Arahan Mitigasi Bencana Abrasi dan Gelombang Ekstrem Berdasarkan Analisis Perubahan Garis Pantai di Kecamatan Besuki, Kabupaten Situbondo

Abstract

Besuki Sub-district, Situbondo Regency, has a coastal area designated as the Urban Local Activity Center (PKL) of Besuki under the Situbondo Regency Spatial Plan (RTRW) 2025–2045. However, it currently faces annual threats of abrasion and extreme waves that damage coastal protection structures and settlements. This study identifies the rate of shoreline change in Besuki Sub-district during 2015–2025, predicts shoreline change for the next 20 years (2026–2046), and formulates mitigation directions for abrasion and extreme wave disasters. A mixed-methods approach was applied, combining spatial and descriptive statistical analysis (quantitative) with triangulation analysis (qualitative). Results based on the Linear Regression Rate (LRR) show that the shoreline of Besuki Sub-district in 2015–2025 was dominated by abrasion, with 97.00% of transects eroding at an average rate of -3.23 m/year (High Abrasion). This is corroborated by the End Point Rate (EPR), showing 76.39% eroding transects at an average of -2.58 m/year (High Abrasion), while the Net Shoreline Movement (NSM) recorded a maximum abrasion of -156.99 m. By 2046, abrasion is projected to reach an average of -78.29 m over 20 years, affecting 36.93 hectares. Meanwhile, existing coastal protection structures cover only 51.89% of the shoreline, with 37.74% of seawalls already damaged. Socioeconomic conditions reveal low community adaptation and preparedness, alongside heavy dependence on the fisheries and marine sector, heightening coastal vulnerability to abrasion and extreme waves. The study concludes that Besuki's coastal area is experiencing High Abrasion (< -2 m/year) and faces continued threats over the next two decades. Accordingly, the mitigation directions derived through triangulation address four key variables: shoreline change, predicted shoreline change, condition of coastal protection structures, and community socioeconomic conditions.