令和2年7月豪雨による熊本県芦北町の浸水被害と学校及び保育施設の事業継続

令和2年7月豪雨では芦北町を流れる佐敷川等が氾濫し，町中心部で1500世帯を超える住戸被害が発生した．この水害で佐敷川沿いに立地する小，中学校や保育施設では0.1～1.6m浸水し，休校・休園を余儀なくされた．水害直後の2020年7月中旬から2021年3月に計3回，浸水痕跡調査とRTK-GNSS測量を実施し，計43地点で浸水深と標高の調査を実施した．また，2021年12月に教育委員会及び保育所を訪問し，事業継続方法と課題についてインタビューした．主要な河川である佐敷川と湯浦川の両流域を対象に平面2次元洪水氾濫シミュレーションを実施し，浸水過程を分析した．これらの結果をもとに浸水エリアに立地する学校・保育所の事業継続の課題と対策について考察した．

The Sashiki River was flooded by the flood disaster caused by the heavy rain in July 2020, and more than 1, 500 houses were flooded in Ashikita Town. Due to this flood, schools and nursery schools in Ashikita Town were closed due to flooding of 0.1 to 1.6 m above the floor. From July 2020 to March 2021, a total of three inundation trace surveys and RTK-GNSS surveys were conducted, and inundation depth and elevation surveys were conducted at a total of 43 points. In December 2021, we visited the Board of Education and the nursery school and interviewed them about business continuity methods and issues. A two-dimensional flood inundation analysis was carried out for both the Sashiki and Yunoura river basins, and the inundation process was analyzed. Based on these results, we considered inundation measures for schools and nursery schools located in inundated areas and proactive measures for business continuity.

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