Huai River

The Huai River is a big river in China. It sits between two other large rivers. It starts in the mountains. The water flows into a large lake. Then, it runs into the Yangtze River.

The Huai River is a major river in East China. It sits midway between the Yellow River and the Yangtze River. The river starts in the Tongbai Mountain. It flows through Henan, Anhui, and Jiangsu provinces. The water flows into Lake Hongze. From there, it runs south into the Yangtze River.

Long ago, the river flowed into the Yellow Sea. But the land changed over time. The Yellow River often changed its path. It moved south and flowed into the Huai River. This brought a lot of silt, which is fine sand or dirt. The silt changed the shape of the land. It made new hills and lakes. These changes made it hard for water to flow. Now, the river often floods. Between floods, the area can be very dry.

Many smaller rivers join the Huai River. These are called tributaries. There are 15 main tributaries. They help water move through the area. People use the river to water their farms. The river is also part of the Grand Canal. This is a famous set of waterways in China.

The Huai River is a major river in East China. It sits almost halfway between the Yellow River and the Yangtze River. These two other rivers are the longest in China. The Huai River flows through several different places. It starts in the Tongbai Mountain in Henan province. Then it moves through Anhui and Jiangsu provinces. The river is a very important part of the land. It helps mark a line between northern and southern China.

Water moves through the river in a specific way. It flows into a large area called Lake Hongze. From there, the water runs south as the Sanhe River. It passes by Gaoyou Lake and Shaobo Lake. Finally, the river empties into the Yangtze River at Sanjiangying. Some water also travels through the Subei Irrigation Canal. This path leads to Biandan Port at the sea. Other paths connect the river to the Xinyi River system.

History shows that the river used to be different. Long ago, it flowed directly into the Yellow Sea. This happened through a wide and level area. However, the Yellow River began to change things in 1194. It moved south and flowed into the Huai River. This brought a lot of silt into the basin. Silt is fine dirt that settles in the water. By 1897, the land had changed quite a bit. New hills and lakes formed from all that dirt.

These changes made the river very hard to manage. Water could not flow easily to the sea anymore. The Second Sino-Japanese War made things even harder. During that time, the Yellow River flowed through a breach. This lasted for nine years and disrupted the system. Because of this, the river is known for flooding. Between 450 and 1950, it had many major floods. On average, there were 94 major floods every century.

Many smaller rivers join the main Huai River. These are called tributaries. There are 15 main tributaries in the system. Some of these are the Hong River and the Ying River. There are also 21 tributaries with very large areas. People use these waters to irrigate their farmlands. In Jiangsu, the river is part of the Grand Canal. This is a large network of connected waterways. It helps people move water and goods around the region.

The Huai River is a major river located in East China. It sits roughly midway between the Yellow River and the Yangtze River. These two other rivers are the longest in China. The Huai River covers a drainage area of about 101,000 square kilometers. It is a vital part of the region's geography. The river helps form the Qinling–Huaihe Line. This line includes the Qin Mountains and the Huai River. It acts as a geographical dividing line between northern and southern China. This boundary closely follows the January isotherm. An isotherm is a line on a map connecting points with the same temperature. It also follows the isohyet, which is a line connecting points with equal rainfall.

The river follows a complex path through several provinces. It originates in the Tongbai Mountain in Henan province. From there, it flows through southern Henan and northern Anhui. It also passes through northern Jiangsu. Much of the water pools into Lake Hongze. From this lake, the river flows southwards as the Sanhe River. This path takes the water through Gaoyou Lake and Shaobo Lake. The river eventually empties into the Yangtze River at Sanjiangying. This location is near Yangzhou. Other passages exist for the water to travel. One is the Huaihe Sea Entryway and Subei Irrigation Canal. This path passes through Huai'an and reaches the sea at Biandan Port.

There are several distinct ways the water moves through this system. In Jiangsu province, the river is interconnected with different waterways. This connection makes it part of the Grand Canal. This helps to circumvent or avoid flooding. Another separate course runs north through the Huaimu River and Huai Shu River. This route connects the Huai River system to the Xinyi River. The Xinyi River is part of the Yishusi River system. This system eventually exits into the sea at Guanyun in Lianyungang. These different channels show how the river system has been managed over time.

The history of the Huai River shows how much the landscape can change. Historically, the river entered the Yellow Sea at Yunti Pass. This was through a broad and level lower course. The river was used to irrigate many farmlands. It was the center of many canals and tributaries. However, the Yellow River began to change the area in 1194. The Yellow River repeatedly changed its course southwards. It began to run into the Huai River. This caused heavy silting in the basin. Silt is fine sand or clay carried by running water. The Yellow River returned to its northern course in 1897. By then, the geography had changed significantly. The silt created new high lands and lakes.

These geological changes caused serious problems for water flow. Water from the midsection could not flow easily into the lower section. At the same time, water in the lower section could not find an outlet to the sea. The situation became even more difficult during the Second Sino-Japanese War. The Nationalist government opened the southern levee of the Yellow River. They did this to check the pace of the Japanese invasion. The main stem of the Yellow River flowed through this breach for nine years. This further disrupted the entire Huai river system. As a result, water from the Huai River began to pool in Lake Hongze. Most of the flow now runs south towards the Yangtze River.

The river is famously vulnerable to flooding. Between the years 450 and 1950, the river experienced many major floods. On average, there were 94 major floods per century. The area also suffered from droughts between these flood events. Engineers have tried to solve these problems for many years. They have focused on building outlets into the Yangtze River and the sea. Currently, much of the flow enters the Yangtze via Lake Hongze. The North Jiangsu Main Irrigation Canal also diverts water. It follows the old historical course toward the sea. There are plans to upgrade this with a new parallel channel. Some former tributaries still carry water to the sea.

The Huai River system includes many different tributaries. There are 15 main tributaries that cover a large area. There are also 21 main tributaries with a catchment area larger than 10,000 square kilometers. A catchment area is the land where water collects and drains into a river. These tributaries include the Hong River and the Ying River. Other rivers include the Guo River and the Bai Lu River. These waterways are essential for the local environment and the people who live there.