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presence of sand bars in the river mouths, beach composition, 
typical wave condition, suitable climatological parameters such 
as rain fall, temperature atract these sea creatures from their 
feeding ground to these rookeries for their mass nesting. 
Satellite remote sensing technology is a pioneering technology 
which can be used for the study of the characterisation of the 
land parameters of the nesting habitats. Besides the other co- 
lateral data of the beaches can be integrated at GIS environment 
for studying suitability of the beaches. 
THE STUDY AREA 
In the present study characterisation of the nesting habitats of 
the Olive ridley sea turtle has been attempted within 10 
kilometer of landmass from the sea water line. The study area 
extends from Dhamra river mouth to Rushikulya river mouth 
covering four coastal districts namely Kendrapara, 
Jagatsinghpur, Puri and Ganjam. 
METHODOLOGY 
Spatial database on landuse/ land cover and coastal landforms 
of the study area are created using multidate Indian Remote 
Sensing Satellite data e,g IRS-1A LISS II of period 1990 and 
IRS-1D LISS III of period 2000. Supervised classification 
system has been adopted in two date data to classify the study 
area separately into different landuse/landcover classes namely 
settlement with vegetation, plantation, coastal sands, 
aquaculture ponds, dense mangrove forest, degraded and 
mangrove swamp forest, dense forest, degraded forest, 
waterlogged and marshy land etc. Different layer of 
information such as power line, drainage, canal , road and rail 
network, demarcated forest boundary, have been superimposed 
on the classified map. The major geomorphological classes are 
visually delineated using IRS-1D LISS III data of period 1998 
and later a coastal geomorphological map was prepared at GIS 
environment showing 25 number of classes. The major classes 
identified are channel island, coastal sand dunes, beach sand, 
beach ridge, strand line, fresh water creek, buried channel, mud 
flat, coastal plain, deltaic plain etc. The non-spatial data base 
such as rainfall, temperature, nesting population, mortality rate, 
predator activities like movement of mechanised trawlers/boats 
are taken in GIS environment. The integration of coastal 
geomorphological map with the two date landuse/ land cover 
maps separately has identified the change in landuse /land 
IAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring”, Hyderabad, India, 2002 
cover classes in each geomorphological units. The integration 
of spatial and non-spatial database of the existing nesting 
beaches at GIS environment has identified suitable common 
parameters for selection of sporadic nesting sites. 
RESULTS AND DISCUSSION 
The population of Olive ridley sea turtle for mass nesting varies 
from time to time because of change in coastal land forms and 
landuse/ land cover classes. The landscape feature of a 
particular region is static and takes a considerable time to 
change whereas the landuse/ land cover class change 
frequently because of conversion of land from one class to 
another class as per the requirement of the people. 
1. Gahirmatha and Nasi sea turtle rookery 
Gahirmatha coast in Orissa hosts mass nesting of thousands of 
Olive ridley sea turtle every year from December to March and 
is considered the world’s largest turtle rookery. 
The turtle laid eggs in four islands viz. Nasi I,.Nasi II, Babubali 
(Long Wheeler island) and a newly formed island. The 
Gahirmatha rookery is having the beach of 60 to 120 meter 
width, 09-2? slope, constituted by coarse to fine sand which is 
more clayey towards the land. The major settlements covering 
in this area are Gahirmatha, Ekakula, Kahnupur, Satabhaya etc. 
This area lies around the Maipura and Dhamara river mouths 
and seriously affected by the lightening effect due to missile 
activities duo to DRDO in Wheeler island. The major landuse/ 
land cover classes of this area are settlement with vegetation, 
plantation, aquaculture ponds, dense mangrove forest, coastal 
sand and degraded mangrove swamp forest The major coastal 
geomorphological classes covering within this area are coastal 
sand dunes, beach sand, mangrove and channel island It is 
observed from the study that the area covering settlement with 
vegetation, degraded scrub forest, aquaculture ponds and 
agricultural land has been increased when compared from 1990 
to 2000 satellite data. Similarly there is maximum decrease in 
degraded mangrove and swamp forest,coastal sand, coastal 
mudflat in this area. The characterisation of nesting habitat map 
of Gahirmatha and Nasi area has been prepared and in shown in 
Fig.-1. The landuse /land cover classes like agricultural land, 
salt pan and marshy and swampy area are not included in the 
map as because they do not have any specific characteristics 
during the mass nesting of ridleys.