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Volume 64 (1955)
- Issue 4 Pages 121-
- Issue 3 Pages 71-
- Issue 2 Pages 31-
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Volume 64, Issue 4
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Tatsutaro HIDAKA, Reiko KAWAI1955 Volume 64 Issue 4 Pages 121-134
Published: December 30, 1955
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSTo discuss population problems, it is very important to grasp the geographical distribution of various factors pertaining to the population phenomena. In this paper the cartographic representation of absolute and relative distribution of the population-as these are the most fundamental facts of the population problems-are treated.
This study has been done accompanying with the compilation of the “Population, Japan, series of Geographic Maps of Japan” (1 : 800, 000) No. 7, published by the Geographical Survey Institute, Ministry of Construction.
Referring to various population maps which have already been made in many countries, the writers made tentatively various sorts of maps showing population distribution, particularly for the scale of 1 : 800, 000. So, simultaneously, the writers had to try to clarify the expressive ability of this small scale map.
Here the writers tried to do some consideration about the distribution maps as follows :
Fig. 1 Population Distribution : In this map the population distribution is represented by dots of uniform size. Each dot represents 500 persons. The size of dots and the given quantity of each dot are determined after some trials. The placing of dots must be done with an understanding of the distribution of population.
In order to place each dot on proper point, the writers used the “Land Use Map” of the same scale
Fig. 2 Urban Population : This is one of trial cases for representation of urban population by shares. Urban population was calculated as follows : Urban population, = (total population of the city) × (urban population ratio) Urban population ratio= {(total of employed pop.) - (agricultural pop.+forest and logging pop. +fishery and aquaculture pop.+ mining pop.)} ÷ (total of employed pop.) The cubic root of shares is proportionated to the urban population. The rural population is represented by two sorts of dots varying in size and in given quantity, each small dot represents 500 persons and the other 2, 000 persons.
These spheres occupy much less space than the circles of corresponding size, so the writers tried to represent the population of agglomerated areas by this system, on the choropleth map of population density.
But the experiments to represent whole country in such way have not shown good result, because partially of the intricacy of representation and partially of the cartographic difficulty. Fig. 3 Distribution of Population Density : This is a choropleth map of population density.
To determine density classes, the representation of regionality is especially concerned, so as to one can recognize regional features of this country by the patterns of each class. While, the meaning of population density is especially great in rural area, so the lower classes are classified in narrower ranges. The area where the density is more than 1, 000 persons per 1 square k.m. may be treated as the urban area. The frequency of 11 classes is shown in Table 2.
Fig. 4 Isopleth Map of Population Density : This map shows the distribution of population density by isopleths. In this case isopleths are transformed from the choropleth map (Fig. 3) taking into consideration the topography and population distribution (Fig. 1). Boundaries between lowland and mountainous areas are represented by the dotted lined. The lowland areas are defined as where the inclination of the land surface is less than one twentieth. By representing the boundaries of lowland areas on this map, the various patterns of distribution of population density in these areas will be recognized.
Fig. 5, Fig. 6 These are isopleth maps of population density. Two drainage areas of Sai-Kawa and Niyodo-Gawa are chosen from the standpoint of view where the representation of population density is very difficult by the above mentioned methods.View full abstractDownload PDF (3214K) -
[in Japanese]1955 Volume 64 Issue 4 Pages 135-146
Published: December 30, 1955
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESS -
Fumio KURAMOCHI1955 Volume 64 Issue 4 Pages 147-160
Published: December 30, 1955
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESS3. The Relation of Dry Condition and Wet Condition
The writer tested the variation of bearing-power of rocks, under dry condition and wet condition.
The experimental rocks are sandstone, slate, limestone and quartz-diorite. And the writer made the test-piece of 5 cm cube from them.
The half of them was in dry condition and the rest was in wet condition which is steeped in water during 18 days. In these condition, the bearing-power of the test-pieces is tested and compared
Consequently, the variation of bearing-power in wet condition and in dry condition was found.
The result are as following :
limestone decrease about 4%
sandstone & quartz-diorite decrease about 10%
slate decrease about 30%
4. The Relation of Artificial Crack-surface of Test-piece and its Load-direction
The writer made the three kinds of test-piece with quartz-diorite, and made several artificial cracks for them.
And he studied the variation of the bearing power of test-pieces whose crack-surface is parallel or vertical to the load-direction.
Consequently, the bearing power of test-piece have a little difference according to the case of parallel or of right-angle.
And the case of right-angle was larger than the parallel case, about 8.8 %.
5. The Relation between Artificial Cracks and these Bearing-power
The writer made several test-pieces of 5 cm. cube, by slate, sandstone, limestone and quartz-diorite.
And made the artificial cracks of 14 stripes, with parallel and same interval on a surface of test-piece.
By means of them, he tested the bearing-power under the variations of crack direction and. road direction.
As the result, in the case of which the crack surface is parallel to road-direction, the bearing-power decreases, as the cracks increase.
In the case of right cross, the bearing-power increases as the cracks increase.
And on the reverse, the bearing-power is decreased by more increasing cracks.
6. The Relation of Bedding Plane and Load-direction
The writer made the 78 pieces of test-piece from three kinds of slate-rocks, and divide them into two parts.
And the bearing-power is tested in the two cases which the load-direction is vertical or parallel to the bedding plain.
As the results, the bearing-power was stronger about 3% in the parallel load-direction to the bedding plain than in the vertical direction.
Accordingly, the case of a bedding plain test-piece, it needs to decide either the load-direction is vertical or parallel to the bedding plain.
The writer, on this case, uses the test-piece which the load-direction is vertical to the bedding plain.View full abstractDownload PDF (2549K) -
[in Japanese]1955 Volume 64 Issue 4 Pages 161-166
Published: December 30, 1955
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSDownload PDF (1155K) -
[in Japanese]1955 Volume 64 Issue 4 Pages 167-168
Published: December 30, 1955
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSDownload PDF (279K) -
[in Japanese]1955 Volume 64 Issue 4 Pages 169-172
Published: December 30, 1955
Released on J-STAGE: November 12, 2009
JOURNAL FREE ACCESSDownload PDF (3265K)
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