In the Lake Biwa plain, there are several districts which the
jori-systems are not yet geographically reconstructed, although many historical researches have been made for this rural planning in ancient Japan. Inukami-gun is a case in point. However, it has become easier to reconstruct the system, owing to the recent and excellent study by Mr. Iyanaga on the two maps of antiquity. These are a sort of cadastral maps in 751 A.D. with respect to the manors of Todai-
ji. viz. Minuma-
sho and Heru-
sho, which originals are now in Shosoin's safekeeping.
The author has invesitgated the
jori-system of Inukami-
gun by means of the analysis of these worn-out maps, many cadestres in the Meiji era and the placenames related to the system etc. The result is indicated as the figure II & III. The designation of
tsubo (1
cho square, about 11.9 ares) was the Paralleling type and the first
tsubo begans as from the north-eastern corner of
sato (6
cho square, about 650 metres square) as the othre
guns in the eastern Biwa basin. And the
jo was reckoned from the northern boundary of
gun to the southern in its number, the
sato from the eastern to the western. In the
jori-system, the land is divided as a rule by lines running like a checker-work. The allotments of the paddy fields based on the system in this district had a direction of N 31°∼34° E along the lengthwise lines as in the cases of Echi-
gun and Kanzaki-
gun. In addition to the fact that the direction of land-division was common to all of the three
guns, one basic line of
jori was perhaps after the model of Tosando which was one of the main roads in ancient times. But we find some diversity and discrepancy between the designations of
tsubo in 3 guns. These facts tell that Tosando was constructed in the first place, the landdivision according to the
jori-system was performed secondly and finally the names of
tsubo, jo and
sato were given. The
jori-system was put in force typically in relation to paddy-fields which was situated on the marginal portion of the fan and the upper older deltas. In these lands, the fields were irrigated mainly from many springs at the fan margin. And the strips has generally a narrow, long form,
nagaji-typed (fig. 1). But becuse this district had belonged to the advanced region in ancient Japan, the fan was brought under cultivation in considerably earlier times. On the case, the irrigation canal “Ichinai” had played a large part. According to fig. II and fig. V which shows 3 head-to-margin profiles of the Inukami fan, we can find the
jori-typed paddy fields even in the middle area of the fan. The period that man setteles in this land, therefore, was not very later than that of the fan margins.
On the lakeward margin of the deltas, there are narrow marshy zone where we can'ot find any
jori-typed. However, by the above mentiond old maps, we understand that this marginal area was reclaimed in ancient times. Consequently, it is considered that in the course of 1200 years a diastrophic subsidence of the delta margins or a elevation of the level of the lake water occured. The change of the level of the water is measured vertically more over 2 meters.
抄録全体を表示