Beginning in the 1990s, surveying of potential debris-flow torrents was commenced. Results were released as they became available. During this time, Taiwan was hit by the 921 Earthquake, as well as typhoons Toraji, Nari, and Morakot, each of which caused alteration to terrain conditions. Related reports and regulations have undergone numerous revisions. In March 2009, a report on potential debris-flow torrents was released that provided a basis for future investigations and announcements. The administration system for disaster mitigation is nearing completion. In recent years, the Soil and Water Conservation Bureau has conducted studies on high-risk areas. These studies include: descriptions of the locality, current status for debris-flow torrents potential risk, potential damage to target area and possible response measures, and evacuation and intervention strategies. Based on these studies, evacuation route maps for debris-flow-prone areas were drawn up as a reference for local residents in the event that evacuation becomes necessary.