The Single Whip Law and Pooling Head Taxes into Land Tax stipulated that corvée labor would no longer be levied, yet in practice it was still imposed. Sedan-chair bearers, postal-station couriers, and the like all counted as corvée labor. The prosperity of the Beijing-Hangzhou Grand Canal began in the Sui dynasty, while Emperor Yang of Sui's conscription of common laborers was also regarded by later generations as a form of tyranny.
The Beijing-Hangzhou Grand Canal could be divided into seven sections: the Jiangnan Canal, Inner Canal, Central Canal, Lu Canal, Southern Canal, Northern Canal, and Tonghui River. Yellow rivers often carried vast amounts of silt and sand. In the late Ming, river-control expert Pan Jixun proposed the method of "Water-Constraining Sand Attack," carrying out a major campaign to regulate the Yellow River. In other words, he used the river's swift current to wash away the sand, though this required extremely sturdy embankments. Though the water at Qingjiangpu was clear, silt still lay on the riverbed. While the silt could be used as fertilizer, it was difficult to conscript enough laborers, and the river mouth was shallow. Once sediment accumulated, it would obstruct grain ships, so frequent dredging was impossible. Fortunately, Qingjiangpu was close to Hongze Lake, whose waters could be diverted eastward to scour the channel.
A highly specialized task like maintaining waterways was not something the former commander of the Guangzhou Naval Forces could truly handle. In fact, although the previous Governor-General of the Southern River had been dismissed, he remained in office because his mother had died and he had returned home to observe mourning. Completing a waterworks project required everyone above and below to work together. In other words, the new governor-general's duties did not involve highly technical matters, and his subordinates knew this well. Whenever questions