Understanding of North Semarang's Land Subsidence Based on InSAR Analysis and Site Reconnaissance

Abstract

The phenomenon of land subsidence has emerged as a critical issue in Semarang, Indonesia, particularly within its northern coastal regions. This issue is primarily attributed to the rapid urbanization and extensive infrastructure development in the area. The present study employs the Interferometric Synthetic Aperture Radar (InSAR) technique, a proven method for effectively monitoring subsidence patterns, to analyze changes occurring between 2020 and 2024. The findings indicate significant subsidence within the northern coastal zones, with rates reaching up to -0.23 meters per year. The primary drivers of this subsidence are identified as excessive groundwater extraction, the presence of soft alluvial soils, and accelerated urban development. The impacts of this land subsidence are multifaceted, including exacerbated flooding risks, disruption of local infrastructure, and increased challenges for urban planning and development. These findings underscore the urgency of implementing mitigation strategies, such as stricter regulation of groundwater extraction and the development of resilient infrastructure designed to adapt to these changing conditions. Furthermore, the study highlights the necessity for long-term, sustainable strategies to address on going subsidence and its associated risks, emphasizing the importance of safeguarding both coastal and inland areas of Semarang. These insights contribute to the broader understanding of urban subsidence and its implications, offering a foundation for developing effective management and adaptation measures in similar rapidly urbanizing regions.