The density of the population on the nearly 132,000 square km, the total area of Java is very high and amounts according to this estimate in 1960 to 429 souls per square km, which compared with the density of the population elsewhere in the world must be thought very high. See table XII-3.
The data about the density of the population in the different countries are not exactly mutually comparable, as the data of all these countries are not of the same year. They date from the period 1950-1956. Though this difference in the dating of the different data exists, we are yet of opinion that this does not hinder the comparability in a considerable degree. More recent data were not at our disposal.
In this survey of data regarding the density of the population it is evident that the population density in the island of Java and Madura is among the highest in the world. Compared to countries with an almost equal area as Java and Madura there is not a single one with such a great density of population. A comparison with the three great territories of the world which have a high density of population: to wit Western Europe, India/Pakistan and the territory of Chine, Japan, Korea, Taiwan, shows that in these three densely populated areas the density is indeed lower but exists over a much more extensive area. The most densely populated countries in Western Europe (Belgium and the Netherlands) have a lower density. The most densely populated districts of India, along the river Ganges, among which the most prosperous province of Bengal, have also been included in table XII-3 and are less densely populated than the islands of Java and Madura.
Data concerning the density of the population in the diverse provinces of South-China, especially Kwangtung and Kwangsi were not at our disposal. Higher figures of population density than Java regard the Indian province of Delhi, the island of Singapore, the peninsula of Hongkong and the basin of the river Nile in Egypt. In the first three cases it concerns a very high density of population in a small area (1,500 square km and less) and includes a big town. The Nile basin in Egypt is smaller in surface than Java but more densely populated.
Table XII – 3.
Data concerning the density of the population in some countries in the period 1950-1956.
Arranged according to decreasing surface.
The island of Java with Madura in the three great provinces of this island has an unequal density of population. According to the data of the 1930 census and the official data of the authorities regarding 1956 the density of population is greatest in the province of Central-Java especially the southern part of this province. In the D.I. Jogjakarta which borders on the region of Central-Java, the density of the population is still higher again than in the province of Central-Java. The data have been placed in table XII-4.
Table XII – 4.
Survey of the population density in Java in the different provinces during the period 1930-1956.
The population density in the region D.I. Jogjakarta is exceptionally high, which is shown by these data. The number of inhabitants in the diverse provinces of the island of Java and Madura are obtained from the civil-registration of the kelurahans and ketjamatans, the incompleteness of which we have already assumed in chapter IV and V. these figures are probably lower than the real number of inhabitants. In the region of the D.I. Jogjakarta we see that the fertile slope of mount Merapi has a much higher density of population than the less fertile mountainous parts of this region. See chapter II, table II-5.
The relation between the fertility of the soil and the population was analyzed by Mohr (1945). As a demonstration-area to prove this relation he chose the area around the volcano Merapi. The most fertile soil types of Java are in the neighbourhood of volcanoes, which were active in the most recent geological period. The volcanic ashes of still active Merapi make the soil around this volcanic very fertile. Merapi, sent its ashes, sand and stones mainly in western and south-western direction. In the north the mountain Merbabu blocks the way. Mohr used the population figures of the census 1930 and compared the density in the different areas around Merapi with the fertility of the arable land of the same regions. He came to the following observations:
To the south and south-west, where the youngest streams of sand and rock came, the density ranged between 543 and 653. This concerns the 13 ketjamatans of Sleman, situated to the north of the city of Jogjakarta.
More to the south the rivers, which sorted out the young fertile soil ingredients, deposited that again as alluvial types of soil in the regions east and south of the city. These alluvial soils are more fertile and less stony than the region of north Sleman. The density in these regions: viz. The ketjamatans of Sleman to the east of the city and the greater part of the kabupaten Bantul, ranged between 840 and 900. The river Progo acts as a barrier on the west for the deposit of volcanic ashes and sand of Merapi. The density across river Progo, that is in the kabupaten Kulon Progo ranged from 378 to 512. Only the coastal plain of Kulon Progo, the soil of which is also of the alluvial type, shows a density of 669.
on the east in the region of the southern mountains no volcanic material of Merapi is deposited. The density in this region was in 1930 210-250.
In the region of Surakarta on the east and also in the region of Magelang on the north and west of the D.I. Jogjakarta, both of which are situated around the Merapi, the same strong relation between fertility of the soil and population density appeared to be demonstrable in the same way as in the D.I. Jogjakarta.
Mohr concluded: “All depends on the volcanic products, on the soil; and rivers act as frontier lines even in the matter of density of population.”
Looking at the differences in density of population in the various kabupatens, the fertility of the ground seems the deciding factor for their explanation. As soon as the necessary food can be found, clothing and housing too appear to be easily arranged, in such a tropical climate, where the demands made on clothing and house by the population are not high.
This very high population density in the region of the D.I. Jogjakarta raises the question: How do all these people find a living in this area? In working out the data of the census 1930 concerning the occupational activities, it appeared that the greater part of the occupational people were active in arming. In the region of the D.I. Jogjakarta this was in 1930 42% of all persons with an occupation. In the province of Central-Java in 1930 56% of the persons with an occupation were farmers. Because in the region of the D.I. Jogjakarta in 1930 there were a great number of sugar estates, where 10% of all persons with an occupation were working, the figure for the D.I. Jogjakarta is lower than that of Central-Java. In the period after 1942 all these 16 sugar plantations in the D.I. Jogjakarta have disappeared. As the people counted were allowed to give only one occupation, viz. the most important, the percentage of the persons with an occupation, who beside their main occupation at the same time were active in agriculture, is not known. As the greater part of the population are still active in the agriculture, we would like – as far as the available data allow this - to study the agrarian circumstances in the area of the D.I. Jogjakarta and to investigate if the population of Java increases more rapidly than the means of subsistence. Has perhaps the population in the D.I. Jogjakarta and of the island of Java and Madura already arrived at the extreme limit drawn by the available amount of food stuffs?