Land Subsidence and Rising Sea Levels: BRIN Warns Java's North Coast Faces Increasing Submergence Threat
The North Coast of Java (Pantura) faces growing dual threats as land subsidence across coastal areas from Jakarta, Bekasi, Indramayu, Cirebon, Subang, Pemalang, Pekalongan, to Demak is exacerbated by sea level rise of up to 4.3 millimetres per year. If not addressed promptly, the combination could lead to permanent flooding.
Agung Syetiawan, a researcher at BRIN’s Geoinformatics Research Centre, stated that excessive groundwater extraction for domestic use and shrimp farming is a primary cause of subsidence in coastal regions.
“GNSS observations from Indonesia Continuously Operating Reference Station show non-linear vertical deformation patterns across most of Pantura,” Agung said on Sunday (31 May).
Based on altimetry data analysis, sea level rise trends range from 2.4 to 4.3 millimetres annually. Geospatial modelling indicates several coastal areas of Pantura could face permanent inundation without mitigation efforts.
Muara Gembong and parts of Jakarta, Tangerang, and Bekasi coasts have already seen expanded flood areas due to these combined factors.
Agung stressed that infrastructure mitigation plans, such as giant sea walls, must consider comprehensive geospatial studies to accurately determine priority areas for intervention.
Data-driven policies are crucial for sustainable coastal development, including groundwater control, mangrove rehabilitation, and sea wall construction evaluations.
To monitor land subsidence more accurately, BRIN collaborates with Bandung Institute of Technology to install permanent benchmark pillars at high-subsidence sites for annual monitoring.
BRIN Geoinformatics Research Centre Head Rokhis Khomarudin emphasised that land subsidence and coastal ecosystem degradation are multidisciplinary issues requiring ongoing geospatial research support.
“Utilising GIS and remote sensing technologies is vital for monitoring, analysis, and developing data-driven mitigation strategies,” Rokhis said. (H-3)