Land subsidence characteristics of the Bandung Basin, Indonesia, as estimated from GPS and InSAR

Abstract The Bandung Basin is a large intra-montane basin surrounded by volcanic highlands, in western Java, Indonesia, inhabited by more than five million people. Based on the results of five GPS surveys conducted in February 2000, November 2001, July 2002, June 2003, and June 2005, it can be concluded that for the period of 2000 to 2005 several locations in the Bandung Basin have experienced land subsidence. Over this 5-year period land subsidence in a few locations reached a magnitude of about 70 cm, with a subsidence speed of about 1–2 cm/month. A similar rate of subsidence was also detected by the InSAR (Interferometric Synthetic Aperture Radar) technique during the period between June 2006 and March 2007. The statistical testing showed no strong correlation between GPS-derived land subsidence and registered groundwater extraction during the period of February 2000 to July 2002. The InSAR technique, however, detected significant subsidence in the textile industry area, which very large volumes of groundwater are usually extracted.