水利開発と農村地域構造の変遷

台湾北部〓殻港地域を例にして

抄録

Since irrigation is the most important way to maintain rice planting agriculture in rural Taiwan, irrigation was thought to be a suitable criterion for the recognition of functional region. According to this point of view, the development of irrigation system in an area concerns the change in the function as well as the need of people to sustain life and their value system in that particular area. Reformation of the irrigation system will be resulted when any of the causes changed.
In order to clarify the change of the structure of the rural settlement derived from the functional change, Ko-Ko-Kang area was selected for a case study. This area is located at the western coast of Tao-Yuan Plateau, Northern Taiwan. It is occupied by the Chinese farmer since the eighteenth century. Because of the shortage of water resource, the farmers of this area depended on private pond irrigation or cultivated on rain-fed land for a long time. The development of irrigation was continued until very recently.
The functional change at Ko-Ko-Kang area can be divided into four stages:
(1) The establishment of San-Chi Canal irrigation area: This canal was constructed in 1794. Six villages along the stream were included into this private canal system. This group of villagers spoke Hakka, a dialect.
(2) The end of the private canal and the establishment of Ko-Ko-Kang Canal area: During the Japanese occupied stage, larger private irrigation systems were registered as public canals controlled by the Japanese official authorities. So was the San-Chi Canal. Because of the difficulties in managing this small canal, the official authority enlarged the irrigation area by constructing a new irrigation system for the other four villages in the area. These four villages were located at the south of the San-Chi Canal.
(3) The introduction of Kuang-Fu Canal: Since the water for the above mentioned canals were derived from the same stream, the problem of water resource was still retained. It was hard to harvest more crops in a year. Soon after the World War II, the Chinese government took the role as a coordinater in the irrigation organization. In 1950 the water of this area was supplemented by introducing surplus water from Tao-Yuan Canal, a big irrigation canal at the northern part of Tao-Yuan Plateau. The canal constructed for this purpose was called Kuang-Fu Canal. However, no great improvement was obtained and many rearrangements and reajustments were performeed. Finnaly, this area was organized into Tao-Yuan irrigation system and the whole plateau was united into a single irrigation system. The struggle in improving the water resource was no longer the work of village dwellers.
(4) Shi-Men Dam and the Ko-Ko-Kang irrigation area: In 1963, Shi-Men Dam System was built for replacing Tao-Yuan Canal. Irrigation function was expanded to cover almost the whole area of the plateau. Rearrangements of the irrigation system at the Ko-Ko-Kang area were also taken: the new area consists of villages of San-Chi Canal and Ko-Ko-Kang Canal less the four villages at the upper part of San-Chi Canal. In the meantime, the method of irrigation was improved. The result of this work not only modernized the irrigation ditch and method, but also changed the landscape of the area. Moreover, the arable land was increased by the lands reclaimed from many small private ponds.
The change of the interior structure of the villages is measured by the increase of population, by the population density on the arable land, and by the variation of arable land of the farmer. As a matter of fact, the change of the interior structure is correlated to the change and the acceleration of the irrigation system.