Current Status of Land Subsidence in Japan

Hiroshi P. SATO


In Japan, land subsidence defined under the Basic Environment Law results from excessive pumping of ground water in area where soft ground lies. Subsidence area has generally decreased recently in Japan, but increases temporarily nation-wide in dry years. The current status of the subsidence is reported and the efficiency of monitoring subsidence with GPS (Global Positioning System) and SAR (Synthetic Aperture Radar) interferometry is examined in this paper.


1. Introduction
2. Current status of subsidence
3. Current major subsidence areas in Japan
  3.1 Subsidence in the Minami-Uonuma area of Niigata prefecture
  3.2 Subsidence in the Northern Kanto Plain area of Tochigi prefecture
4. Effective monitoring of subsidence with GPS and SAR interferometry
  4.1 Monitoring subsidence with GPS
  4.2 Monitoring subsidence with SAR interferometry
5. Conclusion