Method for determination of the hazardous area due to sefiment runoff

提出了泥沙径流危险区的预测方法，用于确定需要疏散或禁止居住的区域；在泥沙径流量预测方面，提出了可用于预测滑坡发生的时间和地点的渗流模拟方法。讨论了天然坝的规模和形态，以及天然坝崩塌产生的泥石流的过程。这些讨论和目前提出的泥石流过程线预报方法将很好地用于确定危险区域划定过程中泥沙径流的数量和质量。给出了泥石流和泥石流洪水和泥石流淤积的数值模拟方法。通过对实际的霍拉达尼泥石流和山体的分析，证明了这些方法的适用性。内瓦德尔鲁伊斯巨大的泥石流以及实验室实验。由于产生的泥石锥侵蚀和下游再沉积造成的危害是灾害风险评估中需要考虑的另一个重要问题，因此建立了一个数值模拟模型。提出了一种可以预测泥石扇表面和内部颗粒尺寸分布的方法。

This study aims to present the methods to predict the hazardous area due to sediment runoff, which will be used to determine the areas to be evacuated or prohibitted to live.In respect to the prediction of the quantity of sediment runoff, a seepage flow simulation method which is usable to predict the time and place of occurrence of landslides is preseeted. Scale and form of a natural dam produced by the inflow of slided sediment into the stream channel and the hydrohraph of a debris flow which is generated by collapse of the natural dam are discussed. These discussions together with so far presented debris flow hydrograph prediction method will be made good use in determining the quantity and quality of sediment runoff in the hazardous zone delineating processes.Numerical simulation methods to predict the flooding and deposition of debris flow and mud flow are given. The applicability of these methods are proves by analysing the actual Horadani debris flow and Mt. Nevade del Ruiz huge mud flow as well as the laboratory experiments. As the hazard due to the erosion of the debris cone thus produced and redeposition downstream is another important problem to be taken into account in the hazard risk assessment, a numerical simulation model is developed. A method which can predict the particle size distribution on the surface as well as inside of debris fan is also presented.