Geomorphometric analysis of a hilly watershed in north east India
Table 2. Morphometric parameters of Um Shipra Watershed
Stream Order (N )
Stream Length (L ) (km)
Basin
Stream Area (A)
u
u
Perimeter
Length
order
(km 2 )
I
II
III
IV
V
I
II
III
IV
V
(P) (km)
(L b ) (km)
V
23.85
327
147
78
45
46
89.00 29.14 12.63
8.77
8.68
32.15
11.32
Mean Stream Length (Ls m )
Stream Length Ratio (R )
Drainage
(km)
l
Total
Relief Ratio Elongation
Texture
relief (H)
(R )
Ratio (R )
I
II
III
IV
V
II/I III/II IV/III V/IV
h
e
(R t )
0.27 0.20 0.16
0.19 0.19 0.33
0.43
0.69
0.99
0.50
0.04
0.49
20.00
Bifurcation Ratio (R b )
Drainage
Infiltra-
Rugge-
Mean
Stream
Form
Circula-
Density
tion
dness
Bifurcation
Freque-
Factor rity ratio
I/II II/III III/IV IV/V
(D) (km.
Number
Number
Ratio (Rb )
m
(R )
(R )
km -2 )
ncy (F s )
f
c
(I f )
(N d )
2.22
1.88
1.73
0.98
1.71
6.22
26.97
0.19
0.29
167.61
3.11
Thestreamlength(L u )isthetotallengthofstreamsina
Yasmin et al. , (2013). The mean stream length of a
particular order. Generally, the total length of stream
channel is a dimensional property and reveals the
segments in the first order is highest and decreases
characteristic size of drainage network components
as the stream order increases. The logarithmic plot of
and its contributing basin surfaces (Strahler 1964).
stream length of a given order versus stream order
Table 2 indicates that the mean stream length for
(Figure 2b) showed a linear pattern indicating the
the watershed ranged from 0.16 to 0.27. The mean
watershed so developed over a homogeneous rock
stream length of any given order is greater than that
material and subjected to weathering and erosion
of lower order. However in the present study, there
(Narendra and Rao 2006). Similar relationships
was a deviation from the trend which may be due
have also been reported by Vandana (2013) and
to variation in slope and topography prevalent in a
hilly watershed system.
Figure 2. Logarithmic plot of (a) stream numbers vs. stream order
(b) stream length vs. stream order for Um Shipra watershed.
33