2024年1月1日の地震により被害を受けた能登半島において，2024年9月20日から23日にかけて記録的豪雨がもたらされ，再び甚大な災害が生じた．顕著な線状降水帯の発生により，半島北部の山間地において新たな斜面崩壊が群発するとともに，先の地震による崩壊地の侵食と崩土の再移動が生じ，大量の土砂と流木が河道に流入した．中下流域では，土砂供給による河床の上昇や，流木停滞による水流の迂回，地震隆起による北流河川の勾配減少などの要因が重なって，大規模な土砂・洪水氾濫が同時多発的に生じた．地震からの復旧途上であったインフラも再び破壊され，地震後に設置された応急仮設住宅も浸水し被災するに至っている．地震と豪雨および社会要因の重なった連鎖複合災害のリスクに，我々はどのように対峙すべきだろうか．地球科学・土木工学・人文社会学の協働による事象の機構と過程の理解，そして予測評価の高度化と実効的な社会還元方法の開拓が望まれている．本セッションでは連鎖複合災害現象の予測可能性や社会的対応策に関する知見を集約するとともに，開かれた議論の場を提供すべく，防災学術連携体との共催にて実施する．

The Noto Peninsula, which was damaged by the earthquake on January 1, 2024, was again hit by a record-breaking heavy rainfall from September 20 to 23, 2024, resulting in another devastating disaster. Pronounced rain bands provided more than 500 mm in total rainfall with intensity over 100 mm/h. Many new landsliding, as well as expansion of landslide rim, erosion of bare hillslopes, and reworking of debris caused by the previous earthquake produced large amounts of sediment and driftwood that flowed into channel networks mainly in the northern part of the peninsula. In the lower/middle reaches of the rivers, massive mud-water overflow caused severe casualties and house damage resulted from combined factors such as riverbed rise due to the sediment supply, water detour due to driftwood stacking, and possible drainage stagnation due to gradient reduction along the north-flowing rivers due to coseismic crustal uplift. Many infrastructures under reconstruction were partially destroyed again, and emergency temporary housing set up after the earthquake was also damaged by the flooding. How should we face the risk of such cascading disasters caused by the combination of earthquakes and heavy rains, with multidimensional social factors? We need to understand the mechanisms and processes of various disaster-related phenomena through collaboration of earth sciences, civil engineering, and social sciences, and to establish advanced methods of hazard assessment and disaster prediction and methods and effective social contribution methods. In this session, we expect researchers from a wide range of fields to present their research results for gathering knowledge and to have an open discussion forum regarding the predictability of the disaster chain and effective counter measures. This session will be co-organized with Japan Academic Network for Disaster Reduction.