ABSTRACT
A cycle occurring with great frequency in the Huai valley was flood, followed by weed overgrowth, which in turn provided the environment for waves of locusts. During the last 2,000 years the Huai River valley has changed significantly. By the end of the Ming dynasty ecological degradation was well underway, leading to the impoverishment of the Huai valley by the beginning of the twentieth century. China’s first large-scale irrigation works first appeared in the Huai valley during the Warring States period. By the Spring and Autumn period control and development of water systems became intimately tied to political processes. During the Sui and Tang dynasties imperial governments became increasingly dependent upon the growing prosperity of the agricultural regions of the Huai and Yangtze valleys. At the beginning of the Sui the canal system was largely completed. Hydraulic conditions in the lower Huai valley in northern Jiangsu Province deteriorated significantly by the nineteenth century.
