Kwangkuk Ahn

Mathematical modeling of soil mixture flow surge and its application to coastal area

ABSTRACT The purpose of this study is to investigate debris flow surge that is set up with a numerical model using governing equations applied by the dynamics of a liquid–solid mixture. This model is performed by applying the finite difference method to display elapses of time. To measure the behavior mechanisms of the debris flow surge, the following are analyzed: the flow discharge, flow depth, and sediment volume concentration at the end of downstream channel. The flow discharge and flow depth only surge right after the debris flow reaches the downstream channel as the berm width shortens. In contrast, as the berm width lengthens, the flow discharge and water flow recede. As the berm width decreases, the sediment concentration shows a high concentration and a great height difference at the inflection point. Vice versa, when the berm width increases, an inflection point can be seen, but it reveals a low concentration and a low height difference. The numerical model of this study was applied to the coast of South Korea and analyzed. This study will provide information in predicting disasters caused by debris flow and in planning for various counter measures to prevent disasters.