Page 204 - Microsoft Word - DIGITAL ATLAS THOOT-1

Plate No ATM.09

Using the digital atlas thematic map layers such as satellite image and

Administrative boundary, the changes in the coral reef around Rameswaram island is
identified. The changes in coral reefs are compared for 1988 and 2000. Using the

unsupervised classification technique in ERDAS Imagine, the difference in the coral
reef is identified. The total distribution of coral in the year 1988 is noted as 359.04

hectares. The coral reefs in the year 2000 is about 401.98 hectares. The newly grown
corals are given in red colour and the degraded coral are given in green colour.

Plate No ATM.10

Using the digital atlas thematic map the digital elevation model is created for

Virudhunagar district. The 3D analyst tool of Arc GIS 9.3 is used to create the Digital
Elevation Model. The relief layer in digital atlas is used to create the elevation model.

The elevation is categorized as High to Low. High represent the area which has the
elevation of about 1600 m above sea level and low represent the plain region of the

district. Elevated regions are seen towards the western side of the district whereas the

eastern side forms a plain region with lower values.

Plate No ATM.11

Using the Digital Atlas Thematic maps the impact of climate change on land

use / land cover is analysed using the statistical correlation. The thematic map plates
such as Annual temperature, Seasonal temperature, Annual Rainfall, Seasonal

Rainfall, Land use/ Land cover are used in the study. The 11 variables are correlated

significantly with each other. Settlement and River are well correlated, Fallow land
and Others, Crop land and Fallow Land, Crop land and Others, Fallow land and Tank

,tank and crop land, Tank and fallow land, Tank and other, others and settlement,
Barren and Cropland, Barren and fallow land, Barren and Tank

Plate No ATM.12

Using the Digital Atlas thematic map Plates namely Satellite Imagery and

land use / land cover the temporal Land cover change in forest land of
Agasthiyarmalai Biosphere Reserve(ABR) has been detected between the years 1990

to 2006. Using the unsupervised classification techniques in ERDAS Imagine