Cracknell,
ic matter,
raters and
ver about
pics. It is
st. It has
have been
) 4460 sq.
has been
ny places,
'ersion of
Coast and
o used as
ignificant.
ed due to
particular
'iÓronment,
linity and
mangrove
sment and
n. Dense,
| areas can
Aizpuru,
ratio are
(Nayak et
found that
nangroves
mangrove
ra forest,
sing LISS
al reefs is
easures to
00,000 sq
OT multi-
ious coral
ing, atoll,
-flat, reef
| coralline
[I data on
al. 1996,
helf, coral
> mapped.
tifying the
es. It was
s problem
[he felling
increased
iversity. It
eases with
in Puerto
ecological
'eflectance
ar column
IAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring”, Hyderabad, India, 2002
correction and contextual editing increased the classification
accuracy (Mumby et al. 1998). IRS-1C LISS III and PAN
merged data have been used for coral reef zonation study
(Nayak et al. 1996). It is possible to identify reef edge, reef
crest, algal ridge, coral knolls, reef platform, reef flat
(consisting of sea grass, algae/seaweed, shallow pools, mud
over reef and sand apron). The branching coral, massive coral,
healthy and bleached coral have distinct spectral characteristics.
IRS LISS III green band (520-590 nm) is quite useful. The live
coral area as small as 50-sq. m was possible to identify. Such
zonation was possible even on a coral (Nayak et al. 1996).
3.4 Protected Areas
Many ecologically fragile areas are designated as ‘Protected
Areas’ to preserve and conserve such ecosystems. However, it
is not known, how much area will be sufficient for conserving
biodiversity in vital/critical habitats, such as mangroves, coral
reefs and wetlands. It is necessary to monitor these areas to
assess impact of conservation measures as well as
anthropogenic activities. The repetitive coverage of the IRS
satellites is quite adequate for monitoring such changes. In one
such study, in the Marine National Park, Jamnagar, on the
Gujarat coast significant changes in the mangrove vegetation
and coral reef area were observed during the period 1975 to
2000 (Nayak et al. 1989, Nayak and Bahuguna, 2001). Degra-
dation of both ecosystems continued till 1985 on account of
mining of coralline sand and use of mangroves as fuel and
fodder. In 1983, this area was declared as a marine park
(protected area). Extensive measures were initiated for
conservation of mangrove and coral reef areas by the marine
park authorities. This resulted in reversing the trend of
degradation after 1985 and has certainly helped towards
restoring the environment. However, recent industrialisation,
development of ports, etc. have again put these ecosystems
under stress, as evident from recent satellite data. It is necessary
to develop such areas for eco-tourism.
3.5 Marine Fishery
Marine living resources provide animal protein requirement of
human being. Fishing and aquaculture are major source of
employment and economically very important, especially in
developing countries. The assessment of stock is one of the
important activities for conserving the marine living resources.
India has high potential for marine fisheries development. The
present fish production in the country is mainly from the coastal
waters (up to depth of 50 m). An improved knowledge of
identification of marine living resources in EEZ is required to
harness full potential of commercial fishery. Phytoplankton
forms the first link in the ocean food chain and gives an
indication about the standing stock of green biomass, which
helps in predicting the third level productivity. Today, satellite-
based observing systems having narrow spectral bands in the
visible region are providing better insight into our
understanding of the ocean productivity. They also provide
better understanding of the role played by ocean productivity in
the uptake of carbon dioxide from atmosphere. IRS P4 Ocean
Colour Monitor (OCM) has been providing ocean colour data
every two days for the Indian regions. The potential Fishing
Zone (PFZ) maps are generated based on oceanographic
features such as thermal boundaries, fronts, eddies, rings, gyres,
meanders and up welling regions (Narain et al. 1992). The
chlorophyll and SST, derived from OCM and NOAA AVHRR
have been integrated to provide fishery forecast to predict likely
availability of fishes more accurately (Solanki et al. 1998, 2001,
Dwivedi, et al. 2002). It was observed that this technique is
373
quite useful for pelagic and demersal fishery. It was observed
that such forecast are 70-90 per cent accurate results in 70-100
per cent increase in catch. The information on surface wave,
wind, topography, coastal circulation using microwave data are
being integrated in developing an integrated model for fishery
forecasting. Apart from this, new resources through sea
ranching and mari-culture in enclosed and semi-enclosed
bodies will have to be tapped. Efforts are continuing to predict
primary productivity and link it to fish stock. All these efforts
will lead to achieve food self-sufficiency in developing
countries.
4. SHORELINE PROTECTION
In world, many areas are being eroded and threaten the life and
property of local population. The economic and human costs of
the coastal erosion are growing as more people migrate towards
coast. Healthy coastal ecosystems cannot completely protect
coast from impacts of storms and floods, but they do play an
important .role in stabilizing shorelines and buffering coastal
development from impact of storm. One of the major
requirements of planning coastal protection work is to under-
stand coastal processes of erosion, deposition, and sediment-
transport, flooding and sea-level-changes, which continuously
modify the shoreline. The historical and functional approaches
to study shoreline changes along with various landforms help in
deciphering the coastal processes operating in an area (Shaikh
et al. 1989, Nayak, 2000). Coastal geomorphology of the
Godavari delta was studied using airborne X band SAR and
IRS LISS II images (Madhavan, et al. 1999). Multi-date
satellite data have been used to study shoreline change and
coastal landforms, which provided insight into large area
sediment transport studies and detecting long-term change in
entire coastline (Nayak, 2000). The planimetric accuracy was
15 m at the 1:50,000-scale (Chauhan and Nayak, 1995). Use of
digital terrain model along with tidal heights can improve
shoreline change detection (Chan and Raul, 1998).
Shoreline-change mapping (1967-68, 1985-89, 1990-92
periods) for the entire Indian coast has been carried out using
LANDSAT MSS/TM and IRS LISS II data on '1:250,000 and
1:50,000 scale. Erosion has been observed north of
Visakhapatnam, Paradip, and Ennore, north of Madras, near
Nagapattiam and Kanyakumari ports on the East Coast of India
while deposition has been observed south of these ports. These
changes are attributed to construction of artificial barriers like
breakwater, jetties, etc. (Nayak et al. 1992, 1997, Chauhan et al.
1996).). It is recently realised that construction of dam on
rivers significantly alters coastal environment at least for some
time. The Dhuvaran Thermal Power Station located on the
northern bank of the Mahi estuary in the Gulf of Khambhat
(Cambay) had experienced severe erosion during 1979-1981.
The analysis of multi-date satellite imagery indicated
significant shoreline changes in the Mahi estuary, western coast
of India, between 1972 and 1988 (Nayak and Sahai, 1985).
These changes were attributed to construction of dams on the
Mahi and Panam rivers in upstream regions during 1975.
Remedial measures in the form of diaphragm wall and spurs
have certainly helped to check the erosion. Recently available
high-resolution images will be extremely useful for such
analysis
The knowledge about suspended sediment movement helps in
understanding near-shore water flow. In one such study, a
sediment plume emerging from the Kochi harbour d a sharp
contact with the sediments along the coast indicating two
different water masses. This clearly indicated that the plume is
