Upstream
The upper reaches of the Yangtze River above Yichang in Hubei Province is 4,504 kilometers long and has a drainage area of ??1 million square kilometers. Across the first and second rungs of China’s geographical ladder. The Yangtze River originates from the Tanggula Mountain Glacier. The water systems above the Chumar River mouth of the Tongtian River are the source of the Yangtze River. The main stream of the Yangtze River down to Yibin, Sichuan is called the Jinsha River. After the Min River merges into it, it is called the "Yangtze River".
The main stream of the Yangtze River, also known as the "Sichuan River", runs from the mouth of the Minjiang River to Yichang, passing through the southern edge of the Sichuan Basin and the Badong Gorge.
Midstream
The main river channel of the middle reaches of the Yangtze River runs from Yichang City, Hubei Province to Hukou, Jiujiang City, Jiangxi Province, with a length of 955 kilometers and a drainage area of ??680,000 square kilometers. Among them, the section from Yidu City, Hubei Province to Chenglingji, Dongtinghukou, Yueyang City, Hunan Province is also called Jingjiang River because the Yangtze River flows through the ancient Jingzhou area.
The Jingjiang river is tortuous and the water flow is sluggish, causing a large amount of sedimentation. The river bed is increasingly raised, and the flood level can be more than 10 meters above the ground. It is the section of the Yangtze River that is most prone to flooding. There is a saying that "the Yangtze River is dangerous for thousands of miles." Jingjiang". In order to reduce the threat of floods, the Jingjiang Flood Diversion Project and the Lower Jingjiang Bend Project were built.
Wuhan, along the middle reaches of the Yangtze River, is the largest city in central China and one of the national central cities. It is also the administrative center of the Yangtze River Water Conservancy Commission, which manages the entire Yangtze River Basin.
Downstream
The Yangtze River is downstream from the mouth of Jiujiang Lake in Jiangxi Province to the mouth of the Yangtze River. It is 938 kilometers long and has a drainage area of ??120,000 square kilometers. The river section in Anhui is also called "Wanjiang River". It flows roughly northeastward until Nanjing, Jiangsu Province, and then turns eastward and enters Zhenjiang and Yangzhou. Therefore, the vast area on the right bank of this section has been called Jiangdong since ancient times.
This section of the river meanders between the hills of southern Anhui, central Anhui and Ningzhen and the plains on the north bank. There are often rocky rocks facing the river on the right bank. The riverbed narrows and then widens at the rocky rocks, forming an alternate pattern of wide and narrow. The node-shaped river bed. The section of the river below Tongling Datong is affected by the tide, the water is gentle, and the sandbar is exposed.
The main tributaries include Qingyi River-Shuiyang River, Chu River, Qinhuai River, etc. The Yangtze River is about 312 kilometers long from Zhenjiang to the Yangtze River Estuary. This section of the river that is about to enter the sea is also called the "Yangtze River" because there was a Yangzijin ferry in ancient times. The river section below Jiangyin is also called the estuary section. The river surface rapidly widens in a trumpet shape from more than 1,200 meters near Jiangyin to the east, and is as wide as 91 kilometers at the mouth of the Yangtze River.
The Beijing-Hangzhou Canal intersects with the Yangtze River in Yangzhou and Zhenjiang. 80 to 90% of the Huaihe River water flows into the Yangtze River from the north bank through the Beijing-Hangzhou Canal. Taihu Lake in the south of the Yangtze River is the third largest freshwater lake in China. The river basin is densely covered with rivers, forming a huge irrigation system and inland water transport network. Except for a small amount of lake water flowing into the Yangtze River through some rivers in Jiangyin and Taicang, most of the water flows eastward through the Huangpu River, the last important tributary of the Yangtze River, and merges into the Yangtze River at Wusongkou.
The Yangtze River carries about 486 million tons of sediment into the sea every year, forming the Yangtze River Delta with Zhenjiang and Yangzhou as its apex in the west, Tongyang Canal in the north, Hangzhou Bay in the south, Damao Mountain and Tianmu Mountain as its southwest boundary. Including parts of Jiangsu and Zhejiang provinces and the entire city of Shanghai, it covers an area of ??40,000 square kilometers. It is a vast plain with only a few low mountains standing like isolated islands on the plain.
The coastline here is straight, the water is yellow and muddy, and there is an intertidal shoal about several kilometers to tens of kilometers wide. Since the Holocene, the delta has advanced seaward by an average of about 40 meters per year.
Extended information:
Water volume
The Yangtze River is the richest river in China, with a total water resource of 961.6 billion cubic meters, accounting for approximately the total river runoff in the country. 36% of the river, which is 20 times that of the Yellow River. It ranks third in the world after the Amazon River and the Congo River (Zaire River) in the equatorial rainforest zone.
The Paraná-La Plata River in South America and the Mississippi River in North America, which are located in similar latitude zones as the Yangtze River Basin, have basin areas larger than those of the Yangtze River, but the water volume is much less than that of the Yangtze River. The former It is about 70% of the Yangtze River, and the latter is about 60% of the Yangtze River.
Due to the large population in the basin, the per capita water volume is 2,760 cubic meters, which is only 1/4 of the world's per capita water volume. The water resources characteristics of the Yangtze River are mainly reflected in the spatial and temporal distribution of river runoff. The surface water resources in the basin account for 99% of the total water resources; among the surface water resources, river runoff accounts for more than 96%.
River runoff during the flood season generally accounts for 70% to 75% of the annual runoff. The distribution of runoff areas is also very uneven. The water production per unit area is the smallest in the Jinsha River and Han River systems, and the largest in the Poyang Lake and Dongting Lake systems.
Reference: Baidu Encyclopedia-Yangtze River