On the Geographical Method of Land Utilization Survey

Abstract

The one-six hundredth cadastral maps of Japanese villages were prepared in or a little before 1873, but they are too incorrect to measure the area on them. Therefore it is now urgently necessary for our own country to make a modern correct maps of large scale and to survey land capability rind utilization in every acre by it. Such a map and the results of survey should be the most fundamental material to the improvement of landuse, and to synthetic land plannings. In the Land Division of the Japanese Resources Committee established in 1947 a Subcommittee was organized to research how the aerophotographs of one to 40, 000 are valuable for the understanding of real landuse, and to determine the method for the detailed land utilization survey in every piece of cultivated land to which the large scale map made from the developed aerophotograph should be adopted. This base map of one to 2, 500 in scale is to be made from the one thousandth aerophotograph by the development and amendment of distortion in aerophoto. The staffs of the Geographical Institute of Tokyo University and Tokyo Bunrika University were entrusted with the task to determine the method for the fine land utilization survey and to investigate land use in field under the method on that base map. They arranged to adopt the long fractional code method for the survey and its descriptions which Prof. V. Finch and D. Hudson practised and developed. Our survey items consist mainly of the observable phenomena in field; but they partly include the questionings to the farmer. The items are as follows: I natural elements- 1. the topographical location of each cultivated land. 2. the direction and degree of slope. 3. the duaration of sunshine. 4. the humidity of soils. 5. the color of soils. 6. soil texture. 7. the amount of gravel contained. 8. the depth of top soil. 9, the acidity of soil. 10. soil type. 11. the efficiency of irrigationa and drainage. 12. disasters (soil erosion, soil accumulation, and etc.) II human elements- 1. main sort of landuse 2. the sort of crop (intercrop, crop rotation, endicsing crop, etc.) 3. the ..width and direction of ridge, and the height of terrace. 4, tillage method. 5. weeding rnethod. 6. length of fallows. 7. the distance to the farmer's house. 8. the quantity and kind of manure given a year, 9. farmer's own land or not. 10. the age of land cleared or of land improved. 11. labor days a year. 12. the present degree of arable land. These items were checked to select the necessary elements in every piece of cultivated land in a section of Tsurukawa-mura of Tokyo Prefecture, included in Tama Hills, The fractional code was described in note-book. The results of the land utilization survey in Tsurukawa-mura may be described in another paper. The survey like this may be allowed only in sampling, for it consumes too much expenses, labor, and time. Then it is necessary to survey landuse in the smallest homogeneous unit area. For the demarcation of this unit area the thoughts of “Okotop or natlurliche Standortseinheit” are very sugestive. The survey items on this unit area were also devised by us but were not yet checked in field.