The extraordinary rainfall occurred in the small river basin （called Asano River） of Kanazawa city, Ishikawa prefecture middle part of Japan, July 2008. The center of the city was affected by severe damages by the b...The extraordinary rainfall occurred in the small river basin （called Asano River） of Kanazawa city, Ishikawa prefecture middle part of Japan, July 2008. The center of the city was affected by severe damages by the big flood due to the extraordinary rainfall. This study aims to make clear the probability of the extraordinary rainfall, the mechanism of the flood, the flood fighting activities etc. and to prepare to the future big flood. For this purposes, the analysis of probability of rainfall events is carried out by use of three methods. They are Gumbel method, Hazen plot and Momentum method. The return period is estimated 250 years. Next runoff analysis by use of the Tank model method was carried out. This model consists of several series of rainfall storage tanks. The upper tank corresponds to surface runoff and the lower tank corresponds to inter runoff and ground water runoff. The result shows that the observed and simulated discharge is similar. So the future flood by the extraordinary rainfall events is able to predict the amounts of the flood. Finally, the problem of the flood fighting activity is cleared for the safety of the people in the river basin.展开更多
文摘The extraordinary rainfall occurred in the small river basin （called Asano River） of Kanazawa city, Ishikawa prefecture middle part of Japan, July 2008. The center of the city was affected by severe damages by the big flood due to the extraordinary rainfall. This study aims to make clear the probability of the extraordinary rainfall, the mechanism of the flood, the flood fighting activities etc. and to prepare to the future big flood. For this purposes, the analysis of probability of rainfall events is carried out by use of three methods. They are Gumbel method, Hazen plot and Momentum method. The return period is estimated 250 years. Next runoff analysis by use of the Tank model method was carried out. This model consists of several series of rainfall storage tanks. The upper tank corresponds to surface runoff and the lower tank corresponds to inter runoff and ground water runoff. The result shows that the observed and simulated discharge is similar. So the future flood by the extraordinary rainfall events is able to predict the amounts of the flood. Finally, the problem of the flood fighting activity is cleared for the safety of the people in the river basin.
