ABSTRACT
As China emerged from the classical feudal period in the third century b.c., unity was achieved for the first time when the First Emperor of the Ch’in dynasty conquered the various feudal states and brought the whole of China under one rule. The state of Ch’in grew strong and powerful in the valleys of the Chin and Wei Rivers, the territory of the present Shensi province in the heart of the loess region in North China. Political and socio-economic conditions may give rise to a rebellious movement capable of driving the ruling power out of the Key Economic Area and taking its place. The crowning success of the period was the Po Canal situated in the heart of the Key Economic Area of Kuanchung. It was a reconstruction of the Cheng-kuo Canal which had become silted up and practically useless. The Chengkuo Canal laid the foundation for the irrigation system in central Shensi for many centuries to come.
