The development of compound inundation analysis model in urban area and its application

本文研究的重点是城市内部径流引起的淹没。讨论了复合淹没分析模型的发展及其在各种淹没措施中的应用。这项研究的结果如下所示。1)建立了城区内径流淹没分析模型，分析了东海暴雨对名古屋市的淹没情况。研究结果表明，在综合排水系统较为发达的城市地区，地面向下水道的落流量评价对于洪水分析具有重要意义。2)探讨了考虑下水道系统的淹没分析模型在水害对策中的应用。主题是下水道系统对洪水的影响，污水的分布，等等。特别指出了对淹水期间卫生问题的检查结果。3)建立的分析模型同时处理了海区、河区和城区的水行为。利用本文所处理的分析模型对洪水与风暴潮的重叠进行了检验。从该研究中可以看出水闸对风暴潮的重要性。4)许多位于湾区的大城市都有联合下水道系统，在排水过程中受到河流水位（或潮位）的影响。本文研究了全球变暖导致的海平面上升对内流淹没的影响。因此，海平面上升小于1.0m对内径流淹没影响不大。然而，如果全球变暖导致降雨强度变大，海平面上升的影响就会显现出来。5)对分析网格中考虑微地平面的淹没分析模型进行了检验，验证了其适用性。

The focus of this study is inundation due to interior runoff in urban area. The development of compound inundation analysis model and its application to various measures for inundation are discussed. The results of this study are shown below.1) Analysis model for the inundation due to interior runoff in urban area was examined and inundation situation of Nagoya city due to Tokai heavy rain was analyzed. From this study, it is found that the evaluation of the fall flow quantity from overland to sewer was very important for inundation analysis in the urban area where combined sewer system developed.2) An application of the inundation analysis model considered sewer system to the measures for water disaster was examined. The topics are the effect of the sewer system to inundation, distribution of the filthy water, and so on. In particular, the examination results for the issue of hygiene during inundation were shown.3) The developed analysis model dealt with the water behavior in sea area, river area and urban area simultaneously. The overlapping between flood and storm surge was examined by using the analysis model treated here. From this study, the importance of the water gate for storm surge was shown.4) Many big cities located in bay area have the combine-sewer system and are affected by the river water level (or, tide level) in the drainage process. Here, influence of sea level rise due to global warming to the inundation due to interior runoff was examined. As a result, the sea level rise less than 1.0m does not give much influence to the inundation due to interior runoff. However, if rain intensity becomes high due to global warming, the influence of sea level rise appears greatly.5) The inundation analysis model considered micro ground level in analysis grid was examined and its applicability was verified.