This study clarified the characteristics of irrigation system of reclaimed land in the early 19th century on fan tableland in Kashobara, southern part of Saijo Basin, Hiroshima, SW Japan based on physical geographical and literature historical methods. The most important to open the reclaimed land on fan tableland for rice fields in those days was to obtain sufficient water for agriculture through a newly-built irrigation system. I identified the relationship the dirrigation system and landform using the 5m grid Digital Elevation Model, air photos and mapping of irrigation pattern by handy GPS. Descriptions of official documents relating the reclaimed land written by the chief of village, and information of detailed drawings of planning of the reclaimed land in those days, provided us to understand the then planner's intention to collect and distribute the waters to cultivated land on tableland. This fact contributed to development of transdisciplinary lesson between geography and Japanese history for school education.