摘要：The continuous observations on forest cover through the spaceborne technology known as remote sensingprovide relative accuracy for temporal variation, changes and spatial distribution of forest biodiversity. Thepresent study describes the temporal changes in forest cover and their spatial distribution in DevanampattiReserved Forest in Tiruvannamalai District of Tamilnadu using change detection matrices technique byintegrating remote sensing and GIS. Remote sensing technology provides satellite imagery with synapticcoverage on large area and high spatial resolution to identify individual species in biodiversity and delineatingvarious forest types at national, regional and local level, and that facilitates to manage and conserve theforest biodiversity worldwide. The present study carried out using Landsat TM and ETM+ imageries acquiredin 1977, 1991 and 2006 during the same seasonal period. The present study has brought the view oftemporal variation of forest cover and its distribution in various periods. This also revealed the changes andspatial distribution of particular forest types into what types of spatial feature from the past period to present.The study showed rapid changes of forest cover between the two decades; the result of change detectionanalysis reveals that the deciduous forest cover spatially distributed to about 57.35 km 2 in 1977 and ittremendously decreased to 29.60 km 2 in 1991 and 23.56 km 2 in 2006. The decreasing rate per year between1977 and 2006 was estimated at 0.65 %. The area of mixed forest cover was estimated to be about 35.30km 2 in 1977, which decreased to 41.75 km 2 in 1991 and 18.96 km 2 in 2006 with the decreasing rate of0.018% per year. Unfortunately, the rich forest biodiversity degraded into sandy gravel or eroded landform,and range of area cover was about 18.93 km 2 in 1977 and 24.30 km 2 in 2006 and rocky exposure increasedin its area from 44.67 km 2 in 1977 to 77.79 km 2 in 2006. The changing rate of these landforms increased peryear to about 0.11 % and 0.63 % respectively.
