1975 年 48 巻 2 号 p. 128-135
This paper deals with remains of the Joni system, the grid-pattern land development of the Ancient Ages, located in the vicinity of Ashikaga City of the northern Kanto District. The original layout of the Joni is recognized in the area covering three ancient villages, Tanaka, Sukedo and Kakabo, on the both sides of the Watarase River.
Tanaka is situated on an alluvial fan, and conserved the original land allotment of the Joni system until fifteen years ago. Changes of watercourse of the Watarase River in the latter half of the sixteenth century destroyed the Joni structure, especially in the northern part, and that portion was separated from the rest of the village land by the river. A new irrigation channel was constructed right after that. Sukedo and Kakabo lie on flood plain in hilly area, and the flat land is used for paddy field as at Tanaka. The paddy field is irrigated by several tributaries of the Watarase River.
Existence of land patterns derived from the Joni system was confirmed in the area by consulting with old cadastral maps and other documents, and the former state of the Joni was restored as one unit stretching on both sides of the river. Most of the remains of the Joni system dealt with in this paper has been destroyed these sixty years.