Editing Yellow River (section)

===Imperial times===
[[File:Ming Zuling.png|thumb|right|225px|The Yellow River and [[Huai River|Huai]] surrounding [[Si Prefecture (Huai valley)|Sizhou]] and the [[Ming Zuling]] in the ''[[Complete Library of the Four Treasuries]]'' edition of [[Pan Jixun]]'s ''Overview of River Maintenance''. By the time of the [[Qing-era]] edition, both had been entirely lost during the 1680 flood.]]
From around the beginning of the 3rd century, the importance of the [[Hangu Pass]] was reduced, with the major fortifications and military bases moved upriver to [[Tong Pass|Tongguan]]. In AD 923, the desperate [[Later Liang (Five Dynasties)|Later Liang]] general [[Duan Ning]] again broke the dikes, flooding {{convert|1000|sqmi|sp=us}} in a failed attempt to protect his realm's capital from the [[Later Tang]]. A similar proposal from the [[Southern Song|Song]] engineer Li Chun concerning flooding the lower reaches of the river to protect the central plains from the [[Liao dynasty|Khitai]] was overruled in 1020: the [[Chanyuan Treaty]] between the two states had explicitly forbidden the Song from establishing new moats or changing river courses.<ref name="Sedtime">Elvin, Mark & Liu Cuirong<!--sic--> (eds.) ''Studies in Environment and History:'' ''[https://books.google.com/books?id=tAxmcRXKpaUC&pg=PA554 Sediments of Time: Environment and Society in Chinese History]'', pp. 554 ff. Cambridge Uni. Press, 1998. {{ISBN|0-521-56381-X}}.</ref>

Breaches occurred regardless: [[1034 Yellow River flood|one at Henglong in 1034]] divided the course in three and repeatedly flooded the northern regions of [[Dezhou]] and [[Bozhou (modern Shandong)|Bozhou]].<ref name="Sedtime"/> The Song worked for five years futilely attempting to restore the previous course{{spaced ndash}}using over 35,000 employees, 100,000 conscripts, and 220,000 tons of wood and bamboo in a single year<ref name="Sedtime"/>{{spaced ndash}}before abandoning the project in 1041. The more sluggish river then occasioned a breach at [[Shanghu]] that sent the main outlet north towards [[Tianjin]] in 1048.<ref name="Treg"/>

In 1128, Song troops under the [[Kaifeng]] governor [[Du Chong]] {{nowrap|({{lang|zh|{{linktext|杜|充}}}},}} ''Dù Chōng'', d.{{nbsp}}1141) breached the southern dikes of the Yellow River in an effort to stop the advancing [[Jin dynasty (1115–1234)|Jin]] army. The resulting major river [[avulsion (river)|avulsion]] allowed the Yellow to [[stream capture|capture]] the [[Si River|Si]] and other tributaries of the [[Huai River]].<ref>{{cite journal |last1=Chen |first1=Yunzhen |last2=Syvitski |first2=James PM |last3=Shu |first3=Gao |last4=Overeem |first4=Irina |last5=Kettner |first5=Albert J |title=Socio-economic Impacts on Flooding: A 4000-Year History of the Yellow River, China |journal=Ambio |date=2012 |volume=41 |issue=7 |pages=682–698 |doi=10.1007/s13280-012-0290-5 |pmid=22673799 |pmc=3472015|bibcode=2012Ambio..41..682C }}</ref> For the first time in recorded history, the Yellow River shifted completely south of [[Shandong Peninsula]] and flowed into the [[Yellow Sea]]. By 1194, the mouth of the Huai had been blocked.<ref name="R. Grousset">Grousset, Rene. ''The Rise and Splendour of the Chinese Empire'', p. 303. University of California Press, 1959.<!--Although note material error in source's claim the river remained on only this path until 1853--></ref> The buildup of silt deposits was such that even after the Yellow River later shifted its course, the Huai could no longer flow along its historic course, but instead, its water pools into [[Hongze Lake]] and then runs southward toward the [[Yangtze River]].<ref>{{cite book |last1=Pietz |first1=David A. |title=The Yellow River |date=2015 |publisher=Harvard University Press |isbn=9780674058248 |page=50}}</ref>

A flood in [[1344 Yellow River flood|1344]] returned the Yellow River south of Shandong. The [[Yuan dynasty]] was waning, and the emperor forced enormous teams to build new embankments for the river. The terrible conditions helped to fuel rebellions that led to the founding of the [[Ming dynasty]].<ref name="Gascoigne"/> The course changed again in [[1391 Yellow River flood|1391]] when the river flooded from [[Kaifeng]] to [[Fengyang County|Fengyang]] in [[Anhui]]. It was finally stabilized by the eunuch Li Xing during the public works projects following the [[1494 Yellow River flood|1494 flood]].<ref name="eunuch"/> The river flooded many times in the 16th century, including in 1526, 1534, 1558, and 1587. Each flood affected the river's lower course.<ref name="eunuch">Tsai, Shih-Shan Henry.<!--sic--> ''SUNY Series in Chinese Local Studies'': ''[https://books.google.com/books?id=Ka6jNJcX_ygC&pg=PA200 The Eunuchs in the Ming Dynasty]''. SUNY Press, 1996. {{ISBN|0791426874}}, 9780791426876.</ref>[[File:Ma Yuan - Water Album - The Yellow River Breaches its Course.jpg|thumb|''The Yellow River Breaches its Course'' by [[Ma Yuan (painter)|Ma Yuan]] (1160–1225, [[Song dynasty]]). Flooding of the river has been the cause of millions of deaths.]] The [[1642 Yellow River flood|1642 flood]] was man-made, caused by the attempt of the Ming governor of Kaifeng to use the river to destroy the peasant rebels under [[Li Zicheng]] who had been besieging the city for the past six months.<ref>Lorge, Peter Allan. ''[https://books.google.com/books?id=SE2Gw8rjuXQC&pg=PA147 War, Politics and Society in Early Modern China, 900–1795]'', p. 147. Routledge, 2005. {{ISBN|978-0-415-31691-0}}.</ref> He directed his men to break the dikes in an attempt to flood the rebels, but destroyed his own city instead: the flood and the ensuing famine and plague are estimated to have killed 300,000 of the city's previous population of 378,000.<ref>[[Xu Xin (Judaic scholar)|Xu Xin]].<!--This order--> ''[https://books.google.com/books?id=GAAWkYBNu5sC&pg=PA47 The Jews of Kaifeng, China: History, Culture, and Religion]'', p. 47. Ktav Publishing Inc, 2003. {{ISBN|978-0-88125-791-5}}.</ref> The once-prosperous city was nearly abandoned until its rebuilding under the [[Kangxi Emperor]] in the [[Qing dynasty]].

The question of how aggressively flooding should be controlled, and whether it should be steered back to its original channels when it migrated, was a topic of controversy in the imperial court. Rival cliques made arguments based on budgetary, technical and strategic criteria. Geographer Charles Greer identifies two competing schools of thought on how to control the Yellow River. One, which he identifies as [[Confucianism|Confucian]], advocated containing the river between higher levees, thus maximizing the amount of river basin land that could be cultivated. The other, which he associates with [[Taoism]], favored lower levees separated by as much as 5–10 kilometers.<ref>{{cite book |author=Davis, Mike |title=Late Victorian Holocausts|publisher=Verso|pages=387–88|isbn=978-1-78168-061-2}}</ref> In one particular long-running debate during the 11th century reigns of the [[Emperor Renzong of Song|Renzong]] and [[Emperor Shenzong of Song|Shenzong]] emperors, when the river repeatedly broke its levees and migrated north and west, officials battled over whether expensive measures should be taken to return the river to its former channels. The Shenzong emperor ultimately decreed that the river be allowed to remain in its new course.<ref>{{cite book |author=Lamoroux, Christian|title=From the Yellow River to the Huai, chapter 15 in Elvin and Ts'ui-jung, Sediments of Time|publisher=Cambridge University Press|date=1998|pages=556–571|isbn=0-521-56381-X}}</ref>

Traditional [[flood control]] techniques made use of [[levee]]s, [[revetment]]s to absorb the energy of the water, overflow basins, drainage canals and [[polder]]s.<ref>{{cite book |author=Davis, Mike |title=Late Victorian Holocausts|publisher=Verso|page=388|isbn=978-1-78168-061-2}}</ref> Treatises on traditional flood control techniques were written by officials such as [[Pan Jixun]],<ref>''Overview on River Management'' {{nowrap|({{lang|zh|《河防一覽》}}}} {{transliteration|zh|Héfáng yīlǎn}}), 1590.</ref> who argued that joining branches of the river increased the water's power and this in turn increased its ability to flush sediment.<ref>{{cite book |author=Elvin, Mark and Su Ninghu|title=The Influence of the Yellow River on Hangzhou Bay since AD 1000, chapter 10 in Elvin and Ts'ui-jung, Sediments of Time|publisher=Cambridge University Press|date=1998|page=400|isbn=0-521-56381-X}}</ref> The difficult situation around the confluence of the Yellow River, the Huai, and the Grand Canal, however, still led to a major flood of the regional center [[Si Prefecture (Huai valley)|Sizhou]] and Pan's dismissal from court. Subsequently, the river's 1680 flood entirely submerged Sizhou and the nearby [[Ming Ancestors Mausoleum|Mausoleum to Ming Ancestors]] beneath Hongze Lake for centuries until modern irrigation and flood control lowered the water level enough to permit their excavation and the tombs' restoration starting from the 1970s.