Unexpected! This North Coast Java Region Has Already Sunk
The National Research and Innovation Agency (BRIN) has disclosed that the coastal area of North Coast Java, spanning from Serang Regency to Situbondo Regency, has recorded erosion across 65.8% of its shoreline. The high rate of coastal abrasion has resulted in environmental degradation that directly impacts the loss of residents’ living spaces and disrupts economic infrastructure in the region.
This was comprehensively revealed based on the latest research data by Researcher from the BRIN Centre for Climate and Atmospheric Research, Tubagus Solihuddin, during the Earth and Maritime Research Organisation (ORKM) Expose and Focus Group Discussion (FGD) themed “Resilient Pantura, Sustainable Indonesia for the Integration of Science, Innovation, and Coastal Resilience”, at the B.J. Habibie Building, Jakarta, on Thursday (30/4/2026), as quoted on Saturday (9/5/2026).
Tubagus highlighted that the development of settlements and economic activity centres in Pantura has been extremely rapid due to high demographic pressure. This has led to uncontrolled extraction of marine and coastal resources.
“So, 84% of North Coast Java consists of fluvial deposits and delta deposits. Geologically, the deposits forming North Coast Java are still unconsolidated. They are not yet strongly compacted, making them very susceptible to erosion and compaction,” he explained.
This vulnerability is worsened by the morphological conditions in the area. Morphologically, North Coast Java is dominated by low-relief beaches or lowland beaches with elevations below 10 metres, accounting for 83% of the total length of North Coast Java.
Furthermore, analysis of shoreline changes using Sentinel satellite imagery from 2000 to 2024 shows a worrying trend. Tubagus detailed that shoreline changes are dominated by an erosion rate of 65.8%, while accretion (land addition) is only at 34.2%.
He highlighted an anomaly from the monitoring data, where massive erosion is occurring in delta environments that are naturally areas of sedimentation. This condition is closely related to upstream modification activities, such as canalisation, river diversion, and dam construction, which ultimately disrupt sediment supply to coastal estuary areas.
The impacts of these anthropogenic modifications are clearly recorded at various points. In Tanjung Pontang, Serang, an area of 1.72 square kilometres of land has been lost to erosion due to the diversion of the Ciujung Baru River flow. In the Pantai Bahagia area, Muara Gembong, Bekasi, seawater has intruded up to 4 kilometres inland, permanently submerging public infrastructure and flooding over 1,000 hectares of residents’ ponds.
Besides Bekasi, similar incidents have been recorded in Legonkulon, Subang, where seawater intrusion up to 2 km has submerged 700 hectares of ponds. Abrasion has also eroded village roads spanning 500 metres to 1 km in Krangkeng, Indramayu.
Specifically in the Demak region, Tubagus provided a historical note that the area was part of the Muria Strait waters in the 15th-16th centuries, which was later covered by sedimentation to become land. Now, seawater has returned, intruding 5 to 6 kilometres inland in Demak, swallowing rice fields and settlement areas.
This is exacerbated by sea level rise (SLR) and land subsidence. Based on altimetry data modelling (1993-2025), the sea level rise trend in Pantura averages 0.41 to 0.42 centimetres per year, resulting in a cumulative rise of up to 15.5 centimetres over 32 years.
In addition to abrasion and sea level rise, the Pantura coast also faces land subsidence issues. Citing geospatial data (2017-2023), Tubagus explained that the highest land subsidence rate was recorded in Demak at 16 cm/year, followed by Jakarta (15 cm/year), Sidoarjo (14 cm/year), and Pekalongan (11 cm/year). Land subsidence was also identified in Surabaya (8 cm/year), Brebes (7 cm/year), and Serang, Cirebon, and Indramayu (6 cm/year each).
“Pantura Java is facing a real crisis. As mentioned earlier, the challenges are not just erosion, abrasion, flooding, but also sea level rise and land subsidence. And this is not a local issue; it is a national issue. Considering that Pantura Java is the backbone of the national economy,” Tubagus emphasised.