Landcover change analysis of besitang watershed, Langkat-North Sumatera

Watershed is an ecosystem area bordered by topographic pattern and serves as serves as a collector, storage and distributor of water, sediments, pollutants and nutrients in the river system and throughout by a single outlet. The high of population growth led to greater land use change. This research aimed to identify land cover classes and land cover change in Besitang watershed between 1990, 2005 and 2015. This research used Landsat 5 imagery in 1990 and 2005, and Landsat 8 imagery in 2015 with supervised classification using method maximum likelihood classifier. The result showed that there were 12 classes of land cover in the Besitang watershed, they were primary forest, secondary forest, mangrove forest, scrub, rubber plantations, oil palm plantations, dry land agriculture, bare land, settlement, fishpond and water body. The largest area of land cover area is primary forest covering an area of 38,542.43 hectares (39.94%) in 1990, 34,279.16 hectares (35.52%) in 2005, and 34,620.41 hectares (35.88%) in 2015. The largest area of land cover change between 1990 until 2005 is mangrove forest to fishpond with covering an area of 2,364.21 hectares change. While the largest area of land cover change between 2005 until 2015 is mangrove forest to oil palm plantation with covering an area of 1,016.82 hectares changes. (paper)