Strategi Mitigasi Dampak dan Adaptasi Banjir Rob Terhadap Budidaya Tambak di Legonkulon, Subang

Abstract

SILFIA NURJIJAR. Strategi Mitigasi Dampak dan Adaptasi Banjir Rob Terhadap Budidaya Tambak di Legonkulon, Subang. Dibimbing oleh BAMBANG WIDIGDO, TARYONO dan FERY KURNIAWAN.

Banjir rob di Kecamatan Legonkulon, Kabupaten Subang, semakin meningkat akibat interaksi kenaikan muka air laut, penurunan muka tanah, dan topografi pesisir yang rendah. Kondisi ini menyebabkan genangan meluas dan mengancam keberlanjutan budidaya tambak melalui penurunan produktivitas, kerusakan infrastruktur, kehilangan hasil panen, dan peningkatan biaya operasional. Penelitian ini bertujuan untuk: (1) menganalisis distribusi spasial-temporal genangan rob tahun 2025 dan proyeksinya tahun 2030, (2) menganalisis keterkaitannya dengan produktivitas tambak, (3) mengestimasi kerugian ekonomi, dan (4) menentukan prioritas strategi mitigasi dampak dan adaptasi. Distribusi genangan dianalisis melalui integrasi citra Sentinel-1, DEMNAS, kenaikan muka air laut, pasang tertinggi, dan penurunan muka tanah menggunakan Google Earth Engine dan ArcMap 10.8. Kerugian ekonomi diestimasi dengan pendekatan Damage and Loss Assessment (DaLA), meliputi kerugian langsung, tidak langsung, dan biaya tambahan berdasarkan observasi lapangan serta wawancara pembudidaya. Prioritas strategi ditentukan menggunakan Analytical Network Process (ANP) berdasarkan penilaian pakar dengan mempertimbangkan aspek ekologi, ekonomi, sosial, kelembagaan, dan teknologi. Hasil penelitian menunjukkan luas genangan diproyeksikan meningkat dari 423 ha pada 2025 menjadi 444 ha pada 2030, dengan luas tambak terdampak meningkat dari 96 ha menjadi 102 ha. Peningkatan paparan genangan berkaitan dengan penurunan produktivitas pascabencana dan peningkatan kerugian ekonomi. Total kerugian diperkirakan mencapai Rp4.662.552.773 pada 2025 dan meningkat menjadi Rp5.891.177.611 pada 2030, dengan kerugian langsung sebagai komponen terbesar. Hasil ANP menempatkan aspek ekologi sebagai prioritas utama, diikuti ekonomi, sosial, kelembagaan, dan teknologi. Strategi yang direkomendasikan meliputi pengaturan waktu produksi melalui pemanenan sebelum banjir atau penebaran benur setelah banjir, restorasi mangrove secara terukur yang didukung pembangunan APO sebagai solusi berbasis ekosistem untuk mengurangi energi gelombang dan perluasan genangan, serta diversifikasi produk budidaya tambak dan mangrove untuk mempertahankan pendapatan masyarakat. Penelitian ini berkontribusi melalui integrasi pemetaan genangan, estimasi kerugian berbasis DaLA, dan penentuan strategi prioritas menggunakan ANP dalam satu kerangka analisis terpadu. Meskipun dibatasi pada kawasan tambak di Legonkulon dengan proyeksi hingga 2030 dan belum mencakup dampak ekonomi jangka panjang serta jasa ekosistem pesisir secara menyeluruh, hasil penelitian dapat menjadi dasar ilmiah bagi kebijakan mitigasi dampak dan adaptasi banjir rob guna meningkatkan ketahanan budidaya tambak dan mendukung pengelolaan pesisir berkelanjutan. Kata kunci: Banjir rob, budidaya tambak, kerugian ekonomi, prioritas mitigasi dampak.

SILFIA NURJIJAR. Mitigation and Adaptation Strategies for Tidal Flood Impacts on Brackish Water Aquaculture in Legonkulon, Subang. Supervised by BAMBANG WIDIGDO, TARYONO, and FERY KURNIAWAN. Tidal flooding in Legonkulon District, Subang Regency, has intensified due to the interaction of sea-level rise, land subsidence, and the low-lying coastal topography. This condition has expanded inundation and threatened the sustainability of pond aquaculture through reduced productivity, infrastructure damage, crop losses, and increased post-disaster operating costs. This study aimed to: (1) analyze the spatial and temporal distribution of tidal flooding in 2025 and project its extent to 2030, (2) examine its relationship with pond aquaculture productivity, (3) estimate the resulting economic losses, and (4) determine priority mitigation and adaptation strategies. Flood inundation was analyzed by integrating Sentinel-1 imagery, the National Digital Elevation Model (DEMNAS), sea-level rise, highest tidal levels, and land subsidence data using Google Earth Engine and ArcMap 10.8. Economic losses were estimated using the Damage and Loss Assessment (DaLA) approach, covering direct losses, indirect losses, and additional costs based on field observations and interviews with pond farmers. Priority strategies were determined using the Analytical Network Process (ANP) based on expert assessments, incorporating ecological, economic, social, institutional, and technological aspects. The results showed that the inundated area is projected to increase from 423 ha in 2025 to 444 ha in 2030, while affected pond areas are projected to increase from 96 ha to 102 ha. Increased flood exposure was associated with reduced post-disaster aquaculture productivity and higher economic losses. Total losses were estimated at IDR 4,662,552,773 in 2025 and projected to increase to IDR 5,891,177,611 in 2030, with direct losses constituting the largest component. The ANP results ranked ecological aspects as the highest priority, followed by economic, social, institutional, and technological aspects. Recommended strategies include adjusting production schedules through harvesting before flooding or stocking fry after flooding; measured mangrove restoration supported by the construction of APOs as an ecosystem-based solution to reduce wave energy and limit flood expansion; and diversification of pond aquaculture and mangrove-based products to maintain community income. This study contributes by integrating flood inundation mapping, DaLA-based economic loss estimation, and ANP-based priority strategy formulation within a comprehensive analytical framework. Although the study is limited to pond aquaculture areas in Legonkulon District, with projections through 2030 and without fully accounting for long-term economic impacts and coastal ecosystem services, its findings provide a scientific basis for developing tidal flood mitigation and adaptation policies to strengthen aquaculture resilience and support sustainable coastal management. Keywords: Tidal flooding, Aquaculture, economic losses, mitigation priority.