Dynamics of changes in the land cover of mangrove by historically time from 1989 to year 2019 in 9 subdistricts in Langkat Regency, North Sumatera

Abstract

Indonesia has problems in environmental management, including land use and damage to the coastal environment. This study aims to identify and to analyze the extent of coastal environmental damage through the dynamics of changes in mangrove land use in 9 subdistricts of Langkat Regency, North Sumatra, historically (1989-2019). This study used quantitative approach by conducting field survey methods to identify species diversity and to know the mangrove cover area by using Multitemporal Series Landsat Image at spatial resolution of 30 m. The qualitative approach through PSR (Pressure-State-Response) was used to understand the dynamics of changes on mangrove cover area in Langkat Regency. In this area, 25 real mangrove species and one associated mangrove species was identified. In 1989, mangroves were 36,362.40 Ha. In 2019, mangrove area was reduced by 28,702,0402 Ha. This study showed that the dynamics trend of mangrove cover change in 30 years from 1989-2019 indicated a high rate of land subsidence. In 1989-1999 showed a decrease of 9,638 ha, then in 1999-2009 the areas indicated an increase by 3,314 ha while decreased again in 2009-2019 with an insignificant amount of 1,237 ha. These were caused by aquaculture land, field clearing, and natural conditions.