Urban Flood Control Considering River Basin

本研究从流域包括城市区域的角度来研究一次城市洪水及其治理。对近期城市洪涝灾害的发生机理进行了研究，探讨了由工程措施和非工程措施组成的防洪体系。主要研究成果如下：1.建立了考虑水坝控制的分布式降雨径流预报系统。试验模拟结果表明，该系统能够定性和定量地再现大坝预泄、削峰、群调等洪水调度方式。2.建立了由山区、河网、污水管网和流域四个子模型组成的暴雨淹没流模型，并将其应用于日本内牙河流域。通过将计算结果与实际淹没面积或河网水位进行比较，验证了该模型的有效性。并利用相似模型对小型蓄雨设施防洪效果进行了研究。研究结果表明，它们可以减少重现期小于50年的降雨淹没面积。3.建立了能够同时处理城市地面和地下空间淹没的蓄水池模型。模型中使用了连续性方程、动量方程和液滴公式。将该模型应用于日本福冈市，对1999年福冈市的洪水进行了模拟。计算结果与实际记录吻合较好。

This study treats an urban flood and its control from the viewpoint of river basin including urban area. The mechanism of recent urban flood is studied and the suitable flood control system constituting structural and non-structural measures is discussed. The main results obtained are as follows.1.A distributed rainfall-runoff prediction system is developed considering flow regime control by dams in the Yodo River basin in Japan. The test simulation results show that the system can reproduce qualitatively and quantitatively flood regime control by dams such as pre-release, peak cut and group operation.2.An inundation flow model by heavy rainfall is developed which consists of four sub-models (mountainous area, river network, sewerage network and drainage basin) and applied to the Neya River basin in Japan. The validity of this model is confirmed by comparing the numerical results with the actual inundation area or the water level of the river network. Also, by using the similar model, the effects of small rain storage facilities for flood control are studied. It is found that they can reduce the inundation area for rainfall whose return period is less than 50 years.3.A storage pond model is developed which can treat inundation of both ground and underground spaces in urban area. The continuity equation momentum equation and drop formula are used in the model. The model is applied to Fukuoka City in Japan, and Fukuoka flood in 1999 is simulated. The computation results show good agreement with the actual record.