IDENTIFICATION OF FOREST COVER VARIATION IN MANNAR DISTRICT, SRI LANKA USING GIS AND REMOTE SENSING TECHNIQUES

Abstract

Geographic Information System (GIS) and Remote sensing acting a vital part in identifying changes in the forest cover. One of the most prominent feature is forest in Mannar district. It is crucial to estimate forest cover change on spatial and temporal scale for a sustainable forest resource management. And there were no any well studies taken to find out areal extent of forest cover change. The main objective of this study was to estimate the magnitude of forest cover change for the years 1997, 2008 and 2015. Also identify its spatial distribution and analyse the spatio temporal changes of the forest. Further forest cover maps were produced of the study area for the respective years. Research study was used the supervised, unsupervised and NDVI classification to evaluate the total forest cover. The results revealed high kappa accuracy in percentage of forest cover for the years 1997, 2008 and 2015 were 82%, 74% and 81% and overall accuracies were 86%, 81% and 87% respectively for the supervised classification. According to the supervised classification study indicates the forest cover extent of 1997, 2008 and 2015 were 1,254 km 2 (63%), 1,299 km 2 (65%) and 1,161 km 2 (59%). It revealed that, 2% of forest cover was increased from 1997 to 2008 and 6% was reduced from 2008 to 2015. The study indicated that forest cover change is an immense problematic issue in the district, where about 119 km 2 (6%) of forest cover decreased in 2015. The main factors of forest cover reduction in the district might be anthropogenic activities.