Agriculture Reference
In-Depth Information
Table 2.2
Loss of mangroves in Nicobar group of islands
Island
2003
(Pre-tsunami)
2005
(Post-tsunami)
2007
(Post-tsunami)
Change from
2003 to 2007
Great Nicobar
610
86 (−524)
ND (−86)
(−610)
Little Nicobar
104
27 (−77)
ND (−27)
(−104)
Car Nicobar
133
90 (−43)
60 (−30)
(−73)
Katchal
588
21 (−567)
18 (−3)
(−570)
Trinket
330
213 (−117)
26 (−187)
(−304)
Kamorta & Nancowry
1000
808 (−192)
227 (−581)
(−773)
Teressa
ND
ND
ND
ND
Bompoka
ND
ND
ND
ND
Chowra
ND
ND
ND
ND
Total
2745
1245 (
−
1500) 331 (
−
914)
(
−
2414)
Figures in parentheses show change in mangrove cover per hectare
ND
not discernible
(-) indicates loss
Table 2.3
Change in mangrove cover in ANI
Islands
2003
(Pre-tsunami)
2005
(Post-tsunami)
2007
(Post-tsunami)
Change from
2003 to 2007
Andaman
631
623 (−8)
612 (−11)
(−19)
Nicobar
27
12 (−15)
3 (−9)
(−24)
Total
658
635 (
−
23)
615 (
−
20)
(
−
43)
Figures in parentheses show change in mangrove cover per km
2
(-) indicates loss
assessment done by FSI describes changes in forest cover which include mangrove
cover also. No area figures are separately provided for mangrove cover by FSI in
this study. Study by Ramachandran et al. (
2005
) covers only four islands. A com-
parison of changes in mangrove swamps shown by them in Table
2.2
shows some
variation in the area figures, but both the studies confirm that there was a significant
loss in mangrove cover of these islands. The variation in the area figures may be due
to the fact that in the present study SWIR band has been used in combination with
red and green bands while in the study carried out by Ramachandran et al. (
2005
)
conventional bands were used. In most of the places in ANI, mangrove swamp is
immediately followed by dense forest vegetation cover making it difficult to delin-
eate forest vegetation from mangrove forest. Application of SWIR band has been
shown to help in better discrimination of crop with more water contents (Ibrahim
et al.
2010
; Panigrahy et al.
2009
). The study carried out by Sridhar et al., (
2006
) is
confined to Great Nicobar Island only and there is not much variation between the
figures reported by them and as given in Table
2.2
.
Table
2.3
shows the change in mangrove cover in Andaman group of islands and
Nicobar group of islands from 2003 (pre-tsunami period) to 2007 (post-tsunami
period). Total loss of mangrove cover in ANI had been 23 km
2
between 2003 and
