...

63 M/15

72 A/4

I
72 8/5

63 M/16

72 8/10

72 F/4

72 G/6

FIGURE 1: BANK LINES OF GANDAK RIVER - TOPOSHEET

----
In the present studies bank lines were extracted from Satellite data for the years
1988, 1994, 1999 & 2004. These data were extracted using EASIPACE software available
in Remote Sensing Laboratory of CWPRS. The bank line data were super imposed on the
available year SOl Toposheets to identify likely locations where erosion is taking place.
Since the sensor selection for Satellite data is varies LlSS II to LlSS III locations where
measurable changes in bank line was noticed to identify through super imposition. For this
purpose the location of SOl Toposheets was selected and transferred to Satellite data using
 -------------------------------------------- ~~
J,.- __

I
I Geo-reference technology. The changes in bank line have been measured and combined
for different stretches in study area. The study area was divided into seven zones having

I overlap on either or both upstream and downstream sections, depending on the locations of
the zone. Review of the analysis indicates that there are 18 locations where erosion is

I taking place. sal Toposheets were used for identifying the nearby town where erosion was
identified.

I Analysis of stream flow and sediment data at Triveni and Dumariaghat has been

I carried out to review the changes in the pattern of sediment being carried in river Gandak.
The results showing the area wise equations of sediment transport between discharge and
corresponding sediment flow indicate that the exponent in the attempted relation

b
Q=AQ
I
_ 5

The power is changing from minimum of 0.6946 to a maxlmumvof 1.7311. The

attempts were affected by clubbing the data as per the availability of bank lines from Satellite
data. The results indicate that there is no major change in the regression coefficient of the
sediment transport equation.

The studies carried out indicate that there are 18 locations in the study area where
erosion is taking place. Further 10 locations have been identified and observations to
identify and confirm the changes in bank line due to deposition.

~======="---------===-----=--=---:-=----=-===- -=--=----:-=-==-=---===----==-~ - -- "

 J,.- __

I
I Geo-reference technology. The changes in bank line have been measured and combined
for different stretches in study area. The study area was divided into seven zones having
overlap on either or both upstream and downstream sections, depending on the locations of
the zone. Review of the analysis indicates that there are 18 locations where erosion is

I taking place. sal Toposheets were used for identifying the nearby town where erosion was
identified.

I Analysis of stream flow and sediment data at Triveni and Dumariaghat has been

I carried out to review the changes in the pattern of sediment being carried in river Gandak.
The results showing the area wise equations of sediment transport between discharge and
corresponding sediment flow indicate that the exponent in the attempted relation

The power is changing from minimum of 0.6946 to a maxirnumxot 1.7311. The

attempts were affected by clubbing the data as per the availability of bank lines from Satellite
data. The results indicate that there is no major change in the regression coefficient of the
sediment transport equation.

The studies carried out indicate that there are 18 locations in the study area where
erosion is taking place. Further 10 locations have been identified and observations to
identify and confirm the changes in bank line due to deposition.
 .,

INDEX

SI. No. CHAPTER Page

EXECUTIVE SUMMARY

INDEX
I, 1 INTRODUCTION 1

I 2

3
STUDY AREA

TERMS OF REFERENCE/ METHODOLOGY

3

I 4

5
ANALYSIS, RESULTS AND DISCUSSIONS

CONCLUSIONS
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67

I 6 ACKNOWLEDGEMENT 73

I
I LIST OF APPENDIX

I, APPENDIX -I 74

I APPENDIX -11

APPENDIX -Ill
77

79

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 Table No. List of Tables Page

3.1 Details of satellite data used 7

4.1 Zone co-ordinates 20

4AR Comparison of Toposheet right bank line in zone A 36

4AL Comparison of Toposheet left bank line in zone A 37

I 4BR

4BL
Comparison of Toposheet right bank line in zone B

Comparison of Toposheet left bank line in zone B

38

39

I 4CR

4CL
Comparison of Toposheet right bank line in zone C

Comparison of Toposheet left bank line in zone C

.,
40

40
.-~

I 4DR Comparison of Toposheet right bank line in zone D 41

4DL Comparison of Toposheet left bank line in zone D 41

I 4ER Comparison of Toposheet right bank line in zone E 42

4EL Comparison of Toposheet left bank line in zone E 42

I 4FR Comparison of Toposheet right bank line in zone F 43

4FL Comparison of Toposheet left bank line in zone F 43

I 4GR Comparison of Toposheet right bank line in zone G 44

I 4GL

4.2
Comparison of Toposheet left bank line in zone G

Rate of change of right bank line of river Gandak in zone A

44

45

I 4.3
4.4
Rate of change of left bank line of river Gandak in zone A

Rate of change of right bank line of river Gandak in zone B

46

47

I 4.5 Rate of change of left bank line of river Gandak in zone B 48

4.6 Rate of change of right bank line of river Gandak in zone C 49

I 4.7 Rate of change of left bank line of river Gandak in zone C 49

4.8 Rate of change of right bankliiieof river Gandak in zone D 50

I 4.9 Rate of change of left bank line of river Gandak in zone D 50

4.10 Rate of change of right bank line of river Gandak in zone E 51

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-

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I 4.11

4.12
Rate of change of left bank line of river Gandak in zone E

Rate of change of right bank line of river Gandak in zone F

51

52

I 4.13 Rate of change of left bank line of river Gandak in zone F 52

4.14 Rate of change of right bank line of river Gandak in zone G 53

I 4.15 Rate of change of left bank line of river Gandak in zone G 53

Maximum and minimum values of Gauge and Discharges at

4.16 59
I Triveni site

Maximum and minimum values of Gauge and Discharges at

4.17 60
Dumariaghat
I 4.18 Summary of rating curves river Gandak at Triveni 65

I 5.1A

5.18
Summary of change in right bank line of river Gandak

Summary of change in left bank line of river Gandak

68

69

I 5.2 Summary of rate of change in bank line of river Gandak 71

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Figure No. List of Figures Page

I
3.1 Bank line of Gandak river - Toposheet 6
I 4.1 Bank lines of Gandak river - 1988 9

4.2 Bank lines of Gandak river - 1994 10

I 4.3 Bank lines of Gandak river - 1999 11

I 4.4

4.5
Bank lines of Gandak river - 2004

Superimposed bank lines - Toposheet & 1988

12

13

I 4.6 Superimposed bank lines - Toposheet & 1994

Superimposed bank lines - Toposheet & 1999 ,

14

15
4.7
..~
I 4.8 Superimposed bank lines - Toposheet & 2004 16

4.9 Superimposed bank lines Toposheet, 1988, 1994, 1999 & 2004 17

4.10 Zoning of river Gandak 19

4.11 Changes in bank lines of river Gandak for zone A 22

I 4.12 Changes in bank lines of river Gandak for zone B 23

4.13 Chanqes in bank lines of river Gandak for zone C 24

4.14 Changes in bank lines of river Gandak for zone 0 25

4.15 Changes in bank lines of river Gandak for zone E 26

4.16 Changes in bank lines of river Gandak for zone F 27

4.17 Changes in bank lines of river Gandak for zone G 28

4.18 Locations of towns/ villages - zone A 29

4.19 Locations of towns/ villages - zone B 30

4.20 Locations of towns/ villages - zone C 31

4.21 Locations of towns/ villages - zone 0 32

4.22 Locations of towns/ villages - one E 33

4.23 Locations of towns/ villages - zone F 34

4.24 Locations of towns/ villages - zone G 35

4.25 Sediment rating curve: river Gandak at Triveni - 1988 61

4.26 Sediment rating curve: river Gandak at Triveni - 1989 61

4.27 Sediment rating curve: river Gandak at Triveni - 1990 61

4.28

4.29
--
Sediment rating curve: river Gandak at Triveni - 1991

Sediment rating curve: river Gandak at Triveni - 1992

62

62

4.30 Sediment rating curve: river Gandak at Triveni - 1993 62

4.31 Sediment rating curve: river Gandak at Triveni - 1994 63

4.32 Sediment rating curve: river Gandak at Triveni - 1995 63

4.33 Sediment rating curve: river Gandak at Triveni - 1996 63

4.34 Sediment rating curve: river Gandak at Triveni - 1997 64

4.35 Sediment rating curve: river Gandak at Triveni - 1998 64

4.36 Sediment rating curve: river Gandak at Triveni - (1988 - 1993) 65

4.37 Sediment rating curve: river Gandak at Triveni - (1994 - 1999) 66

",

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 CHAPTER 1

INTRODUCTION
 Morphological studies of river Gandak using satellite and SOl Data

Technical Report No. 5015 Month: November, 2012

MORPHOLOGICAL STUDIES OF RIVER GANDAK USING SATELLITE AND SOl DATA

1.0 INTRODUCTION

Alluvial rivers in India as well as in other countries are facing the problem of erosion
and deposition. These phenomena occur in the river due to inbalance in sediment transport
capacity and inflow of sediment. It is known that erosion is likely to take place when inflow of
sediment in the stream is less than the carrying capacity; as against this depositions will take
place if sediment inflow is more than transporting capacity of the river. Either of these
phenomena are posing dlfflculties to the planners as well as causing damages to the
adjoining area where agricultural fields or towns, available monuments that,~re likely to be
located. Examples are available where the large sectors of agricultural fieJas have been
washed away during the change of course of alluvial rivers.

It is, therefore, necessary to give protection against the erosion to the properties and
monuments located on the bank of river. In this direction, an attempt is proposed in river
Gandak for identifying erosion areas. A meeting was held by Member (RM), CWC, New Delhi
'. on 26 May 2004. It was decided in the meeting that different rivers where the problem of
erosion I deposition is experienced are to be identified. The task was carried out and different
rivers were recognized. Study of these rivers was assigned to different organizations like
NIH, CWPRS etc. Out of these rivers, it was decided that morphological studies of river
Gandak might be carried out by CWPRS.

It was further, decided that bank like data of river Gandak is to be collected from
Survey of India toposheets of 1974-76 and bank line of latter years are to be extracted using
satellite data. The satellite data are to be collected at an interval ranging from 4 to 6 years,
as per the availability of cloud free dates, collected from National Remote Sensing Centre
(NRSC), Hyderabad. Accordingly, attempts have been made to collect the SOl toposheets in
the first phase. It was decided after review 0 ailable toposheets that in lieu of the
toposheets for 1974-76, the toposheets as available at CWPRS are to be used. Accordingly,
the data on bank like of river Gandak from SOl toposheets and satellite imagery were
collected and analyzed. An interim report was submitted to CWC in March 2006. The report
was reviewed and observations received in May 2006 were complied in subsequent meeting
held in October I December 2006.

" "
CWPRS, Technical Report No. 5015 for November 2012
':.,~.,.,.•~"•.••,.,l
I Morphological studies of river Gandak using satellite and 501 Data

I Further,
incorporated
comments were communicated.
and draft final was submitted to ewe
Replies to these comments
for getting clearance to submit final
were

I copies. The clearance

comments. Attempts
was received in October,
have been made to comply these comments
2012 with suggestions and additional
by dividing a total of
stretch of river Gandak in different zones in order to identify locations on left and right bank
where major changes have taken place. In addition, gauge and discharge data at Triveni I

I Dumariaghat has been collected from ewe, Patna I Lucknow.

This report has been prepared after compliance of comments I observations

I communicated to eWPRS by ewe.

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CWPRS, Technical Report No. 5015 for November 2012 2

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CHAPTER 2

STUDY AREA
Morphological studies of river Gandak using satellite and 501 Data

·~

MORPHOLOGICAL STUDIES OF RIVER GANDAK USING SATELLITE AND SOl DATA

2.0 STUDY AREA

Gandaki River or Kali Gandaki, also known as the Narayani in southern Nepal and
the Gandak in India, is one of the major rivers of Nepal and a left bank (north bank) tributary
of river Ganga in India. Kali Gandaki starts at the north of Tibetan plateau of the Himalayas in
the Mustang District of Nepal, near the Tibetan border. The two headwaters of river, Nup
Chhu and Shar Chhu meet near the town of Lo Manthang in upper Mustang. These two
rivers are also known as "West River" and "East River". These rivers then flow southwest
with the name of Mustang Khola. In Kagbeni a major tributary, Kak Khola, flowing from
Muktinath, meets Mustang Khola, and since then together this river is called the Kali
Gandaki. The course of this river advents southwards through a steep gorge known as the
Kali Gandaki Gorge, or Andha Galchi, between the mountains Dhaulagiri (rising up to 8167
",
m) to the west and Annapurna (8091 m) to the east side. If one measur~ the depth of a
canyon by the difference between the river bed and the heights of the highest peaks on
either side, the Gorge is the world's deepest. The course of the river between the Dhaulagiri
and Annapurna massifs is at an elevation between 1300 m and 2600 m. The river is much
older than the Himalayas.

The river is joined by Rahught Khola at Galeshwar on the south of the gorge, Myagdi
Khola at Beni, Modi Kh61a near Kushma and Badigaad at Rudrabeni. The river then takes a
right-angle turn and runs east. The largest hydroelectric project in Nepal is located along this
stretch of the river. A major tributary Trisuli joins Kali Gandaki at Devighat just as the river
exits the foothills of the Himalayas into the southern plains of Nepal. Masryanadi is a major
tributary of Trisuli. From Devighat, the river flows southwest and is called Narayani or Sapt
Gandaki.

The river then meanders back towards the southeast and enters India. The entry
point of the river at the Indo-Nepal border is at the convergence of Gandak, near Triveni.
Here, the rivers meet with Pachnad and Son ha also sliding into India from Nepal. Pandai
River flows into the Indian state of Bihar -Trc5Tn Nepal in the eastern end of the Valmiki
Sanctuary and finally meets Masan. The river flows across the Gangetic plain of Bihar state
and eventually merges with river Ganga near at Hajipur. Before merging with river Ganga,
river flows through the districts of Champaran, Sarang and Muzaffarpur. The river has a total
catchment area of 46,300 sq. km out of which 7620 sq. km is located in India. The Gandaki
river basin is known to contain 1025 glaciers and 338 lakes. The basin also contains 3 of the

..
CWPRS, Technical Report No. 5015 for November 2012 3
 Morphological studies of river Gandak using satellite and SDI Data

world's 14 highest mountains over 8,000m. After the entry in India at Triveni, river flows for
an extended length of 300 km out of total length of 630 km and then joins Ganga.

River Gandak rises in the Great Himalaya Range in Nepal after it flows southwest into

I India and then turns southeast along the Uttar Pradesh-Bihar

Indo-Gangetic Plain. Gandak river study reach in India is covered in 15 sal toposheets.
state border and across the

Photographs of river Gandak in study area are presented in Appendix-I.

----

,.~., CWPRS, Technical Report No. 5015 for November 2012 4

"'~"O~ ••
 CHAPTER 3

TERMS OF REFERENCEI
METHODOLOGY

----
 Morphological studies of river Gandak using satellite and SOl Data

MORPHOLOGICAL STUDIES OF RIVER GANDAK USING SATELLITE AND 501 DATA

3.0 TERMS OF REFERENCEI METHODOLOGY

3.1 It was desired by ewe that the following work components be carried out at eWPRS:

3.1.1 To demarcate pre and post monsoon course of river Gandak for the years
1990, 1994, 1999 and 2003. These courses are to be superimposed on the
river course of 1974 -76 toposheets from Survey of India.

3.1.2 To study and identify shifting of course, critical locations and rate of shifting

3.1.3 The sal Toposheets available at eWPRS were reviewed and the position was
communicated to ewe. Accordingly, available toposheets were used for
'~

preparing the reference line for comparison.

The available cloud free data from NRSA were reviewed and necessary changes
I
were made in the data used for comparison. Thus, in place of 1990, the data of 1988 was
used and in place of 2003, data for 2004 were considered in the studies.
I
3.2 As indicated above, the reach of river Gandak is covered in 15 toposheets. Out of
I these toposheets, 63M14 and 63M05 were not available at eWPRS as well as sal office at
Dehradun. The reach as could be delineated from sal toposheets was identified and bank
I lines were marked as shown in Figure 3.1. These vectors were used later on for the purpose
of superimposition.

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 Morphological studies of river Gandak using satellite and sal Data

63 M/15
Toposheet
S. No. Year Scale
Number
1 63 M/15 1963 One cm
72 A/4 2 63 M/16 1984 : 500 m
3 72N4 1928
4 72 B/1 1930
5 72 B/5 1958

I 72 8/5
6
7
72 B/6
72 B/7
1931
1931
8 72 B/10 1958 One

I 63 M/16
9
10
72 B/11
72 B/15
1931
1930
inch:
One
11 72 B/16 1932 mile

I 72 8/10 12
13
72 C/13
72 F/4
1936
1948
14 72 G/1 1935

I 15
16
72 G/2
72. G/6
1935
1935
'.~

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72 8/11

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I 72 G/6

I FIGURE 3.1: BANK LINES OF GANDAK RIVER - TOPOSHEET

3.3 Request was filed with then Mls NRSA, Hyderabad to inform the dates on which
cloud free data over the entire river reach are available. Accordingly, the data of the study
reach were collected as given in Table 3.1.

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,~; CWPRS, Technical Report No. 5015 for November 2012 6
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Morphological studies of river Gandak using satellite and SOl Data

..
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TABLE 3.1: DETAILS OF SATELLITE DATA USED

SI. No. Satellite Sensor Path/Row Date of Pass Toposheet

1 IRS-P6 LlSS-11I 103/52 31.10.2004 SOI-72A 4

2 IRS-P6 LlSS-11I 103/53 31.10.2004 SOI-72B 6
3 IRS-P6 LlSS-11I 104/53 29.11.2004 SOI-72B 16
4 IRS-P6 LlSS-11I 103/52 31.10.2004
5 IRS-P6 LlSS-11I 103/53 31.10.2004
6 IRS-P6 LlSS-11I 104/53 29.11.2004
7 IRS-1D LlSS-11I 103/52 17.11.1999
8 IRS-1D LlSS-11I 103/53 17.11.1999
9 IRS-1D LlSS-11I 104/53 14.11.1999
10 IRS-1D LlSS-11I 105/54 11.11.1999
11 IRS-1B LlSS-11 23/48 27.11.1994
12 IRS-1 B LlSS-11 23/48 27.11.1994
13 IRS-1 B LlSS-1I 23/49 27.11.1994
14 IRS-1 B LlSS-1I 22/49 22.02.1995
15 IRS-1 B LlSS-1I 22/49 22.02.1995
16 IRS-1 B LlSS-1I 22/49 22.02.1995
17 IRS-1 B LlSS-1I 21/50 12.10.1994
18 IRS-1A LlSS-11 23/48 16.10.1988
19 IRS-1A LlSS-11 23/48 19.03.1989
20 IRS-1A LlSS-1I 23/49 16.10.1988
21 IRS-1A LlSS-11 23/49 21.12.1988
22 IRS-1A LlSS-1I 22/49 07.12.1989
23 IRS-1A LlSS-1I 22/49 15.10.1988
24 IRS-1A LlSS-1I 22/49 15.10.1988
25 IRS-1A LlSS-1I 21/50 14.10.1988

3.4 As per the decisions taken in the meeting with ewe, the bank line data for a period of
16 years from 1988 -1989 to 2004 - 2005 were collected at an interval of about 4 to 6 years.
Broadly, the data were collected for the followingtyears:

.:. 1988 -1989

.:. 1.994 -1995
.:. 1999 -2000
.:. 2004 -2005

CWPRS, Technical Report No. 5015 for November 2012 7

 ---------:iV"""-------------------...,..,_
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Morphological studies of river Gandak using satellite and SDI Data

-,,", '.:y-

3.5 The satellite data received from NRSA was geo-coded using the information available
in sal toposheets. The bank lines were marked on satellite data of each year and the
vectors were saved using the utility available in EASIPACE software at CWPRS.

3.6 The bank line vectors thus obtained were superimposed in different pairs of the 5
year period bank lines. The changes in the bank lines thus became clear on
superimposition. These are identified as likely areas that may require attention for damages
during the floods.

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'-~-' CWPRS, Technical Report No. 5015 for November 2012 8

• "'O"Q~~'
 , -

CHAPTER 4 "-
.

ANALYSIS, RESULTS
AND
DISCUSSIONS
I Morphological studies of river Gandak using satellite and SOl Data

I MORPHOLOGICAL STUDIES OF RIVER GANDAK USING SATELLITE AND SOl DATA

I
4.0 ANALYSIS, RESULTS AND DISCUSSIONS

I 4.1 The first stage of the work was completed by delineating the bank line from the
available toposheets of SOl. Thereafter the information from SOl toposheet was used for
I geocoding the satellite data received from NRSA. The bank lines of satellite data were
delineated on each year. The bank lines for 1988, 1994, 1999 and 2004 are shown in
I Figures 4.1 to 4.4 respectively.

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I FIGURE 4.1: BANK LINES OF GANDAK RIVER -1988

,,~; CWPRS, Technical Report No. 5015 for November 2012 9

'~'V"g~,.
 Morphological studies of river Gandak using satellite and SOl Data
...

FIGURE 4.2: BANK LINES OF GANDAK RIVER -1994

I ,.{i" CWPRS, Technical Report No. 5015 for November 2012 10

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 / ..- -

Morphological studies of river Gandak using satellite and sal Data

..

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I FIGURE 4.3: BANK LlNES- GANDAK RIVER -1999

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I Morphological studies of river Gandak using satellite and SOl Data
.;

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I FIGURE 4.4: BANK LINES OF GANDAK RIVER - 2004

I 4.2 In order to identify the changes in the bank lines, two years' bank lines were
superimposed in the following manner:

i SI. No. Source

Com.oi!.Lson with
Figure No.
bank line for the year

I 1
2
1988
1994
4.5
4.6
Toposheet
j 3 1999 4.7
4 2004 4.8
.5 Toposheet 1988, 1994, 1999,2004 4.9

CWPRS, Technical Report No. 5015 for November 2012 12

 l' ,,- .-

Morphological studies of river Gandak using satellite and SOl Data

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i ____ Toposheet ____ 1988

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FIGURE 4.5: SUPERIMPOSED

----
BANK LINES - TOPOSHEET & 1988

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CWPRS. Technical Report No. 5015 for November 2012 13
I Morphological studies of river Gandak using satellite and SOl Data
.r

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____ Toposheet ____ 1994

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Morphological studies of river Gandak using satellite and SDI Data

____ Toposheet ____ 1999

-':'"

·,

.~':#*~~
~)4"'!.,; i'

FIGURE 4.7: SUPERIMPOSED

---
BANK LINES - TOPOSHEET & 1999

CWPRS. Technical Report No. 5015 for November 2012 15

I Morphological studies of river Gandak using satellite and 501 Data

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____ Toposheet ......•.... 2004

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FIGURE 4.8: SUPERIMPOSED ---
BANK LINES - TOPOSHEET & 2004

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CWPRS, Technical Report No. 5015 for November 2012 16
 ;/:- -'

Morphological studies of river Gandak using satellite and SOl Data

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Toposheet
1994
1988
1999
2004

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FIGURE 4.9: SUPERIMPOSED BANK LINES TOPOSHEET, 1988, 1994, 1999 & 2004

I 4.3 The review of the bank lines as identifiea-above indicates that

I i) The stretch of river considered in the studies can be divided in three broad
regions as :

I I
11
Hilly region near origin
Intermediate region as the river enters plain area and

I III Outfall of river Gandak in river Ganga

I CWPRS, Technical Report No. 5015 for November 2012 17

 Morphological studies of river Gandak using satellite and SOl Data

~I

ii) There are no major changes in bank lines from the sal toposheet to 2004 in hilly
region.

I iii) Similarly, major changes in bank lines were not discernible in the area near
confluence of river Gandak with river Ganga.
iv) A comparison of bank lines from toposheets with 1988 satellite data (Figure 4.5)
shows that there has been shifting of course of river Gandak in the zones

I identified as I, 11and Ill. It can be seen that both the banks are shifted downwards
in zone I and widening of channel can be seen in zone 11. As against this, the
shifting of both banks leading to formation of meander can be noticed near region
I Ill. A shifting of left bank of river Ganga on upstream of confluence can be seen
at the confluence of river Gandak.
v) A comparison of bank lines of toposheets and 1994 (Figure 4.6) shows that the
changes taken. place between toposheet and 1988 have tried to readjust between
I 1988-1994 at certain places. The overall picture shows no sigQificant change in
the bank lines of 1988 and 1994 with respect to bank lines in toposheets.
vi) A comparison of bank lines of toposheet and 1999 is presented in Figure 4.7.
The general trend of change in the bank line with respect to toposheet is similar to
the change noticed during 1994. The bank line of 1999 in the region 11appears to
shift towards left as compared to its position noticed in toposheet. The course of

I river Gandak shows narrowing of river width at the end of region Ill.
vii) A superimposition of bank line is obtained from toposheet and 2004 satellite data
is presented in Figure 4.8.
viii) A comparison of bank lines presented in Figures 4.5 and 4.8 further shows that
the river is trying to gain the position as present in the year 1988. Some
transitions could be noticed in the region 11and Ill. Some changes at the
confluence of river Gandak with river Ganga are likely to have taken place, since
the bank lines of river Ganga as obtained in 1988 and 2004 indicate changes.

4.4 A comparison of all the five bank lines viz. toposheet, 1988, 1994, 1999 and 2004 is
presented in Figure 4.9. It can be seen that there is shifting in left bank of river Gandak
between the bank lines of toposheet and 2004 in the hilly region. Similar changes in bank
lines are also noticed between toposheet and 2 4 in the intermediate zone. The bank lines
from the toposheet to 2004 in the last stretch of river Gandak before confluence with river
Ganga appear to be by and large at the same location.

4.5 A meeting was held at ewe, New Delhi in NovemberlDecember 2006 wherein the
draft report was discussed and comments/observations were communicated. Further studies

,-.~f CWPRS, Technical Report No. 5015 for November 2012 18

• "~,,,w~~.,"

--- ----------------------------------------~
I Morphological studies of river Gandak using satellite and SOl Data

~,

I have been carried out at CWPRS for compliance of observations/comments of the

Committee Members.

I The total stretch of river Gandak under study has been divided in 7 different zones.
The reach covers area of river Gandak downstream of origin in hilly area upto the confluence

I with River Ganga near Hajipur. The boundaries of these zones are shown in Figure 4.10 and
coordinates of diagonal are presented in Table 4.1. The care has been taken to provide

I overlap of down stream zone B for the first zone on upstream side A. Similarly overlaps of
interim zones from B to F have been provided for both upstream and downstream zones.
The last zone G has overlap only on the upstream Zone F.
I
I ZONE A

I
I
I
I
I
I
I
I
I
I
I FIGURE 4.10: ZONING OF RIVER GANDAK

CWPRS, Technical Report No. 5015 for November 2012 19

 ---
,1:- _
..•

Morphological studies of river Gandak using satellite and SDI Data

.'J

TABLE 4.1: ZONE CO-ORDINATES

X (Top Left Corner) Y (Bottom Right Corner)

S. No. ZONE Longitude Latitude Longitude Latitude

D M D M D M D M

1 A 83 45 27 36 84 5 27 10

2 B 83 52 27 11 84 25 26 50

3 C 84 5 26 55 84 35 26 35

4 0 84 17 26 40 84 50 26 20

5 E 84 30 26 25 85 0 26 10
-
6 F 84 45 26 15 85 15 25 "
50

7 G 85 0 25 55 85 30 25··~ 30

A comparison of bank lines of river Gandak during 1988, 1994, 1999 and 2004 has
been made with bank lines of river Gandak as prevailed during the year in which Survey of
India toposheet was available. Comparisons of bank lines for Zone A are shown in Figure
4.11. Figure contains sub part a, b, c and d showing the comparison of bank lines for the
year 1998, 1994, 1999 and 2004 respectively. A review has been taken for identifying the
erosion/deposition of area on left and right bank of river Gandak within each zone. The
delineation of locations on bank lines of left and right bank has been done for identification of .
I

changes and rate of change of bank line with reference to the toposheet. Computations have
I
further been continued for each of the year and these changes have been vectorially added
upto year 2004. In order to achieve these, reference points were identified on bank line of
I toposheet. These are denominated in the form of determination is given as

I XYI
where, X= Zone name A to G
I Y=
I =
----
Bank line of river either left (L) or right (R)
Serial number of location ranking from 1, 2, 3 etc.
I
Thus, in Figure 4.11 changes on right bank in zone A have been identified as AR1,

I AR2 to AR4 whereas changes in left bank have been identified as AL 1, AL2 to AL6. The
coordinates of the reference points have been identified and presented in Table AR for right

I
I ,
-"~. ' •••• g~ ••• i~
CWPRS, Technical Report No. 5015 for November 2012 20
I Morphological studies of river Gandak using satellite and SOl Data

bank and AL for left bank. The length of segments between reference points has been
measured by using EASIPACE software utility available at CWPRS.

I
Similarly, the work has been continued and corresponding changes in the bank line

I for zones B to G are presented. The details of Tables and Figures for each zone are given
below:

I Figure No
showing
Figure No
showing
Table showing
coordinates of
Table showing
Rate of change
Item Zone Reference
changes nearby townl in Bank lines
Points
I No. No.
for Bank
line (s)
villages for
each zone
Right Left Right Left
Bank Bank Bank Bank
1 A 4.11 4.18 4AR 4AL 4.2 4.3

2 B 4.12 4.19 4BR 4BL 4.4 4.5

-
3 C 4.13 4.20 4CR 4CL 4.6 4.7

4 0 4.14 4.21 4DR 4DL 4.8 .s, 4.9

5 E 4.15 4.22 4ER 4EL 4.10 4.11

6 F 4.16 4.23 4FR 4FL 4.12 4.13

7 G 4.17 4.24 4GR 4GL 4.14 4.15

The data in Table 4ZR and 4ZL (Z refers to zone from A to G) has been further
utilized to find out rate of change in bank line of right and left bank separately. The lengths
have been measured with respect to toposheets and the changes in length of segment are
presented in Table 4ZR are for right bank and Table 4ZL for left bank. Positive sign is
assigned if there is erosion with respect to toposheet and negative sign is assigned for
deposition with respect to toposheets. These changes have been measured with respect to
toposheets for 1998 and subsequently between the year for 1994, 1999 and 2004. Rate of
change in bank line has also been determined and added vectorially to derive cumulative
rate of change in bank line.

In order to identify the locations like AR1, AR2 etc where changes in bank line have taken
place, attempts were made to identify towns/villages in the vicinity using available
toposheets. The changes of locations in each left an right bank are shown in Figure 4.18 to
4.24 for zone A to G respectively. These are marked on bank line data of 1988 for all the
zones.

,~; CWPRS, Technical Report No. 5015 for November 2012 21

'~'~~g~
~.
 Morphological studies of river Gandak using satellite and SOl Data
7

TABLE 4AR: COMPARISON OF TOPOSHEET RIGHT BANK LINE IN ZONE A

RIGHT BANK
From (Toposheet) To
Change
Legend Year Sign Longitude Latitude Longitude Latitude
inm
D M S D M S D M S D M S
AR1 1988 - 83 56 43.2 27 28 6.2 83 56 49.5 27 28 6.2 173.97
1994 - 83 56 49.5 27 28 6.2 173.97
1999 - 83 56 49.5 27 28 6.1 175.89
2004 - 83 56 49.4 27 28 6.2 176.17
AR2 1988 - 83 49 2.8 27 24 45.8 83 51 42.8 27 24 45.8 4438.85
1994 - 83 51 41.6 27 24 45.8 4404.35
1999 - - 83 51 41.1 27 24 45.8 4392.50
2004 - 83 51 41.1 27 24·",45.8 4392.50
AR3 1988 + 83 51 13.4 27 20 17.3 83 50 55 27 20 17.4 512.62
1994 + 83 50 53.3 27 20 17.4 559.74
1999 + 83 50 51.8 27 20 17.2 595.73
2004 + 83 50 47.4 27 20 17.3 719.07
AR4 1988 + 83 51 11.1 27 14 59.4 83 50 30.7 27 14 59.4 1114.89
1994 + 83 49 57.4 27 14 59.4 2034.17
1999 + 83 49 58 27 14 59.4 2014.57
2004 + 83 49 58 27 14 59.4 2014.57

CWPRS, Technical Report No. 5015 for November 2012 36

 Morphological studies of river Gandak using satellite and sal Data

~,

TABLE 4AL: COMPARISON OF TOPOSHEET LEFT BANK LINE IN ZONE A

LEFT BANK
From (Toposheet) To
Change
Legend Year Sign Longitude Latitude Longitude Latitude
inm
0 M S 0 M S 0 M S 0 M S
AL1 1988 + 83 53 4.2 27 25 53.6 83 53 4.2 27 25 44 299.39
1994 + 83 53 4.2 27 25 45.7 245.38
1999 + 83 53 4.2 27 25 43.9 309.10
2004 + 83 53 4.2 27 25 39.4 442.38
AL2 1988 + 83 52 19 27 22 45.5 83 53 26.7 27 22 45.5 1881.56
1994 + 83 53 35.6 27 22 45.5 2123.42
1999 + 83 53 55.8 27 22 45.5 2691.90
2004 + 83 53 56 27 22 45.5 2685.46
,
AL3 1988 - 83 52 49 27 20 50 83 51 55.8 27 20 .;..?O 1476.82
1994 - 83 51 33.8 27 20 50 2087.30
1999 - 83 51 37.4 27 20 50 1984.06
2004 - 83 52 49.6 27 20 50 1977.97
AL4 1988 + 83 51 6.8 27 18 26 83 52 21 27 18 26 2068.84
1994 + 83 50 57 27 18 26 273.19
-. 1999 + 83 52 16.7 27 18 26 1932.65
2004 + 83 52 13.2 27 18 26 1834.86
AL5 1988 - 83 59 10.5 27 13 32.6 83 58 23 27 13 32.6 1317.12
1994 - 83 55 54.2 27 13 32.6 5455.80
1999 - 83 55 28.1 27 13 32.6 6177.73
2004 - 83 55 35.1 27 13 32.6 6023.17
AL6 1988 - 84 1 21.8 27 10 30.2 84 0 47.2 27 10 30.2 957.93
1994 - 83 58 52.1 27 10 30.2 4158.11
1999 - 83 59 13 27 10 30.2 3580.29
2004 - 83 58 39.9 27 10 29.9 4596.55

CWPRS, Technical Report No. 5015 for November 2012 37

 Morphological studies of river Gandak using satellite and SDI Data

-:c:'
TABLE 4BR: COMPARISON OF TOPOSHEET RIGHT BANK LINE IN ZONE B

RIGHT BANK
From (Toposheet) To
Change
Legend Year Sign Longitude Latitude Longitude Latitude
inm
D M S D M S D M S D M S
BR1 1988 - 83 56 8.4 27 10 27,5 83 56 31.5 27 10 27.5 852.46

1994 - 83 57 59.8 27 10 27.5 3283.69

1999 - 83 57 59.8 27 10 27.5 3283.69

2004 - 83 58 7.7 27 10 27.5 3313.37

BR2 1988 + 83 58 22.3 27 7 0.1 83 57 43.1 27 7 0.1 1078.80

1994 - 83 59 39.7 27 7 0.1 2133.32

1999 + 83 57 51.2 27 7 0.1 856.76
-
2004 - 83 59 41.1 27 7 0.1 1965.93
"

BR3 1988 + 84 5 4.4 27 3 42.4 84 5 4.4 26 59 2.5~4 7909.92

1994 + 84 5 4.4 26 59 56.8 6943.96

1999 + 84 5 4.4 26 59 32.7 7686.21

2004 + 84 5 4.4 26 59 23.7 8040.78

BR4 1988 + 84 9 43.3 26 59 23.9 84 7 31.5 26 59 23.9 3634.48

.'
1994 + 84 7 38.5 26 59 23.9 3440.32
~ 1999 + 84 7 34.3 26 59 23.9 3554.98
2004 + 84 7 44.4 26 59 23.9 3308.24

BR5 1988 + 84 14 24.1 26 52 59.8 84 12 29.9 26 52 59.8 3152.74

1994 + 84 12 40.7 26 52 59.8 2855.83

1999 + 84 12 10.3 26 52 59.8 3694.72

2004 + 84 11 31 26 52 59.8 4826.88

'.~, CWPRS, Technical Report No, 5015 for November 2012 38

Morphological studies of river Gandak using satellite and SOl Data

.,

TABLE 4.12: RATE OF CHANGE OF RIGHT BANK LINE OF RIVER GANDAK IN ZONE F

Rate of change in
Toposheet Change Bank Lines (m/yr)
Legend Year Sign
Year inm
Individual Cumulative
FR1 1988 1932 + 818.23 14.61 14.61
1994 + 948.90 21.78 36.39
1999 + 1033.56 16.93 53.32
2004 + 1036.41 0.57 53.89

TABLE 4.13: RATE OF CHANGE OF LEFT BANK LINE OF RIVER GANDAK IN ZONE F "

Rate of change in
Toposheet Change Bank Lines (m/yr)
Legend Year Sign
Year inm
Individual Cumulative
FL 1 1988 1932 + 1565.17 27.95 27.95
1994 + 1512.68 -8.75 19.20
1999 + 1565.17 10.50 29.70
2004 + 1590.01 4.97 34.67
FL3 1988 1932 + 267.14 4.77 4.77
1994 + 1446.90 196.63 201.40

1999 + 1541.68 18.96 220.35

2004 + 1560.81 3.83 224.18
FL5 1988 1932 - 952.22 17.00 17.00
1994 + 745.14 -34.51 -17.51
1999 + 745.14 0.00 -17.51
2004 - 1036.41 58.25 40.74

----

CWPRS, Technical Report No. 5015 for November 2012 52

 Morphological studies of river Gandak using satellite and SOl Data

-"':'

TABLE 4BL: COMPARISON OF TOPOSHEET LEFT BANK LINE IN ZONE B

LEFT BANK
From (Toposheet) To
Change
Legend Year Sign Longitude Latitude Longitude Latitude
inm
0 M S 0 M S 0 M S 0 M S
BL1 1988 - 84 10 21.4 27 3 15.3 84 8 51.4 27 3 15.3 2479.09
1994 - 84 8 24.1 27 3 15.3 3231.31
1999 - 84 8 27 27 3 15.3 3153.17
2004 - 83 58 31.1 27 3 15.3 4580.76
BL2 1988 - 84 14 55.5 26 57 58.4 84 12 57.6 26 57 58.4 3254.06
1994 - 84 12 34.5 26 57 58.4 3888.52
1999 - 84 12 25.8 26 57 58.4 4181.59
2004 - 84 12 25.8 26 57 58.4 4181.59
BL3 1988 + 84 16 31.9 26 52 59.8 84 17 1 26 52 5~.8 811.30
1994 - 84 15 27.7 26 52 59.8 1764.55
1999 - 84 15 29.3 26 52 59.8 1720.69
2004 - 84 12 25.8 26 52 59.8 4181.59

CWPRS, Technical Report No. 5015 for November 2012 39

 Morphological studies of river Gandak using satellite and SOl Data

TABLE 4CR: COMPARISON OF TOPOSHEET RIGHT BANK LINE IN ZONE C

RIGHT BANK

From (Toposheet) To
Change
Legend Year Sign Longitude Latitude Longitude Latitude
inm
D M S D M S D M S D M S
CR1 1988 + 84 16 50.9 26 50 5.8 84 13 25.8 26 50 5.8 5661.45
1994 + 84 13 26.3 26 50 5.8 5647.70
1999 + 84 13 27.2 26 50 5.8 5624.56
2004 + 84 13 12 26 50 5.8 6044.68
CR2 1988 + 84 21 53.1 26 41 54.8 84 19 50.3 26 41 54.8 3396.70
1994 + 84 19 30.9 26 41 54.8 3933.06
1999 + 84 19 39.1 26 41 54.8 3704.95
2004 + 84 19 19.9 26 41 54.8 4235.89
,
. -

TABLE 4CL: COMPARISON OF TOPOSHEET LEFT BANK LINE IN ZONE C

LEFT BANK
.' From (Toposheet) To
Change
Legend Year Sign Longitude Latitude Longitude Latitude
~ inm
D M S D M S D M S D M S
CL1 1988 - 84 20 27.4 26 48 3.9 84 19 56.9 26 48 3.9 844.28
1994 + 84 20 46.9 26 48 3.9 537.55
1999 - 84 20 3.9 26 48 3.9 650.68
2004 + 84 23 14.3 26 48 3.9 4607.94
CL2 1988 + 84 22 24.6 26 41 54.4 84 25 53.9 26 41 54.4 5785.92
1994 + 84 25 51.9 26 41 54.4 5731.58
1999 + 84 25 54.7 26 41 54.4 5806.40
2004 + 84 25 54.7 26 41 54.4 5806.40

----

CWPRS, Technical Report No. 5015 for November 2012 40

 ;1..-

Morphological studies of river Gandak using satellite and SOl Data

TABLE 4DR: COMPARISON OF TOPOSHEET RIGHT BANK LINE IN ZONE D

RIGHT BANK
From (Toposheet) To
Change
Legend Year Sign Longitude Latitude Longitude Latitude
inm
D M S D M S D M S D M S
DR1 1988 84 27 46.7 26 35 55.4
1994 84 25 6.7 26 38 5.8
1999 84 24 22.1 26 37 36.2
2004 84 24 25.7 26 36 25.2
DR2 1988 + 84 29 42.8 26 32 33.2 84 27 41.9 26 32 33.3 3349.34
1994 + 84 29 42.8 26 32 33.3 4360.99
1999 + 84 29 42.8 26 32 33.3 4609.20
2004 + 84 26 40.3 26 32 33.2 5055.21
-,

DR3 1988 - 84 34 29.6 26 28 18.8 84 35 17.6 26 28 1~.8 1331.02

1994 - 84 35 25.3 26 28 18.8 1544.58
1999 + 84 31 5.7 26 28 18.8 5644.95
2004 + 84 31 21.1 26 28 18.8 5219.89
. DR4 1988 - 84 34 29.6 26 28 18.8 84 34 29.6 26 28 46.7 861.11
1994 - 84 34 29.6 26 28 30 344.63
»,

1999 + 84 34 29.6 26 25 30.2 5191.51

2004 + 84 34 29.6 26 25 33.9 5079.31
DR5 1988 + 84 43 37 26 24 7.5 84 43 10.6 26 24 7.5 731.37
1994 + 84 42 57.5 26 24 7.5 1093.80
1999 + 84 42 46.8 26 24 7.5 1390.76
2004 + 84 42 46.8 26 24 7.5 1390.76

TABLE 4DL: COMPARISON OF TOPOSHEET LEFT BANK LINE IN ZONE D

LEFT BANK
From (Toposheet) To
Change
Legend Year Sign Longitude Latitude -- --Longitude Latitude
inm
D M S D M S D M S D M S
DL1 1988 + 84 42 46.8 26 25 1.7 84 44 2.3 26 25 1.7 2099.92
1994 + 84 42 46.8 26 25 1.7 2335.42
1999 + 84 44 19.1 26 25 1.7 2565.12
2004 + 84 44 19.1 26 25 1.7 2565.12

CWPRS, Technical Report No. 5015 for November 2012 41

 Morphological studies of river Gandak using satellite and SDI Data

TABLE 4ER: COMPARISON OF TOPOSHEET RIGHT BANK LINE IN ZONE E

RIGHT BANK
From (Toposheet) To
Change
Legend Year Sign Longitude Latitude Longitude Latitude
inm
D M S D M S D M S D M S
ER1 1988 + 84 44 43.2 26 22 36 84 44 23.3 26 22 36 554.15
1994 + 84 44 18.7 26 22 36 685.59
1999 + 84 44 11.5 26 22 36 881.53
2004 + 84 44 2.5 26 22 36 1139.94
ER2 1988 - 84 47 41.5 26 17 12.4 84 49 3.4 26 17 12.4 2271.95
1994 - 84 49 33.6 26 17 12.4 3102.01
1999 - 84 48 46.5 26 17 12.4 1803.38
.
2004 - 84 48 52.1 26 17 12.4 1961.72
ER3 1988 + 84 52 38.2 26 14 14.7 84 51 8.8 26 14 14.J 2482.97
1994 + 84 50 46.9 26 14 14.7 3086.81
1999 + 84 50 30.9 26 14 14.7 3533.44
2004 + 84 50 31.5 26 14 14.7 3518.44

TABLE 4EL: COMPARISON OF TOPOSHEET LEFT BANK LINE IN ZONE E

<.
LEFT BANK
From (Toposheet) To
Change
Legend Year Sign Longitude Latitude Longitude Latitude
inm
D M S D M S D M S D M S
EL1 1988 - 84 45 43.4 26 22 25 84 45 12.6 26 22 25 854.81
1994 - 84 45 3 26 22 25 1120.13
1999 - 84 45 9.7 26 22 25 934.13
2004 - 84 45 9.7 26 22 25 934.13
EL2 1988 - 84 48 47.5 26 19 50.1 84 47 0.5 26 19 50.1 2968.49
1994 - 84 46 53.7 26 19 50.1 3155.62
1999 - -
~ 47 1.3 26 19 50.1 2945.62
2004 - 84 47 1.3 26 19 50.1 2945.62
EL3 1988 + 84 55 26.6 26 11 31.8 84 56 23.7 26 11 31.8 1581.94
1994 + 84 56 29.1 26 11 31.8 1732.42
1999 + 84 56 26.1 26 11 31.8 1649.35
2004 + 84 56 26.1 26 11 31.8 1649.35

CWPRS, Technical Report No. 5015 for November 2012 42

 Morphological studies of river Gandak using satellite and SOl Data

TABLE 4FR: COMPARISON OF TOPOSHEET RIGHT BANK LINE IN ZONE F

RIGHT BANK
From (Toposheet) To
Change
Legend Year Sign Longitude Latitude Longitude Latitude
inm
0 M S 0 M S 0 M S 0 M S
FR1 1988 + 85 6 5.2 25 54 46.1 85 5 35.8 25 54 46.1 818.23
1994 + 85 5 31.2 25 54 46.1 948.90
1999 + 85 5 28.1 25 54 46.1 1033.56
2004 + 85 5 28.4 25 54 46.1 1036.41

TABLE 4FL: COMPARISON OF TOPOSHEET LEFT BANK LINE IN ZONE F

LEFT BANK
From (Toposheet) To
Change
Legend Year Sign Longitude Latitude Longitude Latitude,
inm
0 M S 0 M S 0 M S 0 M S
FL1 1988 + 84 56 37.1 26 8 23.7 84 57 33.4 26 8 23.7 1565.17
1994 + 84 57 31.6 26 8 23.7 1512.68
1999 + 84 57 33.5 26 8 23.7 1565.17
.'
2004 + 84 57 33.5 26 8 23.7 1590.01
F-L2 1988 84 57 6.8 26 3 50.4 84 57 6.8 26 3 50.4

1994 84 57 41.7 26 4 36.4

1999 84 57 33.9 26 4 32.7

2004 84 57 37.9 26 4 32.7

FL3 1988 + 84 56 59.3 26 3 39.6 84 57 9 26 3 39.6 267.14

1994 + 84 57 51.4 26 3 39.6 1446.90
1999 + 84 57 54.8 26 3 39.6 1541.68
2004 + 84 57 54.8 26 3 39.6 1560.81
FL4 1988 84 57 10.3 26 3 28 84 57 10.3 26 3 28
1994 84 57 45.1 26 3 4.4

1999
2004
-- ",].4

84
57
57
47.6
45.5
26
26
2
3
55.6
4.1

FL5 1988 - 85 6 51 25 54 46 85 6 16.7 25 54 46 952.22

1994 + 85 7 17.7 25 54 46 745.14
1999 + 85 7 17.7 25 54 46 745.14
2004 - 85 5 28.4 25 54 46 1036.41

CWPRS, Technical Report No. 5015 for November 2012 43

 Morphological studies of river Gandak using satellite and sal Data

TABLE 4GR: COMPARISON OF TOPOSHEET RIGHT BANK LINE IN ZONE G

RIGHT BANK
From (Toposheet) To
Legend Year Sign Longitude Latitude Longitude Latitude Change
inm
0 M S 0 M S 0 M S 0 M S

GR1 1988 - 85 6 46 25 52 12.2 85 6 59.3 25 52 12.2 367.88

1994 - 85 7 9.3 25 52 12.2 646.33
1999 + 85 6 39.2 25 52 12.2 192.72
2004 - 85 7 7.4 25 52 12.2 602.88
GR2 1988 + 85 9 57.9 25 48 38.7 85 9 22.4 25 48 38.7 987.40
1994 + 85 9 24.7 25 48 38.7 924.03
-
1999 + 85 9 29.2 25 48 38:7 802.62
2004 + 85 9 29 25 48 38') 810.70

TABLE 4GL: COMPARISON OF TOPOSHEET LEFT BANK LINE IN ZONE G

., LEFT BANK
From (Toposheet) To
Change
Legend Year Sign Longitude Latitude Longitude Latitude
inm
0 M S 0 M S 0 M S 0 M S
GL1 1988 - 85 8 47.2 25 51 41.5 85 8 4.8 25 51 41.5 1182.76
1994 - 85 7 56.4 25 51 41.5 1433.00
1999 - 85 7 56.4 25 51 41.5 1433.00
2004 - 85 7 56.4 25 51 41.5 1433.00
GL2 1988 + 85 10 27.8 25 48 38.7 85 10 35.4 25 48 38.7 210.83
1994 + 85 10 35.4 25 48 38.7 210.83
1999 + 85 10 35.4 25 48 38.7 210.83
2004 + -ss, 10 35.4 25 48 38.7 210.83

,,~, CWPRS, Technical Report No. 5015 for November 2012 44

Morphological studies of river Gandak using satellite and SDI Data

TABLE 4.2: RATE OF CHANGE OF RIGHT BANK LINE OF RIVER GANDAK IN ZONE A

Rate of change in
Toposheet Change
Bank Lines (m/yr)
Legend Year Year Sign inm
Individual Cumulative
AR1 1988 1963 - 173.97 6.96 6.96
1994 - 173.97 0.00 6.96
1999 - 175.89 0.38 7.34
2004 - 176.17 0.06 7.40

AR2 1988 1963 - 4438.85 177.55 177.55

1994 - 4404.35 -5.75 171.80
1999 - 4392.50 -2.37 169.43

2004 - 4392.50 0.00 169.43

AR3 1988 1963 + 512.62 20.50 20.50

1994 - + 559.74 7.85 28.36
1999 + 595.73 7.20 35.5{3
2004 + 719.07 24.67 60.22
AR4 1988 1963 + 1114.89 44.60 44.60
1994 + 2034.17 153.21 197.81
1999 + 2014.57 -3.92 193.89
2004 + 2014.57 0.00 193.89

CWPRS, Technical Report No. 5015 for November 2012 45

Morphological studies of river Gandak using satellite and SDI Data

TABLE 4.3: RATE OF CHANGE OF LEFT BANK LINE OF RIVER GANDAK IN ZONE A

Rate of change in
Toposheet Change Bank Lines (m/yr)
Legend Year Sign
Year inm
Individual Cumulative
AL1 1988 1963 + 299.39 11.98 11.98
1994 + 245.38 -9.00 2.97
1999 + 309.10 12.74 15.72
2004 + 442.38 26.66 42.37
AL2 1988 1963 + 1881.56 75.26 75.26
1994 + 2123.42 40.31 115.57
1999 + 2691.90 113.70 229.27
2004 + 2685.46 -1.29 227.98
AL3 1988 1963 - 1476.82 59.07 59.07
1994 - 2087.30 101.75 160.82
1999 - 1984.06 -20.65 14Q.17
2004 - 1977.97 -1.22 138.95
AL4 1988 1963 + 2068.84 82.75 82.75
1994 + 273.19 -299.28 -216.52
1999 + 1932.65 331.89 115.37
2004 + 1834.86 -19.56 95.81
AL5 1988 1984 - 1317.12 329.28 329.28
1994 - 5455.80 689.78 1019.06
1999 - 6177.73 144.39 1163.45
2004 - 6023.17 -30.91 1132.53
AL6 1988 1984 - 957.93 239.48 239.48

1994 - 4158.11 533.36 772.85

1999 - 3580.29 -115.56 657.28
2004 - 4596.55 203.25 860.53

CWPRS, Technical Report No. 5015 for November 2012 46

Morphological studies of river Gandak using satellite and SDI Data

TABLE 4.4: RATE OF CHANGE OF RIGHT BANK LINE OF'RIVER GANDAK IN ZONE B

Rate of change in
Toposheet Change Bank Lines (m/yr)
Legend Year Sign
Year inm
Individual Cumulative
BR1 1988 1984 - 852.46 213.12 213.12
1994 - 3283.69 405.21 618.32
1999 - 3283.69 0.00 618.32
2004 - 3313.37 5.94 624.26
BR2 1988 1928 + 1078.80 17.98 17.98
1994 - 2133.32 175.75 193.73
1999 + 856.76 -255.31 -61.58
2004 - - 1965.93 221.83 160.26
BR3 1988 1928 + 7909.92 131.83 131.83
1994 + 6943.96 -160.99 -29:-f6
1999 + 7686.21 148.45 119.29
2004 + 8040.78 70.91 190.20
BR4 1988 1930 + 3634.48 62.66 62.66
1994 + 3440.32 -32.36 30.30
1999 + 3554.98 22.93 53.24
2004 + 3308.24 -49.35 3.89
BR5 1988 1930 + 3152.74 54.36 54.36
1994 + 2855.83 -49.49 4.87
1999 + 3694.72 167.78 172.65
2004 + 4826.88 226.43 399.08

CWPRS, Technical Report No. 5015 for November 2012 47

Morphological studies of river Gandak using satellite and SOl Data

.">

TABLE 4.5: RATE OF CHANGE OF LEFT BANK LINE OF RIVER GANDAK IN ZONE B

Rate of change in
Toposheet Change Bank Lines (m/yr)
Legend Year Sign
Year inm
Individual Cumulative
BL 1 1988 1928 - 2479.09 41.32 41.32
1994 - 3231.31 125.37 166.69
1999 - 3153.17 -15.63 151.06
2004 - 4580.76 285.52 436.58
BL2 1988 1930 - 3254.06 56.10 56.10
1994 - 3888.52 105.74 161.85
1999 - 4181.59 58.61 220.46
2004 - 4181.59 0.00 220.46
BL3 1988 1958- + 811.30 27.04 27.04
1994 - 1764.55 158.88 185.92
1999 - 1720.69 -8.77 177.1'~
2004 - 4181.59 492.18 669.33

CWPRS, Technical Report No. 5015 for November 2012 48

Morphological studies of river Gandak using satellite and SOl Data

TABLE 4.6: RATE OF CHANGE OF RIGHT BANK LINE OF RIVER GANDAK IN ZONE C

Rate of change in
Toposheet Change Bank Lines (m/yr)
Legend Year Sign
Year inm
Individual Cumulative
CR1 1988 1931 + 5661.45 99.32 99.32
1994 + 5647.70 -2.29 97.03
1999 + 5624.56 -4.63 92.40

2004 + 6044.68 84.02 176.43

CR2 1988 1931 + 3396.70 59.59 59.59

1994 + 3933.06 89.39 148.98
1999 + 3704.95 -45.62 103.36
2004 + 4235.89 106.19 209.55

TABLE 4.7: RATE OF CHANGE OF LEFT BANK LINE OF RIVER GANDAK IN' tONE C

Rate of change in
Toposheet Sign Change Bank Lines (rn/vr)
Legend Year
Year inm
Individual Cumulative
CL 1 1988 1931 - 844.28 14.81 14.81
1994 + 537.55 -51.12 -36.31
1999 - 650.68 22.63 -13.68
2004 + 4607.94 791.45 777.77
CL2 1988 1931 + 5785.92 101.51 101.51
1994 + 5731.58 -9.06 92.45

1999 + 5806.40 14.96 107.41

2004 + 5806.40 0.00 107.41

CWPRS, Technical Report No. 5015 for November 2012 49

Morphological studies of river Gandak using satellite and SOl Data

TABLE 4.8: RATE OF CHANGE OF RIGHT BANK LINE OF RIVER GANDAK IN ZONE 0

Rate of change in
Toposheet Change Bank Lines (m/yr)
Legend Year Sign
Year inm
Individual Cumulative
DR2 1988 1931 + 3349.34 58.76 58.76
1994 + 4360.99 168.61 227.37
1999 + 4609.20 49.64 277.01
2004 + 5055.21 89.20 366.21
DR3 1988 1931 - 1331.02 23.35 23.35
1994 - 1544.58 35.59 58.94
1999 + 5644.95 820.07 879.02
2004 + 5219.89 -85.01 794.01
DR4 1988 1931- - 861.11 15.11 15.11
1994 - 344.63 -86.08 -70.9.7
1999 + 5191.51 969.38 898.4'8

2004 + 5079.31 -22.44 875.96

DR5 1988 1931 + 731.37 12.83 12.83
1994 + 1093.80 60.41 73.24
1999 + 1390.76 59.39 132.63
2004 + 1390.76 0.00 132.63

TABLE 4.9: RATE OF CHANGE OF LEFT BANK LINE OF RIVER GANDAK IN ZONE 0

Rate of change in
Toposheet Change Bank Lines (rn/vr)
Legend Year Sign
Year inm
Individual Cumulative
DL 1 1988 1931 + 2099.92 36.84 36.84
1994 + 2335.42 39.25 76.09
1999 + 2565.12 45.94 122.03
2004 + 256&..12.,. 0.00 122.03

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Morphological studies of river Gandak using satellite and SDI Data

TABLE 4.10: RATE OF CHANGE OF RIGHT BANK LINE OF RIVER GANDAK IN ZONE E

Rate of change in
Toposheet Change Bank Lines (rn/vr)
Legend Year Sign
Year inm
Individual Cumulative
ER1 1988 1931 + 554.15 9.72 9.72
1994 + 685.59 21.91 31.63
1999 + 881.53 39.19 70.82
2004 + 1139.94 51.68 122.50
ER2 1988 1930 - 2271.95 39.17 39.17
1994 - 3102.01 138.34 177.51
1999 - 1803.38 -259.73 -82.21
2004 - 1961.72 31.67 -50.54
ER3 1988 1932 + 2482.97 44.34 44.34
1994 + 3086.81 100.64 144..98

1999 + 3533.44 89.33 234~so

2004 + 3518.44 -3.00 231.30

TABLE 4.11: RATE OF CHANGE OF LEFT BANK LINE OF RIVER GANDAK IN ZONE E

Rate of change in
Toposheet Change Bank Lines (m/yr)
Legend Year Sign
Year inm
Individual Cumulative
EL 1 1988 1930 - 854.81 14.74 14.74
1994 - 1120.13 44.22 58.96
1999 - 934.13 -37.20 21.76
2004 - 934.13 0.00 21.76
EL2 1988 1930 - 2968.49 51.18 51.18
1994 - 3155.62 31.19 82.37
1999 - 2945.62 -42.00 40.37
2004 - 2945.a2 0.00 40.37
EL3 1988 1932 + 1581.94 28.25 28.25
1994 + 1732.42 25.08 53.33
199~ + 1649.35 -16.61 36.71
2004 + 1649.35 0.00 36.71

'-.~, CWPRS, Technical Report No. 5015 for November 2012 51

-, "'.~.~
•...
Morphological studies of river Gandak using satellite and SOl Data

TABLE 4.14: RATE OF CHANGE OF RIGHT BANK LINE OF RIVER GANDAK IN ZONE G

Rate of change in
Toposheet Change Bank Lines (m/yr)
Legend Year Sign
Year inm
Individual Cumulative
GR1 1988 1935 - 367.88 6.94 6.94
1994 - 646.33 46.41 53.35
1999 + 192.72 -90.72 -37.37
2004 - 602.88 82.03 44.66
GR2 1988 1935 + 987.40 18.63 18.63
1994 + 924.03 -10.56 8.07
1999 + 802.62 -24.28 -16.21
2004 + 810.70 1.62 -14.60

<,

'.~

TABLE 4.15: RATE OF CHANGE OF LEFT BANK LINE OF RIVER GANDAK IN ZONE G

Rate of change in
Toposheet Change Bank Lines (m/yr)
Legend Year Sign
Year inm
Individual Cumulative
GL1 1988 1~35 - 1182.76 22.32 22.32
1994 - 1433.00 41.71 64.02
1999 - 1433.00 0.00 64.02
2004 - 1433.00 0.00 64.02
GL2 1988 1935 + 210.83 3.98 3.98
1994 + 210.83 0.00 3.98
1999 + 210.83 0.00 3.98
2004 + 210.83 0.00 3.98

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 ,1..-

Morphological studies of river Gandak using satellite and SOl Data

...
4.6 The observations on changes in bank line in each of the zones A to G are given
below:

Zone A - Right Bank: Review of Table 4.2 indicates that there are four locations where
major changes have taken place with respect to bank lines of toposheet (1963). These are
identified as AR1 to AR4. It can be seen that the changes that have taken place at AR1 near
Trivenighat have remained practically same. Thus, it can be considered that the bank is not
showing any major change from 1994 to 2004.

At location AR2 near Nansahi Jangal the trend is similar to the trend observed for
AR1. The bank is nearing stable state.

At location AR3 opposite Bettiah RF the changes in bank line from 1963 to 2004 via
1988, 1994 and 1999 shows an increasing trend. This leads to the likely location of bank
erosion.
".
The trend of change in bank line at AR4 is similar to the trend observed-at AR3.
However, the rate of change is tending to be zero between 1999 and 2004.

Zone A - Left Bank: From Table 4.3, at location AL 1 opposite Nansahi Jangal the left bank
. has undergone changes of the order of 299 m between 1963 and 1988 and the change
continued to 442 m in 2004. The rate of change in bank initially goes down from 1963 to
1988/1994 and rises upto 2004.

At location AL2 near Sohgibarwa there is large change in bank line as compared to
AL 1. The rate of change in bank line shows the overall increasing trend. This location may
possibly be considered as location where erosion is taking place.

At location AL3 near Bettiah RF the change in bank line is reversing as compared the
change in AL2. The magnitude of change is somewhat lower than the change in bank line at
AL2. At this location bank line shows tendency of deposition.

The location AL4 near Basai shows the trend similar to the AL2 direction. The
magnitude is declining from 1988 to 1994 and trying t ore towards 1988 position.

The trend of change in bank line is reversed at location AL5 opposite to Bhaisaha as
compared to change at AL4 and the bank is Showing similar trend to location AL3. At this
location maximum change of about 6000 m was noticed between 1994 and 1999/2004.

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Morphological studies of river Gandak using satellite and SOl Data

The change in bank line at AL6 below the Bagaha has similar trend to the change in
bank line observed at AL5. The magnitude of change in bank line is fluctuating from 1988 to
2004. The overall trend of cumulative rate of bank line follows the trend of change in bank
line.

Zone B - Right Bank: In Zone B there are five locations on right bank and three locations
on left bank that show change in bank line. Out of the five locations, on right bank deposition
is observed at first location and trend of erosion is shown at the last three locations. The
second location shows the fluctuating trend of erosion and deposition.

At location BR1 there is deposition from 1984 to 2004. Initially there is a change of
about 850 m upto 1988 which rises to about 3200 m by 1994 and 1999 and further,
increases to 3300 m in 2004. Thus it can be seen that the right bank has started to change
from 1988 to 1999 and is becoming practically stable upto 2004.

At location BR2 the change is alternating in nature i.e. deposition and erosion are
noticed in alternative years. The similar trend is noticed in individual and cumulative rate of
change in bank line.

At other three locations viz. BR3, BR4 and BR5 the trend of erosion is observed. The
magnitude of change is maximum in BR3 near Madhubani PO with a value of about 8000 m
between 1928 and 2004. The overall change in bank line is reducing from BR3 to BR5. The
-.
reach between BR3 to BR5 needs to be kept under observations for possible erosion/
deposition.

Zone B - Left Bank: In Zone B along left bank the trend of deposition is observed. The
maximum change in bank line has occurred at BL 1 near Ratwal of about 4500 m from 1928
to 2004. Similar order of magnitude of change in bank line is observed at location BL2 near
Nawalpur. Howerver, the change in bank line between 1958 and 2004 is of the order of 4100
m at location BL3 near Jogapatti. It can be observed that overall there has been deposition
along the left bank of Zone B.

Zone C - Right Bank and Left Bank: There are two locations each along right bank and left
bank where changes in bank line were noticed. There is tendency of erosion along right
bank. Along left bank the change is alternative in nature at location CL 1 near Malahi and
trend of erosion is displayed at location CL2 near Nutan Dube. The maximum change in
bank line of 6000 m is observed at CR1 and minimum change of bank line of about 530 m is
observed near location CL 1. The changes in bank line at CR1 appear to reach stability upto

,-.~l CWPRS, Technical Report No. 5015 for November 2012 55

Morphological studies of river Gandak using satellite and sal Data

1999. However, increasing trend is displayed between 1999 and 2004. At CR2 the change in
bank line is varying between 3300 m to 4200 m.

Zone 0 - Right Bank: It was noticed towards north west corner of Zone 0 left bank of
toposheet is crossing the right bank of river Gandak from 1988 to 2004. The river was taking
an almost 90° turn around OR 1. The shape of river has changed around this location and it
can be seen that there is a shift in river course towards south east with respect to toposheet
at this location.

There are four locations in Zone 0 on right bank. These are identified as OR2, OR3,
OR4 and OR5. A trend of erosion was noticed at OR2 and OR5, where as initially deposition
was seen upto 1994 in OR3 and OR4. The pattern had changed from deposition to erosion
between 1994 and 1999. This trend had continued upto 2004.

-
In Zone 0 minimum change in bank line of about 340 m was noticed at OR4 between
",

1988 and 1994 and maximum change in bank line of 5600 m was noticed betweel\,1931 and
1999 at location OR3 near Gopalganj, It can be seen that the trend of erosion at OR2 shows
an increasing values whereas the erosion noticed at OR5 appears to be stabled by 2004,

.Zone D - Left Bank: Along left bank only one location OL 1 at Oumaria was noticed during
review of bank line from 1991 to 2004, The trend of erosion can be labeled at this location
which appears to be stabilized by 2004,

Zone E - Right Bank: Three locations could be identified where change in bank line were
noticed, The first and third location viz, ER1 and ER3 indicated possible erosion whereas
signs of deposition are likely to be there at location ER2, At location ER1 near Sidhwalia RS
the rate of change in bank line shows rising trend whereas at location ER3 near Faizullapur
the cutting of bank line appears to reach stable value by 2004, At this location maximum
change in bank line of about 3500 m was noticed between 1932 and 1999,

The deposition pattern is likely to be observed at ER2, The change in bank line
shows rise from 1930 to 1988 and continued upto 1994, Thereafter, the change is remaining
between 1800 m and 1900 m for 1999 and 2004 respectively,

Zone E - Left Bank: Three locations could be identified where measurable change in bank
line was noticed, The first two locations viz EL 1 opposite Sidhwalia RS and EL2 near
Kesariyal Sundarpur indicated a deposition pattern whereas erosive pattern was displayed at
EL3, At all the locations EL 1, EL2 and EL3 the change in bank line shows rising trend from
1988 to 1994 which is declining upto 1999 and remain at the same value by 2004,

CWPRS, Technical Report No. 5015 for November 2012 56

Morphological studies of river Gandak using satellite and SOl Data

Zone F - Right Bank: One location viz. FR1 near Manrar and could be identified that shows
change in bank line. The trend of erosion is indicated at this' location. The change in bank
line appears to reach a nearly constant value of about 1000 m by 2004.

Zone F - Left Bank: Three locations could be noticed during the review of change in left
bank line of Zone F. Erosive trends nearly reach the stable value by 2004 was noticed at FL 1
near Mohabbatpur. A trend of erosion could be seen at FL3. The change in bank line
indicates rising trend at location FL3. FL2 and FL4 are the locations of intersection of left
bank of toposheet and right bank of satellite data of respective year. The co-ordinates of
intersection points are presented in Table 4FL.

Zone G - Right Bank: This is the last zone of the study area, which is near the confluence
of river Gandak with wholly river Ganga. The confluence is near Hajipur town. The changes
in bank lines are likely to be affected by hydraulic and morphological conditions as well as
sequence of water and sediment flow experienced in both the rivers. It is, therefore,
considered appropriate to review the changes in bank lines of river Gandak arc location
suffiCiently upstream of the confluence where the above factors are not influencing the flow
conditions in river Gandak. Accordingly, the study reach was restricted upstream of
confluence of river Ganga. In this reach two locations each on right bank and left bank could
be identified. The deposition trend is shown at location GR 1 upto 1994 followed by reduction
in deposition in 1999 and continuation of deposition further upto 2004. A location GR2
erosive trend could be noticed during comparison of bank line of 1935 to 2004. The change
in bank line indicates reducing trend upto 2004.

A trend of deposition was noticed in GL 1 near Lalganj and trend of erosion was
displayed at GL2 near Gurmia and opposite Mangarpal Naran. In both the cases the
respective trend is likely to reach a constant value of 1400 m at GL 1 and 200 m at GL2.

4.7 Analysis of Gauge, Discharge and Sediment Data:

4.7.1 It was desired during the meeting that available gauge discharge and sediment data
of river Gandak at Triveni and Dumariaghat be collected and analyzed. Accordingly, request
was sent to ewe, Patna and following data were m e available to eWPRS after approval
of the Ministry of Water Resources:

CWPRS, Technical Report No. 5015 for November 2012 57

Morphological studies of river Gandak using satellite and SDI Data

Daily Data Ten Daily Average Data

Site Water level/Gauge (m) and Discharge (m3/s) and Sediment
Discharge (m3/s) (gll)
Triveni 1961 to 2008 1988 to March, 1999
Dumariaghat June, 1997 to March, 2008 ---
Remarks At Triveni site:
• The daily water levels of 1987, 1988, 1990 to 1994 and 1996 years
were not available.
• The daily discharges of 1965 to 1968 and 1996 years were not
available.

Discharge data at Triveni was analyzed and annual maximum and minimum values of
discharge and corresponding water level were extracted. These are given in Table 4.16. It
can be observed that annual maximum discharge varies from minimum of 1140 cum/s to a
maximum 20427 cum/so Similarly, minimum discharge is varying from a minimum of 11
".
cum/s to a maximum of 426 cum/so ..~

CWPRS, Technical Report No. 5015 for November 2012 58

 • .f ••

Morphological studies of river Gandak using satellite and SOl Data

Table 4.16: Maximum and minimum values of gauge and discharges at Triveni site

Maximum Minimum
Date Gauge Discharge Date Gauge Discharge
(m) (m3/s) (m) (m3/s)
1 2 3 4 5 6
21.08.1961 112.392 20427.000 21.02.1961 105.000 234.000
19.08.1962 110.712 7853.020 28.02.1962 105.792 426.500
22.08.1963 109.572 10343.470 04.03.1963 105.602 292.310
04.08.1964 110.552 8802.460 11.04.1964 105.682 234.340
29.08.1965 111.142 --- 13.03.1965 105.692 279.050
25.08.1966 110.962 --- 14.04.1966 105.852 ---
11.07.1967 110.492 --- 16.12.1967 106.662 ---
24.07.1968 111.142 --- 03.01.1968 106.692 ---
22.08.1969 106.615 4160.040 27.11.1969 103.735 244.880
21.07.1970 108.200 19542.630 15.04.1970 103.305 142.630
09.08.1971 107.700 6409.500 05.02.1971 104.000 171.130
29.07.1972 108.200 12625.790 01.02.1972 103.740 195.040
13.09.1973 108.500 13402.000 26.02.1973 103.500 96.300
06.08.1974 108.480 13902.000 02.03.1974 103.033 97.350
28.07.1975 108.500 12416.510 23.02.1975 102.090 42.780 -,
24.08.1976 107.700 10322.000 09.05.1976 102.050 63.390' ~
14.08.1977 107.400 9452.000 08.03.1977 102.220 67.600
17.06.1978 108.350 10885.000 08.02.1978 101.800 66.000
22.08.1979 107.730 6795.000 31.01.1979 102.080 41.900
07.09.1980 107.500 8700.000 28.04.1980 102.550 61.070
01.08.1981 108.200 8140.000 09.01.1981 102.120 75.050
14.09.1982 107.550 7820.000 28.02.1982 102.390 85.980
18.07.1983 107.300 7322.320 28.02.1983 101.610 15.230
08.09.1984 108.130 11080.000 23.03.1984 102.400 30.010
06.19.1985 106.925 7197.350 04.01.1985 102.800 11.370
15.09.1986 108.960' 12700.000 11.02.1986 102.890 22.640
13.08.1987 --- 12200.000 14.03.1987 102.630 24.000
16.08.1988 --- 6598.000 07.03.1988 --- 57.510
30.07.1989 107.400 10500.000 27.02.1989 --- 16.330
19.07.1990 --- 5617.000 02.03.1990 102.255 24.780
17.08.1991 --- 4050.000 18.03.1991 --- 24.150
28.08.1992 --- 4975.000 06.02.1992 --- 25.840
07.09.1993 --- 7900.000 04.03.1993 --- 16.240
28.07.1994 --- 5913.000 15.05.1994 --- 12.610
12.07.1995 108.100 7750.000 18.03.1995 --- 48.880
--- --- 11.03.1996 103.200 42.310
13.08.1997 107.520 6052.000 17.02.1997 102.930 37.510
22.08.1998 108.810 10220.000 28.03.1998 103.090 80.450
04.07.1999 109.010 12700.000 24.03.1999 103.120 62.440
03.08.2000 108.540 9290.000 04.03:WOO 103.770 87.340
01.08.2001 109.450 14950.000 26.03.2001 103.630 130.000
24.07.2002 109.500 15200.000 01.04.2002 103.900 234.000
01.08.2003 109.450 14950.000 18.02.2003 104.000 280.000
12.07.2004 108.080 7858.000 25.03.2004 103.840 208.000
20.08.2005 108.100 7915.000 28.04.2005 103.800 190.000
28.08.2006 107.800 6830.000 04.04.2006 103.990 275.000
07.09.2007 109.100 13250.000 25.12.2007 104.200 388.000
31.05.2.008 105.000 1140.000 22.02.2008 103.700 157.000

CWPRS, Technical Report No. 5015 for November 2012 59

Morphological studies of river Gandak using satellite and SDI Data

The data at Dumariaghat from June 1997 to March 2008 were collected by CWPRS.
The analysis data has been carried out and results showing minimum and maximum values
of water level and discharge at Dumariaghat are presented in Table 4.17.

Table 4.17: Maximum and minimum values of gauge and discharges at Dumariaghat

Maximum Minimum
Date Gauge Discharge Date Gauge Discharge
(m) (m3/s) (m) (m3/s)
1 2 3 4 5 6
16.08.1997 --- 6000.000* 09.06.1997 --- 283.000
24.08.1998 --- 10260.000* 26.03.1998 --- 133.000
29.08.1999 --- 10000.000* 19.03.1999 --- 104.000
05.08.2000 --- 9000.000* 14.03.2000 --- 85.000*
03.08.2001 --- 11500.00* 25.02.2001 --- 158.000*
27.07.2002 --- 11350.00* 27.03.2002 --- 178.000*
03.08.2003 --- 9880.000* 12.03.2003 --- 50.000*
23.08.2004 --- 3780.000* 05.03.2004 --- 40.000~
29.08.2005 --- 3560.000* 22.03.2005 --- 70.000*\...
30.08.2006 61.920 4310.000 03.04.2006 --- 65.000*
10.09.2007 63.140 11400.000 08.03.2007 57.990 87.290
27.03.2008 57.790 78.000
* Computed discharce

In addition, analysis of Ten-daily average discharge and sediment data at Triveni site
in river Gandak for a period of 12 years from 1988 to March 1999 were supplied. These data
have been analyzed and results are presented in Section 4.7.2.

Attempts were being made to collect additional data at Station Lalganj site. However,
these data could not be collected due to the difficulties during collection.

4.7.2 The 10-daily average discharge and sediment load at Triveni site on river Gandak
was collected from CWC, Patna. These are reviewed for identification of outliers 1
exceptionally high or low value of discharge and corresponding sediment. Data for the period
from 1988 to 1998 has been analyzed to derive year to year sediment rating curve in the
form of discharge (cum/s) versus sediment load (g/l). These are shown in Figure 4.25 to
Figure 4.35 respectively.
----

,{if
.'~,~~~~.-
CWPRS, Technical Report No. 5015 for November 2012 60
Morphologicalstudies of river Gandak using satellite and sal Data

8000
-- Power (1988)
7000·
•
6000·
•
~ 5000· •
:::l
o •
-; 4000 • •
e'ra •
s:
..., 3000
en
is 2000

1000·
Y = 1059.3xo.8904
• R2 = 0.8187
0 •
0.0 1.0 2.0 3.0 4.0 5.0
I

Sediment Load (g/l)

1

FIGURE 4.25: SEDIMENT RATING CURVE: RIVER GANDAK AT TRIVENI-1988

10000
9000 • -- Power (1989)
k
8000 .,\.:::

-
.!!1
E
7000· •
:::l 6000
•
•• •
~
Q) 5000
e' •
ra
.c 4000 • •
..., •
en
is 3000
2000
•
Y = 1203xo.7728
1000 R2 = 0.4955
0 •• •
0.0 1.0 2.0 3.0 4.0 5.1
Sediment Load (g/l)

FIGURE 4.26: SEDIMENT RATING CURVE: RIVER GANDAK AT TRIVENI-1989

6000.------------------------~
-- Power (1990) •
•
1_ 5000·
• •

I ~ 4000·
• •
:::l
.!:!.. •
~ 3000·
•
ra
s:
lil 2000· •
is
• y = 1563.6xo.8246
1000· •
o ~._L-~ • •• R2 = 0.8177
~

0.0 0.5 1.0 1.5 2.0 2.5 3.0

_______________________ S_ed_i_m_e_n_t_Lo_a_d_(_9/_1) ~ 1

FIGURE 4.27: SEDIMENT RATING CURVE: RIVER GANDAK AT TRIVENI -1990

CWPRS, Technical Report No. 5015 for November 2012 61

Morphological studies of river Gandak using satellite and SOl Data

- Power (1991)
•
••
3500·
• • •
•
-§
.!!!
3000

2500
•
•

~
Cl) 2000· •
e'ca
"5 1500
III •
Cl 1000.
y = 1307.7xo.7536
500 • R2 = 0.521
0·~L-~~·~~~~---+~~~~-r~~--~+---~~~
0.0 0.5 1.0 1.5 2.0 2.
Sediment Load (g/l)

FIGURE 4.28: SEDIMENT RATING CURVE: RIVER GANDAK AT TRIVENI-1991

- Power (1992)
5000
•
~ 4000·
•
E
~
o •
-; 3000· • • •
e'ca
.c
:il 2000·
I Cl

j
1000· y = 1487.1 XO.6946
R2 = 0.7366
•
o~~~~~~~~~~--~~--~--~~----~~~~
0.0 0.5 . 1.0 1.5 2.0 2.5 3.
Sediment Load (g/l)

FIGURE 4.29: SEDIMENT RATING CURVE: RIVER GANDAK AT TRIVENI-1992

60000 .-----------------------1
.- Power (1993)
1

50000·'
•
~ 40000
I ~u
-; 30000
e'ca y = 1619.1xo.951
.c R2 = 0.908
:il 20000
Cl

1000:1·~~~~~=:~~==~======================~·~
00 1~ 20 ao 4~ ~O 6~ ~~
Sediment Load (g/l) J
FIGURE 4.30: SEDIMENT RATING CURVE: RIVER GANDAK AT TRIVENI -1993

CWPRS, Technical Report No. 5015 for November 2012 62

Morphologicalstudies of river Gandak using satellite and SDI Data

."
9000.-----------------------------------------------.
- Power (1994)
8000

7000

~ 6000
I l
Cl)
5000·

e'
ca 4000· • •
.s:;
~ 3000·
s
2000·
y = 6152.4x1.7311 I
1000 R2 = 0.8516
••
O~. --~~~~~--~~~~~~~----~~~----~ 2
0.0 0.2 0.4 0.6 0.8 1.0 1.
Sediment Load (gll) I

FIGURE 4.31: SEDIMENT RATING CURVE: RIVER GANDAK AT TRIVENI-1994

6000·
- Power (1995)
5000

-
.!!! 4000·
E
• •
•
:::I
~ •
Cl) 3000·
e'ca
.s:;
• •
o
m 2000·
0
1000· y = 1138.3xo.9253
R2 = 0.8516
O.
0.0 1.0 2.0 3.0 4.0 5.0 6.
Sediment Load (g/l)

FIGURE 4.32: SEDIMENT RATING CURVE: RIVER GANDAK AT TRIVENI-1995

7000 .-------------------------------------------1 I
- Power (1996) •
6000· •
Ui 5000
E ••
l 4000·
Cl)

~ 3000
s:
o
m •
o • •
2000·

1000
• ---- y = 4186.2x1.1883
R2 = 0.8945

O~L-------------------------------------------~
0.0 0.4 0.8 1.2 1.6
Sediment Load (g/l)

FIGURE 4.33: SEDIMENT RATING CURVE: RIVER GANDAK AT TRIVENI -1996

\~; CWPRS, Technical Report No. 5015 for November 2012 63

- "'''~''~..
Morphological studies of river Gandak using satellite and SDI Data

10000
9000

8000
.1- Power (1997) •

I:F 7000
E
6000·
I~ Q) 5000
e' •
/11
4000
•
I~o 3000 • • •
•• • I

2000 • = 9315.1x1.7046
• y
1000 • R2 = 0.7842 I
0
0.0 0.2 0.4 0.6 0.8
1.01
Sediment Load (g/l)

FIGURE 4.34: SEDIMENT RATING CURVE: RIVER GANDAK AT TRIVENI-1997

8000'1 ----------------------------------------------~ I
-Log. (1998) • •
7000·

1_
I
.!!1
§
6000·

5000
•
•
• ·1
I ~ 4000· I
/11
"5 3000·
• •
III

CS 2000. I
• y = 1264.4Ln(x) + 3511.8
1000 . R2 = 0.6861 I
o ~----~.~------~--~--~----------------------~
0.0 1.0 2.0 3.0 4.0 5.0 6.01

Sediment Load (g/l)

FIGURE 4.35: SEDIMENT RATING CURVE: RIVER GANDAK AT TRIVENI-1998

It can be observed that except for the year 1998 power relation can be fitted to rating
curve. The rating curve equation is in the form of

where
a = discharge in cum/s
A &b = regression coefficients and ----
as = sediment in (g/I)
The summary of rating curve equation is given in Table 4.18 below:

CWPRS, Technical Report No. 5015 for November 2012 64

Morphological studies of river Gandak using satellite and sal Data
.J

TABLE 4.18: SUMMARY OF RATING CURVES RIVER GANDAK AT TRIVENI

Regression Co-efficient
Year R2
A b
1988 1059.3 0.8904 0.8187
1989 1203.0 0.7728 0.4955
1990 1563.6 0.8246 0.8177
1991 1307.7 0.7536 0.5210
1992 1487.1 0.6946 0.7366
1993 1619.1 0.9510 0.9080
1994 6152.4 1.7311 0.8516
1995 1138.3 0.9253 0.8516
1996 4186.2 1.1883 0.7842
-
1997 9315.1 1.7046 0.7842
1998 Q= 1264.4 Ln(x)+3511.8 0.6861 ,.

These data were further analyzed to review the possibility of change in fluvial
characteristics of river Gandak. The data were clubbed into two groups as 1988 to 1993 and
1994 to 1998. These divisions were made as per the availability of bank line from satellite
data. The data were combined in above two groups and attempts were made to derive
re~ression relations. The curves developed along with plots are presented in Figures 4.36
and 4.37.

10000

8000·

.. ..
en
E:::J
6000
.
.. ..
.. ...· ... .• •• . ..
.!::!.
Ql
4000·
e'
.-. .
/11
..c:

.
U

.... ......·
III
2000
:
0

0 ---- y = 741.71Ln(x) + 2330.8

R2 = 0.5225
-2000·
0 2 3 4 5

Sediment load (g/l)

FIGURE 4.36: SEDIMENT RATING CURVE: RIVER GANDAK AT TRIVENI - (1988-1993)

CWPRS, Technical Report No. 5015 for November 2012 65

Morphological studies of river Gandak using satellite and SOl Data

,">

10000

8000

:F 6000
E
::J
..!:!.
Cl) 4000
Cl
L-
ca
s:
u
VI
CS 2000

0
y = 1099.9Ln(x) + 2991.2
R2 = 0.6255
-2000
0 2 3 4 5
6 I
Sediment load (g/l)

FIGURE 4.37: SEDIMENT RATING CURVE: RIVER GANDAK AT TRIVENI - (1994-1999)

It can be observed from Table 4.18 that except for the year 1998 power' relations
could be obtained for sediment rating curve. The power is changing from minimum of 0.6946
to a maximum of 1.7311. For the year 1998 logarithmic relation has been derived is as given
'below:

Y = 1264.4 Ln (X) + 3511.8

It can be observed from the regression relations that the variation in R2 coefficient for
the individual year and group data for 1993 to 1998 is from 0.49 to 0.90 and 0.52 to 0.62
respectively. These variations can be considered as marginal in nature. These can be
considered as indicative trend and river Gandak to be nearly stable from the point of view of
sediment transport capacity.

4.8 Compliance of the Comments:

4.8.1 The interim report submitted by CWPRS was reviewed and comments were received.
The compliances of these comments have been made while preparing the draft report.
However, the compliance of the items also is encloses-as Appendix 11.

4.8.2 Comments on draft final report were received from CWC. These have been replied
and cognisance of comments is taken while preparing final report. However, compliance of
comments is also presented as Appendix Ill.

CWPRS, Technical Report No. 5015 for November 2012 66

--~--.J.""'"'"""- ---_==~=

SNOlsnl~NO~

. S ~31d"H~
Morphological studies of river Gandak using satellite and SOl Data

MORPHOLOGICAL STUDIES OF RIVER GANDAK USING SATELLITE AND SOl DATA

5.1 CONCLUSIONS

Studies have been carried at CWPRS to identify erosion and deposition area in
Gandak river basin. The stretch of river Gandak from entry into Indian Territory near Triveni
upto confluence of river with Ganga near Hajipur, opposite Patna, Bihar has been
considered. The morphological changes including changes in bank lines have been studied.
Bank line data on the above reach of river Gandak have been collected from Survey of India
(Sal) toposheets and satellite data collected from NRSC, Hyderabad. The total stretch has
been divided into 7 zones identified as A, B, C, D, E, F and G. The details of zones are
described in Table 4.1.

Studies have been carried out by extracting the bank line data from soi fuposheets.
The bank lines were extracted from satellite data using EASIPACE software available in
Remote Sensing Laboratory of CWPRS. Bank line data from cloud free dates in the year
1988, 1994, 1999 and 2004 were extracted and superimposed individually on the bank line of
sal Toposheets (Figures 4.11 to Figure 4.17) in zone wise. It can be concluded from the
studies carried out that

1. There are number of places on left and right bank of river Gandak in each of the 7
zones from A to G considered in the studies where changes in bank line could be
identified. The changes in bank line are ranging from 174 m upto few kilometers. The
details of changes in bank line are given in Tables 4AR to 4GL. An abstract of the
results of analysis showing number of locations on each bank line with minimum and
maximum change in bank line of right and left bank in each zone are given in Table
5.1A and 5.1 B respectively.

CWPRS, Technical Report No. 5015 for November 2012 67

 Table 5.1A: SUMMARY OF CHANGE IN BANK LINE OF RIVER GANDAK

Number of Change in right bank line (m)

Zone
S. No. location(s) on
number
right bank
Minimum Location Place Maximum Location Place
1 A 4 - 173.97 AR1 Tribeni Ghat - 4438.85 AR2 Nansahi Jangal
2 B 5 - 852.46 BR1 Bodhi Chappra + 8040.78 BR3 Madhubani PO
3 C 2 + 3396.70 CR2 Dowath + 6044.68 CR1 Thakraha
4 D 4 - 344.63 DR4 Gopalganj + 5644.95 DR3 Gopalganj
5 E 3 + 554.15 ER1 Sidhwalia RS + 3533.44 ER3 Faizullapur
J ::0

6 F , 1 + 818.23 FR1 Manrar + 1036.41 FR1 Manrar

7 G 2 + 192.72 GR1 Parasbava + 987.40 GR2 Mangarpalnaryan

Note: Negative sign indicates deposition and Positive sign shows erosion with reference to bank line prevailing in sal toposheets

,,(1 ..'

~~
;.

CWPRS, Technical Report No. 5015 for November 2012 68

Morphological studies of river Gandak using satellite and SOl Data

Table 5.1 B: SUMMARY OF CHANGE IN BANK LINE OF RIVER GANDAK

Number of Change in left bank line (m)

Zone
S. No. location(s) on
number
left bank Minimum Location Place Maximum Location Place
1 A 6 + 245.38 AL1 Bhainsalotan - 6177.73 AL5 Bagaha
2 B 3 + 811.30 BL3 Joga Patti - 4580.76 BL1 Ratwal
3 C 2 + 537.55 CL1 Malahi + 5806.40 CL2 Nutan Dube
4 D 1 + 2099.92 DL 1 Dumaria + 2565.12 DL 1 Dumaria
:;.
5 E
,i 3 - 854.81 EL1 Dumaria Ghat - 3155.62 EL2 Sunderpur 1

6 F 5 - 267.14 FL3v Fatehabad + 1590.01 FL 1 '- Mohabatpur

7 G 2 + •.... 210.83 GL2 Gurmia - •.. 1433.00 GL1 Lalganj

Note: Negative sign indicates deposition and Positive sign shows erosion with reference to bank line prevailing in SOl toposheets

f;(" ....

~~
;,

CWPRS, Technical Report No. 5015 for November 2012 69

Morphological studies of river Gandak using satellite and sal Data
.'Y

It can be seen from the above Table 5.1A and 5.1 B that
a) There is at least one location in each zone where measurable changes could
be noticed with reference to the bank line prevailing in sal toposheets. Thus,
there is minimum of one location on each of left and right bank of river
Gandak and a maximum of 5 locations on right bank and 6 locations on left
bank of river Gandak.
b) The minimum change in right bank is ranging from lower value of 174 m at
AR1 to high value of about 3400 m at location CR2. Further, maximum
change in right bank is varying from 987 m at GR2 to 8040 m at location BR3.
c) Similarly, minimum change in left bank in each zone is varying between 210 m
at GL2 and about 2100 m at DL 1. Further, maximum change in left bank is in
the range of 1430 m at GL 1 and 6177 m at AL5.

2. The details of changes in the bank line have been discussed in Section 4.6 of the
report. This can be summarized to indicate that the six locations i.e. BR3;~R1, DR3,
ER3, FR 1 and GR2 can be considered as places on right bank where erosion is likely
to take place within the range of data considered in the studies. Further, deposition in
all the zones is likely to take place at location AR2. Similarly, erosion is noticed at
CL2, DL 1, FR1 and GL 1 and deposition can be seen at AL5, BL 1 and EL2.

3. The rate of change in bank line has been estimated for each zone at the location
where measurable changes have been noticed (Section 4.6 of the report). These
rates have been estimated using the reference bank line of sal toposheets for the
available year (Section 3.2 of Report) and subsequent, bank line extracted from
satellite data. Thereafter, rate of change is determined with reference to bank line of
previous year to the year extracted from satellite imagery. These rates have been
added vectorially. It is noticed that at the three locations i.e. BR2, CL 1 and GR5 the
river is showing fluctuating trend of deposition followed by erosion and vice-versa at
other locations. The details of estimation of rate of change in bank line are presented
in Tables 4.2 to 4.15. These have summarized in Table 5.2. A review of Table 5.2
indicates that

a) The minimum rate of change in right bank is ranging from lower value of 4
m/yr at BR4 to high value of 176 m/yr at location CR1. Further, maximum rate
of change in right bank is varying from 44 m/yr at GR1 to 876 m/yr at location
DR4.

CWPRS, Technical Report No. 5015 for November 2012 70

Morphological studies of river Gandak using satellite and sal Data

TABLE 5.2: SUMMARY OF RATE OF CHANGE IN BANK LINE OF RIVER GANDAK

Rate of change in bank lines (m/yr)

Zone Right Bank Left Bank
Min Place Max Place Min Place Max Place
A 7.40 AR1 193.89 AR4 42.37 AL1 1132.53 AL5
B 3.89 BR4 624.26 BR1 220.46 BL2 669.33 BL3
C 176.43 CR1 209.55 CR2 107.41 CL2 777.77 CL1
0 132.63 DR5 875.96 DR4 122.03 DL 1 122.03 DL 1
E - 50.54 ER2 231.30 ER3 21.76 EL 1 40.37 EL2
F 53.89 FR1 53.89 FR1 34.67 FR1 224.18 FR3
G - 14.60 GR2 44.66 GR1 3.98 GL2 64.02 GL1

b) Similarly, minimum rate of change in left bank in each zone is varying between
4 m/yr at GL2 and about 220 m/yr at BL2. Further, maximum rate: of change
in left bank is in the range of 40 m/yr at EL2 and 1132 m/yr at AL5.·~

4. It is considered pertinent to indicate here that the changes in the bank line that were
noticed over the periods from earliest year 1928 upto 2004. It is difficult to identify the
cause of results of natural processes like erosion and deposition. Each of these
processes is dependent on number of factors, which are varying in space and time;
discharge and sediment load can be identified as some of the factors. In addition, the
base material of bed and bank also plays a significant role in the process. It is,
further, noticed that it is very difficult to identify the exact location of erosion/
deposition over a long period. The prediction made so far, have been either over a
short period are for the identified locations. These aspects are equally applicable for
stretch of river Gandak included in the studies.

5. It is, therefore, indicated that the year to year bank line changes at the locations
identified in 3 above can be considered and necessary protection measures can be
provided in the form of spur/ percupines with pitching banks using stones, bricks,
concrete blocks or combination of these u in wire crates. The wire can be either
metallic or synthetic in nature. The hydraulic parameters are, therefore, required to
decide the details of protection works as well as other protection to be provided at the
identified locations.

CWPRS, Technical Report No. 5015 for November 2012 71

Morphological studies of river Gandak using satellite and 501 Data

••
5.2 LIMITATIONS OF THE STUDY

The studies for identifying the changes in bank line have been carried out using SOl
and Satellite data collected from NRSA, Hyderabad. It was noticed during the study that the
SOl Toposheets are not available for the same year. This leads to use of available year
Toposheet. Sensor used in Satellite data is varying from LlSS 11to LlSS Ill, which implies that
there is limitation in measuring/ identifying the length, over which changes in bank line are
noticed, due to the pixel size of each sensor.

Initially, it was contemplated to study the effect of structure along river Gandak on the
changes in bank line. It is pertinent to indicate here that changes in bank line in turn typical
in river channels. The river channel position is affected due to the structure like spurs,
porcupine, barrage etc. The effect of these structures becomes measurable or prominent
after the time period which varies from couple of years to few decades. As such it is very
difficult to identify whether the changes in bank line can be attributed solely to the structure
or is combined effect on structure and other morphological changes taking place in river due
to time and space variations in of flow and sediment load.

The studies have limitations due to the pixel size as indicated above. The availability
of discharge and corresponding sediment data on account of concurrency. Further out of
these data discharge varies at faster rate than the sediment transport which is relatively
slower process. This type of change in behavior with respect of time and space imposes
another limitation on the studies.

CWPRS, Technical Report No. 5015 for November 2012 72

 ".

CHAPTER 6

ACKNOWLEDGEMENT
Morphological studies of river Gandak using satellite and SOl Data

MORPHOLOGICAL STUDIES OF RIVER GANDAK USING SATELLITE AND SOl DATA

6.0 ACKNOWLEDGEMENT

Studies have been carried out at CWPRS at the request of CWC, New Delhi. The co-
operation of the officers from Morphological Directorate as well as Field Circle from Patna
and Lucknow of CWC is acknowledged with thanks. The studies were carried out in by Shri V
G Shave Joint Director, River and Reservoir Systems Modeling (R&RSM) Group of CWPRS.
Dr. I. D. Gupta was Director, CWPRS and Shri S. Govindan was Additional Director during
conduct of studies. The studies were initially supervised by S/Shri P. S. Deolalikar and P K
Khare Joint Directors (Retired) CWPRS. Efforts taken by Shri M.K. Pawar, Chief Research
Officer in procurement and analysis of satellite data are appreciated. Major assistance is
given by Shri C. Srishailam, Research Officer in analysis of bank line data, compilation of the
results, analysis of satellite and bankline data, preparation of maps etc have be.~ of great
help in conduct of the studies and preparation of the report. In addition, support and
cooperation received from officers of Remote Sensing Laboratory of CWPRS are also
acknowledged. The staff members of SWH and Physics Division have provided excellent
assistance/cooperation in conduct of the studies and preparation of the report.

CWPRS, Technical Report No. 5015 for November 2012 73

APPENDICES
Morphological studies of river Gandak using satellite and sal Data

APPENDIX-I

PHOTOGRAPHS OF RIVER GANDAK IN STUDY REACH

Gandak river in study reach displays braided channels in certain places (Photo 1).
These are situated at different locations in the states of UUar Pradesh and Bihar. Further,
river Gandak flows at certain locations along the border of Uttar Pradesh and Bihar.
Protection measures in the form of embankments and spurs are provided along the length.
The embankments require careful maintenance and it is known that these are prone to failure
in absence of maintenance (Photo 2). Spurs are provided at number of locations in study
reach. Protection with crates from brick/stone is provided. These also need maintenance and
state of some spurs is shown in Photos 3 and 4.

.1

PHOTO 1: BRAIDED CHANNELS IN RIVER GANDAK

CWPRS, Technical Report No. 5015 for November 2012 74

Morphological studies of river Gandak using satellite and SOl Data

... "

PHOTO 2: BREACH IN EMBANKMENT OF RIVER GANDAK

PHOTO 3': SERIES OF DAMAGED SPURS ON RIVER GANDAK

CWPRS, Technical Report No, 5015 for November 2012 75

Morphological studies of river Gandak using satellite and sal Data

",

PHOTO 4: DAMAGED SPURS WITH STONE PITCHING

CWPRS, Technical Report No, 5015 for November 2012 76

 v:-£'c------------------I"""'!"!---

Morphological studies of river Gandak using satellite and SDI Data

APPENDIX - 11

s. No. Observations Compliance

1. The bank line migration parameters of river Total stretch of river Gandak
Gandak presented in the reports are of general under study is divided in to seven
nature. Quantitative information may be zones. Comparison of bank lines
provided in detail with respect to space and from sal Toposheets and
time using the satellite data. Study of satellite data is carried out to
aggradation and degradation in different quantity the changes. Details of
reaches of the river (erosion/deposition analysis are presented in section
patterns) identification of stable and unstable 4.6 of the report.
reaches along the river considering the
usefulness of the study in solving the flood
problems namely due to inundation, erosion of
banks, and changes of course of river.
Appraisal of plan form morphological changes/
including causes of aggradation/ degradation
and its variation/changes in plan form of river
Gandak may be included. The problem of river
instability and consequent bank erosion
(present and future trends) if any along the
river is also to be discussed in the report for
river Gandak.
2. Possible generation of cross-section, reduced Studies have been carried out to
level and top width with respect to space and quantity change in bank line, that
time using satellite data could be done and would lead to change in width of
compared with the hydrographical data. river. Details are given in section
4.6 of report.

3. As per the terms of reference (TOR), the This aspect would require special
objective of the study included the performance study with fine grid satellite data.
evaluation of major flood control structures Further, this may be duplication
executed so far, as well as their effect on river of efforts put in by Gandak High
morphology. This study aspect has to be Level Committee.
included discussing also the adverse effects/
desired benefits of the flood control structures/
protection works like flood embankments, anti
erosion works like spurs, revetments, bank
pitching, bed bars etc undertaken.
4. To give better perception of river and its linkage Complied
with its tributaries and Master River, drainage
system of the rivers, its tributaries and it's
association with the master river system may
be shown in the introduction part of the report.
Index map should also be provided highligfl.t~Bg
the location of different flood control/river
training structures.
5. Identified zones A-I may be shown on larger Complied and details presented
scale to the extent possible to enhance the in section 4.5 and Figures 4.11 to
visual understanding 4.17.

6. Water spread area during flood season and Attempts are made to study
also water spread area during lean period may channel migration through
be discussed in the report in detail with the help changes in bank line, water

CWPRS, Technical Report No. 5015 for November 2012 77

Morphological studies of river Gandak using satellite and SOl Data
.f

of figure including about the channel migration/ spread area proposed to be

palio channels, longitudinal slope/cross studied would require availability
sectional slope etc. at vulnerable points. of satellite data of cloud free
dates and on smaller resolution.
It is difficult to get cloud free data
during flood period as sky
remains overcast in such
situation due to occurrence of
rainfall.
7. Trend of switch over of thalweg from one side Complied and added in report
to the other side of the river and development
of new fluvial form indicators may be studied to
identify severity during floods.
8. Prioritization of channel improvement zones Erosion areas have been
and general trend of longitudinal bed profile identified. Priority can be decided
changes of the river Gandak may also be by the implementing agency
discussed. through discussions with design
agency, funding organization and
research organization conducting
the study.
9. Study may also be carried out to achieve This is beyond scope of study
implementation of hydrodynamic flow and would need studies on 2-0/
simulation modeling for macro level stream bed 3-D model required. Additional
changes due to any channel modifications. data, funds and time frame would
be required.
10. CWPRS is also requested to take up This can be taken up after
preparation of a comprehensive report, finalization of current report.
reviewing earlier report and inclusion of Other reports can be decided
subsequent hydrodynamic parameters of which through mutual discussions with
the present report through remote sensing concerned institutions.
would be a part. It could be on the lines of
CWC/MoWR guidelines published in April 1991

----

CWPRS, Technical Report No. 5015 for November 2012 78

 -
.. .-
~. S(

Morphological studies of river Gandak using satellite and sal Data

APPENDIX - III

S. No. Observations Compliance

1. Report may be organized chapter-wise. Report is organized chapter wise

Executive Summary may be included as a part and section on limitations is
of Final Report. A separate chapter on added
Conclusions with point wise deliberations
followed by Limitations in the study e.g. (a)
non-availability of Toposheets for the required
period (1974-76), (b) practical problems in
evaluation of performance of hydraulic
structures, (c) major morphological problems
with reasons not including these in the report
etc.; ma be included in the re ort.
2. Refer Table.13, at S.No.6, location of Complied
Maximum Change in Left bank lines is FL 1 (not
FR1) and location of Minimum Change in Left
bank lines is FL3 (not FR3). At S.No.7, sign of ~",

minimum change in Left bank lines is + (not-) .'~

and sign of maximum change in Left bank lines

is - not + .
3. The magnitude of river shift in terms of yearly Place name is added in the
rate as well as direction of shifting especially at Figures 4.18 to 4.24 as desired
critical locations may be elaborated. The map
of each zone showing backline shifting with the
location points (in terms of chaingage, place-
name, latitude, longitude) is essential for
making these details more comprehensive as
well as self ex lanato .
4. The Table of Content with page numbers, List Complied
of Tables, Figures, Symbols, etc. may be
provided in the report. All colored figures are
re uired to be roduced on A3 size a er.

CWPRS, Technical Report No. 5015 for November 2012 79

Central Water and Power Research Station (CWPRS), Pune,
has grown from a. humble beginning dealing with twin problems of irrigation and
drainage in 1916 to an institution of international standing over the last EIGHT
decades. CWPRS is one of the very few institutions of its kind in the world
concerned with the entire life cycle of water, from its occurrence to its joining the
ocean and dealing with the various uses of water on one hand and water-related
disasters on the other. The global scenario of water use today is centered around
sustainable development and associated environmental issues. The responsibility of
CWPRS is to find and provide technical solutions to various problems associated
with projects on ater resources, energy and water-borne transport including coastal
and harbour engineering. As the Regional Laboratory of ESCAP since 1971, CWPRS
has offered its services to a number of projects in the neighbourhood as well as
countries in the Middle East. and Africa. The activities of CWPRS encompass the
studies undertaken in the following major disciplines:

- Hydrology and Water Resources Analysis

- River Engineering
- Reservoir and Appurtenant Structures
- Coastal and Offshore Engineering
- Ship Hydrodynamics
- Hydraulic Machinery
- Earth Sciences
- Mathematical Modelling ·1
- Foundations and Structures
- Instrumentation and Control Engineering

With the capabilities of the Research Station, developed through multilateral and
bilateral aid programmes, in-house developme ts, governmental support and the
expertise gained during the course of last 8 decades, CWPRS is well equipped to
meet the challenges ahead and contribute in the nation building endeavours.
Morphological studies of river Gandak using satellite and SOl Data

TOPOSHEET
1988
1994
1999
2004

FIGURE 4.11: CHANGES IN BANK LINES OF RIVI

,~: CWPRS, Technical Report No. 5015 for November 2012

~, ...~•...
..... ,
 TOPOSHEET
1988
1994
1999
2004

BANK LINES OF RIVER GANDAK FOR ZONE A

.
 ·,

Morphological studies of river Gandak using satellite and SOl Data

TOPOSHE
1988
1994
1999
2004

FIGURE 4.16: CHANGES IN BANK LINES OF

~~j CWPRS, Technical Report No. 5015 for November 2012

 TOPOSHEE

1988
: ..
1994 .... ,:

1999
2004

~ANK LINES OF RIVER GANDAK FOR ZONE F

27
 Morphological studies of river Gandak using satellite and 501 Data

rose
1988
1994
1999
2004

FIGURE 4.17: CHANGES IN BANK LINES

'~l CWPRS, Technical Report No. 5015 for November 2?12

--..,......-.:...-~---~-~~~----, ..~~.~~-~----------~---~

TOPOSHEE

1988
1994
1999
2004

~NK LINES OF RIVER GANDAK FOR ZONE G

28
 I~ ~
)
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Morphological studies of river Gandak using satellite and SDI Data

:~

••

FIGURE 4.18: LOCATIONS OF TOWNSI VILLAGES - ZONE A

-"".::,,_ •......
'~l CWPRS, Technical Report No. 5015 for November 2012 29
 I Il l
Morphological studies of river Gandak using satellite and SOl Data

.
t-

:~
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FIGURE 4.19: LOCATIONS OF TOWNSI VILLAGES - ZONE B

30
;'~l
..... .. CWPRS,
~.~ Technical Report No. 5015 for November 2012
 1 _
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Morphological studies of river Gandak using satellite and SOl Data

~~
t .

'"

FIGURE 4.20: LOCATIONS OF TOWNSI VILLAGES - ZONE C

CWPRS, Technical Report No. 5015 for November 2012 31

\~l
 .----------------------------------
(]

Morphological studies of river Gandak using satellite and SOl Data ...

.
' :>

~~
t
,,'
'

FIGURE 4.21: LOCATIONS OF TOWNSI VILLAGES - ZONE D

~~I CWPRS, Technical Report No, 5015 for November 2012 32

""h.~··
 I _
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Morphological studies of river Gandak using satellite and sal Data

:~
:.t

FIGURE 4,22: LOCATIONS OF TOWNSI VILLAGES - ZONE E

\~l CWPRS, Technical Report No. 5015 for November 2012 33

..•.. -•..•.
 "I l .. 1 l
Morphological studies of river Gandak using satellite and sal Data

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FIGURE 4.23: LOCATIONS OF TOWNSI VILLAGES - ZONE F

\~, CWPRS, Technical Report No. 5015 for November 2012 34

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Morphological studies of river Gandak using satellite and SOl Data

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FIGURE 4.24: LOCATIONS OF TOWNS I VILLAGES - ZONE G

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CWPRS, Technical Report No. 5015 for November 2012 35
Morphological studies of river Gandak using satellite and SOl Data

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1988
1994
1999
2004

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FIGURE 4.12: CHANGES IN BANK LINES

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• TOPOSHEE
1988
1994
1999
2004

3ANK LINES OF RIVER GANDAK FOR ZONE 8

23
Morphological studies of river Gandak using satellite and SOl Data
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1988
1994
1999
2004

.,

FIGURE 4.13: CHANGES IN BANK LINES OF I

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'-~; CWPRS, Technical Report No. 5015 for November 2012
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 TOPOSHEE
1988
1994
1999
2004

.,

JNES OF RIVER GANDAK FOR ZONE C

----,-----------------------------------------------------------
24
Morphological studies of river Gandak using satellite and SOl Data

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198
199
199
200

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FIGURE
c= 4.14:
__________________________________________________________ CHANGES IN BANK LINES
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TOPOSHEE

1988
1994
1999
2004

~ANK LINES OF RIVER GANDAK FOR ZONE 0

25
Morphological studies of river Gandak using satellite and SOl Data

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1988
1994
1999
2004

FIGURE 4.15: CHANGES IN BANK LINES

~~! CWPRS, Technical Report No. 5015 for November 2012

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TOPOSHEE
1988
1994
1999
2004

3ANK LINES OF RIVER GANDAK FOR ZONE E

26