Spatial Analysis of Vegetation Density Using the Normalized Difference Vegetation Index Method Based on Landsat 8 Imagery in Pematangsiantar, North Sumatra, Indonesia. YKP JOURNAL, [S. l.], v. 2, n. 1, p. 30–39, 2026. DOI: 10.63639/%ykp. Disponível em: https://ykpjournal.org/index.php/ykpjournal/article/view/146. Acesso em: 30 jul. 2026.