Urban Gravity Measurements for the Subsurface Mapping; Case Study Kaliawi

Abstract

Gravity method is a passive geophysical method that can measure and obtain subsurface models based on rock density. Gravity method can be done in urban areas to obtain information about subsurface model as a reference in making urban policies related to disaster mitigation and urban development based on earth potential. Gravity research was conducted in Kaliawi, Bandar Lampung. Kaliawi has many problems including dense settlements and slums, areas prone to floods and landslides and has limited availability of fresh water. Based on the Complete Bouguer Anomaly results, the western area of Kaliawi has a low anomaly (36.8-38.2 mGal) with lithology of sandy-clay sedimentary rocks. Whereas the eastern area of Kaliawi has a high anomaly (38.4-40.8 mGal) with tuff lithology and can be bedrock. Based on the gravity anomaly and lithology, the western area of Kaliawi is a landslide area and recharge area while the eastern area of Kaliawi is good for settlement because it has bedrock.