Study on Formation of Huge Waves due to Landslide in a Reservoir

大约200年前的1792年，日本九州岛岛原半岛的Mayuyama发生了一次大滑坡，大约有15亿份沉积物滑落并流入有明湾。在这种情况下，山体滑坡产生了海啸等巨浪，浪高超过20米，沿海地区有1.45万人丧生。这场灾难是日本最严重的灾难之一。本项目在二维滑坡模型的基础上建立了二维海啸数值模拟模型，并应用于Mayuyama灾害。在滑坡模拟中，计算结果与有明湾地区滑坡终止后的时间实际最终形态、长度和高度基本吻合。在这种情况下，滑坡现象可能在触发崩塌后约100s结束，速度和厚度分别接近100m/s和30m。在波浪模拟中，通过与模拟结果和观测结果的比较，发现本文所引入的计算方法很好地再现了滑坡伴随的水位变化。

Almost 200 years ago, in 1792, a big landslide occurred at Mayuyama in Shimabara peninsula, Kyusyu island, Japan About 1.5 hundred millions of sediments slid and flowed into the Ariake Bay. In this case, the huge waves like Tsunami were generated by the landslide and the wave height became more than 20m and 14,500 people were killed in coastal area. This disaster is one at the most huge disaster in Japan. In this project, a two-dimensional numerical simulation model for Tsunami based on two-dimensional landslide model has developed and is applied to Mayuyama disaster. In the simulation of landslide, A result of calculation is closed agree with time actual final shape of the landslide after the termination, the length and the height in the area of Ariake bay. In this case, the phermomena of landslide might finish in about 100sec after the collapse was triggered, and the velocity and the thickness are almost 100m/sec and 30m respectively. And In wave simulation, according to comparison with simulation results and the observed one, it is found how well the calculation method introduced here recreates the change in water level which is accompanied the landslide.