Pemetaan Perubahan Garis Pantai di Pesisir Kabupaten Subang, Jawa Barat dengan Menggunakan Citra Sentinel-2A

Abstract

Kabupaten Subang yang memiliki garis pantai sepanjang 48,20 km telah mengalami perubahan pesisir berupa abrasi dan akresi akibat faktor alami dan antropogenik. Penelitian ini bertujuan untuk mengetahui perubahan garis pantai yang telah terjadi dengan melakukan pemetaan spasial menggunakan citra Sentinel-2A periode 2016 dan 2024. Ekstraksi garis pantai dilakukan melalui metode Modified Normalized Difference Water Index (MNDWI), diikuti dengan koreksi pasang surut dan analisis menggunakan Digital Shoreline Analysis System (DSAS). Hasil menunjukkan bahwa perubahan garis pantai di Kabupaten Subang didominasi oleh akresi sangat berat dan abrasi sangat berat, khususnya pada Zona D (Kecamatan Pusakanagara). Nilai akresi maksimum mencapai 1.021,08 m dengan laju 123,49 m/th, sedangkan abrasi tertinggi sebesar 1.048,74 m dengan laju 126,84 m/th. Selain faktor utama seperti sedimentasi dan degradasi mangrove, perubahan dipengaruhi oleh faktor spasial lain termasuk angin, arus, gelombang, batimetri, dan pasang surut. Temuan ini menunjukkan pentingnya pemantauan spasial jangka panjang sebagai dasar mitigasi kerusakan pesisir dan perencanaan wilayah secara berkelanjutan.

Subang Regency, with a coastline of 48.20 km, has experienced coastal change such as abrasion and accretion due to both natural and anthropogenic factors. This study aimed to identify shoreline changes that had occurred through spatial mapping using Sentinel-2A imagery from 2016 and 2024. Shoreline extraction was carried out using the Modified Normalized Difference Water Index (MNDWI) method, followed by tidal correction and analysis with the Digital Shoreline Analysis System (DSAS). The results showed that shoreline changes in Subang Regency were dominated by very severe accretion and very severe abrasion, particularly in Zone D (Pusakanagara District). The maximum accretion reached 1,021.08 m with a rate of 123.49 m/year, while the highest abrasion was 1,048.74 m with a rate of 126.84 m/year. In addition to major factors such as sedimentation and mangrove degradation, the changes were also influenced by other spatial factors including wind, currents, waves, bathymetry, and tides. These findings highlight the importance of long-term spatial monitoring as a basis for mitigating coastal damage and supporting sustainable regional planning.