while in
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to April
serious
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ector of
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let that
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shallow
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IAPRS & SIS, Vol.34, Part 7, *Resource and Environmental Monitoring", Hyderabad, India, 2002
8 >
7 =
"= 6
iB
D s |
E 4-
©
2 4
1
1 2 3 4
LISS- 1 BANDS
[a]
93
8 =
"e y
am
D 8 1
E: 5-
o
E:
E 4
3 A
|
24 j i |
1 2 3 4
LISS- 1 BANDS
[b]
Figure 3: ^ Remotely sensed radiance over
[a] Submerged vegetation [b] Shallow
water in Chilka Lagoon
3.4 Yellow Substance Index (YSI) and Benthic
Biomass Index (BBI)
Figure 4 depicts the temporal variation in
YSI and BBI values as derived from the band
radiance of submerged vegetation. YSI values are
negative but with relatively higher magnitude
than BBI, which are small positive values.
However, the trend of both YSI and BBI are
observed to be similar. The values during January
and July are observed to be minimum while April
and May values are maximum. Interestingly, April
is the period having maximum area of submerged
vegetation. The area of submerged vegetation
during May 1998 (151.7 km?) was less than
January 1995 (306.4 km?). This could be due to
high salinity (maximum 229/99) observed during
May 1998 as compared to other periods of
observation.
389
YSI
9. | | £9
8 + 0.9
» 1 08
ji 107
- 0.6
-5 À iA
: Los Æ
«4:4
E Yel 104
De —X—BBI
103
?- +02
"11 Jan 95 Apr95 Ju'96 May 987 O^!
0 : / | 0
Figure 4: Temporal variation of Yellow substance
Index (YSI) and Benthic Biomass Index
(BBI) as derived from the band radiance
of submerged vegetation in Chilka
Lagoon
Table... 2: /presents the «covariance. matrices... of
different IRS-1B LISS-1 bands of the submerged
vegetation during
different periods of
observation. The variation of band radiance have
been studied through covariance matrices.
Band1 Band2 Band3 | Band4
Band1 0.88 0.59 0.52 0.06
Band2 0.81 0.52 0.06
Band3 0.63 0.9
Band4 0.39
Band1 1.66 1.56 1.39 -0.59
i Band2 2.19 1.67 -0.71
Band3 1.67 -0.69
Band4 0.98
Band1 3.706 3.668 2.447 | -0.142
T Band2 4.695 2.809 | -0.023
Band3 2.782 0.854
Band4 2.313
Band1 2.084 2.504 1.99 1.333
IV Band2 4.647 2.962 2.373
Band3 2.537 1.554
Band4 4.966
Table 2 Covariance matrices for the different IRS-1B LISS-I
bands of the submerged vegetation (I-January 1995,
II-April 1995, III July 1996, IV-May 1998
