The Arableland Density of Nakadori-lowland-belt in Fukushima Prefecture

Abstract

In Nakadori lowland-belt of Fukushima prefecture, several plains are contained, and the pattern of land is locally different. Therefore, from the measurement of 12 sheets of 1:50, 000 topographical map containing this lowland-belt, the writer made three distribution-maps and one density-table. With both the author described the arableland-density of this lowland-belt, and compared the degree of land-development of each plain. (1) The writer divides the lowland into six basins on topography as the following : - 1) Fukushima basin, 2) Motomiya B., 3) Koriyama B., 4) Yabuki B., 5) Shirakawa B., 6) Kujigawa valley. Fig. [1] shows these six basins. (2) According to Yoshimura's method (1933), the measurement was used, and three distribution-maps were written by many isopleth lines at an interval of 10%. Namely, Fig. [2] shows the distribution of paddy land-density. Fig. [3] shows the Dis, of field-density. Fig. [4] shows the Dis. of arable land-densty. Note : An arable land is equal to both a paddy land and a field. (3) The density of paddy lands is large in the northern district and small in the southern of lowland-belt. Especially the whole zone of Kikuta in Koriyama basin shows high degree of over 80%, on the other and, most of Yabuki basin is less than 20%. (4) As to the density of fields, the district showed with high density is more limited than that of paddy lands. The district of over 60% is the flood plain of the river Abukuma in Fukusima basin. Generally speaking, the density of fields is smaller than of paddy lands, but the density is large in north and is small in south as well as the case of paddy lands. (5) The density of arablelands shows higher degree than the above-mentioned two distribution-maps. But the pattern of the density as them. Namely, the regions of over 60% are occupied by most of Fukushima, Motomiya and Koriyama, and in the south of the lowland-belt the regions are only running along allvrial lowlands on the sides of main rivers. (6) In order to treat equally the topographical condition of each basin, the writer added up the whole area of paddy lands, fields, settlements, forests and waste land only in level lands except hills in basins and counted each density of every basin. Note : look No. 3 table. Making the degree of land-development of six basins compared, the author tried to mention them from high to low as the following : - In the first rank Fukushima-basin is, which shows the density of arablelands of 70.3% and has the smallest land undeveloped. In the second Motomiya and Koriyama basins are mentioned, and Kujigawa valley and Sirakawa basin are thirdly, and Yabuki basin is in the last. The arable land-density in the last basin merely shows 55.5%, and that of the undeveloped areas containing forests and waste lands shows the largest percent of all six basins.