Historical evolution of flood control

In primitive communes and slave societies, the level of productivity is low. In order to survive, people can only adapt to the characteristics of water, seek advantages and avoid disadvantages, that is, live on weeds and choose hills. In feudal society, with the development of productive forces, simple engineering measures such as earth dikes were gradually adopted to prevent floods, and dike projects were gradually built on some rivers, and comprehensive flood control was also carried out in areas with rapid development. Such as Egypt, Babylon, China and other ancient civilizations have a long history of flood control. In 3400 BC, the first Pharaoh of the Egyptian menes Dynasty began to build dams on the Nile to protect the capital from floods. In the 20th century BC, Babylonia built dams on the Mesopotamian plain of the Euphrates-Tigris River for flood control and irrigation.

According to an ancient legend in China, during the flood of more than 2000 years BC, residential areas and cultivated land may be protected by dikes. In this paper, the method of dredging the river channel and leading the stagnation to flow into the sea is further adopted, that is, dredging the main river channel to introduce the flood overflowing the river bed into the sea. During the Warring States period, dikes were common in the lower reaches of the Yellow River, and all vassal States had long dikes to protect them. After Qin Shihuang unified China (22 1 year BC), he implemented the policy of "dredging Sichuan", that is, the scattered dikes in the vassal states in the lower Yellow River were transformed into unified dikes. Seawalls have been built in estuaries and coasts of Jiangsu and Zhejiang provinces to prevent moisture. By the Han Dynasty, great progress had been made in the technology of dike building, mouth plugging and canal opening, and comprehensive management of various measures began to appear. For example, in the Western Han Dynasty, Guo Chang dug three bends in the lower reaches of the Yellow River. In the Tang Dynasty, the river narrowed to the east of Yongji Canal in Haihe River Basin (later a section of Beijing-Hangzhou Canal), and a new waterway was added to the sea. To the west of Yongji Canal, a large number of depressions and lakes are used for flood detention. In the Ming Dynasty, Pan Jixun built four dams (namely overflow weirs) in Cui Zhen, Xusheng, Ji Tai and Sanyi in the lower reaches of the Yellow River to reduce floods. The construction of Gaojiayan in Huaihe River made the original swamp form Hongze Lake to store Huaihe River flood.

The theory of river regulation in ancient China has developed greatly since the Western Han Dynasty, mainly through the flood control practice of the Yellow River, such as Jia Rang's three strategies for river regulation and Zhang Rong's theory of water and sediment in the Yellow River. From the third year of Jingming in the Northern Wei Dynasty (502) to the third year of Zhengshi (506), Cui Kai suggested to set up a diversion port to prevent catastrophic floods. In the first year (1 10 1), Zuo He-ren put forward the method of remote dike flood control. In the second year of Taihe in Jin Zhangzong (1202), the "River Defense Order" was issued, which stipulated the laws and regulations for the defense and maintenance of the Yellow River during the flood season. In the first year of Yuan Dynasty (132 1), Shan Si compiled the Theory of River Defense, which described the specific technology of river engineering. In the 11th year of Zheng Zheng (135 1), when Jia Lu blocked the breach of the Yellow River levee, he took the measures of digging, dredging and blocking simultaneously. During Jiajing period of Ming Dynasty (1522 ~ 1566), Liu Tianhe summarized the Yellow River disaster as good siltation, good determination and good migration. In the 18th year of Wanli in Ming Dynasty (1590), Pan Jixun wrote "Overview of River Defense", expounding the thought of river management and the system and measures to strengthen dike maintenance.

1640 After the British bourgeois revolution, with the development of productive forces and the improvement of science and technology, modern science and technology were used in flood control, and large-scale flood control systems were built for rivers or regions, and large-scale river regulation projects and reservoir flood control projects were built. About 1800, Germany put forward a report on the regulation of the Rhine River, 1807 put forward urban and rural flood control planning, 18 17 ~ 1824, and four river bend cutting projects were built in Karlsruhe area. 1863, the United States established the Army Corps of Engineers, which is responsible for flood control, navigation, hydropower generation and river regulation projects of major rivers in the United States in addition to military projects. From 1870 to 1875, Austria built a flood control system in Vienna. Around 1885, France and Switzerland regulated the Rhine section between the two countries. 1877, Russia started the Kuban river basin flood control project. 1879, the federal government of the United States approved the establishment of the Mississippi River Committee under the Army Corps of Engineers and began to harness the Mississippi River. At the beginning of the 20th century, Dayton built five flood control reservoirs on the Miami River. Congress passed the first flood control law. In the late Ming Dynasty, China began to reinforce dikes in the lower reaches of the Yellow River with silt. Five dams in Guihai and ten dams in Gui Jiang were built in the lower reaches of Huaihe River in Qing Dynasty. 19 19 set up the Yellow River Hydrological Station in Xihe, Shan County, Henan Province and Luokou, Shandong Province. Hydrological observation began with scientific methods, and water level and flow were reported by telegraph. 19 15 years, Li Yizhi began to introduce western water conservancy theory and river defense technology, investigate and study the Yellow River, formulate the overall plan for harnessing the Yellow River, and cultivate and repair the Beijin levee. Because modern China was invaded by imperialism, domestic political and economic corruption declined, and science and technology were backward, so the theory and practice of flood control made slow progress.

Before and after World War II, science and technology entered a new stage of development, with rapid development of productivity, dam technology and reservoir construction. River regulation, due to large-scale reservoir construction, has entered a new stage of comprehensive utilization of water resources combining flood control with profit promotion, and reservoir flood control has also been greatly developed. For example, the Tennessee Valley in the United States has developed integrated management of flood control, shipping and hydropower generation. With the development of cities and large industrial areas, urban flood control has been strengthened. The flood control systems of major rivers in some economically developed countries have been basically completed, such as the Mississippi River in the United States, the Danube and Rhine Rivers in Europe, the Nile River in Egypt, Yinchuan and Dianchuan in Japan. The Soviet Union, Canada, India and other countries have successively built large-scale flood control projects after World War II. Because it is neither economical nor reasonable to completely adopt engineering measures for flood control, especially to prevent rare floods, non-engineering measures for flood control have been paid more and more attention. Since 1970s, some countries have gradually attached importance to the unification of economic, social and environmental benefits in river management and development.