCATION
254
232
218
502 15
09
5061
9841
4267
1326
658
486
1009
1
0
2000
4000
6000
8000
10000
12000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Flow
(ft3 /s
)
0
50
100
150
200
250
300
Flow
(m3 /s
)
ATABAD LANDSLIDE
OBSERVED MONTHLY AVERAGE FLOWS ATDANIYOR, GILGIT AND PARTAB BRIDGE
0
1000
2000
3000
4000
5000
6000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Flow
(m3 /s
)
0
50
100
150
200
Flow
x 1
000
(ft3 /s
)
Hunza River at Daniyor Gilgit river at Alam Bridge Indus River at Partab/Bunji
ATABAD LANDSLIDE
ESTIMATED TIME TO OVERTOP
ATABAD LANDSLIDE
ESTIMATED TIME TO OVERTOP
ATABAD LANDSLIDE
ESTIMATED TIME TO OVERTOP
ATABAD LANDSLIDE
DAM-BREAK STUDIES HYDROLOGIC ENGINEERING CENTRE’S RIVER ANALYSIS SYSTEM (HEC-
RAS) VER-4.0 HAS BEEN USED IN THIS DAM BREAK STUDIES
HEC-RAS IS A ONE-DIMENSIONAL HYDRODYNAMIC MODEL DEVELOPED BY U.S ARMY CORPS OF ENGINEERS
HEC-RAS CAN MODEL BOTH OVERTOPPING AND PIPING FAILURE OF EARTHEN DAMS
THE RESULTING FLOOD WAVE IS ROUTED DOWNSTREAM USING UNSTEADY FLOW EQUATIONS
ATABAD LANDSLIDEDAM-BREAK STUDIES
ESTIMATION OF BREACH PARAMETERS
THE BREACH PARAMETERS INCLUDE TIME TO BREACH BOTTOM WIDTH OF BREACHED SECTION BOTTOM ELEVATION OF BREACHED SECTION SIDE SLOPES AT BREACHED SECTION BREACH WEIR COEFFICIENT
0 200 400 600 8002250
2300
2350
2400
2450
2500
2550
Latest Cross sections70_1_n = 0.1 Plan: 70 3/16/2010 RS = 100100 IS
Station (m)
Ele
vatio
n (m
)
Legend
WS Max WS
EG Max WS
Ground
Bank Sta
.1
ATABAD LANDSLIDEDAM-BREAK STUDIES
ESTIMATION OF BREACH PARAMETERS
BOTTOM WIDTH OF BREACHED SECTION HAS BEEN ESTIMATED AS 190 M BOTTOM ELEVATION OF BREACHED SECTION HAS BEEN ESTIMATED AS
2300 M LEFT AND RIGHT SIDE SLOPES HAS BEEN ESTIMATED AS 1 VER. : 1 HOR. BREACH WEIR COEFFICIENT HAS BEEN ESTIMATED AS 2.6 VARIOUS TIME TO BREACH HAS BEEN ANALYZED RANGING FROM 1 HOUR
TO 24 HOUR
ATABAD LANDSLIDEDAM-BREAK STUDIES
ESTIMATION OF BREACH PARAMETERS
ATABAD LANDSLIDEDAM-BREAK STUDIES
OUTFLOW FLOOD HYDROGRAPH
THE FLOOD HYDROGRAPH AS A RESULT OF RELEASE OF ALL LAKE CONTENTS
2300 2400 0100 0200 0300 040030Dec2009 31Dec2009
0
20000
40000
60000
80000
Plan: 70 River: Hunza Reach: 1 RS: 101935.7
Time
Flow
(m3/
s)
Legend
Flow3,319,578 ft3/s
ATABAD LANDSLIDE
DAM-BREAK STUDIESSUMMARY OF SCENARIO ANALYSED
SCENARIO ID TIME TO BREACH DESCRIPTION
18-1 1 hour
Cut Depth = 18 mOvertopping Level =2398 m
Dam Height = 108 mLake Volume = 195 MCM
18-3 3 hour
18-6 6 hour
18-24 24 hour
30-1 1 hour
Cut Depth = 30 mOvertopping Level =2386 m
Dam Height = 96 mLake Volume = 133 MCM
30-3 3 hour
30-6 6 hour
30-24 24 hour
ATABAD LANDSLIDE
Lake
DAM-BREAK STUDIESRIVER SCHEMATISATION
LAKE
LANDSLIDE
HUNZA RIVER
River Reach Length = 100 kmfrom landslide location to
confluence with Gilgit River
Confluence with Gilgit River
ATABAD LANDSLIDE
0 20000 40000 60000 80000 100000 1200001200
1400
1600
1800
2000
2200
2400
Latest Cross sections70_1_n = 0.1 Plan: 70 3/16/2010
Main Channel Dis tance (m)
Ele
vatio
n (m
)
Legend
EG 29DEC2009 2400
WS 29DEC2009 2400
Crit 29DEC2009 2400
Ground
DAM-BREAK STUDIESRIVER BED PROFILE
LAKE
LANDSLIDE
HUNZA RIVER
Reach Length = 100 kmSlope of River = 0.009
(900 meters drop in 100 km)
Confluence with Gilgit River
ATABAD LANDSLIDE
DAM-BREAK STUDIESFLOOD WAVE PROPOGATION
LAKE
LANDSLIDE
Confluence with Gilgit River
ATABAD LANDSLIDE
0 20000 40000 60000 80000 100000 1200001200
1400
1600
1800
2000
2200
2400
Latest Cross sections70_1_n = 0.1 Plan: 70 3/17/2010
Main Channel Dis tance (m)
Ele
vatio
n (m
)
Legend
EG Max WS
WS Max WS
Crit Max WS
Ground
DAM-BREAK STUDIESMAXIMUM WATER SURFACE ALONG THE RIVER
LAKE
LANDSLIDE
Confluence with Gilgit River
ATABAD LANDSLIDE
MAX WATER COMPUTATIONS COMPUTATIONSSCHEMATISATION
SUMAIR
KARIMABAD
ATABAD LANDSLIDE
0 100 200 300 400 5002060
2080
2100
2120
2140
2160
2180
1 hour breach@2398 Plan: 70 3/23/2010 RS = 84943.89
Station (m)
Elev
atio
n (m
)
Legend
EG 30DEC2009 0006
WS 30DEC2009 0006
Ground
Bank Sta
MAX WATER COMPUTATIONS
ATABAD LANDSLIDE
0 100 200 300 400 5002060
2080
2100
2120
2140
2160
2180
1 hour breach@2398 Plan: 70 3/23/2010 RS = 84943.89
Station (m)
Elev
atio
n (m
)
Legend
EG Max WS
WS Max WS
Ground
Bank Sta
Max Depth =35m
Depth above Left
Bank =22m
Depth above RightBank =28m
MAX WATER COMPUTATIONS
ATABAD LANDSLIDE
MAX WATER COMPUTATIONS
ATABAD LANDSLIDE
0 200 400 600 800 1000 1200 1400 16001540
1560
1580
1600
1620
1640
1660
1 hour breach@2398 Plan: 70 3/23/2010 RS = 25125.99
Station (m)
Elev
atio
n (m
)
Legend
EG 30DEC2009 0006
WS 30DEC2009 0006
Ground
Bank Sta
MAX WATER COMPUTATIONS
ATABAD LANDSLIDE
0 200 400 600 800 1000 1200 1400 16001540
1560
1580
1600
1620
1640
1660
1 hour breach@2398 Plan: 70 3/23/2010 RS = 25125.99
Station (m)
Elev
atio
n (m
)
Legend
EG Max WS
WS Max WS
Ground
Bank Sta
MAX WATER COMPUTATIONS
Microsoft Office PowerPoint 97-2003 Pres
ATABAD LANDSLIDE
Overtoping at El. 2398m, Dam height 108m1 hour Breach
0
20000
40000
60000
80000
100000
21:3
6
22:4
8
00:0
0
01:1
2
02:2
4
03:3
6
04:4
8
06:0
0
07:1
2
08:2
4
09:3
6
10:4
8
12:0
0
Flow
(m3 /s
)
Just Downstream Landslide At Confluence with Gilgit
DAM-BREAK STUDIESFLOOD WAVE PROPOGATION
SCENARIO-18-1
Time From Start of Breach to Arrival of Peak at Gilgit Confluence
= 4.5 hrs3,248,950 ft3/s
706,000ft3/s
ATABAD LANDSLIDE
Overtoping at El. 2398m, Dam height 108m3 hour Breach
05000
1000015000200002500030000350004000045000
21:3
6
22:4
8
00:0
0
01:1
2
02:2
4
03:3
6
04:4
8
06:0
0
07:1
2
08:2
4
09:3
6
10:4
8
12:0
0
Flow
(m3 /s
)
Just Downstream Landslide At Confluence with Gilgit
DAM-BREAK STUDIESFLOOD WAVE PROPOGATION
SCENARIO-18-3
Time From Start of Breach to Arrival of Peak at Gilgit Confluence
=5.25hrs
1,447,900 ft3/s
671,000 ft3/s
ATABAD LANDSLIDE
Overtoping at El. 2398m, Dam height 108m6 hour Breach
0
5000
10000
15000
20000
25000
21:3
6
22:4
8
00:0
0
01:1
2
02:2
4
03:3
6
04:4
8
06:0
0
07:1
2
08:2
4
09:3
6
10:4
8
12:0
0
Flow
(m3 /s
)
Just Downstream Landslide At Confluence with Gilgit
DAM-BREAK STUDIESFLOOD WAVE PROPOGATION
SCENARIO-18-6
Time From Start of Breach to Arrival of Peak at Gilgit Confluence
= 6.5 hrs 812,000 ft3/s
600,000 ft3/s
ATABAD LANDSLIDE
Overtoping at El. 2398m, Dam height 108m24 hour Breach
01000200030004000500060007000
21:3
6
22:4
8
00:0
0
01:1
2
02:2
4
03:3
6
04:4
8
06:0
0
07:1
2
08:2
4
09:3
6
10:4
8
12:0
0
13:1
2
14:2
4
15:3
6
16:4
8
18:0
0
19:1
2
20:2
4
21:3
6
Flow
(m3 /s
)
Just Downstream Landslide At Confluence with Gilgit
DAM-BREAK STUDIESFLOOD WAVE PROPOGATION
SCENARIO-18-24
Time From Start of Breach to Arrival of Peak at Gilgit Confluence
= 11 hrs 247,000 ft3/s 212,000 ft3/s
ATABAD LANDSLIDE
DAM-BREAK STUDIESFLOOD WAVE JUST DOWNSTREAM OF LANDSLIDE
SUMMARY OF SCENARIO 18-1, 18-3, 18-6 & 18-24
Overtoping at El. 2398m, Dam height 108m
0100002000030000400005000060000700008000090000
100000
21:3
6
22:4
8
00:0
0
01:1
2
02:2
4
03:3
6
04:4
8
06:0
0
07:1
2
08:2
4
09:3
6
10:4
8
12:0
0
Flow
(m3 /s
)
1 hour Breach 3 hour Breach 6 hour Breach 24 hour Breach
3,248,950 ft3/s
1,447,900 ft3/s
812,000 ft3/s
247,000 ft3/s
ATABAD LANDSLIDE
Overtoping at El. 2386m, Dam height 96m1 hour Breach
01000020000300004000050000600007000080000
21:3
6
22:4
8
00:0
0
01:1
2
02:2
4
03:3
6
04:4
8
06:0
0
07:1
2
08:2
4
09:3
6
10:4
8
12:0
0
Flow
(m3 /s
)
Just Downstream Landslide At Confluence with Gilgit
DAM-BREAK STUDIESFLOOD WAVE PROPOGATION
SCENARIO-30-1
Time From Start of Breach to Arrival of Peak at Gilgit Confluence
= 5.25 hrs 2,684,000 ft3/s
635,600 ft3/s
ATABAD LANDSLIDE
Overtoping at El. 2386m, Dam height 96m3 hour Breach
05000
100001500020000250003000035000
21:3
6
22:4
8
00:0
0
01:1
2
02:2
4
03:3
6
04:4
8
06:0
0
07:1
2
08:2
4
09:3
6
10:4
8
12:0
0
Flow
(m3 /s
)
Just Downstream Landslide At Confluence with Gilgit
DAM-BREAK STUDIESFLOOD WAVE PROPOGATION
SCENARIO-30-3
Time From Start of Breach to Arrival of Peak at Gilgit Confluence
= 6 hrs 1,025,000 ft3/s
530,000 ft3/s
ATABAD LANDSLIDE
Overtoping at El. 2386m, Dam height 96m6 hour Breach
0
5000
10000
15000
20000
21:3
6
22:4
8
00:0
0
01:1
2
02:2
4
03:3
6
04:4
8
06:0
0
07:1
2
08:2
4
09:3
6
10:4
8
12:0
0
Flow
(m3 /s
)
Just Downstream Landslide At Confluence with Gilgit
DAM-BREAK STUDIESFLOOD WAVE PROPOGATION
SCENARIO-30-6
Time From Start of Breach to Arrival of Peak at Gilgit Confluence
= 7.5 hrs 565,000 ft3/s
388,000 ft3/s
ATABAD LANDSLIDE
Overtoping at El. 2386m, Dam height 96m24 hour Breach
0
1000
2000
3000
4000
5000
21:3
6
22:4
8
00:0
0
01:1
2
02:2
4
03:3
6
04:4
8
06:0
0
07:1
2
08:2
4
09:3
6
10:4
8
12:0
0
13:1
2
14:2
4
15:3
6
16:4
8
18:0
0
19:1
2
20:2
4
21:3
6
Flow
(m3 /s
)
Just Downstream Landslide At Confluence with Gilgit
DAM-BREAK STUDIESFLOOD WAVE PROPOGATION
SCENARIO-30-24
Time From Start of Breach to Arrival of Peak at Gilgit Confluence
= 12.5 hrs 177,000 ft3/s
172,000 ft3/s
ATABAD LANDSLIDE
DAM-BREAK STUDIESFLOOD WAVE JUST DOWNSTREAM OF LANDSLIDE
SUMMARY OF SCENARIO 30-1, 30-3, 30-6 & 30-24Overtoping at El. 2386m, Dam height 96m
0100002000030000400005000060000700008000090000
100000
21:3
6
22:4
8
00:0
0
01:1
2
02:2
4
03:3
6
04:4
8
06:0
0
07:1
2
08:2
4
09:3
6
10:4
8
12:0
0
Flow
(m3 /s
)
1 hour Breach 3 hour Breach 6 hour Breach 24 hour Breach
2,684,000 ft3/s
1,025,000t3/s
565,000 t3/s
177,000 t3/s
ATABAD LANDSLIDE
DAM-BREAK STUDIESFLOOD PEAK ARRIVAL TIMEFOR VARIOUS SCENARIOS
Scenario
Time from Start of Breach to
Peak Reaching Gilgit Confluence
(hours)18-1 4.5018-3 5.2518-6 6.50
18-24 11.030-1 5.2530-3 6.0030-6 7.50
30-24 12.50
ATABAD LANDSLIDEDAM-BREAK STUDIES
FLOOD PEAK COMAPARISON FOR VARIOUS SCENARIOS
Scenario
Peak Flow at Landslide
Peak flow reaching Gilgit
Confluence
Max. Water Depth at
Landslide
Max. water depth reaching
Gilgit Confluence
(m3/s) (m3/s) (m) (m)
18-1 92,000 20,000 52 15
18-3 41,000 19,000 24 15
18-6 23,000 17,000 19 14
18-24 7,000 6,000 11 9
30-1 76,000 18,000 33 14
30-3 29,000 15,000 21 13
30-6 16,000 11,000 16 12
30-24 5,000 5,000 9 8
ATABAD LANDSLIDE
DAM-BREAK STUDIESMAX DEPTH, VELOCITY AND TIME TO MAX DISCHARGE
ALONG HUNZA RIVER (18-1 SCENARIO)
VillageMax Depth
above river Bed (m)
Max velocity (m/s)
Time of maximum Discharge
Ahmedabad 47.2 10.6 30 min
Faisabad 49.4 11.2 40 min
Atit 52.0 12.7 55 min
Karimabad 40.4 8.6 1 hour
Aliabad, Sumair 46.4 7.5 1 hour 15 min
Murtazabad 50.6 10.3 1 hour 30 min
Toshot 46.0 9.4 1 hour 40 min
ATABAD LANDSLIDE
DAM-BREAK STUDIESMAX DEPTH, VELOCITY AND TIME TO MAX DISCHARGE
ALONG HUNZA RIVER (18-1 SCENARIO) (Cont..)
VillageMax Depth
above river Bed (m)
Max velocity (m/s)
Time of maximum Discharge
Miacher 40.0 13.5 1 hour 50 minMinapin Nagar ,
Pisan 37.3 11.0 1 hour 55 min
Kahnabad, Thole nagar 48.8 5.8 2 hours 5 min
Nilt Nagar 48.8 5.8 2 hours 5 min
Jafarabad 48.8 5.8 2 hours 5 min
Sikandarabad 48.8 5.8 2 hours 5 min
Chalt 30.5 6.3 2 hours 25 min
ATABAD LANDSLIDE
DAM-BREAK STUDIESMAX DEPTH, VELOCITY AND TIME TO MAX DISCHARGE
ALONG HUNZA RIVER (18-1 SCENARIO) (Cont..)
VillageMax Depth
above river Bed (m)
Max velocity (m/s)
Time of maximum Discharge
Jaglot 22.6 8.4 3 hours 30 min
Nomal 15.8 5.1 3 hours 50 min
Danyor 15.0 11.1 4 hours 15 min
ATABAD LANDSLIDE
DAM-BREAK STUDIESHISTORIC OBSERVED INSTANTANEOUS FLOOD PEAKS
HUNZA RIVER AT DANIYOR
0
5000
10000
15000
20000
25000
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
Flow
(m3 /s
)
Flood Peak in 18-1 Scenario
Flood Peak in 30-1 Scenario
ATABAD LANDSLIDE
DAM-BREAK STUDIESHISTORIC OBSERVED INSTANTANEOUS FLOOD PEAKS
HUNZA RIVER AT DANIYORScenario
Peak flow reaching Gilgit Confluence
(m3/s)
Compared with Historic Peak at Daniyor Bridge
Danger level
18-1 20,000 3.8 times Exceptionally High
18-3 19,000 3.7 times Exceptionally High
18-6 17,000 3.3 times Exceptionally High
18-24 6,000 1.2 times High
30-1 18,000 3.5 times Exceptionally High
30-3 15,000 2.9 times Exceptionally High
30-6 11,000 2.1 times Exceptionally High
30-24 5,000 Same High
ATABAD LANDSLIDEDAM-BREAK STUDIES
IMPACT ON TARBELA RESERVOIR
IN ORDER TO CHECK THE IMPACT OF THIS FLOOD WAVE ON INDUS RIVER UP TO TARBELA RESERVOIR, THE MODEL HAS BEEN EXTENDED UPTO THAKOT ON INDUS RIVER.
A RIVER REACH OF 350 KM FROM GILGIT CONFLUENCE TO BESHAM HAS BEEN ANALYZED USING HECRAS.
TARBELA RESERVOIR IS ABOUT 100 KM DOWNSTREAM OF BESHAM.
CROSS-SECTIONS HAVE BEEN EXTRACTED FROM ASTER DATA.
ATABAD LANDSLIDE
WAVE PROPOGATION
FROM GILGIT TO BESHAM,
ATABAD LANDSLIDE
DAM-BREAK STUDIESFLOOD WAVE PROPOGATION
FROM GILGIT TO BESHAM, SCENARIO-18-1
Safe Safe
danger
ATABAD LANDSLIDE
DAM-BREAK STUDIESFLOOD WAVE PROPOGATION
FROM GILGIT TO BESHAM, SCENARIO-18-3
SafeSafe
danger
ATABAD LANDSLIDE
DAM-BREAK STUDIESFLOOD WAVE PROPOGATION
FROM GILGIT TO BESHAM, SCENARIO-30-1
Safe Safe
ATABAD LANDSLIDE
PartabHistoric Instantaneous Peaks
02000400060008000
1000012000140001600018000
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
Flow
(m3 /s
)DAM-BREAK STUDIES
FLOOD WAVE PROPOGATION Historic Peaks at Partab/Bunji
Flood Peak in 18-1 Scenario
Flood Peak in 30-1 Scenario
ATABAD LANDSLIDE
ShatialHistoric Instantaneous Peaks
0
2000
4000
6000
8000
10000
12000
14000
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
Flow
(m3 /s
)DAM-BREAK STUDIES
FLOOD WAVE PROPOGATION Historic Peaks at Shatial
Flood Peak in 18-1 Scenario
Flood Peak in 30-1 Scenario
ATABAD LANDSLIDE
BeshamHistoric Instantaneous Peaks
02000400060008000
10000120001400016000
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
Flow
(m3 /s
)DAM-BREAK STUDIES
FLOOD WAVE PROPOGATION Historic Peaks at Besham
Flood Peak in 18-1 ScenarioFlood Peak in 30-1 Scenario
ATABAD LANDSLIDE
DAM-BREAK STUDIESFLOOD INNUNDATION
MAP
ATABAD LANDSLIDE
DAM-BREAK STUDIESFLOOD INNUNDATION
MAP
ATABAD LANDSLIDE
DAM-BREAK STUDIESFLOOD INNUNDATION MAP
ATABAD LANDSLIDE
THE LANDSLIDE AT ATABAD TOOK PLACE ON 4TH JANUARY 2010
THAT CREATED A LANDSLDIE DAM ACROSS THE HUNZA RIVER.
THE LOCATION IS ABOUT 30 KM UPSTREAM OF ALIABAD AND ABOUT
10 KM DOWNSTREAM OF GULMIT.
THE LANDSLIDE TOOK PLACE AT THE AREA LOCATED ON A FAULT
LINE, WHICH HAS CREATED A HIGHLY CRUSHED ROCK MASS.
THE LANDSLIDE MATERIAL CONSISTS OF A MIXTURE OF LARGE
BOULDERS, COBBLES, SILT AND PLASTIC CLAY. THE PERCENTAGE
OF EACH VARIES ON THE LANDSLIDE MASS.
CONCLUSIONS
ATABAD LANDSLIDE
THE LANDSLIDE DAM HEIGHT (lowest point) IS 126 (413 ft) METERS
ABOVE THE RIVER BED LEVEL, WIDTH 250 TO 350 METERS AND
LENGTH ALONG THE RIVER IS 2000 METERS.
THE LANDSLIDE DAM CREATED A POTENTIAL STORAGE OF 305 MCM
IF IT FILLED TO THE TOP.
WITH A SPILLWAY CUT DEPTH OF 18 METERS THE STORAGE
POTENTIAL REDUCES TO 195 MCM (36% reduction).
A SPILLWAY CUT DEPTH OF 30 METERS REDUCES THE STORAGE
POTENTIAL TO 133 MCM (56% reduction).
CONCLUSIONS (Cont)
ATABAD LANDSLIDE
USING RIVER FLOW DATA, WITH THE PRESENT 18 METER (about 60 ft)
DEEP SPILLWAY CUT, IT IS ESTIMATED THAT THE LANDSLIDE DAM
WOULD START OVERTOPPING BETWEEN 12TH MAY TO 21ST JUNE,
2010.
WITH A 30 METER (about 100 ft) DEEP SPILLWAY CUT IT IS
ESTIMATED THAT THE LANDSLIDE DAM WOULD START
OVERTOPPING BETWEEN 30TH APRIL TO 10TH JUNE, 2010.
CONCLUSIONS (Cont)
ATABAD LANDSLIDE
HYDROLOGIC ENGINEERING CENTRE’S RIVER ANALYSIS SYSTEM
(HEC-RAS) Ver-4.0 HAS BEEN USED BY NESPAK IN THE DAM BREAK
STUDIES.
TWO DIFFERENT SPILWAY CUT DEPTHS HAVE BEEN ASSUMED i.e. 18
METERS AND 30 METERS.
FOR EACH SPILLWAY CUT DEPTH, FOUR DIFFERENT TIMES TO
BREACH HAVE BEEN MODELLED i.e. 1 HR, 3 HR, 6 HR AND 24 HR.
THUS IN TOTAL EIGHT DIFFERENT DAM BREAK SCENARIOS
HAVE BEEN MODELLED.
THE MODEL HAS BEEN BASICALLY RUN TO SHOW THE EFFECT TILL
GILGIT BUT THE MODEL HAS BEEN EXTENDED TO SHOW RESULTS
UP TO BESHAM
CONCLUSIONS (Cont)
ATABAD LANDSLIDE
FOR A 18 METER DEEP SPILLWAY CUT, THE RESULTS OF DAM BREAK
STUDY ARE SUMMARISED AS:
CONCLUSIONS (Cont)
ScenarioPeak Flow at
Landslide(m3/s)
Peak flow reaching Gilgit Confluence
(m3/s)
Max Depth* at Gilgit
Confluence (m)
Time to maximum dischargeat Gilgit
Confluence(hours)
1-hour Breach 92,000 20,000 15 4.5
3-hour Breach 41,000 19,000 15 5.25
6-hour Breach 23,000 17,000 14 6.5
24-hour Breach 7,000 6,000 9 11
* From River Bed
ATABAD LANDSLIDE
FOR A 30 METER DEEP SPILLWAY CUT, THE RESULTS OF DAM BREAK
STUDY ARE SUMMARISED AS:
CONCLUSIONS (Cont)
ScenarioPeak Flow at
Landslide(m3/s)
Peak flow reaching Gilgit Confluence
(m3/s)
Max Depth* at Gilgit
Confluence (m)
Time to maximum dischargeat Gilgit
Confluence(hours)
1-hour Breach 76,000 18,000 14 5.25
3-hour Breach 29,000 15,000 13 6
6-hour Breach 16,000 11,000 12 7.5
24-hour Breach 5,000 5,000 8 12.5
* From River Bed
ATABAD LANDSLIDE
WHEN COMPARED TO HISTORICAL FLOOD DATA:CONCLUSIONS (Cont)
ScenarioPeak flow reaching Gilgit Confluence
(m3/s)
Compared with Historic Peak at Daniyor Bridge
Danger level
18-1 20,000 3.8 times Exceptionally High
18-3 19,000 3.7 times Exceptionally High
18-6 17,000 3.3 times Exceptionally High
18-24 6,000 1.2 times High
30-1 18,000 3.5 times Exceptionally High
30-3 15,000 2.9 times Exceptionally High
30-6 11,000 2.1 times Exceptionally High
30-24 5,000 Same High
ATABAD LANDSLIDE
THE MODEL HAS BEEN EXTENDED UP TO BESHAM.
CONCLUSIONS (Cont)
ScenarioPeak flow reaching
Partab Bridge(m3/s)
Compared with Historic Peak at Partab Bridge
Danger level
18-1 15,600 1.25 times Exceptionally High
30-1 11,000 0.9 times High
ATABAD LANDSLIDE
THEREFORE, IT CAN BE SAID THAT EXCEPT FOR THE SCENARIOS
18-1 AND 18-3, THE FLOOD PEAK AT PARTAB BRIDGE WOULD BE
LESS THAN THE HISTORICAL PEAK OF 1963.
THE EFFECT DOWNSTREAM OF PARTAB BRIDGE WILL NOT BE
HIGHER THAN ANY HISTORICAL FLOOD OF RECENT PAST (1960
ONWARDS) FOR ALL SCENARIOS
THE EFFECT AT TARBELA WILL NOT BE SIGNIFICANT.
CONCLUSIONS (Cont)
ATABAD LANDSLIDE
AN EMERGENCY PREPAREDNESS AND ACTION PLAN (EPAP) SHOULD
BE PREPARED ON THE BASIS OF THE DAM BREAK STUDY RESULTS.
THE GUIDING PRINCIPLE SHOULD BE TO “PREPARE FOR THE WORST
WHILE HOPING FOR THE BEST”.
THE 18-1 SCENARIO (18 meters deep cut; 1 hr time to breach) IS THE
WORST CASE SCENARIO. THIS SHOULD BE USED TO PREPARE THE
EMERGENCY PLANS.
THE MAIN IMPACT OF THE DAM BREAK WILL BE FROM FLOOD
INUNDATION AND HIGH VELOCITY OF FLOOD WAVE
THE SECONDARY EFFECT WILL BE FROM LANDSLIDES IN THE LAKE
AREA DUE TO RAPID DRAWDOWN AND IN THE DOWNSTREAM AREA
DUE TO RIVER BANK EROSION.
RECOMMENDATIONS
ATABAD LANDSLIDE
THE RESULTS INDICATE DANGER TO:
PEOPLE LIVING ON LOWER ELEVATIONS CLOSE TO THE RIVER
BANKS
PEOPLE LIVING CLOSE TO TERRACE EDGES OR ON UNSTABLE
SLOPES
ROADS AND BRIDGES ON LOWER ELEVATIONS WHERE FLOOD
WATER IS EXPECTED TO RISE.
ALL THE PEOPLE AT RISK WILL HAVE TO BE EVACUATED AND MOVED
TO HIGHER ELEVATIONS / STABLE AREAS.
EMERGENCY PLANS SHOULD BE PREPARED KEEPING IN MIND THAT
THE ROADS AND BRIDGES COULD BE WIDELY DAMAGED UP TO
CONFLUENCE WITH INDUS / RAIKOT BRIDGE
RECOMMENDATIONS (Cont)
ATABAD LANDSLIDE
A 24 HR MONITORING OF THE LANDSLIDE DAM SHOULD BE STARTED.
LINES OF COMMUNICATION AND WARNINGS SHOULD BE ESTABLISHED
FOR UPSTREAM AND DOWNSTREAM COMMUNITIES.
ALL THE COMMUNITIES LIVING IN THE DANGER AREA SHOULD BE
ALERTED NOW AND GIVEN THE KNOWLEDGE ABOUT THE DAM BREAK
SCENARIOS AND WHAT TO DO IN CASE OF EMERGENCY (EVACUATION
PLAN).
RECOMMENDATIONS (Cont)
ATABAD LANDSLIDE
THREE ALERT STATES SHOULD BE MADE:
LEVEL ONE: WATER LEVEL JUST TWO METERS BELOW CUT LEVEL
LEVEL TWO: WATER STARTS TO FLOW OVER THE CUT
LEVEL THREE: DAM EROSION IN PROGRESS; DAM BREACH IS
IMMINENT.
NESPAK SURVEYORS SHOULD MOVE WITH THE NDMA / ARMY TEAMS
TO MARK HIGHEST FLOOD LEVELS FOR THE 18-1 SCENARIO
IMMEDIATELY.
ALL STAKE HOLDERS (ARMY, FWO, NDMA, LOCAL ADMINISTRATION)
SHOULD BE TAKEN ON BOARD FOR THE EMERGENCY PREPAREDNESS
AND ACTION PLAN (EPAP).
RECOMMENDATIONS (Cont)
ATABAD LANDSLIDE
THANK YOU
National Engineering Services Pakistan (Pvt.) Ltd.
ATABAD LANDSLIDEFLOOD MARK AT SARAT BRIDGE
35 m above Bridge Deck (18-1 Scenario)
Flow Direction
ATABAD LANDSLIDEFLOOD MARK AT GANESH BRIDGE
25 m above Bridge Deck (18-1 Scenario)
Flow Direction
Ganesh Bridge
ATABAD LANDSLIDEFLOOD MARK AT BAST FAIZA ABD BRIDGE
25 m above Bridge Deck (18-1 Scenario)
Flow Direction
Bridge
ATABAD LANDSLIDE
FLOOD MARK AT SIKANDRABAD BRIDGE15 m above Bridge Deck
(18-1 Scenario)
Bridge
Flow Direction