Abstract
This paper simulates drainage of infuluent water caused by tsunami of the Nankai earthquakes. The target area is Okinosu, Tokushima. To simulate inlands water flow, we attempted 3 layers model, which is composed of ground, channel, and sewer. These 3 layers exchange water each other. Finally, water is drain to foreland by drainage pumps. In a simulation using the Ansei Nankai earthquake source model as input, if all drainage pumps works, the drainage finish about 16 hours after the earthquake. But, some water is not drained because of sunken place. If pumps that are top 3 of the drainage capacity don't work, the drainage finish about 72 hours after the earthquake. In this case, water which is not drained is increased. In a simulation using case 3 of Cabinet Office earthquake source models as input, because of big displacement in this area, certain boundary area becomes lower than sea level. So, water comes inland always.
