Flood- temporary significant flooding of the area as a result of the rise of water in a river, lake or sea, as well as the formation of temporary watercourses. Floods, along with wars, epidemics, earthquakes and fires, are considered one of the greatest disasters in the history of many peoples.

catastrophic flooding- a flood that caused human casualties, damage to human health, destruction or destruction of objects and other material values ​​in a significant amount, as well as causing serious damage to the environment.

Floods occur for the following reasons:

seasonal snowmelt;

melting of glaciers and snow cover in the mountains;

intense rains;

congestion and congestion ( congestion occur in the spring when rivers open up and the ice cover breaks up; they are characterized by the accumulation of ice in the riverbed, which makes it difficult to flow; congestion- accumulation of loose spongy sludge and small-sized ice in the riverbed are observed at the beginning of winter);

wind surges of water (surge waves);

• baric waves;

  destruction of dams and other hydraulic structures.

A short-term rise in the water level in rivers and other bodies of water, which occurs due to the melting of snow, ice, heavy rains, etc., is called flood. Such floods are observed on most rivers of the Russian Federation.

high water- flooding of the river, which occurs at a certain time due to the melting of snow and ice, seasonal rains, traffic jams, ice jams. It is characterized by a significant and rather long rise in the water level in the river.

Floods caused by seasonal, usually spring, snowmelt are periodically observed on most rivers of the European part of the Russian Federation and Siberia. The occurrence of catastrophic floods contribute to congestion, which occur in the spring when rivers open up and the ice cover breaks up. The jam water level on the Yenisei and Tom, for example, can reach 7-10 m, and on the Lower Tunguska - sometimes 20 m.

Floods resulting from heavy rains are typical for Siberia and the Far East.

Tsunami waves formed during the eruption of underwater volcanoes and during underwater earthquakes . Unlike wind waves, they cover the entire water column. In the open ocean, the speed of propagation of tsunami waves is about 800 km / h, the height is about 0.5 m, but with access to coastal shallow water, their height rapidly increases and in some cases reaches 20-30 m, and sometimes more. Tsunami waves are very dangerous. Simultaneously with tsunami waves during an underwater earthquake, a “shock wave” occurs, which propagates at the speed of sound (5,400 km / h), that is, 6-7 times faster than a tsunami wave. These phenomena can be recorded by seismographs and hydrophones and warn the population about the danger of a tsunami.

The world's largest tsunamis were noted: in 1883 on the island of Krakatoa - 36 thousand people died, in 1923 in Japan - 99.3 thousand people died, in 1976 in the Philippine Islands - 65 thousand people died. In Russia, tsunamis are dangerous for all coastal regions. Especially strong tsunamis were registered on the coastline of Kamchatka, Sakhalin and the Kuril Islands in 1737, 1780, 1898, 1919, 1923, 1952 and 1963.

catastrophic floods can occur during the destruction of dams and other hydraulic structures during earthquakes, prolonged rains and other phenomena. In this case, extensive zones of flooding occur after the passage of a destructive wave of breakthrough.

In terms of frequency of occurrence, area of ​​distribution, total average annual damage, floods rank first in Russia among dangerous hydrological phenomena and processes. By loss of life and damage per unit area of ​​damage, they occupy second place after earthquakes.

Hydrodynamically hazardous objects include structures or natural formations that create a difference in water levels (dam dams). A feature of flooding during accidents at such facilities is the appearance of a breakthrough - the main damaging factor of the accident, which is formed as a result of a rapid fall of water from the upstream.

In addition to the damaging factors characteristic of other floods (drowning, mechanical injuries, hypothermia), in case of accidents at hydrodynamically dangerous objects, people are affected by factors caused by the kinetic energy of the breakthrough wave:

direct dynamic impact on the affected wave of the breakthrough;

the traumatic effect of fragments of buildings, structures, destroyed by a breakthrough wave;

the damaging effect of various objects involved in the movement of a breakthrough wave.

In case of accidents at such facilities, the total losses of the population located in the zone of action of the breakthrough wave can reach 90% at night, and 60% during the day, while among the total losses, irretrievable losses can be; at night - 75%, during the day - 40%, and sanitary - 25 and 60%, respectively.

Depending on the extent of flooding, the speed of water movement, the distance of a settlement from a hydraulic structure or a hazardous natural phenomenon, 4 areas of catastrophic flooding:

The first is adjacent directly to the hydraulic structure, a dangerous natural phenomenon. It extends for a distance of 6-12 km, is characterized by a rapid flow of water with a current speed of 30 km/h or more.

The second is the fast current zone (15-20 km/h). The length is up to 15-25 km.

The third is the zone of the middle current (10-15 km / h), the length is up to 30-50 km.

The fourth is a zone of weak current (spill), with a current speed of 6-10 km / h. The length of this zone depends on the terrain and can be 35-70 km.

P
Such a division into zones allows rescuers and medical workers to better navigate the current situation in the disaster area, which in turn improves the quality and efficiency of rescue operations.

Value total losses during sudden flooding can average 20-35% of the population in the flood zone. AT cold time of year they can increase by 10-20% depending on the length of stay of the victims in the water.

AT structure of sanitary losses Victims with symptoms of asphyxia, chills, as well as acute disorders of respiratory and cardiovascular activity, soft tissue injuries, and concussions predominate. Some of the victims may be in a state of mental disorder. As a result of the flood, a large number of the population is left without shelter, drinking water and food, exposed to cold water and wind.

The health consequences of floods are characterized by:

violation of the existing system of medical and sanitary provision of the population;

hypothermia of the population located in the flood zone associated with prolonged stay in the water;

the occurrence of mechanical injuries in part of the population (mainly of the limbs and trunk) and stress reactions, cardiovascular, neuropsychiatric diseases or their aggravation;

violation of the life support system and the creation of adverse conditions leading to the emergence of infectious diseases (a large number of people are left without shelter, drinking water, food, exposed to adverse weather conditions);

significant population migration.

In areas of catastrophic flooding, water supply systems, sewerage, drain communications, sewage, garbage collection sites can be destroyed (eroded), and, therefore, there is a danger of the emergence and spread of infectious diseases. This will also be facilitated by the accumulation of the population in a limited area with a significant deterioration in the material and living conditions of life. In mass numbers, patients with traditional intestinal infections - dysentery, colienteritis, dysbacteriosis, salmonellosis - are admitted. The incidence of hepatitis is on the rise. In children's infectious diseases hospitals, the load increases due to meningococcal infection. Following this, zoonoses may appear - leptospirosis, tularemia.

In case of catastrophic flooding, irretrievable losses significantly exceed sanitary ones. The magnitude and structure of population losses will vary depending on the following circumstances:

-
the scale of the flood;

Population density in the flood zone;

Timeliness of notification;

Distances of the settlement from the place of the beginning of flooding;

Location of medical facilities;

The height of the flooding wave and the time of its passage;

Water and ambient air temperatures;

Seasons, time of day and other features.

A massive type of flood damage is drowning. Conventionally, drowning is aspiration ("true"), asphyxic and syncopal (reflex) drowning.

With true drowning, water enters the respiratory tract and lungs, which, as a rule, leads to respiratory distress and respiratory hypoxia. Respiratory and vascular disorders in this case are exacerbated by spasm of the vessels of the pulmonary circulation, the appearance of metabolic and respiratory acidosis. The skin and mucous membranes of "drowners", as a rule, have a bluish color (the so-called "blue drowneds").

Resuscitation measures include cleaning the oral cavity from foreign objects (algae, mud, etc.), removing water from the lungs, performing artificial lung ventilation, chest compressions, and other measures.

With asphyxic drowning, a small amount of water enters the upper respiratory tract, which causes reflex respiratory arrest and laryngospasm. Holding the breath is accompanied by periods of false breaths, which are ineffective due to laryngospasm. The initial period of asphyxic drowning is practically absent, and the agonal period differs little from that in "true" drowning. The cyanosis of the skin and mucous membranes is weakly expressed.

When providing medical care, first of all, water should be removed from the lungs; during artificial ventilation of the lungs, the spasm of the larynx is overcome with the help of a fixed intensive exhalation (preferably the use of oropharyngeal tubes-air ducts).

With syncopal drowning, as a rule, there is a reflex cardiac arrest due to psycho-emotional shock, contact with cold water of the skin and upper respiratory tract. In this case, clinical death occurs immediately. In drowned people, pallor of the skin, absence of a pulse on the carotid arteries, and wide pupils are noted. Water does not enter the lungs, and therefore there is no need to waste time trying to remove it; artificial ventilation of the lungs and indirect heart massage should be urgently started.

Those rescued in the initial period of drowning retain consciousness, but must be under the control of others, since they may have mental disorders and inadequate reactions to the environment. This is due to the fact that the development of the so-called “secondary” drowning syndrome is possible, when, against the background of relative well-being, a hysterical cough suddenly reappears with copious sputum containing streaks of blood, breathing and heart rate increase, hypoxia increases, cyanosis of the skin occurs. Such affected in some cases may require resuscitation.

Can lead to natural disasters. The power of natural disasters is often destructive and leads to serious negative phenomena. Every year, scientists record about 1 million seismic and microseismic vibrations of the earth. Approximately 100 of them are tangible to humans and 1000 cause major damage. More prone to seismic vibrations: the Mediterranean zone, the south of Eurasia from the western side of Portugal to the eastern zone of the Malay Archipelago and the Pacific zone, which surrounds the shores of the Pacific Ocean. This also includes mountain ranges: the Andes, the Cordillera, the Crimea, the Himalayas, the Caucasus, the Carpathians, the Apennines and the Alps.

The strength of an earthquake is measured on a 12-point scale by a seismologist. A weak push is recorded as one point. Each new score means that the next push is 10 times greater than the previous one. The most notorious earthquakes were recorded in 1906 in California (USA) - 10 points, in 1923 in Japan - over 10 points. There are about 150 thousand people who died here. In 1928, Spitak suffered from shocks of 8 points. The city was completely destroyed, more than 25 thousand people were killed. Record holders for the number and strength of earthquakes are Chile and Japan.

Scientists have recorded more than 1,000 Earth wobbles per year in these countries. The strongest shocks from the bowels of the earth occur in the area of ​​the Japanese islands of Suruga and Sagami. Weak fluctuations are observed in the city of Niigata. The locals are so accustomed to this that they no longer worry much. The city is experiencing minor losses: advertising signs are falling and houses are swaying slightly.

Earthquake in Japan

A strong earthquake in Japan is felt in open areas. Cracks form in the soil of the earth. Over time, they become wider, the soil is cracking, as if at the seams. If the vibrations are incredibly active, then the earth is literally distorted by undulating shocks.

Such a phenomenon could be observed in Japan (1923) in the South Kanto region. The point of the earthquake was under Sagami Bay. Almost all residential buildings on its coast were destroyed. Scientists consider this earthquake in Japan the most destructive of all.

Panic terror reigned in the cities of Yokohama and Tokyo. 6 thousand people died. Almost the entire city was destroyed in the resulting fire. Strong fluctuations arose in the afternoon.

Almost immediately, fires appeared everywhere. The gusty wind carried the fire everywhere. Separate pockets of fires merged with each other, and soon it was already blazing from all sides. People ran from everywhere to escape the fire. So, during this earthquake, 3.5 million Japanese were left homeless and 150,000 people died. Japan suffered catastrophic losses, which were 5 times the country's expenses in the Russo-Japanese War.

Volcanoes

Scientists have registered about a thousand active volcanoes. Every 2 years, three new ones are added to the existing volcanoes. This is an unpredictable and amazing phenomenon! According to scientists, the first volcanoes appeared on the planet 4 billion years ago.

The oldest volcano is in Ukraine. Its name is Kara-Dag. Eruptions of this power occurred about 150 million years ago. At the moment, Kara-Dag does not pose a threat, which cannot be stated about his other known brothers.

The State Emergency Management System considers that the correct forecasting of the occurrence and development of natural disasters and early warning of the population is still the main problem. And we need to work on this.

In the event of emergencies, there must be an organization of all existing structures. The united actions of federal and local authorities, departments of the Ministry of Emergency Situations, combined with the competent actions of the population, make it possible to suffer much less loss of life and material loss. In parallel with this, the most effective measures are being taken to eliminate the incident itself and its consequences.

- this is a significant flooding of the area with water as a result of a rise in the water level in a river, reservoir, lake or sea, caused by an abundant influx of water during the period of snowmelt or heavy rains, wind surges of water, as well as during traffic jams, ice jams and other phenomena.

Flooding is a dangerous natural phenomenon, a possible source of emergency, if the flooding of the area causes material damage, damages the health of the population or leads to the death of people, farm animals and plants.

In terms of frequency, distribution area and total average annual material damage, floods on the territory of the Russian Federation rank first in a number of natural disasters, and in terms of the number of human casualties and specific material damage (per unit of the affected area) - the second place after earthquakes.

Rivers differ from each other in different conditions for the formation of water runoff (water runoff is the amount of water flowing through the closing section of the river for any time interval).

According to the conditions of runoff formation and the occurrence of floods, the rivers of the Russian Federation are divided into four types (Table 1).

Table 1

Types of rivers of the Russian Federation depending on the conditions for the formation of the maximum runoff

Formation conditions maximum flow	Distribution areas on the territory of the Russian Federation
Spring snowmelt on the plains	European part of the Russian Federation and Western Siberia
Melting mountain snows and glaciers	North Caucasus
Heavy rainfall	Far East and Siberia
Combined effect of snowmelt and precipitation	Northwestern regions of the Russian Federation

The variety of floods can be reduced to five general groups that combine various floods according to the causes of occurrence and the nature of their manifestation (Table 2).

Within the Russian Federation, floods of the first two types prevail (about 70 - 80% of all cases). They are found on the plains, foothills and mountain rivers, in the northern and southern, western and eastern regions of the country. The remaining three types of floods have a local distribution.

The classification of floods depending on the scale of their distribution and frequency is presented in Table. 3.

table 2

Types of floods depending on the causes and nature of the manifestation

Types of floods	Causes	The nature of the manifestation
high water	Spring snowmelt in the plains or spring-summer snowmelt and rainfall in the mountains	Repeat periodically in the same season. Characterized by a significant and prolonged rise in water levels
high water	Intense rains and snowmelt during winter thaws	There is no clearly defined periodicity. It is characterized by an intense and relatively short-term rise in the water level.
Jam, zazhorny floods (jamming, zazhora)	High resistance to water flow, in certain sections of the river channel, arising from the accumulation of ice material in narrowings or bends of the river during freeze-up (jamming) or ice drift (jamming)	Jam floods form in late winter or early spring. They are characterized by a high and relatively short-term rise in the water level in the river. Jam floods form at the beginning of winter and are characterized by a significant (but less than during a jam) rise in the water level and a longer duration of the flood.
Surge floods (surges)	Wind surges of water in sea mouths of rivers and on windy sections of the coast of the seas, large lakes, reservoirs	Possible at any time of the year. Characterized by the absence of periodicity and a significant rise in the water level
Floods (flooding) formed when dams break	An outflow of water from a reservoir or reservoir, which is formed when a pressure front structure (dams, dams, etc.) breaks through or during an emergency discharge of water from a reservoir, as well as when a natural dam breaks through, created by nature during earthquakes, landslides, collapses, glacier movement	They are characterized by the formation of a breakthrough wave, leading to the flooding of large areas and the destruction or damage of objects encountered on the way of its movement (buildings, structures, etc.)

Table 3

Classification of floods depending on the scale of distribution and frequency

Classes floods	Scale of distribution floods	Repeatability
Low (small)	They do relatively little damage. Covers small coastal areas. Less than 10% of agricultural land is flooded. Almost do not break the rhythm of life of the population.	5-10 years
High	They cause significant material and moral damage, cover relatively large areas of river valleys, flood approximately 10-15% of agricultural land. Significantly violate the economic and everyday life of the population. Lead to the partial evacuation of people.	20-25 years old
Outstanding	They cause great material damage, covering entire river basins. Flood about 50-70% of agricultural land, some settlements. They paralyze economic activity and drastically disrupt the way of life of the population. Lead to the need for mass evacuation of the population and material assets from the flood zone and protection of the most important economic facilities	50-100 years old
catastrophic	They cause enormous material damage and lead to death of people, covering vast territories within one or more river systems. More than 70% of agricultural land, many settlements, industrial enterprises and utilities are flooded. Economic and industrial activity is completely paralyzed, the way of life of the population is temporarily changed	100-200 years

The main characteristics of the water flow are given in table. four.

During flooding, secondary damaging factors may occur: fires (due to breaks and short circuits in electrical cables and wires); collapse of buildings, structures (under the influence of water flow and due to erosion of the base); diseases of people and farm animals (due to contamination of drinking water and food), etc.

Buildings that periodically fall into the flood zone lose their solidity: wood is damaged by rot, plaster falls off, bricks fall out, metal structures corrode, uneven settlement of buildings occurs due to erosion of the soil under the foundation and, as a result, cracks appear.

The main characteristics of the consequences of floods are as follows:

The number of people who find themselves in a zone prone to floods (here they stand out: the number of victims, the number of victims, the number of people left homeless, etc.);
the number of settlements that fell into the zone covered by the flood (cities, urban-type settlements, rural settlements, completely flooded, partially flooded, caught in the flood zone are distinguished here);
the number of objects of various sectors of the economy that ended up in the zone, floods;
the length of railways and roads, power lines, communication and communications lines that are in the flood zone;
number of bridges and tunnels flooded, destroyed and damaged by flooding;
the number of residential buildings flooded, destroyed and damaged as a result of flooding;
the area of ​​agricultural land covered by the flood;
the number of dead farm animals, etc.

Generalized characteristics of the consequences: the magnitude of the damage caused by the flood.

Table 4

Characteristics of the main damaging factor of floods

Basic striking factor	Characteristics of the main damaging factor	Units measurements characteristics
water flow	Maximum water level during the flood (in the considered section of the river)	m or cm
	Maximum water flow during the flood (in the considered section of the river)	m 3 / s
	Current speed (in the considered section of the river)	m/s
	Area of ​​flooded area	km 2
	Duration of area flooding	weeks, days, hours
	Repeatability of the maximum water level	years, months
	Provision of the maximum water level
	Water temperature during a flood	degrees Celsius
	Start time (season) of the flood	month, date
	The rate of rise (intensity of rise) of the water level during the flood	m/h, cm/h
	Layer (depth) of terrain flooding at the considered point	m, cm

The main features of the situation that occurs during floods are: the destructive nature of the emergency, the rapid increase in the parameters of damaging factors, the limited survival time of the victims affected by them; the difficulty of access to the victims, the need to use special floating equipment for this, as well as difficult weather conditions (heavy rains, ice drift, mudflows, etc.).

The main goal of emergency rescue and other emergency work in flood conditions is the search, assistance and rescue of people who find themselves in the flood zone, as soon as possible, ensuring their survival in the current situation.

The success of rescue and other urgent work in the aftermath of floods is achieved by:

Carrying out systematic, advance preparation of command and control bodies and units of civil defense troops, search and rescue units and services for conducting emergency rescue operations; quick response to the occurrence of a natural disaster, alerting and deploying the necessary forces and means, organizing effective reconnaissance and deploying a command and control system;
the use of effective methods and technologies for searching and rescuing victims, as well as methods for protecting the population and economic facilities;

Flood and catastrophic flood rescue operations include:

Search for victims;
ensuring access of rescuers to victims and rescue of victims;
provision of first aid to victims;
evacuation of victims from the danger zone.

Immediate emergency response to floods includes:

Strengthening (construction) of enclosing dams and ramparts;
construction of drainage channels;
elimination of congestion and congestion;
equipment of berths for life-saving equipment;
protection and restoration of road structures;
restoration of power supply;
localization of sources of secondary damaging factors.

The main ways to protect people from the damaging factors of floods are the evacuation of the population from flooded areas, the placement of people in non-flooded parts, undamaged structures and terrain.

Depending on the location of the settlement, the time before the start of its flooding, the state of transport communications and other factors, evacuation can be carried out immediately before receiving a signal about the possible flooding of this area or only with an immediate threat of flooding, on foot or using vehicles. In addition to the evacuation of the population, the export of farm animals, material and cultural values ​​can also be carried out in an organized manner.

The effectiveness of evacuation as a way to protect the population during floods depends mainly on the timely warning of the danger, the degree of preparedness of the population and routes.

To this end, a public warning system is being created in areas of possible flooding, information is provided in advance about the location of settlements regarding a possible danger zone and evacuation routes, training is conducted with the population and evacuation authorities to practice evacuation issues, including independent exit of people to a non-flooded area .

In addition to the direct impact of the water flow, aspiration (entering the respiratory tract) of water, prolonged exposure to cold water, neuropsychic overstrain, as well as flooding (destruction) of systems that ensure the vital activity of the population, especially the failure of systems water supply and sewerage.

With prolonged forced stay of people in water with a low temperature, hypothermia (hypothermia) of the body occurs. When a person gets into the water, hypothermia is possible even at a relatively high temperature (Table 5).

Placement of people on non-flooded parts, non-destructible structures and areas of the terrain is used in cases where the high speed of the water flow causes its rapid arrival in settlements and (or) the population cannot be evacuated to a safe area. In this case, the implementation of such protective measures, as a rule, requires the further implementation of rescue operations to evacuate people from temporary accommodation in the danger zone. At the same time, it should be borne in mind that the population can also use the upper parts of trees as a place of temporary residence (shelter).

Table 5

The safe time for a person to stay in the water

Water temperature, °C	Time of safe stay, min
	420-540
5-15	10-270
	10-15
Up to 2

The decision to carry out emergency rescue and other urgent work in case of floods is made on the basis of intelligence data, which is organized during floods to identify the situation in disaster areas in order to minimize damage.

Determining the boundaries of flooding;
control of flood development dynamics;
establishing the locations of people and farm animals in need of help;
identification of material values ​​to be removed from the disaster zone;
selection and reconnaissance of routes for the evacuation of people, animals and material assets by watercraft, equipment of berths;
selection and equipment of landing sites for helicopters in the disaster area.

To carry out emergency rescue operations, units of the civil defense troops, search and rescue teams (services), reinforced with amphibious assault vehicles, are assigned. To perform other urgent work, taking into account their nature, engineering, engineering and technical, road units and formations are assigned.

When searching for and rescuing victims in the water and in flooded areas, aviation technologies using aircraft and helicopters should be widely used.

The use of certain technologies for eliminating ice blockages (blockages) and landslides depends on the scale of floods and the consequences associated with them. Explosives are the main method of destroying the ice cover, eliminating ice blockages (blocks), as well as rock falls. The work is carried out by pyrotechnic units equipped with watercraft and vehicles equipped for the delivery of explosives and explosives. During catastrophic floods, especially on the large rivers of the North and North-East of Russia, flowing from south to north, the destruction of the ice cover, ice jams and ice jams is practiced using bomber aircraft.

Measures to prevent floods and liquidate their consequences are provided for in action plans for the prevention and liquidation of emergency situations, developed at all levels by emergency commissions.

The organization of interaction between the forces of liquidation, the consequences of floods and catastrophic flooding of territories is one of the most important factors ensuring the success of emergency rescue and other urgent work.

Interaction is organized primarily in the interests of rescue units, the implementation of these works in the shortest possible time.

The experience of recent years in eliminating the catastrophic consequences of floods (Yakutia - 2001, the Southern Federal District - 2002) suggests that in order to improve the protection of the population and territories from floods, the executive authorities of the constituent entities of the Russian Federation, local governments can be recommended:

Accelerate the formation of territorial systems for monitoring, laboratory control and forecasting of emergency situations;
to take measures to develop warning systems for the population, paying particular attention to rural areas;
take measures to create and strengthen bank protection structures, repair dams, deepen and clean river beds;
intensify work on the creation of search and rescue units financed from the budgets of the constituent entities of the Russian Federation;
based on this experience, rework action plans for the prevention and elimination of emergency situations;
create full reserves of financial and material resources for the liquidation of emergency situations;
consider the issue of the need (expediency) of redistributing the budget funds of the constituent entities of the Russian Federation in the direction of increasing funds for urgent measures aimed at the safe functioning of the water management complexes of the regions.

Man and his environment form a system consisting of many interacting elements, having order within certain boundaries and possessing specific properties. Such interaction is determined by many factors and affects both the person himself and the corresponding environment of his habitat. This influence can be, on the one hand, positive, on the other hand, it can be negative (negative) at the same time.

Negative impacts of environmental factors are manifested mainly in emergency situations. These situations can be the result of both natural disasters and human production activities. In order to localize and eliminate negative impacts arising in emergency situations, special services are being created, legal frameworks are being developed and material resources are being created for their activities.

Natural emergencies- this is an unfavorable situation in a certain territory, which has developed as a result of a dangerous natural phenomenon that can lead to human casualties, damage to health, material losses and violations of the living conditions of the population.

An emergency emerges only when, as a result of a dangerous natural phenomenon, a real threat to human life and the environment arises. Natural emergencies are also called natural disasters.

On the territory of Russia there are more than 20 types of dangerous hydrometeorological phenomena. These are strong winds, squalls, tornadoes, dust storms, downpours and thunderstorms, hail, heavy prolonged rains, droughts, frosts, snowfalls, snowstorms, ice-frost phenomena, fogs, severe frosts, floods, snow avalanches, mudflows and others.

On the territory of our region, according to various sources, the most common emergency disaster is a flood. I consider it necessary to dwell on the features of this particular disaster.

Flood

Flood - this is a significant flooding of the area as a result of a rise in the water level in a river, lake or sea during the period of snowmelt, showers, wind surges of water, during traffic jams, ice jams, etc.

Flood classification:

1. storm (rain);

2. floods and floods (associated with the melting of snow and glaciers);

3. jamming and jamming (associated with ice phenomena);

4. overwhelming and breakthrough;

5. surge (wind on the coasts of the seas).

The causes of floods are diverse, and each cause or group of causes has its own type of flood. Below we indicate the four main groups of types of floods:

1. Floods associated with the passage of a very large flow of water for a given river. Such floods occur during the period of spring snowmelt, with heavy rainfall and rainfall, in the event of a collapse of dams and breakthroughs of dammed lakes.

2. Floods, caused mainly by the great resistance that the water flow meets in the river. This usually occurs at the beginning and at the end of winter with ice jams and ice jams.

3. Floods due to both the passage of large water flows and significant resistance to water flow. NT1 includes mudflows on mountain rivers and water-snow flows in gullies, ravines and hollows.

4. Floods caused by wind surges on large lakes and reservoirs.

However, direct causes are associated with the implementation of various hydraulic engineering measures and the destruction of dams. Indirect - deforestation, drainage of swamps, industrial and residential development, this leads to a change in the hydrological regime of rivers due to an increase in the surface component of runoff. The total evaporation is reduced due to the cessation of precipitation interception by forest litter and tree crowns. If all forests are reduced, then the maximum runoff can increase up to 300%.

The effects of floods are almost always devastating. Floods lead to the destruction of bridges, roads, buildings, structures, cause significant material damage, and at high water speeds (more than 4 m/s) and high water rise (more than 2 m) cause death of people and animals. The main cause of destruction is the impact on buildings and structures of hydraulic shocks of water masses, ice floes floating at high speed, various debris, watercraft, etc. Flooding can occur suddenly and last from a few hours to 2-3 weeks.

One of the largest floods in Kurgan and the Kurgan region was the 1994 flood. For a month, from April 19 to May 19, 1994, Kurgan was in a state of emergency due to flooding, which affected about 60 thousand people. And this is only in the regional center. About 200,000 people suffered material damage across the region. Also in the spring of that year, four districts of the region, the cities of Kurgan and Shadrinsk, 114 settlements, over 200 thousand hectares of agricultural land were flooded, incl. 140 thousand hectares of arable land. 37 km of highways were violated, 35 bridges, 183 dams, more than 240 km of power and communication lines, a significant number of residential buildings, tens of thousands of garden plots were destroyed and demolished. Enormous damage was done to the nature of the Trans-Urals.

The extent of the damage caused by the flood is enormous. According to the most conservative estimates, they exceed 200 billion rubles.

The official maximum water level in the Tobol near Kurgan then amounted to 10 meters 7 cm.

FLOODING is a significant flooding of the area as a result of a rise in the water level in a river, lake or sea during the period of snowmelt, heavy rains, wind surges of water, during traffic jams, blockages, etc.

Floods caused by wind surge of water in the mouths of rivers are of a special type. Floods lead to the destruction of bridges, roads, buildings, structures, cause significant material damage, and at high water speeds (more than 4 m/s) and high water rise (more than 2 m) cause death of people and animals. The main cause of destruction is the impact on buildings and structures of hydraulic shocks of water masses, ice floes floating at high speed, various debris, watercraft, etc. Floods can occur suddenly and last from a few hours to 2-3 weeks.

Types of flood

Depending on the cause of the flood, they are divided into 5 types:

• high water - flooding resulting from the melting of snow and the release of a reservoir from its natural banks
• flood - flooding associated with heavy rains
• floods caused by large accumulations of ice that clog the riverbed and prevent water from flowing downstream
• surge floods , occurring due to strong winds that drive water in one direction, most often against the current
• floods resulting from dam break or reservoirs.

high water	high water	Congestion	Zazhor	wind surge
recurring, rather prolonged rise in the water level in rivers, usually caused by spring snowmelt on the plains or rainfall. Floods low terrain.	an intensive relatively short-term rise in the water level in the river, caused by heavy rains, downpours, and sometimes rapid snowmelt during thaws. Unlike floods, floods can occur several times a year. A particular threat is the so-called flash floods associated with short-term, but very intense downpours, which also occur in winter due to thaws.	blockage of the channel by a motionless ice cover and heaping of ice floes during the spring ice drift in the narrowings and on the bends of the river channel, hampering the flow and causing a rise in the water level in the place of ice accumulation and above it. Jam floods are formed in late winter or early spring, and occur due to the non-simultaneous opening of large rivers flowing from south to north. Opened southern sections of the river in its course spring up accumulation of ice in the northern regions, which often causes a significant increase in water levels. Jam floods are characterized by a high and relatively short-term rise in the water level in the river.	ice plug, accumulation of in-water, loose ice during winter freezing in narrowings and on the bends of the channel, causing the rise of water in some areas above the level of the main river channel. Jam floods form at the beginning of winter and are characterized by a significant, but less than during a jam, rise in the water level and a longer duration of the flood.	rise in the water level in the sea mouths of large rivers and in windy areas of the coast of the seas, large lakes, reservoirs caused by the impact of strong winds on the water surface. They are characterized by the absence of periodicity, rarity and a significant rise in the water level, as well as, as a rule, short duration. Floods of this type have been observed in Leningrad (1824, 1924), the Netherlands (1953).
periodically for a long time	fast briefly	ice is standing, piling up water can't get out high level briefly	ice plug loose ice low level for a long time	wind from the sea into the riverbed water can't get out high level brevity

Causes of floods:

1. Long rains
2. snowmelt
3. tsunami wave
4. bottom profile
5. Dam failure
6. Other natural and man-made causes

Flood classification:

1. storm (rain);
2. floods and floods (associated with the melting of snow and glaciers);
3. jamming and jamming (associated with ice phenomena);
4. overwhelming and breakthrough;
5. surge (wind on the coasts of the seas);
6. tsunamigenic (on the coasts from underwater earthquakes, eruptions and large coastal landslides).

River floods are divided into the following types:
1. low (small or floodplain) - a low floodplain is flooded;
2. medium - high floodplains are flooded, sometimes inhabited or technogenically processed (arable land, meadows, vegetable gardens, etc.);
3. strong - terraces with buildings located on them, communications, etc. are flooded, evacuation of the population is often required, at least partial;
4. catastrophic - vast areas are significantly flooded, including cities and towns; emergency rescue operations and mass evacuation of the population are required.

According to the scale of manifestation, there are 6 categories of floods:
1. The global flood;
2. continental;
3. national;
4. regional;
5. district;
6. local.

Anthropogenic causes of floods:

Direct causes - are associated with the implementation of various hydraulic engineering measures and the destruction of dams.
Indirect - deforestation, drainage of swamps (draining of swamps - natural runoff accumulators increases runoff up to 130 - 160%), industrial and residential development, this leads to a change in the hydrological regime of rivers due to an increase in the surface component of runoff. The infiltrating capacity of soils decreases and the intensity of their washout increases. The total evaporation is reduced due to the cessation of precipitation interception by forest litter and tree crowns. If all forests are reduced, then the maximum runoff can increase up to 300%.
There is a decrease in infiltration due to the growth of waterproof coatings and buildings. The growth of water-resistant coatings in an urbanized area increases floods by 3 times.

Human activities leading to floods:
1. Restriction of the free section of the flow along the channel roads, dams, bridge crossings, which reduces the capacity of the channel and raises the water level.
2. Violation of the natural regime of discharges and water levels, as occurs on the lower Volga as a result of seasonal regulation of the flow by overlying reservoirs: the need for winter energy forced a 2-3-fold increase in water discharges in winter, which, in the presence of ice cover, is accompanied by an increase in water level (winter floods), often higher than in high water.
3. Development of territories in the downstream pools of reservoirs of long-term flow regulation. The economic development of the floodplains increases the maximum runoff.

flood classes

1. Low. They usually do minor damage. They cover small coastal areas. Agricultural lands are flooded by less than 10%. Almost do not knock out the population from the current rhythm of life. Repeatability - 5-10 years.

2. High. Cause significant damage (moral and material). They cover large areas of river valleys. They flood about 10-15% of the land. Violate both household and economic way of life of the population. Partial evacuation of people is very likely. Periodicity - 20-25 years.

3. Outstanding. They cause great material damage, covering river basins. Approximately 50-70% of agricultural land, as well as a certain part of settlements, is under water. Outstanding floods not only disrupt the way of life, but also paralyze economic activity. It is necessary to evacuate material assets and the population from the disaster zone and protect the main objects of economic importance. Repeatability - 50-100 years.

4. Catastrophic. They cause huge material damage, spreading over vast territories within one or more river systems. Lead to human casualties. More than 70% of the land is flooded, many settlements, utilities and industrial enterprises. Industrial and economic activity is completely paralyzed, and the way of life of the population is changing. Periodicity - 100-200 years.

Danger factors:

1. height of water level change;
2. the rate of its change;
3. the duration of the rise period;
4. accompanying phenomena (wind, landslides, soil erosion, turbulent streams, destruction of agricultural products, livestock, death of people, etc.).

The flow of water as a damaging factor

Characteristics of the water flow as a damaging factor:

1. The highest water level.

2. The highest water consumption.

3. The speed of the current.

4. Area of ​​flooding.

5. Repeatability of the value of the highest water level.

6. Duration of flooding.

7. Water temperature.

8. Security of the highest water level.

9. Time of start of the disaster.

10. The rate of rise in the water level during the entire time of the flood.

11. The depth of flooding of the territory in the area under consideration.

Damaging factors:

The combined effect of waves, wind, rainfall causes flooding of the area. This is accompanied by a significant erosion of the coast, leads to the destruction of buildings and structures, erosion of railways and roads, accidents on utility networks, destruction of crops and other vegetation, casualties among the population and the death of domestic animals and natural ecosystems. After the water falls, buildings and land sag, landslides and landslides begin.

Flood consequences:

The main features of the situation that arises during such natural disasters are: the rapid increase in the strength of damaging factors, the difficulty of access to the victims, the destructive nature of the situation, the low survival rates of the victims, as well as the presence of difficult weather conditions (mudflows, ice drift, heavy rains, etc.). ).

The amount of damage depends on:
1. - lifting heights;
2. - speed of water level rise;
3. - areas of flooding;
4. - timeliness of the forecast;
5. - availability and condition of protective structures;
6. - the degree of population and agricultural development of the river valley;
7. - the duration of standing flood waters;
8. - the frequency of floods (with repeated rises in the water level, the damage is less than with the initial one).

The passage of floods (flooding of agricultural land) after harvesting leads to less damage than before harvesting.
The severity of emergencies during channel floods depends not so much on the absolute value of the rise in the water level, but on its value relative to the altitude of settlements.

How to prepare for a flood?

If your area often suffers from floods, study and remember the boundaries of possible flooding, as well as elevated, rarely flooded places located in the immediate vicinity of places of residence, the shortest routes to them. Familiarize family members with the rules of conduct during organized and individual evacuations, as well as in the event of a sudden and rapidly developing flood. Remember the places where boats, rafts and building materials for their manufacture are stored. Prepare in advance a list of documents, property and medicines taken out during the evacuation. Put valuables, necessary warm clothes, a supply of food, water and medicines in a special suitcase or backpack.

HOW TO PROCEED DURING A FLOOD

At the warning signal of the threat of flooding and evacuation, immediately, in accordance with the established procedure, leave (leave) the danger zone of possible catastrophic flooding to the designated safe area or to elevated areas of the area, taking with you documents, valuables, necessary things and a two-day supply of non-perishable food. Register at the final evacuation point.

Before leaving the house, turn off the electricity and gas, put out the fire in the heating stoves, secure all floating objects that are outside the buildings, or place them in utility rooms. If time permits, move valuable household items to the upper floors or to the attic of a residential building. Close the windows and doors, if necessary and if there is time, board the windows and doors of the first floors from the outside with boards (shields). In the absence of an organized evacuation, stay on the upper floors and roofs of buildings, on trees or other towering objects until help arrives or the water subsides. At the same time, constantly give a distress signal: during the day - by hanging or waving a clearly visible panel lined with a pole, and in the dark - by a light signal and periodically by voice. When the rescuers approach, calmly, without panic and fuss, in compliance with the precautionary measures, go to the swimming facility. At the same time, strictly follow the requirements of the rescuers, do not overload the boats. During the movement, do not leave the assigned places, do not board the sides, strictly follow the requirements of the crew. It is recommended to get out of the flooded area on your own only if there are such serious reasons as the need to provide medical assistance to the victims, the continuing rise in the water level with the threat of flooding of the upper floors (attic). In this case, it is necessary to have a reliable swimming facility and know the direction of movement. During self-advance, do not stop giving a distress signal.

Help people who are swimming in the water and drowning.

IF A MAN DROWNS

Throw a floating object to a drowning person, encourage him, call for help. When reaching the victim by swimming, consider the course of the river. If the drowning person does not control his actions, swim up to him from behind and, grabbing him by the hair, tow him to the shore.

HOW TO ACT AFTER A FLOOD

Before entering a building, check to see if it is in danger of collapsing or falling.

Ventilate the building (to remove accumulated gases). Do not turn on electric lighting, do not use open flames, do not light matches until the room is completely ventilated and the gas supply system is checked for proper operation. Check the serviceability of the electrical wiring, gas supply pipelines, water supply and sewerage. Do not use them until you have verified that they are working properly with the help of specialists. To dry the premises, open all doors and windows, remove dirt from the floor and walls, pump out water from the basements. Do not eat food that has been in contact with water. Organize the cleaning of wells from the applied dirt and remove water from them.