低平地河川流域における都市域の氾濫水理モデルの開発

Abstract

本報では, 都市域で頻発する内水氾濫に着目し, 山地からの流出, 河川網の洪水流, 堤内地の氾濫流, および下水道による雨水排水過程を表現することのできる総合的な氾濫解析手法を提示するとともに, それを低平地河川である寝屋川流域に適用した。その際に, 治水緑地, 流域調節池, 排水機場などの各種治水対策施設も考慮に入れた。その結果, 本モデルにより都市域の内水氾濫機構が適切に表現できること, および豪雨時の対象域の危険性が確認された。

Recently in Japan, inner water inundation occurs frequently in urban area. An inundation flow model, which treats runoff from the mountainous area, flood flow in the river network, inundation flow in the drainage basin and drainage through sewerage system, is developed in this study. In the application of this model to Neya River basin, a low-lying area, flood control facilities are also taken into account, such as flood control zones, regulating ponds and pump stations. Consequently, it has been found out that this model can express the inundation process in urban area and estimate the effectiveness of those flood control facilities.Keywords: Low-lying river basin; Inner water inundation; Inundation flow analysis; Unstructured meshes; Neya River basin