Mangrove Density Mapping from Landsat 8/9 OLI Imagery in Dompak Island, Indonesia: A Study from 2017 to 2022

Abstract

Dompak Island, a small island in the Riau Islands Province, has experienced massive urban development by local governments over the last decade. This activity has impacted the sustainability of vegetation and mangrove forests on Dompak Island. A decrease in the mangrove area can affect the condition and sustainability of the species. This study aimed to analyze the changes in mangrove density using Landsat 8/9 OLI satellite imagery of Dompak Island, Tanjungpinang City, from 2017 to 2022. This study used an unsupervised classification method, which used the Normalized Difference Vegetation Index (NDVI) to identify the changes and density of mangroves, and an algorithm to obtain the greenness value of vegetation objects. This study found changes in the area and growth of mangroves. There is a decrease in mangrove density globally. The level of rare density in 2017 and 2022 was still at 23%, the medium density increased by 8%, and the high density decreased by 9%. Based on mapping results, the area of mangrove forests has decreased by 4 ha from 2017 to 2022, namely from 93 ha to 89 ha..