The Identification of Land Subsidance by Levelling Measurement and GPR Data at Tanjung Emas Harbour, Semarang

• Main Authors: Purnomo Raharjo, Mira Yosi
• Format: Article
• Language: English
• Published: Marine Geological Institute of Indonesia 2017-10-01
• Series: Bulletin of the Marine Geology
• Subjects: flood; land subsidence; levelling; Tanjung Emas Harbour; Semarang
• Online Access: http://ejournal.mgi.esdm.go.id/index.php/bomg/article/view/351

Recently, the main problem in Semarang City is flood. This area has low relief that consists of coastal alluvial deposits, swamp and marine sediments. The coastline is characterized by muddy, sandy, and rocky coasts, and mangrove coast. Ground Penetrating Radar (GPR) records, show that subsurface geological condition of northern part of Semarang is coastal alluvial deposit and in the south is volcanic rocks. The aims of this this research is to determine land subsidence by levelling measurement in 2005 in Tanjung Emas Harbour area built on 1995. During ten years, there are various land subsidance in this area: in Coaster Street (21 – 41 cm), container wharf (62 – 94 cm), north breakwater (64 – 79 cm), west breakwater (74 – 140 cm), east groin (76 – 89 cm), and stacking area ( 77 – 109 cm). According to this research, it is concluded that one reason causes of flooding in this area is land subsidence.