らく田問題の整理 : 古代紅河デルタ開拓試論

Abstract

The purpose of this article is to criticize the view of ancient Vietnamese agriculture held by some Japanese historians of Vietnam that 'Lac Dien, ' or ricefields of Lac, described in the 'Giao Chau Ngoai Vuc Ky' quoted in the 'Thuy Kinh Chu, ' a Chinese geography in the 6th century can be identified with the tidal irrigation system presently used in 'Thai Binh' province in the Red River Delta. Part 1. From a comparison of this view with other opinions held by Vietnamese and French historians or geographers, and an analysis of the geographical situation and historical background of the tidal irrigation system in 'Thai Binh' province, it is evident that the basis of this view is a misinterpretation of French geographer P. Gourou's information on that irrigation system, and it is impossible to conclude that this system was used in the ancient Red River Delta. Part 2. With identification of the Red River's names in the 'Thuy Kinh Chu' with present Red River Delta geography, indicates that 'Giao Chi' province in the 'Han' Dynasty, which was composed of 10 or 12 counties, was bounded by the mountain area of 'Vinh Yen' and 'Bac Giang' provinces in the west, the 'Phu Ly' River-'Khoai Chau'-Sept Pagodes line on the south and the 'Dong Trieu' mountains in the east. Counties were not established in the lower delta or the 'Thai Binh' Delta. Part 3. Analysis of ethnographical and archeological data suggests that the reclamation in Red River Delta was accomplished by the introduction of the planting complex of fifth-month rice, tenthmonth rice and Aus-type rice, the first and last planted in lower-lying ricefields, for example in the backswamp, before the flood season, and the second planted mostly at higher places, such as hillsides, terraces and natural levees to avoid flooding. Furthermore, in the eastern part of 'Bac Ninh' province, where until the 19th century, the lower ricefields were frequently influenced by tidal movement, rice varieties highly resistant to salt were probably introduced on the mud flat of the river beach. The cultivation of these tidal areas might have attracted the attention of Chinese travellers. Part 4. A comparison of the description of 'Lac Dien' and the tidal areas in 'Giao Chau Ngoai Vuc Ky' with the 'Nam Viet Chi' quoted in 'Thai Binh Quang Ky' suggests that the identification of 'Lac Dien' with the tidal areas is a forced analogy to explain the meaning of 'Lac' as the ethnic name of old Vietnamese. In conclusion, the cultivation of the ancient Red River Delta involved not engineering method, but agronomic farming, so that basis of the ancient 'Lac Tuong' or Generals of 'Lac' and 'Lac Vuong' or king of 'Lac' must lie in other factors than the control of a tidal irrigation system.