Pan Jixun

Pan Jixun (潘季馴; 1521–1595), courtesy name Shiliang (時良), pseudonym Yinchuan (印川), was a Chinese scholar-official and hydrologist of the Ming dynasty. He was noted for his monograph Instant Overview of River Management (Hefang yilan [河防一覽]).

Pan was a native of Wucheng county (Huzhou nowadays), Zhejiang. He passed the provincial examination of 1550. He was made a judge in Jiujiang afterwards, and became the inspecting censor of Guangdong, director of education of the North Metropolitan Area, and undersecretary in the Grand Court of Judicial Review. By leaving Guangdong, he implemented the "fair tax arrangement for the hundred-and-tithing system" (junping lijia fa 均平里甲法) there. Later, he was appointed Right Assistant Censor-in-chief, and then Director-General of the Grand Canal (zongli hedao 總理河道), but he was obliged to resign and mourn his deceased mother soon. He returned to the position in 1570, and built low dyke (lüti 縷堤) from Xuzhou to Pizhou, which incurred criticism for hindering the tribute navigation, and he was demoted in the next year. Zhang Juzheng reinstated Pan in 1578. During that time he had constructed the Gaojia Dyke (高家堰) that made sure that the silt of the Yellow River was cleared by the waters of the Huai River. He was rewarded with the title of Grand Guardian of the Heir Apparent and promoted to Minister of Works, then Right Censor-in-Chief and Director of the Grand Canal (zongdu hedao 總督河道).

The Director-General of the Grand Canal since 1572 to 1574, Wan Gong's solution for the Grand Canal and the Yellow River is building dyke to confine and narrow a section of the watercourse, increasing the velocity of the current ensued, the current with higher velocity would carry more silt, so that the watercourse would discharge silt into the sea. Pan endorsed and generalized that, he summarized it in eight characters: "Entraining silt with confined current by building dykes" (築堤束水, 以水攻沙 in Chinese).

Pan proposed several suggestions towards the emperor of Wanli:

1. Fill breaches to keep the Yellow River follow its original course
2. Build dykes to avoid the river burst again
3. Repair sluices and dams to protect the Grand Canal
4. Build weirs to consolidate embarkment
5. Suspend dredging the estuary to reduce expenses
6. Let the proposal, recovering the defunct course of the Yellow River as a distributary to the sea, lie

During the early 1580, Pan became the minister of War in Nanjing, and then the minister of Justice. He request the emperor to relent and forgive Zhang Juzheng's bereaved family, which led him reduced to commoner status in 1584. Some four year later, the emperor permitted the Grand Secretary Shen Shixing to recall Pan.

Pan used liukun (柳輥, an equipment, usually more than 20 feet in diameter, and 150 feet long, put rod fascines to form a ring around a trunk draped with turfs to make, such a cylinder rarely be moved even in a rapid flow, supposedly) to plug gaps. Besides, he also argued that dykes should never be built as extremely long and continuous embankments. There were constituent dykes of the system. Dykes alongside of a river (lüti) would concentrate the water, parallel dams to these (yaoti 遥堤) would help in case the inner dams break, and transverse dams (geti 格堤) would enable silt to deposit. Later, he put forward that reinforcing the dykes with silt gathered in depressions, by diverting floods, and using silt levees to replace lower lüti, also.

However, his practice impeded the drainage of the Huai River and extended Hongze Lake, the city of Sizhou was submerged and the Ming Ancestors Mausoleum was threatened in the ensuing days. Thus he was censured and forced to resign soon after Shen's removal.