Land subsidence hazard in Indonesia: Present research and challenges ahead

Land subsidence has become a significant silent hazard in the big cities across Indonesia that aggravates future sustainable development. Land subsidence hazards hard-hit Java as the most densely populated island. This paper reviews Indonesia's land subsidence hazards, particularly subsidence cases across the big cities on Java Island, Jakarta, Semarang, and Bandung. Generally, land subsidence research in Indonesia can be categorized into two broad focuses: monitoring subsidence rate and investigating land subsidence mechanism. This paper aims to present a comprehensive summary of the current status of land subsidence research in Indonesia and discusses the challenging issues encountered in research and mitigation measures. A qualitative literature review was used in this study for reviewed articles in the Google Scholar database published in Indonesian and English up to 2020. Land subsidence in Jakarta, Bandung, and Semarang is still ongoing at a high rate. Its mechanism is highly influenced by excessive groundwater withdrawal, although other natural and anthropogenic factors also play a part. This review proposes recommendations to alleviate the impacts of land subsidence hazards in Indonesia and for further research.