What development has Hongze Lake experienced?

Hongyang Lake is located in the northwest of Jiangsu Province, in the middle reaches of Huaihe River. It looks like a swan flying high. With a water area of 1805 km2, it is the fourth largest freshwater lake in China.

The predecessor of Hongze Lake Basin is the ancient thirsty lake. Due to the fault uplift of neotectonic movement, sediment deposition and the continuous advancement of land to the sea, Hooke retreated inland and divided into countless small lakes. The history books recorded the following: Pofu Creek, Baishuitang, Fuling Pond, Mudun Lake, Fangjia Lake and Chengzi Lake. Most of these lakes are connected by waterways. Yang Di took a boat to the south of the Yangtze River and passed a broken kettle stream. When it rained heavily, he renamed the broken kettle creek Hongzepu, hence the name Hongzehu. According to historical records, during the 280 years from 1575 to 1855, the Hongze Lake levee broke 140 times, and every time it broke, He Lixia, Jiangsu Province became a "Zeguo", especially in the 19th year of Kangxi (AD 1680). The Peking Opera "Offering Beads at Hongqiao" tells the fairy story that ancient Sizhou City was swallowed up by floods.

Hongze Lake is a large reservoir in Huaihe River Basin. The lake is a "suspended lake" because it relies on the eastern levee as a barrier and its bottom is 4 ~ 8 meters higher than that of the eastern plain. Hongze Lake levee, formerly known as Gaojiayan, was built in the Eastern Han Dynasty (about 200 AD). It turned out to be a non-dike, 30 miles long. Since the Yellow River captured the Huaihe River in 1 194, the lake surface has expanded and the role of weirs has become more and more important. Later, it was built many times in Yongle and Wanli of Ming Dynasty, and the earth embankment extended to Jiangba, which is the prototype of Hongze Lake levee today. In the eighth year of Wanli in the Ming Dynasty (A.D. 1580), the slope protection of the northern section of the levee was changed into a block stone, which was not completed until the sixteenth year of Qing Qianlong (A.D. 175 1 year), forming a situation that "the dikes and weirs are built and the cities and counties have the shape of the bottom of the kettle". The five dams of benevolence, righteousness, courtesy, wisdom and faith are the crystallization of the wisdom of our working people.

The average water level of Hongze Lake for many years 12. 10 m (Jiangba water level station), the water storage capacity of the lake is 2.44 billion cubic meters, the water level changes from 1.24 to 4. 14 m, and the average permanent water depth of the lake is only 135 m, which is the local maximum water depth.

Rivers flowing into Hongze Lake mainly include Huaihe River, Luantong River, Hesui River, Anhe River and Weiqiao River, most of which are distributed in the west of the lake. Among the rivers in Renhu Lake, the Huaihe River is the largest, with a maximum water volume of 26,500 cubic meters per second. The amount of water entering the lake accounts for more than 70% of the total water in Renhu Lake, which is the main source of water supply for Hongze Lake.

After the founding of New China, the people in the lake area have made great changes after decades of struggle. There are three river locks, two river locks and Gaoliangjian lock along the lake, and two ship locks, Jiangba lock and Gaoliangjian lock. In addition, the Hongze Lake levee was completely renovated, and the main irrigation canal, the second river and the new Huaihe River in northern Jiangsu were excavated, forming a hub project with simultaneous storage and drainage. Now Hongze Lake has become a large water storage reservoir in the lower reaches of Huaihe River. The annual output of the total irrigation canal is about 700 ~ 6543.8+0.4 billion cubic meters, and the irrigation area is expanded to more than 6543.8+0.8 million mu.

Hongze Lake is rich in aquatic biological resources, including Coilia ectenes, whitebait, carp, crucian carp, bream, platinum, grass, silver carp and mullet, as well as shrimp, crab, snail, clam and turtle. In 1950s, the highest annual output of aquatic products in Hongze Lake reached 42 million Jin, and today's output is only half of that at that time. In fish production, the output of whitebait and silver carp increased sharply, and the purchase of silver carp was 370,000 Jin in 19765438, and increased to 1977/0/0.7 million Jin,1938.

The aquatic plants in Hongze Lake are mainly distributed in the west of the lake, and the reeds are mainly distributed on the beach of Shuowei Road in Huaihe River, with a total area of about 60,000 mu. Reed is produced. In addition to directly managing the important raw materials of building materials and paper industry, many towns and villages in the lake area also use reeds to process reed mats and transport them abroad. In addition, the lake area also produces Euryale ferox and lotus seeds, and 197 1 acquired about 80,000 Jin of lotus seeds. Before and after the completion of the 1953 three-way switch, the distribution of large aquatic plants in Hongze Lake has changed greatly. Before 1953, there were many large aquatic plants on the lake, and lotus roots and gorgonian were abundant. It is said that "the head of a chicken and the horseshoe are food for half a year", which shows that their output is very large. After the completion of Sanhe Sluice, the water level of the lake increased obviously, and many beaches were flooded, which greatly reduced their distribution area. At present, most of the lakes have become open water except for the dense west of the lake.

The construction of water conservancy facilities has affected the aquatic resources of Hongze Lake to some extent, but the benefits of water conservancy are enormous. The problem now is how to take appropriate remedial measures to vigorously restore and proliferate aquatic resources in order to achieve the purpose of comprehensive utilization of lakes.