滋賀県湖北地区に位置する姉川・高時川流域は、地形の影響で豪雨時の氾濫流が大きく河川改修のみでは水害を避けることができないと想定される場所があり、市町界を越えた避難を念頭に入れた避難計画を検討する必要がある。本研究では、両川の合流地点に位置する虎姫町での避難計画検討の過程から、広域避難計画作成を支援する情報システムの構築を目的とする。まず、虎姫町民の水害リスクの認知、水害時の避難行動、広域避難に対する意識と平常時の生活行動についてアンケート調査を行う。この分析結果をもとに、マルチエージェントシミュレーション手法を用いた水害避難評価ツールを構築し、広域避難を含めた様々な避難計画に関して考察を行う。Ane and Takatoki River basin which is located in Kohoku area of Shiga prefecture is designated as "flood forecast rivers" by the prefecture's government, which is considered a river that can cause serious floods and damage to the area. In this research, we aim at structuring an information system which supports to create not only the small scale evacuation plan within Torahime town but also the large scale one across the administrative boundaries. First, we investigate the flood risk in the area and compare the two evacuation plan: the small scale and the large scale. Next, we investigate the flood risk cognition of Torahime citizens and what kind of evacuating action they take when a flood happens. Then we can structure an evaluation tool for the flood evacuation which applies multi-agent simulation method, and examine various kinds of evacuation plans including the large scale evacuation.