Analysis of Land Cover Changes and Sustainable Reforestation in Sianjur Mula-Mula District, Samosir Regency, Indonesia

The increase in population and technological advances have had a significant impact on land use changes. there are changes in land cover 2017-2022 in the local ecosystem. there have been significant changes but can still be maintained. This is to prevent the extinction of species such as fish, land animals and other marine animals. Changes in land cover that are getting worse will reduce tourism activities in Lake Toba because the quality of the ecosystem decreases. This also happened in Sianjur Mula-Mula District, which consists of 12 villages. Even though most of the villages in this sub-district are located on hills and steep slopes, the need for new land forces the community to open and utilize these sloping lands into residential areas, agricultural land and community gardens which have an impact on dynamic changes in land cover. Therefore, this research aimed to analyze land cover changes in Sianjur Mula-Mula Subdistrict in 2017 and 2022 using Sentinel 2 imagery and a guided classification method to carry out reforestation of deforested land. The results showed that there were five distinct land cover classes in Samosir Regency: Forest land, settlements, shrubs, rice fields and mixed gardens. In 2017, shrubs dominated, covering an area of 4,689 Ha or 39.68% and a similar pattern persisted in 2022, with a coverage of 4,529 Ha or 38.32%. The most significant increase occurred in forest land, with change amounting to 182 Ha or 1.54%, while the smallest change was observed in rice fields, totally 33 Ha or 0.28%. The largest changes in land cover area occurred in forest with a decrease of 182 Ha or 1.54% and the largest increase was found in the built-up land with an area of 111 Ha or 0.95%. Reforestation must be carried out on 4,529 hectares of shrubs with a total of 5,032,222 seeds so that the water in Lake Toba remains maintained.