State Management of River Dikes in Early China: New Sources on the Environmental History of the Central Yangzi Region.

While it is generally believed that the agricultural colonization of the middle Yangzi wetlands began in Tang-Song times, newly discovered texts show that the early Han state administered river dikes in the region. The texts, which were written between 192 and 121 bce, calculate dike sizes in order to estimate corvée requirements for dike maintenance and discuss the area of new farmland to be created. Our picture of the early history of the Yangzi region has been distorted by the northern focus of early texts, but archaeological discoveries are correcting this bias and suggest that the conversion of the Central Yangzi lowlands to farmland began many centuries earlier than previously believed. [ABSTRACT FROM AUTHOR]