Flood control and flood prevention handwritten newspaper materials

(1) flood. A large flow in a short period of time and a significant rise in water level are called floods. Floods are often ferocious, flooding the beaches and levees, with great destructive power.

(2) Flood level. Divided by the frequency or return period of the flood. Frequency is the reciprocal of the repetition period.

General flood: frequency 20- 10%, return period 5- 10 years;

Great flood: the frequency is 10-5% and the return period is 10-20 years;

Great flood: frequency 5-2%, return period 20-50 years;

Extraordinary flood: the frequency is less than 2% and the return period is more than 50 years.

(3) Flash floods. Rivers in mountainous areas have high velocity and short process, often with high sediment concentration and many stones, and suddenly flood, which is destructive. The main reason is that heavy rainfall is formed under certain terrain, landform and geological conditions. Can be divided into ordinary mountain torrents and debris flow mountain torrents.

(4) floods. The losses and disasters caused by floods to human normal life and production activities are called floods. Flood has the dual attributes of nature and society. With the development of economy and society, the losses and disasters caused by floods of the same magnitude will become more and more serious.

(5) waterlogging. A disaster that cannot be discharged in time due to excessive or concentrated rainfall, resulting in ground water accumulation, is called waterlogging disaster, also known as waterlogging. Waterlogging and flood often go hand in hand.

(6) flood control. According to the laws and characteristics of floods, water conservancy work that studies and adopts various countermeasures to prevent or mitigate flood disasters is called flood control. Flood control measures can be divided into engineering measures and non-engineering measures. Engineering measures include flood storage (detention) project, flood diversion project and river regulation project; Non-engineering measures include flood forecasting, flood warning, dike management, river cleaning, flood insurance, etc.

(7) heavy rain. Daily rainfall of 50- 100 mm is rainstorm, 100-200 mm is rainstorm, and above 200 mm is rainstorm. The rainstorm in Chengdu is mainly concentrated in June-September, and 5438+00 sometimes reappears in April, May and June. The maximum daily rainfall recorded is about 250 mm in Chengdu, 0/060 mm in Zhuang Lin, Henan (1975), 0/672 mm in Xinliao, Taiwan Province (1967) and 0/870 mm in reunion island, France (/kloc-).

(8) rainstorm and flood. The flood formed by rainstorm through runoff production and confluence in the river course is called rainstorm flood. This is the most common and main flood. The magnitude of rainstorm and flood depends on the intensity of rainstorm, weather process, previous rainfall, the location of rainstorm center, the movement of rainstorm center and the underlying surface of the basin.

(9) Dam-break flood (sudden flood). Dam-break flood refers to the flood caused by dam break and dike breach. Dam-break flood has two characteristics of suddenness and ferocity, which poses a great threat to people's lives and property, industrial and agricultural production and transportation in the downstream. There are several reasons for the dam or dike breach: (1) earthquake or geological disaster; (2) Man-made destruction in the war; (3) Too many floods; (4) design problems; (5) quality problems; (6) disease problems; (7) management issues; (8) operational problems.

(10) waterlogging. The process of urbanization has greatly changed the underlying surface, and the problem of waterlogging is more prominent, which should be highly valued.

Second, the main characteristics of the flood

(1) is obviously seasonal.

The season when floods are concentrated is called flood season. The arrival time of the annual flood season of rivers has certain regularity, which is mainly determined by the north-south displacement of the summer rain belt and the frequent typhoon and rainstorm in autumn.

(2) The height of flood peak is large.

Affected by rainstorm, topography, vegetation and other factors, rivers can often form a large peak flow.

(3) The annual variation of river flood is unstable.

The flood peak discharge in rainstorm and flood area changes greatly in wet year and dry year.

Third, how to save yourself in case of flood.

In a short period of time, the continuous rainstorm in an area will cause the river to rise violently, overflow dams, flood farmland and villages, and destroy roads, bridges and houses. This is a flood disaster. How should we save ourselves when the flood comes?

(1) threatened by flood, if there is enough time, it should be moved to hillside, highland and other places in an organized way according to the predetermined route; Ships, rafts, door panels, wooden beds, etc. It should be used for water transfer as much as possible.

(2) When the flood comes too fast to move, you should immediately climb the roof, tall buildings, big trees and high walls, take refuge temporarily and wait for rescue. Don't swim alone.

(3) In mountainous areas, if there is continuous rainstorm, it is easy to flash floods. In this case, do not shelter from the rain under culverts, bridge decks and gullies. You should pay attention to avoid crossing the river and being washed away by mountain torrents, and also to prevent landslides, rolling stones and mudslides.

(4) In rainy days, if the high-voltage tower is found to be toppled, lower or break the wires; Stay away from danger, don't touch or get close to it to prevent electric shock.

(5) After the flood, you should take drugs to prevent epidemics to avoid infectious diseases.

Fourth, flood control engineering measures

Various engineering measures built to control or resist floods and reduce or avoid flood losses are called flood control engineering measures. It mainly includes dike engineering, flood storage (detention) engineering, flood diversion engineering and river regulation engineering.

1, dike project. Water retaining structures built along the river are called dams. After the completion of the dike, the flood is confined in the spillway, and the water depth increases and the flow velocity accelerates, which is beneficial to flood discharge. Dike is a widely used flood control project in the world. The total length of riverbanks in China is about 200,000 kilometers. Built dike project in Pingwu county16.73km.

2. Reservoir flood control project. It is an engineering measure to use the reservoir to store flood detention and undertake the downstream flood control task. Reservoir flood control is generally divided into two categories, namely, reservoirs specially used for flood control and reservoirs that undertake flood control tasks by comprehensive utilization. For example, the Three Gorges Reservoir is a large reservoir with comprehensive utilization. The existing reservoirs in Pingwu county are all aimed at hydropower development, and most of them undertake flood control tasks to some extent.

3. Flood diversion project. Flood control measures to ensure the safety of protected areas by diverting river floods are called flood diversion projects. The flood diversion project consists of flood inlet facilities, flood diversion channels, flood diversion (storage) areas and flood discharge facilities. The most famous flood diversion project in China is the Jingjiang flood diversion project of the Yangtze River, which was built in 1952 and played an important role in the catastrophic flood of the Yangtze River in 1954. The flood storage capacity of the project is 5.4 billion cubic meters. In addition, there are the flood diversion projects of Dongping Lake (water margin) on the Yellow River, Beijindi Flood Diversion Project and Dujiatai Flood Diversion Project on the Han River, with the flood storage capacity of 3,000,200,654,3.8 million and 600,000 cubic meters respectively. The Shidi weir project in Chengdu has the function of flood diversion and cannot be called flood diversion project.

4. River regulation project. The engineering measures taken to stabilize the river course and improve the boundary conditions and flow pattern of the river course are called river regulation projects, including dredging projects, bank protection projects, bend cutting projects, branch blocking projects, beach protection projects and beach siltation projects.