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2017 年九州北部豪雨では，氾濫，土石流，斜面崩壊による被害が多く生じた。北野平野の氾濫は，自然堤防は非浸水か浅い浸水，後背湿地と旧河道は深さ1 m を越す浸水となった。氾濫時の水深は氾濫原の微地形を反映し教科書的な被害となった。三郡山地南端部では，表層崩壊や地すべり性崩壊起源の土砂が土石流化し，家屋，河川施設に多くの被害が生じ，また複数の学校が被災した。被災した各学校は周囲に比べ小高い豪雨災害には比較的安全とみなされる地形に設置されていた。しかし地形判読の結果，各学校は，未離水の地形では堆積，離水した地形では河川の側方侵食に伴う被害を直接受けており，また学校周辺の通学路も氾濫被害や土砂災害を被った。それら被害も学校の災害対応を困難にした。各学校での聞き取り結果から，山地に近い方が警戒対応は早いが，全児童・生徒下校に要する時間は，経路被災の影響で時間を要したことが分かった。また未離水の地形に注意する施設配置の重要性も分かった。したがって学校安全には，校地周囲の詳細な地形区分に加えて，通学路を含んだ包括的な地形区分の双方を必要とし，学校に止まらず校区全体を見据えた災害対応計画が求められる。

Field survey on the flood and sediment disaster which was happen in Tokachi and Tokoro River Basins in Hokkaido in 2016 is performed and the characteristics of the disaster is discussed focusing on levee break phenomena and disasters around bridges. Population density around rivers is low in Hokkaido. Hence, river width between right and left levees is very wide, even though flood discharge is small. As a result, long bridges over rivers from right levee to left one have not been constructed. On the other hand, short bridges over only main channel and connecting roads between levee and bridge are constructed. The connecting roads between levee and bridge decrease the river cross-section and increases the flood risk. Furthermore, land elevation on the floodplain tends to be lower than the river bed elevation in Hokkaido. As a result, the levee breaks without inundation phenomena was happen in Satsunai River. Additionally, flood water tends to return to rivers soon due to the high elevation of floodplain.

Debris flows were occurred in Yagi 3 Chome, Asaminami, Hiroshima on 20 August 2014. The geology around Asaminami area is granite which has many joints and is easy to be weathered. Hence, the permeability of the seepage is high and fine sediment is easy to be produced. In this study, the horizontal two dimensional debris flow model considering the both the laminar and the turbulence flows is developed. Subsequently, the model is applied to the debris flow occurred in Yagi 3 Chome, Asaminami, Hiroshima and discussed the applicability of the model. The differences of the horizontal inundation areas in the residential area between the simulated results and the field data are discussed and it was found that the horizontal distribution of the sediment deposition of the coarse material is reproduced well. When the houses are considered in the analysis, sediment deposited in the upstream region of the houses and the inundation area is reduced.

Drainage problem of inundated water on the lower Chao Phraya River in Thailand is introduced. Furthermore, drainage methods of inundated water on low flat land areas have been discussed by use of horizontal two dimensional bed deformation analysis. Construction of shortcut channel in the fully developed meandering channel can decrease the water surface elevation in the upstream area of the shortcut channel. Furthermore, drainage of inundated water from the irrigation channel to main channel will increase, if the connection points between the main flow and irrigation channels are located along the inner bank. Furthermore, a groin at the upstream of the connection points between the main channel and irrigation channels can decrease the water surface level at the connection points between the main and irrigation channels. As a result, drainage discharge of inundated water from the irrigation channel to the main channel increases.

In the autumn of 2011, the central part of Thailand along Chao Phraya River including some parts of Bangkok was inundated widely. More than 800 persons were killed and over 20000 km2 of farmland were damaged. Many Japanese manufacturing factories were also damaged. A field survey of the Chao Phraya River basin, Bangkok and its suburbs, and the Ayutthaya area, including Rojana industrial park are conducted from 25 November to 2 December 2011. The main purpose of this paper is to present an outline of the flood disaster in the central part of Thailand in 2011. First, sediment disasters are introduced and the problems which the lack of bank protection causes bank erosion and sediment floods lengthen the cleanup activity at the first stage of the recovery are criticized. Inundation disaster is also introduced and the problem which the irrigation canals are not designed to drainage inundated water is criticized.

In recent years, flood damage is occurring frequently by the increase in an impervious area and the change of a rain form under the influence of urbanization. therefore, The measure is performed established of a stormwater runoff control facility frequently. This research conducted flood analysis which considered the stormwater runoff control facilities in musashino city,by applying the NILIM2.0. Using the result, quantification of effects of the rain runoff control institution, and cost effectiveness was verified.

Mie Prefecture suffered from water-related disasters due to the Typhoon T200421 on September 29, 2004. Nine persons died, about 70 houses were destroyed by debris flows, slope failures or landslides, and more than 5,000 households were inundated. In this work, first, we analyze meteorological data and conclude that the heavy rainfall were caused by the existence of a stationary front into which the typhoon supplied warm humid air masses, and the orographic conditions over Mie. Secondly, we estimate the return period of t-hour (t＝1, 2, 3, 6, 12, 24 hours) precipitation at four locations in the prefecture. Finally, disasters due to landslides or debris flows in Miyagawa Village are overviewed and discussed. The above-mentioned meteorological analysis shows a very close relationship between the locations of heavy precipitations during relatively long terms (say 24 hours) and the occurrence of debris flows or landslides., 地球規模水循環システム予測値のスケールダウンと予測の不確実性低減手法の開発

本研究では都市化の進展や産業構造の変化に伴って、河川汚染リスクが複雑化・複合化している可能性について指摘する。その際、低頻度・甚大被害リスクに特に着目する。公表されているPRTR データベースを活用することにより、この種の複合リスクの特定とその潜在的危険性の評価のための研究アプローチと方法論を議論する。具体的には名古屋都市圏を対象に分析を行う。併せて、今後のデータ・情報の整備の必要性についても検討する。, Surface water from rivers has become more important in Japan over the last fewdecades. The water demand of households and industry has increased. This study showshow publicly distributed data (ministries, prefecture administrations and others) can beused to improve the assessment of the risk of surface water contamination includingtriggers and consequences of releases of hazardous substances to surface waters. Toachieve this, six analysis methods based on publicly available data are presented in thisstudy, helping to identify sites at risk, possible threats to these sites, gaps in monitoring, accident analysis and combinations of these for proactive measures. Low frequency, highimpact events like inundation or accidents are mostly neglected in the current attempts topreserve the water resources and to analyse the risk of contamination. Those cases arealso considered in this study.