Accidents at hydraulic structures of obzh. Accidents at hydraulic structures (dam breaks)

Hydrodynamically hazardous objects are structures or natural formations that create differences in water levels. Before such an object there is a high level (upstream), and after it there is a low level (downstream). These include hydraulic structures of the pressure front: dams of hydroelectric power stations, dams for other purposes, dams, dams, water intakes and water intake structures, pressure basins and equalization reservoirs, hydraulic structures, small hydroelectric power stations and structures that are part of the engineering protection of cities and agricultural lands.

Accidents at such facilities are called hydrodynamic. They are divided into the following types:

1) breakthroughs of dams (dams, locks, etc.) with the formation of breakthrough waves, leading to catastrophic flooding of large areas;

2) breaches of dams (dams, cofferdams, etc.), leading to the occurrence of a breakthrough flood;

3) breakthroughs of dams (gateways, dams, etc.), leading to the washout of fertile soils or the deposition of sediment over large areas.

The main damaging factors of hydrodynamic accidents are the breakthrough wave and flooding of the area.

The consequences of accidents at hydrodynamically hazardous facilities are difficult to predict. Most often located within or upstream of rivers near large populated areas, if destroyed, they can lead to catastrophic flooding of vast territories where a significant number of cities, villages, and economic facilities are located. This will lead to massive loss of life, destruction of the infrastructure of large areas, long-term cessation of shipping, agricultural and fishing industries, etc.

The consequences of catastrophic flooding will be aggravated by accidents at potentially hazardous facilities located in this zone, which include water supply systems, sewerage systems, drainage communications, garbage collection sites and other waste. All this crap will pollute the flood zone and spread downstream. The danger of the emergence and spread of infectious diseases is increasing, which will be facilitated by the accumulation of population in a limited area with a significant deterioration in material and living conditions.

The protection and safety of the population in case of hydrodynamic accidents is ensured by a large complex of organizational, engineering and other measures. The main ones are: the correct choice of the location of the dam in relation to nearby settlements, limiting the construction of residential buildings and economic facilities in places exposed to a possible breakthrough wave; embankment of populated areas and agricultural lands; carrying out bank protection works, creating reliable drainage systems to prevent landslides and collapses. Waterproofing devices and special reinforcements on buildings and structures are also created; Low-trunk forests (poplars, alders and birches) are planted, which can reduce the speed of the breakthrough wave.

Again, I want to emphasize that theory and practice are always very different from each other. People often break any rules. For the sake of profit, especially in conditions of capitalist relations, and even under socialism, when one party decided everything, they built and continue to build as they want and where they want. There are a lot of violations, but there is never enough money for real protection, which we just talked about. Therefore, do not be idealists and soberly assess the situation. If you are buying a new apartment or house, choose the right place. For example, on the bank of a river is good, but won’t the first flood flood your house, won’t the wave completely wash it away from the break of a dam, which was blown up by a terrorist offended by the whole world? If you were already born and live under a huge dam that can wash away everything at any moment; you value something in this life, take care of yourself and move to a safer place before it’s too late. Remember the popular saying: “God protects those who are careful!”

In the event of a danger of a breakthrough of artificial dams, the following measures are taken: the water flow is increased and a planned release of water from reservoirs is carried out during the spring flood.

If there is a danger of a natural reservoir breaking, measures are taken to strengthen the walls of such an object. If catastrophic flooding does occur, the following measures are taken:

1) the population is notified of the threat of catastrophic flooding;

2) an emergency evacuation of the population is carried out before the breakthrough wave approaches (independently, less often using transport allocated by special services for this purpose);

3) the population, unable to escape, is located on the upper floors of especially durable buildings and structures, as well as on hills;

4) emergency rescue operations are carried out;

5) qualified and specialized assistance is provided to victims;

6) urgent work is carried out to ensure the livelihoods of the population.

In the final word, I want to warn my reader about all the emergency and catastrophic situations that we have considered here. Don't rely too much on emergency services. They too may suffer from a disaster. Yes, they exist, they work and often help people, but when there is a real threat to life, they often fail to keep up. Is it because we have such a terrible meat grinder on the roads that we lose 3 times more people per year than in 10 years of the entire Afghan war? For example, a person was electrocuted and his heart stopped. Call an ambulance. They will definitely arrive, but this will happen no earlier than half an hour later, and sometimes much later. After half an hour, the ambulance can only write a piece of paper stating death. But you personally can save this person’s life if you don’t disdain yourself and immediately start artificial respiration and cardiac massage. Don't get lost! If you are prepared, you are capable of many things. As Ilf and Petrov said: “The salvation of drowning people is the work of the drowning people themselves.” Don't forget this. And later, special services will definitely help you.

FROM THE HISTORY OF HYDRODYNAMIC ACCIDENTS

St. Francis Dam in California forever entered the analogues of engineering geology as a tragic example of human carelessness. It was built 70 km from Los Angeles with the purpose of storing water for its subsequent distribution through the Los Angeles water supply.

Filling of the reservoir began in 1927, but the water reached its maximum level only on March 5, 1928. By that time, the seepage of water through the dam was already causing concern among local residents, but the necessary measures were not taken. Finally, on March 12, 1928, water broke through the soil, and under its pressure the dam collapsed. It was a terrible sight. The water rushed through the canyon like a wall about 40 m high. After 5 minutes, it demolished a power plant located 25 km downstream. All living things, all buildings were destroyed. Then the water rushed into the valley. Here its height decreased and its destructive power weakened somewhat, but remained quite dangerous. Few in the upper valley managed to survive.

These were people who accidentally escaped in trees or on debris floating in the stream.

By the time the flood reached the coastal plain, it was a muddy wave 3 km wide, rolling at the speed of a fast-walking person. Behind the wave, the valley was flooded for 80 km. More than 600 people died during this flood.

Types of accidents at hydrodynamically hazardous facilities

Hydrodynamic accident - an accident at a hydraulic structure associated with the spread of water at high speed and creating a threat of a man-made emergency.

Such an accident could result in catastrophic flooding.. Flooding of coastal areas with settlements and other objects located on them can occur as a result of the destruction of hydraulic structures (dams, dikes, cofferdams) located upstream of the river, or the system of irrigation structures in irrigated areas.

Flooding is the covering of an area with water. The term “flooding” hereinafter refers to the flooding of an area due to the destruction of hydraulic structures.

In the flooded area, four zones of catastrophic flooding are distinguished:

First zone directly adjacent to the hydraulic structure and extends 6-12 km from it. The wave height here can reach several meters. Characterized by a rapid flow of water with a flow speed of 30 km/h or more. Wave travel time - 30 minutes.

Second zone- fast current zone (15-20 km/h). The length of this zone can be 15-25 km. The wave travel time is 50-60 minutes.

Third zone- middle flow zone (10-15 km/h) with a length of up to 30-50 km. The wave travel time is 2-3 hours.

Fourth zone- zone of weak current (spill). The current speed here can reach 6-10 km/h. The length of the zone, depending on the terrain, can be 35-70 km.

Catastrophic flood zone- a flood zone within which massive losses of people, farm animals and plants occurred, material assets, primarily buildings and other structures, were significantly damaged or destroyed.

In our country there are more than 30 thousand reservoirs and several hundred reservoirs for industrial wastewater and waste. There are 60 large reservoirs with a capacity of more than 1 billion m3. The distribution of hydrodynamically hazardous objects by region of Russia (in%) is shown in the diagram.

Hydrodynamically dangerous objects are structures or natural formations that create a difference in water levels before (upstream) and after (downstream) them. These include hydraulic structures of the pressure front: dams, dams, dikes, water intakes and water intake structures, pressure basins and equalization reservoirs, waterworks, small hydroelectric power stations and structures that are part of the engineering protection of cities and agricultural land.

Hydrodynamic structures of the pressure front are divided into permanent and temporary.

Permanent are called hydraulic structures used to perform any technological tasks (for electricity production, land reclamation, etc.).

Temporary include structures used during the construction and repair of permanent hydraulic structures.

In addition, hydraulic structures are divided into primary and secondary.

The main ones include pressure front structures, the breakthrough of which will entail disruption of the normal life of the population of nearby settlements, destruction, damage to residential buildings or economic facilities.

The secondary ones include hydraulic structures of the pressure front, the destruction or damage of which will not entail significant consequences.

The main damaging factors of hydrodynamic accidents associated with the destruction of hydraulic structures are a breakthrough wave and catastrophic flooding of the area.

Causes of hydrodynamic accidents and their consequences

The causes of accidents accompanied by a breakthrough of hydraulic structures of the pressure front and flooding of coastal areas are most often:

Destruction of the foundations of structures and insufficient spillways;
- impact of natural forces (earthquake, hurricane, collapse, landslide);
- structural defects, violation of operating rules and the impact of floods (Table 14).

The percentage of accidents for groups of dams of various types is presented in Table. 15.

Of the 300 dam failures (accompanied by their failure) in various countries over 175 years, in 35% of cases the cause of the accident was exceeding the calculated maximum discharge flow (water overflowing the dam crest).

DAMAGING FACTORS in case of hydrodynamic accidents, several. In addition to the damaging factors characteristic of other floods (drowning, hypothermia), in accidents at hydrodynamically dangerous objects, damage is caused mainly as a result of the action of a breakthrough wave. This wave is formed in the downstream as a result of the rapid fall of water from the upstream.

Damaging effect of a breakthrough wave manifests itself in the form of a direct impact on people and structures of a mass of water moving at high speed, and the fragments of destroyed buildings and structures and other objects it moves.

Breakthrough wave a large number of buildings and other structures may be destroyed. The degree of destruction will depend on their strength, as well as the height and speed of the wave.

In case of catastrophic flooding A threat to the life and health of people, in addition to the impact of a breakthrough wave, is posed by exposure to cold water, neuropsychic stress, as well as flooding (destruction) of systems that support the life of the population.

The consequences of such flooding may be aggravated by accidents at potentially hazardous facilities falling within its zone. In areas of catastrophic flooding, water supply systems, sewerage systems, drainage communications, garbage collection sites and other waste may be destroyed (eroded). As a result, sewage, garbage and waste pollute flood zones and spread downstream. The danger of the emergence and spread of infectious diseases is increasing. This is also facilitated by the accumulation of population in a limited area with a significant deterioration in material and living conditions.

CONSEQUENCES OF ACCIDENTS at hydrodynamically hazardous objects may be difficult to predict. Being located, as a rule, within or upstream of large populated areas and being objects of increased risk, if destroyed, they can lead to catastrophic flooding of vast territories, a significant number of cities and villages, economic facilities, mass loss of life, long-term cessation of shipping, agricultural and fishing industries.

Population losses, located in the zone of the breakthrough wave, can reach 90% at night, and 60% during the day. Of the total number of victims, the number of deaths may be 75% at night, 40% during the day.

Greatest danger represent the destruction of hydraulic structures of the pressure front - dams and dams of large reservoirs. When they are destroyed, rapid (catastrophic) flooding of large areas occurs and significant material assets are destroyed.

In June 1993, the Kiselyovskoe reservoir dam on the river broke. Kakve and severe flooding in the city of Serov, Sverdlovsk region. The emergency situation arose as a result of a catastrophic flood resulting from heavy rains in the final phase of the spring flood.

With a sharp rise in water in the river. Kakwe flooded 60 km 2 in its floodplain, residential areas in the city of Serov and nine other settlements. The flood affected 6.5 thousand people, of which 12 died. 1,772 houses fell into the flood zone, of which 1,250 became uninhabitable. Many industrial and agricultural facilities were damaged.

A hydraulic structure is an object of economic activity located near the water surface and intended for:

Ø using the kinetic energy of moving water in order to convert it into other types of energy;

Ø cooling of exhaust steam from thermal power plants and nuclear power plants;

Ø protection of coastal areas from water;

Ø water intake for irrigation and water supply;

Ø drainage;

Ø fish protection;

Ø water level regulation;

Ø ensuring the activities of river and sea ports, shipbuilding and ship repair enterprises, as well as shipping;

Ø underwater mining, storage and transportation of minerals.

The danger of flooding in low-lying areas arises when dams, dikes and waterworks are destroyed. The immediate danger is the rapid and powerful flow of water, causing damage, flooding and destruction of buildings and structures. Casualties among the population and destruction occur due to the high speed of a huge amount of water, sweeping away everything in its path.

Destruction (breakthrough) hydraulic structures arise as a result of the influence of natural factors (earthquakes, hurricanes, erosion of dams and dams) or human activity, as well as due to structural defects or design errors.

The main hydraulic structures include: dams, water intake and spillway structures, dams.

Breakthrough – This is damage in the body of a dam, dike, sluice resulting from their erosion with the formation of breakthrough waves and catastrophic flooding or breakthrough flood.

Breakout wave occurs under the condition of the simultaneous superposition of two processes: the fall of water from the reservoir and a sharp increase in the volume of water at the place of the fall. The height of the breakthrough wave and the speed of its propagation depend on the size of the breakthrough, the difference in water levels and the topographic conditions of the river bed and mouth.

The height of the breakthrough wave is 2-50 meters, the speed of movement, as a rule, is in the range from 3 to 25 km/h.

A hydrodynamic accident is an emergency situation associated with the failure (destruction) of a hydraulic structure or part of it and the uncontrolled movement of large masses of water, causing destruction and flooding large areas.

These are accidents at hydraulic structures in which water spreads at high speed, creating the threat of a man-made emergency.

To prevent possible sudden breakthroughs at reservoir dams, to protect the population, territories and material assets, the following measures are carried out in advance:

a) administrative:

Ø restriction of the construction of residential buildings and economic activities in places subject to the influence of a potential wave of possible flooding;

Ø evacuation of the population from zones, the time of approach of the breakthrough wave to which after the destruction of the dam is less than four hours, is carried out urgently, and from the rest of the territory, only in case of a threat of flooding;

b) engineering and technical:

Ø embankment (construction of dams) of populated areas and agricultural lands;

Ø creation of reliable drainage systems;

Ø bank protection works to prevent landslides and landslides;

Ø installation of waterproofing and special fastenings on buildings and structures;

Ø planting low-growing forests of alder, willow, aspen and birch, which increase the roughness of the surface and help reduce the speed of the breakthrough wave.

Ø warning and informing the population;

Ø Possible evacuation routes to elevated areas are planned in advance;

Ø you must beware of broken and sagging wires; report the presence of such damage, as well as destruction of sewer and water supply networks to the relevant utility services;

Ø Do not eat foods that have been in contact with water flows.

For each waterworks, diagrams and maps are drawn up, which indicate the boundaries of the flood zone and give a description of the breakthrough wave. It is prohibited to build housing or businesses in this zone.

In the event of a dam failure, all means are used to notify the population: sirens, radio, television, telephone and public address systems. Having received the signal, you should immediately evacuate to the nearest hills. You should stay in a safe place until the water recedes or you receive a message that the danger has passed.

Evacuation of the population from areas of possible flooding is carried out first of all from settlements located near dams, the wave of a breakthrough of which can reach these settlements in less than four hours, and from other settlements - if there is an immediate threat of flooding.

• Municipal educational institution secondary school No. 50, Volgograd
• 2010

• Accidents
• on hydraulic engineering
• structures
• and their consequences

• Familiarize yourself with the main types of hydraulic structures, learn about hydrodynamic accidents and their consequences

• a) sun rays;
• b) nuclear power plant;
• c) atomic bombs;
• d) radon;
• e) x-ray;
• f) uranium ores.

• Match the concepts:

• natural radioactive radiation

• a) sun rays;
• d) radon;
• f) uranium ores.

• artificial radioactive radiation

• b) nuclear power plant;
• c) atomic bombs;
• d) x-ray.

• violation of technological discipline, deficiencies in professional training of personnel, “human factor”;
• depressurization of the reactor primary circuit or its mechanical damage.

• Complete the phrase:
• “In case of an accident at a nuclear power plant
• necessary:
• 1) listen...; 3) carry out...;
• 2) protect...; 4) pack...

• Listen to a voice message (information) about the danger that has arisen and recommendations for action by the population.
• Protect your respiratory system using available personal protective equipment.
• Seal the room.
• Pack food and drinking water in plastic containers, bags, bottles, place them in closed cabinets, pantries, and refrigerator.

• Sayano-Shushenskaya HPP
• Krasnoyarsk hydroelectric power station
• Bratsk hydroelectric power station
• Ust-Ilimskaya HPP
• Zeyskaya HPP
• Nizhegorodskaya HPP
• Zhigulevskaya HPP
• Volzhskaya HPP
• Saratov HPP

• - These are engineering or natural structures for the use of water resources and to combat the destructive effects of water.

• use of kinetic energy of water (HES);
• land reclamation;
• protection of coastal areas from floods (dams);
• for water supply to cities and irrigation of fields;
• regulation of water levels during floods;
• ensuring the activities of sea and river ports (canals, locks).

• water retaining structures (dams, dams, dams);
• dam named after K. Zubryk
• water supply structures (canals, pipelines, tunnels);
• White Sea-Baltic Canal

• water intake structures –
• are designed to take water from a river or lake to use it for water supply or field irrigation.
• Metelevsky water intake, pumping station,
• Tyumen
• spillway structures –
• are designed to discharge flood water from the reservoir, as well as pass water into the downstream of the dam.
• Spillway
• Volzhskaya HPP named after. XII Congress of the CPSU

• special structures (locks, ship lifts, etc.) –
• designed to raise or lower ships from one water level to another.
• Gateway No. 8
• White Sea-Baltic Canal
• Gateway No. 1
• Volga-Don Shipping Canal
• them. IN AND. Lenin

• - these are structures or natural formations that create a difference in water levels before (upstream) and after it (downstream), accidents on which can lead to catastrophic consequences.

• is an emergency situation associated with the failure (destruction) of a hydraulic structure or part of it and the uncontrolled movement of large masses of water, causing destruction and flooding of vast areas.

• Sayano-Shushenskaya HPP
• August 2009

• 1993 - Break of the dam of the Kiselevsky reservoir (Sverdlovsk region) on the river. Kakva (total damage – 63.3 million rubles)
• 1994 - Destruction of the dam of the Tirlyansky reservoir (Bashkiria) on a tributary of the river. Belaya (total damage – 52.3 million rubles)
• 2002 - Flood in the Krasnodar region led to the destruction of its waterworks, killing 114 people (total damage - 15 billion rubles)
• 2009 - Accident at the Sayano-Shushenskaya hydroelectric power station on the river. Yenisei claimed the lives of 75 people. 21.6 billion rubles will be spent on restoration.

• natural phenomena or disasters;
• technogenic factors;
• Wartime emergencies and terrorist attacks.

• breakout wave:
• is formed in the lower reaches as a result of a dam breaking and the rapid fall of huge masses of water, sweeping away everything in its path.
• threat to human life and health:
• drowning, hypothermia in cold water, neuropsychic stress.

• long-term destruction of the hydraulic transmission system, which entails a shortage of electricity and a decline in production;

• defeat of people, death of animals, destruction of buildings and structures, roads, bridges, power lines by a breakthrough wave;
• destruction of the water supply and sewerage systems, resulting in the risk of infectious diseases;

• flooding of large areas, populated areas, washing away of the fertile soil layer;
• sediments, damage to property by water, environmental pollution.

• Flooding

• Hydrodynamic accident

• Structures with differences in water level.

• Damaging factors of the gastrointestinal tract.

• Hydrodynamically dangerous object

• Catastrophic flood zone

• Covering the area with water.

• The formation of breakthrough waves, a threat to human life and health.

• A structure with a difference in water level.

• A flood zone within which massive losses of people, animals and plants occurred, and material assets were damaged or destroyed.

• The part of the flood zone within which the breakthrough wave propagates.

• Covering the area with water.

• - Damaging factors of the gastrointestinal tract

• - Hydrodynamically dangerous object

• - Hydrodynamic accident

• - Catastrophic flood zone

• - Flooding

• Thank you
• for your attention!

Life safety lesson in 8th grade

Lesson topic: “Accidents at hydraulic structures and their consequences.”

Lesson objectives:

Familiarization of students with hydraulic structures and possible accidents on them, their causes and consequences;

Developing in students a sense of responsibility for their lives and the lives of other people in the event of an emergency;

Raising students’ psychological preparedness for emergencies.

Lesson type:lesson introducing students to new educational material

Forms and methods of the lesson: frontal survey, test, heuristic conversation, explanatory and illustrative.

Equipment:Textbook, blackboard, test tasks, route sheets, task cards, presentation, computer, multimedia projector.

Textbook used:Fundamentals of life safety. 8th grade: textbook for educational institutions under the general editorship of A.T. Smirnova

Lesson Plan

Organizing time.

Updating of reference knowledge

Learning new material.

• Hydraulic structures.

  Types of hydraulic structures

  Hydrodynamic accident.

  Catastrophic flood zone.

  Damaging factors.

  Consequences of accidents.

Consolidation of new material.

Summing up the lesson.

Homework message.

During the classes:

1.Organizational point:

- Mutual greetings between teacher and students

- Checking students' readiness for the lesson!

Five-minute repetition of homework (section 5.7 p. 131)

Updating basic knowledge:

Guys, in the last lesson we studied ....? (ensuring the protection of the population from the consequences of accidents at explosive and fire hazardous facilities).

Accidents at hydraulic structures and their consequences. What will we get acquainted with in class, what will we talk about?

Now, pay attention, there is a test of 6 tasks on your table, complete it.Appendix 1 - After you have completed the test, exchange tests with your neighbor on the desk and check the correctness of execution and the answers on the slide. Slide 1

Now mark the completion of the first task on your route sheet. Appendix 2

Route sheet (in it, students independently evaluate themselves, opposite the corresponding task they mark with colors: green - answer to five, yellow - answer to four, blue - answer to three, red - answer to two)

2. Now work in pairs: fill in the missing words! Appendix 3

Slad 2-3

Self-assessment in route sheets
2. Presentation of program material.

Look at the board, the topic of our lesson:Accidents at hydraulic structures and their consequences. What will we get acquainted with in class, what will we talk about? Slide 4-5

As the new material is presented, students write down the types of hydraulic structures in the form of a diagram.

Hydraulic structures are designed to use water resources for human needs, as well as to combat the destructive effects of water on human life.Slide 6

According to their purpose, hydraulic structures are divided

Slide 7

for water supply (dams, dams, etc.),

water supply (channels, pipelines, tunnels, etc.),

regulatory (half-dams, enclosing shafts, etc.),

water intake,

spillway and special (buildings of hydroelectric power stations (HPP), locks, ship lifts, etc.).Currently, more than 30 thousand reservoirs and several hundred storage tanks for industrial wastewater and waste are in operation on the territory of the Russian Federation. There are about 60 large reservoirs with a capacity of more than 1 billion m 3 .
To the main potentially dangerous hydraulic structuresSlide 8

include dams,

water intake and

spillway structures and sluices.A water intake structure is a hydraulic structure for collecting water from a power source (river, lake, underground source) in order to use it for the needs of hydropower, water supply or field irrigation.Slide 9
Spillway structures are hydraulic structures designed to discharge excess (flood) water from a reservoir, as well as pass water into the downstream. (The pool is a part of a reservoir, river, canal. The upper pool is located downstream above the water pump structure (dam, sluice), the lower pool is located below the water pump structure.)Slide 10

A lock is a network of structures for raising or lowering ships from one water level (river, canal) to another. The largest locks are over 30 m wide and up to several hundred meters long.Slide 11
PHYSMINUTE
Hydrodynamic accidents at these structures can lead to catastrophic consequences, since all these hydraulic structures are located, as a rule, within or above large populated areas and are objects of increased risk. The occurrence of a hydrodynamic accident at such a facility can lead to catastrophic flooding of vast areas and the formation of a catastrophic flooding zone.

Guys, what is a hydrodynamic accident?

A hydrodynamic accident is an emergency situation associated with the failure (destruction) of a hydraulic structure or part of it and the uncontrolled movement of large masses of water, causing destruction and flooding of vast areas.Slide 12

A catastrophic flood zone is a flood zone that arose as a result of a hydrodynamic accident that occurred at a hydraulic structure, within which massive losses of people, farm animals and plants occurred, buildings and various structures were significantly damaged or destroyed.Slide 13
-Now find the causes of hydrodynamic accidents yourself? Textbook page 137

Slide 14
Hydrodynamic accidents at hydraulic structures can occur as a result of natural forces (earthquakes, hurricanes, spills, destruction of a dam by flood waters) or human influence (attacks by modern means of destruction on hydraulic structures and acts of sabotage), as well as due to design defects or errors in design and operation of hydraulic structures.
The main consequences of major hydrodynamic accidents are:Slide 15

damage and destruction of hydraulic structures, short-term or long-term cessation of their functions;
defeat of people and destruction of structures by a breakthrough wave formed as a result of the destruction of a hydraulic structure and having a height of 2 to 12 m and a speed of movement from 3 to 25 km/h (in mountainous areas it can reach up to 100 km/h);


catastrophic flooding of vast territories and a significant number of cities and villages, economic facilities, long-term cessation of shipping, agricultural and fishing production.

Slide 16-18Statistics
Currently, hydraulic structures at 200 reservoirs and 56 waste storage ponds have been in operation without significant reconstruction for more than 50 years, and this increases the likelihood of hydrodynamic accidents occurring there.
History knows several examples of the catastrophic consequences of accidents at hydraulic structures due to the destruction of a dam.
If a dam collapses, water rushes down the river with high speed and pressure. A so-called breakthrough wave is formed, which is the main damaging factor of a hydrodynamic accident.
HISTORICAL FACTS (student reports)
Such an accident occurred on March 12, 1928 at the St. Francis Dam in California (USA). The dam was built 70 km from Los Angeles in the San Francisco Canyon to store water for its subsequent distribution through the Los Angeles water supply (water intake hydraulic structure). The reservoir began to be filled with water in 1927; the water reached its maximum level on March 5, 1928. At this time, water had already begun to seep through the dam, but no protective measures were taken. As a result, on March 12, 1928, the dam was breached by water and collapsed. The water rushed along the canyon in a wall reaching a height of up to 40 m, and hit a power plant located 25 km downstream. The water flooded the valley for 80 km; not many people who found themselves in the path of the water survived. About 600 people died. The cause of this accident was errors in technology during the construction of the dam and failure to take timely measures when water was found to be leaking through the dam.
In June 1993, in our country, the Kiselyovskoye reservoir dam on the Kakva River (located in the Serovsky district of the Sverdlovsk region, 17 km from the city of Serov) broke. The dam was 2 km long and 17 m high. The reservoir was filled with water in 1979. The volume of the reservoir at a normal retaining water level was 32 million m 3 . The volume at the formed retaining level (which could only be allowed for a short time) reached 37 million m 3 .
The emergency situation arose as a result of severe flooding resulting from the superposition of rain flows during the final phase of the spring flood. In connection with this, an increase in discharge flows from the reservoir was made, but the influx of water into the reservoir continuously increased. The normal retaining level was noted on June 12. On June 13, the bottom outlets and all dam gates were completely opened at the dam, but the discharge flow did not compensate for the increasing volume of water in the reservoir. The calculated forced level was reached by the morning of June 14, the water rose to the crest of the dam, and it began to overflow over the dam along the front of about 1900 m, then the dam broke, followed by the dam overflowing to its entire height. The accident led to a sharp rise in water in the Kakwa River below the dam, resulting in flooding of 69 km 2 the floodplain of the river, residential areas of the city of Serov and a number of settlements. The flood affected 6.5 thousand people, 12 people died. 1,772 houses fell into the flood zone, of which 1,250 became uninhabitable. The railway and 5 road bridges were destroyed, 500 m of the main railway track were washed away.
In conclusion, it should be noted that major hydrodynamic accidents do not happen very rarely. It is noted that more than 300 significant hydrodynamic accidents have occurred in the world over the past 180 years.
The consequences of accidents at hydrodynamic structures may be accompanied by side effects. In the zone of catastrophic flooding there may be dangerous production facilities (chemical, fire and explosion hazardous), accidents at which will aggravate the situation. In addition, in the catastrophic flood zone, the operation of the water supply, sewerage, and drainage systems is disrupted. All this creates an unfavorable sanitary and epidemiological situation and contributes to the emergence of mass infectious diseases.
3. Lesson summary

Guys, what did you learn new in class today?

Summing up the route sheet

Grading

Reflection Appendix 4
4. Homework. P.5.8