On 29 June 2011 a slide into an existing stream channel initiated a debris flow that closed the national road for 1 day. The event resulted in four vehicles being buried and the loss of one life.
Events in Seoul were even more serious. There were 81 events occurred in a mountain located in the centre of Seoul in 27 July 2011 and resulted in a loss of 18 people and 50 people injured. Most of the event resulted from the mass movement of weathered soil overlain by bed rocks started from a road constructed at the top of mountain. These led to significant downstream erosion and a debris flow that travelled for 600~800 metres horizontally and 50~70 metres vertically. Many houses were significantly affected and a number of residences up to the second floor of a tower block were badly damaged. At the run-out a large number of cars that were entrained in the debris were destroyed.
Another event in Chuncheon near Seoul was less spectacular in its initiation, this being from a relatively small amount of material from a number of locations in two forks of a stream. However, material entrained from the road constructed in the mountain immediately downstream greatly enhanced the severity of the event and residences were badly damaged causing a loss of 15 people and several cars were destroyed as in the foregoing event. Between these and other events that occurred throughout South Korea from 29th July to 27thJune, 2011, 58 people were killed and more than 100 people were injured.
In the paper I describe these events and their causes before considering the actions that are desirable in terms of management and mitigation and considering the obstacles to progress, these particularly include the governance of land and infrastructure. In doing so I draw on experience of other events of the recent past, including those that have occurred in rural main road and urban environments in South Korea.
Preferred Presentation Type: Oral