Determining the initial time of anthropogenic subsidence in urban area of Indonesia

Abstract

Land subsidence in urban area of Indonesia like Jakarta, Bandung, Semarang, Pekalongan and others is quite well known today. Base on the geodetic measurements (e.g. Leveling, GNSS and InSAR) we can identify rates per year and also magnitude in certain periods. Nevertheless the initial time of its occurrence, especially a part influenced by anthropogenic causes, in many cases still remains unclear due to data limitation. This is an interesting research question because the initial time is crucial for determining total magnitude, while this total magnitude is important information for assessing the impact of subsidence. For example to understand the occurrence of tidal inundation, widening area of flood, calculating cost of adaptation, water table inversion, etc. we need to know quite exact the total magnitude of anthropogenic subsidence from its first initiation. Luckily we have long data measurements of subsidence in Jakarta, long data observation of groundwater in several urban areas and times series of images satellite that can be used for determining the initial time of anthropogenic subsidence in urban area of Indonesia. This paper will highlight how these data set answering quite well the research question.