Physiographical environment on the lower Kumozu plain before tenth century.

Abstract

This micro-topographical study of the Kumozu River Plain in present-day Mie Ken, Japan, was undertaken primarily through investigation of boring samples. Careful scrutiny of the morphology of the alluvial plain reveals three major divisions: one portion being 1.5 to 2 m higher than the other, with a third which formed after an advance of the sea during the Holocene epoch. Historical geographical methods were employed, including an investigation of jori land division maps, revealing that the third most recently formed portion of the flood plain developed in two stages after the Yayoi era (approximately 300 BC-300 AD). New agricultural areas appeared in the 8th and 10th centuries AD, after the final development stage. There remains no trace of major seaward expansion along the Ise Bay coast line since the Yayoi era. Such expansion probably disappeared during a small rise in sea level during the 9th and 10th centuries.- Richard Louis Edmonds