IAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring", Hyderabad, India, 2002 
iv) ^ Impact of engineering structures and dams on 
coastal processes of erosion, deposition and 
sediment transport 
v) Suspended sediment dynamics 
vi) Changes in bottom topography 
Coastal water quality 
i) Non-point and point pollution 
ii) Phytoplankton blooms 
Coastal Hazards and Climate Change 
i) Cyclones, storm surges, sea-level rise and 
possible effects 
ii) Emergency response plans for natural disasters 
such as cyclones, sea level rise, or anthropogenic 
activities such as oil spills. 
Coastal development 
i) Appropriate site selection for industries, landfall 
points, aquaculture, recreational activities, etc. 
il) Assessment of conditions in regulation zones, 
areas under construction setback —lines, mega- 
cities, etc. 
3. COASTAL ECOSYSTEMS AND MARINE 
RESOURCES 
3.1Coastal Ecosystems 
Coastal habitats, especially wetlands, coral reefs, mangroves, 
salt marshes, and sea grasses, are highly productive, serve 
important ecological functions, provide coastal protection and 
are critical resources for food, energy, tourism and economic 
development. Such coastal systems are under stress or 
threatened from various sources, both natural and human. 
Satellite imagery has immensely helped mapping of coastal 
ecosystems. Analysis of satellite data provided estimates of 
alteration in land cover in coastal ecosystem. It was observed 
that about one-third land within 100 km of coastline have been 
converted to either agricultural or urban uses, mainly due to 
increase in population. The loss of coastal habitats such as 
mangroves, sea-grass and wetlands is a direct measure of 
declining condition of biodiversity in coastal habitats. This 
ultimately results in reduction in fish catch. 
In India, many places such as Kochi, wetlands have been 
drained for development and for prevention of malaria. The 
construction of canals for flood control especially on the East 
Coast of India has resulted in loss of wetlands. The information 
on loss of tidal wetlands is important as they provide a vital link 
in the marine energy flow through transfer of solar energy into 
forms, which are readily usable by a wide variety of estuarine 
organisms. The knowledge about areal extent, condition and 
destructive uses of wetlands is vital for coastal management 
programs. A baseline information on coastal habitat 
(critical/vital) and associated shore land features along the 
entire Indian coast on 1:250,000/1:50,000 scale has been 
carried out through visual interpretation of multi-spectral IRS 
LISS II and LANDSAT TM data for macro-level planning 
(Jagtap et al. 2001). The degradation of about 25 per cent of 
mangroves and coral reefs of the Gulf of Kachchh and 
reclamation of lagoons, mudflats, and mangroves was observed 
(Desai et al. 1991, Nayak et al. 1991, 1992 a, Nayak, 1996, 
Nayak and Bahuguna, 2001). Synergistic use of SAR and 
optical data improve distinction of wetlands (Kushwaha, 2000). 
Attempts are being made to use interferometric SAR to study 
small elevation changes in the inter-tidal zone (Cracknell, 
1999). 
3.2 Mangroves 
Mangroves help in the production of detritus, organic matter, 
recycling of nutrients and thus enrich the coastal waters and 
support benthos population of sea. Mangroves cover about 
200,000 sq km areas on the globe, mainly around tropics. It is 
not known that how much mangroves have been lost. It has 
been estimated that half of the world mangroves may have been 
lost. In India, mangroves have reduced from 6740 to 4460 sq. 
km (Nayak, 1992). The Forest Survey of India has been 
providing estimates of mangroves since 1987. At many places, 
mangroves are degraded and destroyed due to conversion of 
these areas for agriculture, aquaculture on the East Coast and 
industrial purposes on the West Coast. They are also used as 
fuel and fodder; however, their impact is not very significant. 
However, in some regions, mangroves have increased due to 
plantation as well as regeneration. 
Mangroves are characterised by the presence of particular 
dominant communities/species, physico-chemical environment, 
extent and frequency of inundation by tidal waves, salinity and 
a soil types. Information regarding different mangrove 
community zonations is a vital for bio-diversity assessment and 
for preparing management plans for conservation. Dense, 
degraded, mangrove afforestation areas and reclaimed areas can 
be distinguished (Nayak et al. 1996, Blasco and Aizpuru, 
2002). Principal component analysis and band ratio are 
important techniques for distinguishing mangroves (Nayak et 
al. 1985, Nayak, 1994, Green et al. 1998). It was found that 
spectral resolution is more crucial in distinguishing mangroves 
(Gao, 1999a, 1999b). It is possible to identify major mangrove 
communities such as Avicennia spp.; Rhizophora forest, 
Sonneratia spp., Phoenix spp. and mangrove scrub using LISS 
IIT and PAN data on the Indian sub-continent. 
3.3 Coral Reefs 
The information about extent and condition of coral reefs is 
required for planning conservation and preventive measures to 
protect this fragile system. Coral reefs cover about 300,000 sq 
km areas. IRS LISS III, LANDSAT TM and SPOT multi- 
spectral data have shown potential in identifying various coral 
reef features. Coral reef features such as type (fringing, atoll, 
platform, patch, coral heads, sand cays, etc.), reef-flat, reef 
vegetation, degraded reef, lagoons, live corals and coralline 
shelf have been mapped using IRS LISS II and III data on 
1:50,000 scale for the Indian reefs (Nayak et al. 1996, 
Bahuguna and Nayak, 1998). Uncharted coralline shelf, coral 
heads, live coral platform and coral pinnacle were mapped. 
These maps have been used as a basic input for identifying the 
boundaries of protected areas and biosphere reserves. It was 
observed that coral reef degradation is more serious problem 
than total destruction (Bahuguna and Nayak, 1998). The felling 
of mangroves and clearing of forests have increased 
sedimentation and affected live coral and species diversity. It 
was observed that annual growth of coral reefs decreases with 
increase in sediment loading in the Mayaquez bay in Puerto 
Rico (Miller and Cruise, 1995). 
Coral reefs show distinct morphological and ecological 
characters. Water column modifies the apparent reflectance 
spectrum of an object on the sea bottom. Water column 
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