2909 Kennametal Inc Engineering Change Mgmt With New Engineering Record
Geo-Analyst , ISSN 2249-2909 2014gswb.in/wp-content/uploads/2014/08/Subhajit.pdf · Geo-Analyst ,...
Transcript of Geo-Analyst , ISSN 2249-2909 2014gswb.in/wp-content/uploads/2014/08/Subhajit.pdf · Geo-Analyst ,...
Geo-Analyst , ISSN 2249-2909 2014
27
THE RELATIONSHIP BETWEEN SOME OF CHANNEL GEOMETRIC
PARAMETERS AND CONSEQUENT SINUOSITY RATIO - A CASE STUDY
OF LOWER DUDUYA RIVER COURSE
Subhajit Chakraborty*
ABSTRACT
Duduya or Dudhuya is one of the main tributary rivers of Jaldhaka. In lower Duduya
river course, some channel geometric properties i.e. Channel length ( C L ) , Valley
length ( V L ) , Meander wavelength ( M L ) , Radius of curvature ( r m ) , Meander
amplitude ( A ) & Sinuosity ratio ( S I ) , are calculated with the help of satellite map
(Google Earth & measuring tools ) , Cadastral map ( scale – 16 inch to 1 mile ) &
field observations . For this purpose , the lower Duduya river course is divided
into five ( 5 ) segments ( A- B , B- C , C- D , D- E , E- F ) and calculated these
properties. As a result , it is seen that some of these properties are perfect positive
degree to no degree of correlation with each other and with sinuosity ratio . The
present study has exhibited how these parameters can change sinuosity ratio of
selected segments and their interrelationships. It was found that meander amplitude (A)
has maximum effort to increase sinuosity ratio in the lower part of Duduya
river.
KEYWORDS
Meander wavelength , Meander amplitude , Sinuosity ratio , Channel length , Valley length,
Radius of curvature .
INTRODUCTION
River is more or less straight for a certain distance , but no river can ever flow straight
path . The wavy river channel is clearly viewed in satellite map and aerial photographs .
Meandering is formed where banks resist erosion, so forming deep & narrow
channels. But till now , why rivers appear as meander is not clearly understood . But
few ideas are developed behind the formation of meander like (1) the distribution &
dissipation of energy within a river ( 2 ) helical flow & ( 3 ) the interplay of bank
erosion .
*Assistant Teacher in Geography, Jurapani High School , Jalpaiguri, West Bengal
CHANNEL GEOMETRIC PARAMETERS
Channel geometric parameters includes meander wavelength , meander amplitude , radius
of curvature , channel length , valley length , sinuosity ratio etc . and their
interrelationships ( Singh , 1998 ) .
Fig 2, Some of chan
Meander Wavelength (M L)
It is the axial length of one meander i.e. the tangential distance between
the corresponding points of a meander.
Meander Amplitude (A) It is the maximum distance from the down valley axis to the sinuous axis of
a meander loop.
Radius of Curvature ( r m )
It is the radius of a circle drawn through the apex of meander bend and two
crossover midpoints.
Channel Length (C L)
It is the representative curvilinear distance measurement along the centre of the channel
valley length.
Valley Length (V L) It represents representative horizontal distance measurement in the thalwag of two cross
sections in a linear depression between adjacent uplands .
Sinuosity Ratio ( S I ) It refers to departure of actual channel course (C L) from the expected theo
straight line (V L), (Schumm, 1963).
Geo-Analyst , ISSN 2249-2909
28
CHANNEL GEOMETRIC PARAMETERS
geometric parameters includes meander wavelength , meander amplitude , radius
of curvature , channel length , valley length , sinuosity ratio etc . and their
interrelationships ( Singh , 1998 ) .
Fig 2, Some of channel geometric parameters
It is the axial length of one meander i.e. the tangential distance between
the corresponding points of a meander.
It is the maximum distance from the down valley axis to the sinuous axis of
a meander loop.
( r m )
It is the radius of a circle drawn through the apex of meander bend and two
crossover midpoints.
curvilinear distance measurement along the centre of the channel
valley length.
It represents representative horizontal distance measurement in the thalwag of two cross
sections in a linear depression between adjacent uplands .
It refers to departure of actual channel course (C L) from the expected theoretical
, 1963).
2014
geometric parameters includes meander wavelength , meander amplitude , radius
of curvature , channel length , valley length , sinuosity ratio etc . and their
It is the axial length of one meander i.e. the tangential distance between
It is the maximum distance from the down valley axis to the sinuous axis of
It is the radius of a circle drawn through the apex of meander bend and two
curvilinear distance measurement along the centre of the channel
It represents representative horizontal distance measurement in the thalwag of two cross
sections in a linear depression between adjacent uplands .
retical
OBJECTIVES
( 1 ) To find out meander wavelength , amplitude , & radius of curvature for selected
segments . ( 2 ) To measure channel length & valley length and calculate sinuosity
ratio for each segment . ( 3 ) To compare sinuosity ratio for each section . (4) To
examine correlation between different parameters.
STUDY AREA
Jaldhaka river , is one of the major natural water channels in Duars region ,
Bengal which is formed by several small rivers originating from eastern Himalayan tract .
River Duduya is one of these small rivers.
Fig 3 :- Selected segments of lower Duduya course .
Duduya is originated from Binnaguri region , Jalpaiguri The total length of this river is
almost 53 km . After nourished by Kullaya ( 8 km ) , Angrabhasha ( 8 km ) , Echa ( 7
km ) , Goberghuta ( 10 km ) , Gartoli ( 15 k
has joined to the Jhaldhaka river near Indrerkuthi , Daribas phulbari , Coochbehar
district. The study area lies between the river bridge of NH
mouth of this river . Geographically, the region is located between 26.47° N to
26.54° N latitude and 89.10° E to 89.16° E longitude. It covers an area of 35.18 sq.
km.
Geo-Analyst , ISSN 2249-2909
29
( 1 ) To find out meander wavelength , amplitude , & radius of curvature for selected
segments . ( 2 ) To measure channel length & valley length and calculate sinuosity
ent . ( 3 ) To compare sinuosity ratio for each section . (4) To
examine correlation between different parameters.
Jaldhaka river , is one of the major natural water channels in Duars region ,
Bengal which is formed by several small rivers originating from eastern Himalayan tract .
River Duduya is one of these small rivers.
Selected segments of lower Duduya course .
Duduya is originated from Binnaguri region , Jalpaiguri The total length of this river is
almost 53 km . After nourished by Kullaya ( 8 km ) , Angrabhasha ( 8 km ) , Echa ( 7
km ) , Goberghuta ( 10 km ) , Gartoli ( 15 km ) , Nosai ( 23 km ) etc torrents , this river
has joined to the Jhaldhaka river near Indrerkuthi , Daribas phulbari , Coochbehar
district. The study area lies between the river bridge of NH – 31 D ( Jurapani ) and
mouth of this river . Geographically, the region is located between 26.47° N to
26.54° N latitude and 89.10° E to 89.16° E longitude. It covers an area of 35.18 sq.
2014
( 1 ) To find out meander wavelength , amplitude , & radius of curvature for selected
segments . ( 2 ) To measure channel length & valley length and calculate sinuosity
ent . ( 3 ) To compare sinuosity ratio for each section . (4) To
Jaldhaka river , is one of the major natural water channels in Duars region , West
Bengal which is formed by several small rivers originating from eastern Himalayan tract .
Duduya is originated from Binnaguri region , Jalpaiguri The total length of this river is
almost 53 km . After nourished by Kullaya ( 8 km ) , Angrabhasha ( 8 km ) , Echa ( 7
m ) , Nosai ( 23 km ) etc torrents , this river
has joined to the Jhaldhaka river near Indrerkuthi , Daribas phulbari , Coochbehar
Jurapani ) and
mouth of this river . Geographically, the region is located between 26.47° N to
26.54° N latitude and 89.10° E to 89.16° E longitude. It covers an area of 35.18 sq.
A B
Fig 4 :
DATA COLLECTION & METHODOLOGY
The information about the study
Google Earth & measuring tools ) , cadastral map ( Revenue survey , Jalpaiguri , scale
to 1 mile ) and field observations . Materials used were tracing paper ,
table & rotameter . Rotameter used for measure the channel length , valley length ,
meander wavelength ,amplitude & radius of curvature . The following formula is used for
calculating the sinuosity ratio.
Sinuosity ratio = Channel length ÷ Valley length ( Schumm , 1963 ) .
The scatter plot is used for showing correlation between
RESULTS & DISCUSSION
The analysis of table 1 shows that sinuosity ratio varies for each segment which
indicates differential channel pattern for different sections.
detecting in D – E segment, and E
C & C – D segments are indicating sinuous channel pattern. Overall ( A
sinuosity ratio ( 1.36 ) indicates sin
..
Table no. 1, Measurement of Sinuosity ratio
SELECTED
SEGMENTS
CHANNEL
LENGTH IN
METRE ( C L )
A TO B
B TO C
C TO D
D TO E
E TO F
Over All (A TO F) 10666.66
Source: Computed by Researcher
Geo-Analyst , ISSN 2249-2909
30
C D
Fig 4 :- Photos of study area ( A, B, C, D ) .
DATA COLLECTION & METHODOLOGY
The information about the study area was collected from the satellite map & images (
Google Earth & measuring tools ) , cadastral map ( Revenue survey , Jalpaiguri , scale
to 1 mile ) and field observations . Materials used were tracing paper , drawing pens , light
table & rotameter . Rotameter used for measure the channel length , valley length ,
meander wavelength ,amplitude & radius of curvature . The following formula is used for
calculating the sinuosity ratio.
Sinuosity ratio = Channel length ÷ Valley length ( Schumm , 1963 ) .
The scatter plot is used for showing correlation between different parameters.
The analysis of table 1 shows that sinuosity ratio varies for each segment which
indicates differential channel pattern for different sections. Meandering channel pattern
E segment, and E – F segment are almost identical. Otherwise, A –
D segments are indicating sinuous channel pattern. Overall ( A
sinuosity ratio ( 1.36 ) indicates sinuous channel pattern ( Leopold and Wolman , 1957 )
Table no. 1, Measurement of Sinuosity ratio for each selected segments
CHANNEL
LENGTH IN
METRE ( C L )
VALLEY LENGTH
IN METRE ( V L )
SINUOSITY
RATIO
( S I )
1666.66 1233.33 1.35
1219.99 1166.66 1.05
2333.33 2150.00 1.08
3166.66 1833.33 1.73
2110.00 1466.66 1.44
10666.66 7833.33 1.36
Source: Computed by Researcher
2014
area was collected from the satellite map & images (
Google Earth & measuring tools ) , cadastral map ( Revenue survey , Jalpaiguri , scale - 16˝
drawing pens , light
table & rotameter . Rotameter used for measure the channel length , valley length ,
meander wavelength ,amplitude & radius of curvature . The following formula is used for
The analysis of table 1 shows that sinuosity ratio varies for each segment which
nel pattern
– B, B –
D segments are indicating sinuous channel pattern. Overall ( A – F )
Leopold and Wolman , 1957 )
SINUOSITY
RATIO
( S I )
1.35
1.05
1.08
1.73
1.44
1.36
Meander wavelength , amplitude , radius of curvature & sinuosity ratio are tabulated in
Table no. 2 :- Measurement of meander wavelength , amplitude , radius of
SELECTED
SEGMENTS
MEANDER
WAVELENGTH
IN METRE
A - B 1200.00
B - C 1300.00
C - D 2200.00
D - E 1816.66
E - F 1433.33
Source: Computed by Researcher
meander wavelength and radius of curvature are increasing with each other for each
segment , according to emperical relation proposed by Leopold & Wolman ( M L =
4.7 r m 0.98
, 1960 ) except D
increase of amplitude, sinuosity ratio has increased but with t
wavelength , sinuosity ratio has not increased , instead it has decreased at several
segments .
RELATIONSHIPS AMONG CHANNEL GEOMETRIC PARAMETERS
Geo-Analyst , ISSN 2249-2909
31
Meander wavelength , amplitude , radius of curvature & sinuosity ratio are tabulated in
table no - 2 .
Measurement of meander wavelength , amplitude , radius of
curvature & sinuosity ratio .
MEANDER
WAVELENGTH
IN METRE
MEANDER
AMPLITUDE
IN METRE
RADIUS OF
CURVATURE
IN METRE
SINUOSITY
RATIO
1200.00 733.00 253.33 1.35
1300.00 300.00 276.66 1.05
2200.00 633.33 473.33 1.08
1816.66 1400.00 333.33 1.73
1433.33 933.33 303.33 1.44
Source: Computed by Researcher
The analysis of table no . 2 shows that
meander wavelength and radius of curvature are increasing with each other for each
erical relation proposed by Leopold & Wolman ( M L =
, 1960 ) except D – E segment ( where , M L = 5.45 r m 0.98
) . With the
increase of amplitude, sinuosity ratio has increased but with the increase of meander
wavelength , sinuosity ratio has not increased , instead it has decreased at several
segments .
RELATIONSHIPS AMONG CHANNEL GEOMETRIC PARAMETERS
2014
Meander wavelength , amplitude , radius of curvature & sinuosity ratio are tabulated in
Measurement of meander wavelength , amplitude , radius of
SINUOSITY
RATIO
1.35
1.05
1.08
1.73
1.44
The analysis of table no . 2 shows that
meander wavelength and radius of curvature are increasing with each other for each
erical relation proposed by Leopold & Wolman ( M L =
) . With the
he increase of meander
wavelength , sinuosity ratio has not increased , instead it has decreased at several
RELATIONSHIPS AMONG CHANNEL GEOMETRIC PARAMETERS
Geo-Analyst , ISSN 2249-2909
32
2014
Geo-Analyst , ISSN 2249-2909
33
2014
Fig 5 (A - F) :- Correlation between different geometric parameters by
The analysis shows that interrelationship of different channel geometric parameters have
yielded perfect positive degree to no degree of correlation ( fig
amplitude is moderate positively correlated with channel length & sinuosity ratio ( fig :
5A & 5B ) and weak positively correlated with meander wavelength ( fig
correlation with radius of curvature ( fig
between meander wavelength and sinuosity ratio ( fig
positive degree of correlation between radius of curvature & meander wavelength (
fig – 5 F ) . Weak negative relationship has been identified between radius of curvature and
sinuosity ratio ( fig – 5 G ) and perfect positive correlation has been identified
between meander wavelength and valley length ( fig
of relationship is detected between channel
Geo-Analyst , ISSN 2249-2909
34
Correlation between different geometric parameters by
using Scatter Plot .
The analysis shows that interrelationship of different channel geometric parameters have
yielded perfect positive degree to no degree of correlation ( fig – 5 ) . Meander
ositively correlated with channel length & sinuosity ratio ( fig :
5A & 5B ) and weak positively correlated with meander wavelength ( fig – 5 C ) but no
correlation with radius of curvature ( fig – 5 D ) . Almost no correlation is also found
between meander wavelength and sinuosity ratio ( fig – 5 E ) . There is also moderate
positive degree of correlation between radius of curvature & meander wavelength (
negative relationship has been identified between radius of curvature and
5 G ) and perfect positive correlation has been identified
between meander wavelength and valley length ( fig – 5 H ) . Moderate positive degree
between channel length & sinuosity ratio ( fig – 5 I ) .
2014
Correlation between different geometric parameters by
The analysis shows that interrelationship of different channel geometric parameters have
5 ) . Meander
ositively correlated with channel length & sinuosity ratio ( fig :-
5 C ) but no
orrelation is also found
5 E ) . There is also moderate
positive degree of correlation between radius of curvature & meander wavelength (
negative relationship has been identified between radius of curvature and
5 G ) and perfect positive correlation has been identified
H ) . Moderate positive degree
5 I ) .
Geo-Analyst , ISSN 2249-2909 2014
35
CONCLUSION
It may be concluded that meander wavelength is increasing with increasing radius of
curvature and closely related to each other . But these two geometric parameters
cannot play vital role for changing sinuosity ratio in different selected sections . On the
other hand, channel length and meander amplitude are increasing with each other
and influence the sinuosity ratio . Increase of channel length and meander
amplitude are the result of topographic factors and frequent flooding due to heavy
rainfall in hill region . Finally, it may be concluded that meander amplitude ( A )
has played major role in increasing sinuosity ratio in selected segments in lower
Duduya river course .
ACKNOWLEDGEMENT
I express my thanks to Mr. Bimal ch. Roy for assisting in field observations.
BIBLIOGRAPHY
Bhagabati, A, B & Bhattacharya, P. (2010). Doctoral Research in Geography – A Survey EBH
Publication. Guwahati.
Charlton R (2008). Fundamentals of fluvial geomorphology. Routledge, London & NY
Garde, R.J (2006). River morphology. New age international Ltd. Publication.
Leopold, L.B & Wolman, M. G. & Miller, J. P. (1964). Fluvial processes in
geomorphology. Dover Pub Inc. NY
Singh, S (1998). Geomorphology. Prayag Pustak Bhawan. Allahabad. India.
Tamrakar, N. K & Shrestha, P. (2012). Morphology & Classification of the main stem
Bagmati river, Central Nepal. Bulletein of the Dept. of Geology , Tribhuvan University ,
Nepal.
Uddin. M, Deb. M & Das D (2012). Remote sensing based analysis of critical bends of
Kushiyara River in Bangladesh. Geographia technica , no – 2 , pp . 84 – 94.
Yeasmin. A & Islam, N. M (2011). Changing trends of channel pattern of the Ganges -
Padma River”. International journal of Geomatics & Geosciences, Vol. 2, no – 2.