The Yangtze is the longest river in China and Asia and is generally ranked as the world's third-longest river. Its main stem extends just over 6,300 kilometers, entirely within China. It rises in the Tanggula Mountains region of Qinghai Province and flows generally eastward into the East China Sea, draining a drainage basin of about 1.8 million square kilometers. The main stem, its tributaries, and connected lakes together form a river system spanning the plateaus of western China, the basins of central China, and the plains of eastern China. This system is also important for water supply, shipping, and hydropower. (cjjjd.ndrc.gov.cn)
Names and Headwaters
In ancient Chinese texts, “Jiang” or “Jiangshui” often referred specifically to the Yangtze. “Yangzi Jiang” originally designated a stretch of the lower reaches but was later applied to the entire river in foreign languages, giving rise to the English name “Yangtze River.” In Chinese, “Chang Jiang” is the collective name for the main stem, while individual stretches also have local names. (zh.wikipedia.org)
The Yangtze's headwaters lie in the heart of the Tibetan Plateau, within the Sanjiangyuan region. Conventional geographical accounts identify the Tuotuo River as its principal source stream. The Tuotuo originates at the Jianggendiru Glacier, southwest of Geladandong Peak in the Tanggula Mountains. Other rivers in the headwaters region include the Dam Qu and Chumar River. Because criteria for identifying a river's source and methods of measurement vary, published accounts do not always agree on the source's location or the river's total length. After the source streams converge, the main stem is known successively as the Tongtian River and the Jinsha River, among other names; downstream of Yibin, it is generally called the Chang Jiang. (forestry.gov.cn)
Main-Stem Sections and River System
The Yangtze is usually divided into upper, middle, and lower reaches, with Yichang in Hubei and Hukou in Jiangxi marking the boundaries. The upper reaches, upstream of Yichang, pass through plateaus, mountains, and the Sichuan Basin, with numerous gorges and a substantial drop in elevation. Downstream of Chongqing, the river passes through Qutang Gorge, Wu Gorge, and Xiling Gorge, collectively known as the Three Gorges. The middle reaches extend from Yichang to Hukou, where the river enters flatter plains. Below Hukou lie the lower reaches, where the river generally broadens before entering the East China Sea near Shanghai and Jiangsu. (cjjjd.ndrc.gov.cn)
Major tributaries include the Yalong, Min, Jialing, Wu, and Han rivers. Dongting Lake receives water from the Xiang and Yuan river systems, among others, while Poyang Lake receives water from the Gan River and other systems. Both lakes are connected to the Yangtze's main stem. Some stretches of the middle reaches feature pronounced meanders and extensive floodplains, and exchanges of water between lakes and river channels are an important part of the region's hydrology. Long-term sediment deposition in the lower reaches has formed the Yangtze River Delta. Flow at the estuary is influenced by both upstream inflow and tides. (cjjjd.ndrc.gov.cn)
Hydrology, Floods, and Droughts
Precipitation in the Yangtze basin is unevenly distributed over time and space. Rainfall in the upper reaches is generally more concentrated in time than in the middle and lower reaches, and some areas also experience significant autumn floods. Rainfall generates surface runoff that enters the river network, causing seasonal variations in the main stem's discharge. The timing and combination of flood peaks from different tributary systems also influence how floods develop in the middle and lower reaches. (rmcjzz.cjw.cn)
Stream gauges at Yichang, Hankou, Datong, and other locations monitor conditions along the main stem. According to records from Datong for 1950–2010, the long-term mean discharge was approximately 28,400 cubic meters per second, and the mean annual runoff volume was about 895.6 billion cubic meters. These figures apply to a specific statistical period rather than representing a fixed volume of water every year. Severe floods occurred in both 1954 and 1998, while markedly low flows occurred in years such as 2006. (chongchuan.gov.cn)
Navigation and Water Infrastructure
The Yangtze has long carried passengers and goods between inland and coastal regions, connecting riverside cities such as Chongqing, Wuhan, Nanjing, and Shanghai with their hinterlands. Navigability varies with water depth, current velocity, gorges, and seasonal water levels, so channel improvements, port construction, and reservoir operations all affect transport capacity. (zh.wikipedia.org)
The Three Gorges Project, located at Sandouping in Yichang, Hubei, serves functions including flood control, power generation, navigation, and supplemental water releases. The Three Gorges hydropower station has a total installed capacity of 22.5 million kilowatts. Ship locks and a ship lift enable vessels to pass the dam, while the impoundment of the reservoir has improved navigation along some upstream stretches. Flood protection along the Yangtze does not depend on a single dam alone; it combines coordinated operation of multiple reservoirs with levees, flood diversion and storage areas, and other infrastructure. (ctg.com.cn)
Ecology and Conservation
The Yangtze's main stem, tributaries, and connected lakes form interconnected aquatic ecosystems with rich biodiversity. Representative animals include the Yangtze finless porpoise, Chinese sturgeon, and Yangtze sturgeon. Fishing pressure, water pollution, and habitat changes have affected aquatic biological resources. In its 2022 assessments, the International Union for Conservation of Nature classified the Chinese paddlefish as Extinct and the Yangtze sturgeon as Extinct in the Wild. (cjyzbgs.moa.gov.cn)
Beginning on January 1, 2021, a year-round fishing ban, provisionally set for ten years, took effect in key waters, including the Yangtze's main stem, major connected tributaries, large connected lakes, and designated areas of the Yangtze estuary. The ban prohibits commercial harvesting of wild fishery resources; some protected areas had already introduced fishing bans in 2020. The Yangtze River Protection Law of the People's Republic of China came into force on March 1, 2021, establishing provisions for basin resource conservation, water pollution prevention and control, ecological restoration, and related development and construction activities. (ndrc.gov.cn)