Dynamics of Ujungpangkah Mangrove Forest, Gresik, Indonesia: 10 Years of Evidence from Remote Sensing

Faculty of Forestry, Universitas Gadjah Mada, Yogyakarta, Indonesia

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Mangroves play a critical role in coastal protection and support local livelihoods, yet they remain vulnerable to degradation. Reliable monitoring of mangrove dynamics using time-series satellite images is essential as a baseline for its conservation and management. The Ujungpangkah Mangrove (MUP) in Gresik, covering approximately ±1,554.27 hectares, was designated as Essential Ecosystem Areas (EEA) in 2020. This study quantifies changes in mangroves within the EEA MUP. The Modular Mangrove Recognition Index from 2015 to 2024 was used to identify changes in mangrove cover and density. LandTrendr outputs and trajectory analyses were used to assess disturbance and recovery, the magnitude and duration of changes, and to model mangrove dynamics. The results show that the revegetation is the largest change class. Mangrove cover and density in the EEA MUP indicates significant recovery, particularly from 2020 to 2022, although disturbances were still detected until 2023. The trajectory patterns reflect natural vegetation dynamics that do not necessarily indicate degradation. The dominance of the stable mangrove class since 2015 indicates that mangrove density is maintained. However, persistent localized deforestation, due to coastal abrasion and land conversion, highlights ongoing management challenges.