Interdisciplinary and transdisciplinary collaboration is becoming increasingly critical for disaster risk reduction and climate change adaptation as climate change accelerates. The authors have been leading an international research project between the Philippines and Japan to demonstrate how interdisciplinary and transdisciplinary approaches can explore new solutions toward sustainable development under future climate change. The project aims to evaluate future climate change impacts through the development of hybrid water-related disaster risk assessment technology combining climate change, hydrological, agricultural, and socio-economic models; further, it aims to provide policy recommendations to support sustainable local economic development. As each model had been separately developed by project members, both interdisciplinary and transdisciplinary approaches were necessary to integrate the individual models into a single hybrid model and apply it to the target area. However, project activities were limited due to COVID-19, especially because of travel restrictions and the lack of face-to-face or on-site visiting opportunities. Hence, various measures were adopted to efficiently undertake project activities even under such circumstances. This study analyzes the interdisciplinary and transdisciplinary approaches used under the project, focusing on the process of team building, co-creation of solution-oriented and transferable knowledge, and its integration. The difficulties in each process during COVID-19, the needs for interdisciplinary and transdisciplinary approaches, the ways explored to manage these needs, and lessons are described.

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