Author(s): Masato Sekine; Moe Yoshino; Naoki Takemura; Wataru Baba
Linked Author(s): Masato Sekine
Keywords: Urban inundation; Flooding in urban river; Numerical prediction; Torrential; Rainwater removal system; Inundation risk
Abstract: Rainwater removal system in Japan consists of the drainage network, the street gutter network, the pumping station, the water reclamation center and the urban rivers. The rainwater falls on the ground surface including roads goes into a drainage pipe through street-inlet tank or flows directly into the street gutter. And then the water is transported in urban rivers to the sea. Such a system is designed for rainfall intensity 50mm/h. in most urban area in Japan. Recently extreme weather become more remarkable in Japan, as a result of global climate change. Therefore the magnitude of typhoons become larger. And more serious inundation occurs due to a formation of linear rain band. The countermeasures come to be the urgent problem. The final goal of this series of study is to evaluate inundation risk in major cities in Japan, one of which is the Tsurumi River basins of Yokohama and Kawasaki City by using "S-uiPS" (Sekine’s urban inundation Prediction System) developed by the first author. "S-uiPS" is the sophisticated and acurate prediction system which does not included any model parameters. Huge amount of data about all urban infrastructures is introduced in this computation; for example, road network, drainage pipes network, urban rivers, pumping station, underground reservoir, etc. As a result, time-series of digital maps of both inundation depth and river depth can been obtained just like video images. Such images can be the reliable information with high precision which should be used for mitigation.