The eruptive activity caused great damage to the Shimabara Peninsula, especially Shimabara City and Fukae Town. The main factor that led to damage were debris flows and lahars, initiated by heavy rain which destabilized pyroclastic flow and ash debris previously deposited on the slopes. The Mizunashi basin, as well as the Senbongi district and parts of Shimabara were severely damaged. In addition, there was concern about the collapse of Mt. Mayuyama, which previously caused the 1972 disaster. In this eruptive activity, however, Mt. Mayuyama protected the center of Shimabara from the pyroclastic flows. In areas other than Shimabara and Fukae, there was ash fall depending on the wind direction, and at Kumamoto Airport, it had an impact on the arrival and departure of aircraft. Since the eruptions, heavy rains have frequently remobilised pyroclastic material, generating lahars. Dikes have been constructed in several river valleys to channel lahar flows away from vulnerable areas, and warning systems and evacuation plans have been developed and deployed. Among the areas destroyed by the pyroclastic flows, the area around Heisei Shinzan and the upper part of the Mizunashi River are still designated as warning areas because of the possibility of collapses of the mountain. The Mizunashi River was completely filled by earth and sand dredging. Dykes and bridges have been strengthened. In the downstream area, there was too much sediment, so a new residential area was built on the sediment. In addition, a roadside station Mizunashi Honjin Fukae was installed on National Route 251. On the coast, a landfill (Heisei-cho) was built by the earth and sand transported, and the Unzendake Disaster Memorial Hall, Shimabara Reconstruction Arena and Shimabara Workers General Welfare Center were built there. 10 million yen of support was provided to the residents with completely destroyed households. A new residential area – the "Nita housing complex" – was created on a hill for the victims. Various assistance was provided to prevent farmers from leaving the area. The Agricultural Improvement and Extension Center conducted interviews with all affected households (667 households) and held consultations for those who wished to resume agriculture until 1999. Training allowances were provided for those who plan to change the crops handled, and the reconstruction fund received a subsidy for the installation of a greenhouse or relocation costs. In parallel, the irrigation facilities in the affected areas were also developed. At the time of resuming agriculture in 2000, the