Okawa Yuko

The purpose of this paper is to analyze the development of the Si chuan 四川 region from late Warring States to the Han 漢 period, focusing on alluvial fan water control systems. The western part of Si chuan was called "Shu" 蜀 in ancient times. Shu was conquered by the Qin Dynasty in the late 4 century. Li ping 季冰, the governor of Shu constructed a dam on the Du Jiang Yan 都江堰. It has been regarded that after its completion the Du Jiang Yan was used successfully for irrigation and Shu changed to a granary region, becoming a great source of strength for the Qin state and empire. The Du Jian Yan was constructed on the large chend Du plain. At the beginning it supplied water only to the central part of the alluvial fan at chen Du 成都 and Bi 〓. Many people immigrated to cheng Du in order to deveolp the plain. The Qin hydraulic system was limited to the chend Du plain, but during the Han period systems were built on every compound alluvial fan. The cities of the chuan Xi 川西 compound alluvial fan were located on the traffic route from Qin to chend Du. cities were located on 495m above sea level on the every alluvial fan, the height of cheng Du. Before the hydraulic systems were completed, these cities were very important for transportations. With the spread at water systems their function changed as every plain in chuan Xi developed as granary regions.