10:45 AM - 11:00 AM
[ACG42-06] Development of sediment runoff simulation system from mountainous areas and applying for disaster prevention works
★Invited Papers
Keywords:sediment runoff, simulation, disaster prevention, debris flow, sediment and flood damage
Debris flows often cause substantial losses of human life. Damage can be estimated using numerical simulation models that describe the debris flow process. Some models can be used to determine the influence area and possible effects of sabo dams. However, the existing simulation systems currently did not have efficient user interfaces, making it difficult for non-experts to run debris flow simulations without the aid of specialists. Furthermore, each of them was developed to express limited condition, so to apply simulations from steep mountainous streams to downstream housing area or to consider the effective countermeasures, even experts were required to use several models with complicated procedures.
We developed a system that produces one- and two-dimensional debris flow simulations and is equipped with a graphical user interface (GUI). The system is based on an integration model and employs one-dimensional simulations of gully areas and two-dimensional simulations of alluvial fan housing areas; it then considers mutual influences in boundary areas between gullies and alluvial fans. Sabo dams can be easily set on the gully, and sediment runoff such as sediment sheet flow and bed load can also have described in the model. Data can be input easily and viewed on the monitor, and users can see visualized images of a debris flow. The interface enables users to run a debris-flow simulation without expert knowledge of the model. Furthermore, the integration model enables advanced investigation of sediment runoff simulations and disaster prevention planning with the developed system for both expert and non-expert users.
We then improved the user interface part by incorporating a geographic information system (GIS) function making input and output operation even easier. For applying information from recent studies, the system can incorporate new advances in simulation parts. For debris flows containing much fine particles, we have found that some fine sediment behaves as fluid phase instead of solid phase from the turbulence caused by different size sediment mixing in debris flows. And setting the increased fluid phase density due to the sediment phase shift to fluid, simulation can express the debris flow behavior containing fine sediment with higher mobility comparing to stony debris flows. We also have found applying high resolution landform data and considering the building height, simulation can express the realistic debris flows behavior in housing area. Applying the system with suitable scenario setting, it showed sediment and flood damage caused by sediment flowing into residential areas several kilometers downstream from the steep landslides and debris flows occurring area due to heavy and long lasted rainfall.
In this presentation, author introduce development of sediment runoff simulation system from mountainous areas and applying for disaster prevention works.
We developed a system that produces one- and two-dimensional debris flow simulations and is equipped with a graphical user interface (GUI). The system is based on an integration model and employs one-dimensional simulations of gully areas and two-dimensional simulations of alluvial fan housing areas; it then considers mutual influences in boundary areas between gullies and alluvial fans. Sabo dams can be easily set on the gully, and sediment runoff such as sediment sheet flow and bed load can also have described in the model. Data can be input easily and viewed on the monitor, and users can see visualized images of a debris flow. The interface enables users to run a debris-flow simulation without expert knowledge of the model. Furthermore, the integration model enables advanced investigation of sediment runoff simulations and disaster prevention planning with the developed system for both expert and non-expert users.
We then improved the user interface part by incorporating a geographic information system (GIS) function making input and output operation even easier. For applying information from recent studies, the system can incorporate new advances in simulation parts. For debris flows containing much fine particles, we have found that some fine sediment behaves as fluid phase instead of solid phase from the turbulence caused by different size sediment mixing in debris flows. And setting the increased fluid phase density due to the sediment phase shift to fluid, simulation can express the debris flow behavior containing fine sediment with higher mobility comparing to stony debris flows. We also have found applying high resolution landform data and considering the building height, simulation can express the realistic debris flows behavior in housing area. Applying the system with suitable scenario setting, it showed sediment and flood damage caused by sediment flowing into residential areas several kilometers downstream from the steep landslides and debris flows occurring area due to heavy and long lasted rainfall.
In this presentation, author introduce development of sediment runoff simulation system from mountainous areas and applying for disaster prevention works.