The Mid-Niigata Earthquake caused a lot of landslides and subsidence of reclaimed land used for residential housing. Landslide damage has occurred historically, and was notable following the Miyagi-ken offshore Earthquake in 1978 with widespread damage to reclaimed land in urban areas.
In 2006, Ministry of Land, Infrastructure and Transport revised the “Land Reclamation Act, ” which was promulgated in 1961, to retrofit and reinforce reclaimed districts against earthquakes. According to the revised Act, local governments have to implement risk assessment research on reclaimed land, and publish a risk-map of reclaimed lands. High-risk districts are designated as retrofitting zones. A new subsidy system involving both national and local governments promotes retrofitting and reinforcement projects for reclaimed land in these zones.
