SUMMARY

Land subsidence in a few urban areas (cities) of Indonesia, i.e. Jakarta, Bandung and Semarang, have been confirmed to be real phenomena. A few other cities, e.g. Medan, Surabaya and Denpasar are also suspected to experience land subsidence. There are four different types of land subsidence that can be expected to occur in the urban areas, namely: subsidence due to groundwater extraction, subsidence induced by the load of constructions (i.e. settlement of high compressibility soil), subsidence caused by natural consolidation of alluvium soil, and geotectonic subsidence. Land subsidence phenomena can be inferred from ground water level observations, estimated using geological and hydrological parameters, or measured by using geodetic techniques such as Leveling surveys, GPS surveys and INSAR (Interferometric Synthetic Aperture Radar). The geodetic techniques of Leveling, GPS Surveys and/or INSAR technique have been used to study and monitor land subsidence phenomena in Jakarta, Bandung and Semarang. In this paper, the capabilities and constraints of these techniques will be discussed by using the results obtained from the land subsidence study using Leveling surveys, GPS surveys and INSAR in Jakarta and the results given by GPS surveys in Bandung. The paper will be su