STUDY ON INTEGRATED SEDIMENT MANAGEMENT IN AN ACTIVE VOLCANIC BASIN
Abstract
Mass and sediment movements in a river basin give us benefit as well as natural
disasters. Mass movement such as pyroclastic flows, debris flows, and landslides
causes often destructive sediment disasters to human being as a short term event. Also,
sediment movement such as erosion, bed load, suspended load and wash load
generates important problems on basin management such as reservoir sedimentation
as a long-term event. The mass and sediment movements give negative impacts on a
river basin and human being. This is an aspect of natural disaster in mass and
sediment movements. On the other hand, sediment deposits of bed load, suspended
load, debris flow, and so on are the potential sediment resources in a basin. Huge mass
movement brings excess sediment, but it is also one of the important sediment
resources. This is an aspect of natural resources in mass and sediment movements. In
sediment management for a basin, it is essential to consider these two aspects together.
In other words, sediment disaster management and sediment resources management
should be well synchronized. For example, sabo works and channel works for sediment
disaster mitigation influence a role of sediment as resources in a river basin.
Inappropriate sediment resources management could result in devastation of the basin
and produce many weak points for sediment disaster management. The sediment
disaster management can function only under an appropriate sediment resources
management.