Predictive Modelling of Land Subsidence Due to Groundwater Level Decline in Gedebage District, Bandung, Indonesia

Abstract

The Gedebage district in Bandung city has experienced a vast physical development in recent years. Previous geodetic studies showed that the area undergoes high-rate land subsidence. The subsurface soil of the Gedebage area has remarkably high compressibility, void ratio, and water content. A thick sequence of soft organic clay of 20-27 m exists, making the area prone to subside. As the district continues to develop, it is important to predict the future rate of land subsidence in the area. This paper aims to analyze the contribution of groundwater exploitation to the land subsidence rate. A combination of 1-dimensional Terzaghi consolidation analytical analysis and numerical modeling was employed in this study. Groundwater level data up to 2015 was used, and hydrostatic condition was assumed to occur in 1986. Results show that the Gedebage area has subsided as much as 161 cm since 1986. Modeling results are consistent with geodetic survey results. It is predicted that the land subsidence will slow down in the next 40 years, provided that the groundwater level remains stable.