Forest cover change detection using geo-informatics technology: a spatiotemporal analysis based on Pottuvil and Thirukkovil divisional secretary division in Ampara district, Sri Lanka

Abstract

Forest resources are declining as the land use changes take place. There are opportunities to achieve sustainable development by maintaining the balance of forests when heading towards an integrated approach to protect the forest resources. Therefore, this study is to detect the spatio-temporal change in forest cover in Pottuvil and Thirukovil areas during the period from 2007 to 2020. Landsat 7 ETM+ imagery of 2007 and Landsat 9 OLI imagery of 2022 have been used to detect the forest cover change within the period with the aid of geoinformatics technology. The accuracy assessment was calculated to validate the data accordingly, the overall accuracy computed as 88.9% in 2007 and 89.6% in 2022. Also, the user accuracy is 80.4% in 2007 and 82.5% in 2022. The producer accuracy for these two years is 90.1% and 91.0% respectively. In this sense, in 2007, 23,769 hectares of forest cover were identified in the study area. However, by the beginning of 2022, it had decreased to 22,020 hectares of which had been converted into Agricultural lands (1,709ha), Buildup lands (18ha.), Wetland (7ha.), and Barren lands (16ha). It has been found that deforestation in this region, mostly due to the agricultural expansion, is causing various challenges to ecology and biodiversity. Legal action should be taken against this increasing deforestation through concerned authorities. Integrated approach is a must to protect the endangering forest resources in the study area.