Method of Making Population Density Map by Landform Division and Accumulated Result

Abstract

Intending to make a population density map based on the natural regional unit instead of the administrative one of Shi (city) and Machi (town) and Mura (village), we divide the territory of Japan into landform divisions and calculate the population density by each landform division. As for the elements which will be useful for establishing the natural regional units, we have to consider climate, soil, vegetation etc.. However, in case of Japan which belongs to the Circurn Pacific Orogenic Zone and whose lands are divided into many pieces of block mountains and small planes, landform should be considered having the first priority as the base of population distribution and suitable to represent the detailed regional differences of population distribution. Establishment of landform division The whole land is classified as following landform areas based on its morphology and developmental mechanism. mountain : mountain, volcano, hill land flat land : piedmont gentle slope, volcanic flank, upland, lowland When one kind of landform area is too large, we divide it into minor landform units according to the difference of form and construction material such as fan, delta, peat-bog or sand dune in lowland area, and maturely dissected mountain or elevated peneplain in mountain area. The areas of each landform unit is measured by using planimeter on the map of 1:200, 000 and decided by giving the necessary corrections. Calculation of population of landform unit Population of each landform unit is readjusted from the population of Shi, Machi and Mura illustrated in the population census. When the administrative unit is completely included in one landform unit, its population is simply tabulated, but when it extends over two or more landform units, its population is divided into each landform unit basing upon the number of dots found on the population map 1. Urban population The urban podulation living in the urban agglomerations with area of 0.25km2 or more is excluded in the tabulation of population of landform unit, because it spreads over the boundary of urban agglomeration and makes the population density of the whole unit up too high. The population of urban agglomeration is estimated by multiplying the definite coefficient as following classification getting from sampling to the total population of Shi, Ku (ward) and Machi. 1) Five major Shi 2) Shi with inhabitants of more than 100, 000 or established before 1940 except the five major Shi 3) Other Shi 4) Machi 2) and 3) are subdivided into two according to the area of urban agglomeration and population growth caused by amalgamation of Shi, Machi and Mura from 1950 to 1955. Map and appendix (See Fig. 1 and Table 1) The scale of the map is 1:800, 000 and the map covers the whole of Japan. There are three sheets in one set with 7 colors including boundaries of landform divisions, symbols of the kinds of landf orms and index number of landform units. Population density is presented in the map in grades from yellow, tan to dark brown tone by shading method. The situation and size of urban agglomeration are presented according to its size in its physical shape or definite round shape in brownish red. The base map which includes contour lines, limits of water body, administrative boundaries, settlements and place names are doubly printed in grey color. The appendix includes index number of landform divisions, place names, areas, number of inhabitants and population density, These were published as population census of Japan 1955, population maps of Japan 3. Population density by landform devision in JapanPopulation density by landform division of whole Japan and each district are shown in Table 2 and Table 3. Mountains and Volcanoes which occupy 61% of the whole land are almost low density areas, especially in a volcanic area.