Editing Yangtze (section)

==Geography==
[[File:Portrait map of China.jpg|thumb|right|250px|A topographical map of China depicting the Yangtze's steady course and the former route of the [[Yellow River]] south of Shandong to the [[Huai River|Huai]] mouth, after its stabilization by the Grand Eunuch [[Li Xing (eunuch)|Li Xing]]'s public works following the [[1494 Yellow River flood|1494 flood]]]]{{Additional citations|date=August 2024}}
The river originates from several tributaries in the eastern part of the [[Tibetan Plateau]], two of which are commonly referred to as the "source." Traditionally, the Chinese government has recognized the source as the Tuotuo tributary at the base of a glacier lying on the west of [[Geladandong]] Mountain in the [[Tanggula Mountains]]. This source is found at {{coord|33|25|44|N|91|10|57|E|display=inline|region:CN-QH}} and while not the furthest source of the Yangtze, it is the highest source at {{cvt|5342|m|ft}} above sea level. The true source of the Yangtze, hydrologically the longest river distance from the sea, is at Jari Hill at the head of the Dam Qu tributary, approximately {{cvt|325|km|mi}} southeast of Geladandong.<ref name="Winchester">{{cite book|last1=Winchester|first1=Simon|title=The River at the Center of the World|date=1996|publisher=[[Henry Holt (publisher)|Henry Holt]]|isbn=978-0-8050-3888-0|title-link=The River at the Center of the World}}</ref> This source was only discovered in the late 20th century and lies in wetlands at {{coord|32|36|14|N|94|30|44|E|display=inline|region:CN-QH}} and {{cvt|5170|m|ft}} above sea level just southeast of Chadan Township in [[Zadoi County]], [[Yushu Prefecture]], Qinghai.<ref>Wong How Man (2005) [http://www.cers.org.hk/index.php?option=com_content&view=category&id=27&layout=blog&Itemid=61 New and longer Yangtze source discovered.] {{Webarchive|url=https://web.archive.org/web/20101028215804/http://www.cers.org.hk/index.php?option=com_content&view=category&layout=blog&id=27&Itemid=61 |date=October 28, 2010 }}</ref> As the historical spiritual source of the Yangtze, the Geladandong source is still commonly referred to as the source of the Yangtze since the discovery of the Jari Hill source.<ref name="Winchester" />

These tributaries join and the river then runs eastward through [[Qinghai]] (Tsinghai), turning southward down a deep valley at the border of [[Sichuan]] (Szechwan) and [[Tibet Autonomous Region|Tibet]] to reach [[Yunnan]]. In the course of this valley, the river's elevation drops from above {{convert|5000|m|abbr=on|sp=us}} to less than {{convert|1000|m|abbr=on|sp=us}}. Thus, over the first {{convert|2,600|km|mi|abbr=on}} of its length, the river has fallen more than {{convert|5,200|m|ft|abbr=on}}.<ref>{{Cite web |title=Yangtze River – The lower course {{!}} Britannica |url=https://www.britannica.com/place/Yangtze-River/The-lower-course |access-date=2023-05-08 |website=www.britannica.com |language=en}}</ref>

It enters the basin of Sichuan at [[Yibin]]. While in the Sichuan basin, it receives several large tributaries, increasing its water volume significantly. It then cuts through [[Mount Wushan]] bordering [[Chongqing]] and [[Hubei]] to create the famous [[Three Gorges]]. Eastward of the Three Gorges, [[Yichang]] is the first city on the [[Yangtze Plain]].

After entering Hubei province, the Yangtze receives water from a number of lakes. The largest of these lakes is [[Dongting Lake]], which is located on the border of [[Hunan]] and Hubei provinces, and is the outlet for most of the rivers in Hunan. At [[Wuhan]], it receives its biggest tributary, the [[Han River (Hanshui)|Han River]], bringing water from its northern basin as far as [[Shaanxi]].

At the northern tip of Jiangxi province, [[Lake Poyang]], the biggest freshwater lake in China, merges into the river. The river then runs through [[Anhui]] and [[Jiangsu]], receiving more water from innumerable smaller lakes and rivers, and finally reaches the [[East China Sea]] at Shanghai.

Four of China's five main freshwater lakes contribute their waters to the Yangtze River. Traditionally, the upstream part of the Yangtze River refers to the section from Yibin to Yichang; the middle part refers to the section from Yichang to [[Hukou County]], where [[Lake Poyang]] meets the river; the downstream part is from Hukou to Shanghai.

The origin of the Yangtze River has been dated by some geologists to about 45&nbsp;million years ago in the [[Eocene]],<ref>{{cite journal | last1 = Richardson | first1 = N.J. | last2 = Densmore | first2 = A.L. | last3 = Seward | first3 = D. Wipf M. Yong L. | year = 2010 | title = Did incision of the Three Gorges begin in the Eocene? | url = http://dro.dur.ac.uk/7236/1/7236.pdf | journal = Geology | volume = 38 | issue = 6 | pages = 551–554 | doi = 10.1130/G30527.1 | bibcode = 2010Geo....38..551R | s2cid = 129790601 | access-date = July 11, 2019 | archive-url = https://web.archive.org/web/20180723074400/http://dro.dur.ac.uk/7236/1/7236.pdf | archive-date = July 23, 2018 | url-status = live }}</ref> but this dating has been disputed.<ref>{{cite journal | last1 = Wang | first1 = JT | last2 = Li | first2 = CA | last3 = Yong | first3 = Y | last4 = Lei | first4 = S | year = 2010 | title = Detrital Zircon Geochronology and Provenance of Core Sediments in Zhoulao Town, Jianghan Plain, China | journal = Journal of Earth Science | volume = 21 | issue = 3| pages = 257–271 | doi=10.1007/s12583-010-0090-4| bibcode = 2010JEaSc..21..257W | s2cid = 129316271 }}</ref><ref>{{Cite journal|last=Jietao|first=Wang|title=Geomorphological Evolution of the Hengshixi Anticline of The Three Gorges Area Through Isobases: A Model of Yangtze River Capture|url=http://ijssst.info/Vol-17/No-43/paper17.pdf|journal=International Journal of Simulation: Systems, Science and Technology|volume=17|issue=4|pages=17.1–7|access-date=June 16, 2017|archive-url=https://web.archive.org/web/20190130102446/http://ijssst.info/Vol-17/No-43/paper17.pdf|archive-date=January 30, 2019|url-status=live}}</ref>