Phenomena occurring in the hydrosphere. Hydrosphere of the earth. Due to heavy rainfall, the village of St. Lorenz in Austria

Often natural processes and phenomena turn into spontaneous natural phenomena. In cases where they cause damage to the economy and pose a danger to human life, they are called natural disasters . Natural disasters usually include earthquakes, floods, mudflows, landslides, snow drifts, volcanic eruptions, landslides, droughts, hurricanes, storms, etc.

Natural disasters can occur either independently of each other or in conjunction: one of them can lead to another. Some of them often arise as a result of human activity (for example, forest and peat fires, industrial explosions in mountainous areas, during the construction of dams, foundation (development) of quarries, which often leads to landslides, snow avalanches, glacier collapses, etc.) .

Regardless of the source of occurrence, natural disasters are characterized by significant scales and varying durations - from several seconds and minutes (earthquakes, avalanches, limnological disasters) to several hours (mudflows), days (landslides) and months (floods).

Examples of natural disasters

During 2009, more than 900 hazardous natural phenomena were observed on the territory of the Russian Federation, of which 385 caused significant damage to sectors of the economy and the life of the population (in 2008 there were 348). In the cold period there were 85 of them, in the warm period - 300.

The most frequently reported hazardous events were: very heavy rain (heavy downpour) – about 16% and very strong wind (including squalls) – more than 14% of the total. A significant part was also accounted for by hydrological phenomena (mudflows, exceeding dangerous levels of water levels in rivers during periods of spring floods and rain floods, etc.) - more than 14% of the total number of dangerous phenomena.

In a number of cases, individual hazardous events caused significant damage to the economy and livelihoods of the country's population.

Heavy accumulation of wet snow was observed in the Volgograd region on January 23-24, 2009 and in the Tver region on January 28-29, 2009. In five districts of the Volgograd region, 105 power line supports were damaged and toppled; power lines are damaged; in the Tver region, due to an emergency shutdown of 475 transformer substations, there was a disruption in the power supply in 8 districts of the region (322 settlements were left without electricity).

As a result of snow avalanches in January-March 2009 in the regions of the North Caucasus, the Trans-Caucasus Highway, local and federal roads were repeatedly blocked, and several people died.

Very strong winds (gusts up to 25 m/s) in the Lipetsk and Tambov regions on April 18, 2009 led to numerous damage to power lines, and power was cut off in a number of settlements. In the Lipetsk region, due to the loss of power to the water intake, 120 thousand people were left without water for 7 hours, the work of vehicles was hampered, and the roofs of houses were damaged; In the Tambov region, 1,845 houses remained without power supply.

Frosts were observed (temperature -10...-3 o C, in some places down to -12 o C) in the Southern Federal District in the periods from April 10 to 15 and from April 20 to 27. In the Kabardino-Balkarian Republic, the Republic of North Ossetia-Alania, the Krasnodar and Stavropol Territories, the Astrakhan and Rostov Regions, damage and death of winter, spring, vegetable and seed crops, as well as fruit and berry plantings were noted.

Severe and prolonged (from late May to August) drought (atmospheric and soil) in the republics of Bashkortostan, Kalmykia, Tatarstan, the Kabardino-Balkarian Republic, the Udmurt Republic, the Astrakhan, Volgograd, Rostov, Samara, and Ulyanovsk regions caused significant damage to grain crops . Crops were written off on the following areas: in the Republic of Tatarstan - 313 thousand hectares, Samara and Orenburg regions - over 1 million 120 thousand hectares, Saratov region - over 555 thousand hectares, Ulyanovsk region - over 116 thousand hectares.

In the Moscow region on June 3, in the Krasnodar and Stavropol territories on July 4, 5, 12 and 13, large hail damaged the roofs of houses, power lines, and agricultural crops.

As a result of very heavy rain in the Republic of Dagestan on September 20-21 and 26-28, 2009, residential buildings were flooded and in some places partially destroyed, household plots were flooded, roads were washed out, and in the Kizilyurt district - 150 m of the railway track, which caused the accident freight train.

What is the importance of water for the nature of the Earth?

Water is the basis of life on Earth. Life itself originated in water. Water is sediment. Living organisms contain water. She is the main participant in many chemical reactions. Water is a habitat for many organisms.

What parts does the hydrosphere consist of?

The hydrosphere consists of the waters of the World Ocean, land waters, groundwater and glaciers.

How are all parts of the hydrosphere connected to each other?

All parts of the hydrosphere are interconnected by the water cycle.

Questions and assignments

1. What adverse natural phenomena are associated with the hydrosphere? Which ones are available in your area?

The water element is the cause of destructive natural disasters that pose a great threat to humans. Common adverse events are floods and avalanches.

2. What are the main causes and consequences of river floods?

Of all the natural disasters that occur on Earth, floods cause the greatest damage. This is the flooding of an area with water as a result of its rising in the sea, river or lake. Floods occur on 3/4 of the land area. Water floods settlements, buildings, and fields. Buildings are destroyed, crops are destroyed, and there are casualties. Floods on rivers occur due to prolonged rains, rapid melting of snow, and dam breaks. On the shores of the World Ocean they happen when the wind pushes water onto land. To protect against them, special structures are erected - dams.

3. What is the importance of rivers and lakes in the life and economic activities of people?

River waters are used for irrigation in arid areas and for the construction of hydroelectric power stations. Large rivers are used for navigation. Lakes most often have recreational value. Many lakes become objects of fisheries. The waters of some lakes are used in industry and energy for cooling.

4. How has human water consumption changed over time?

Human water consumption is growing every year. During the 20th century, water consumption increased more than 12 times.

5. Why are dams built on rivers and reservoirs created?

Dams and reservoirs are built on rivers to generate energy from hydroelectric power plants.

6. What influence does man have on the hydrosphere?

Half of all water used by people is spent on irrigating fields. Another 1/4 of the share is consumed by industry. In third place are urban services and human needs. This use causes pollution of the hydrosphere. Waters are polluted by chemicals and mechanical particles. Thermal pollution also occurs, which affects the microclimate. Many rivers and lakes have become shallow due to excessive water intake. Groundwater pollution and depletion occurs.

7. Why should a person care about the quantity and quality of water?

Fresh water reserves are small. They are distributed unevenly across the territory of our planet. Human water consumption is growing every year. Many areas are already experiencing a severe shortage of drinking water. In addition, the degree of pollution of the hydrosphere is growing. Life without water is impossible for humans, so it is necessary to take care of the state of the hydrosphere.

8. If chemicals are used in the river basin and in the fields, is it possible for them to appear at the river mouth and why?

The chemicals will almost certainly end up at the river mouth. Together with precipitation, chemicals will flow into the river waters. The water in the river moves towards the mouth. Therefore, all substances dissolved in the water will end up at the mouth of the river.

Dangerous (natural) hydrological phenomena include various fast-moving floods, accompanied by high water levels (during floods, floods, congestion, ice jams, surges, etc.) and slow changes in the level of the ocean and closed lakes, exceeding particularly dangerous (critical) levels water for specific settlements and economic facilities.

Flood is understood as a significant inundation of an area with water as a result of a rise in the water level in a river, lake, reservoir and sea and their spilling above the normal horizon, which causes material damage, harms the health of the population, and leads to the death of people.

Floods occur during floods and freshets, i.e. when the water level rises in the spring from melting snow and in the fall due to heavy rains, from the accumulation of ice during ice drifts that reduce the cross-sectional area of ​​the river, from the intensive melting of glaciers and snow cover located high in the mountains, and also during winds from the sea (surge floods). In addition, flooding can occur as a result of the formation of blockages or bridges on rivers during earthquakes, mountain falls or mudflows, under the influence of gravitational waves from an underwater earthquake, as well as when dams break.

Floods (not counting the surges that accompany hurricanes) rank first in the world in terms of the number of created or natural disasters (40% of all emergencies), second or third place in the number of victims, place in the top three in terms of the long-term average and the maximum one-time value of direct economic damage.

In terms of frequency, area of ​​distribution and total average annual material damage nationwide, floods rank first among natural disasters, and in terms of human casualties and damage per unit of affected area, they rank second after earthquakes.

Let's look at the main characteristics of floods.

The water level is considered to be the height of the water surface in a river (lake) above a conventional horizontal comparison plane, called the zero point of the post. The height of this plane is measured from sea level. In the mouth areas of rivers flowing into the sea, the water level is measured above the ordinary level, that is, above the average long-term level at a given point. The sum of two quantities - the water level at the post and the zero mark of the post - represents the absolute level mark, i.e. the excess of the water surface in the river above the sea surface. In the Baltic height system, heights are calculated from the average level of the Gulf of Finland near the city of Kronstadt.

Water flow is the amount of water (in m3) flowing through the end of a river per second. The graphical relationship between flow and water level is called a flow curve, and the graph of changes in water flow over time is called a runoff hydrograph.

The criterion for natural hydrological phenomena is the maximum water level, which is associated with some other important characteristics of the flood - area, layer, duration and rate of water level rise.

For cities and towns there are concepts of flooding and inundation. When flooding occurs, water penetrates into the basement through the sewer system (if it has outlets into the river), through various kinds of filled-in ditches and trenches (they contain heating, water supply and other networks) or due to groundwater back-up. In the event of flooding, the area is covered with a layer of water of varying heights.

Factors of danger (damage) during flooding are:

the height of the level change, which affects the area of ​​the area being flooded or drained;

rate of change of water level;

the duration of the period of deviation of the water level from the norm;

accompanying phenomena (wind, air temperature, landslides and soil erosion, etc.).

Rivers differ from each other in different conditions for the formation of water flow. According to the conditions for the formation of runoff and, consequently, according to the conditions for the occurrence of floods, the rivers of the Russian Federation are divided into four types (Table 2.12).

Table 2.12 - Distribution of factors influencing the occurrence of floods by region of Russia

The variety of floods can be reduced to five groups based on the reasons for their occurrence and the nature of their manifestation (Table 2.13). On the territory of the Russian Federation, floods of the first two types predominate (70-80% of all cases). They are found on lowland, foothill 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.

Table 2.13 - Types of floods

Factors influencing the magnitude of the maximum rise in water level during various types of floods are given in Table. 2.14. Based on the initial causes, floods are divided into surge, storm (rain), floods (associated with the melting of snow and glaciers), ice jams and jams, dams and breakthroughs.

Table 2.14 - Factors influencing the scale of flooding

Floods passing along rivers are divided by height:

to low or small ones (low floodplains are flooded);

medium (high floodplains, partially populated, are flooded);

strong or outstanding (cities and communications are partially flooded, evacuation of the population is required);

catastrophic (cities are significantly flooded, major rescue operations, mass evacuation are required).

Different types of floods occur in each region, with severe and catastrophic ones usually created by the coincidence of two or more factors (for example, snowmelt plus rainfall, rainfall plus dam failure, etc.), which made it possible to develop a classification of floods taking into account the scale of their distribution and frequency ( Table 2.15).

Table 2.15 - Classification of floods by scale

Measures in case of threat of flooding of populated areas and territories

Flood protection measures are divided into operational (urgent) and technical (preventive).

Operational measures do not solve the problem of flood protection as a whole and must be carried out in conjunction with technical measures.

Technical measures include advance design and construction of special structures. These include: regulation of flow in the riverbed; drainage of flood waters; regulation of surface flow on spillways; embankment; river channel straightening and dredging; construction of bank protection structures; backfilling of the built-up area; restriction of construction in areas of possible flooding, etc.

The greatest economic effect and reliable protection of floodplain areas from floods can be achieved by using an extensive set of measures, combining active protection methods (drainage regulation) with passive methods (embankment, channel dredging, etc.). The choice of protection methods depends on a number of factors: the hydraulic regime of the watercourse, the terrain, engineering-geological and hydrogeological conditions, the presence of engineering structures in the riverbed and on the floodplain (dams, dikes, bridges, etc.), the location of economic facilities subject to flooding.

The main directions of action of executive authorities in the event of a threat of flooding are:

analysis of the situation, identification of sources and possible timing of flooding;

forecasting types (types), timing and scale of possible flooding;

planning and preparation of a set of standard measures to prevent flooding;

planning and preparation for emergency rescue operations in areas of possible flooding.

At the federal level, the Russian Ministry of Emergency Situations carries out planning and preparation of events on a national scale. At the regional level, regional centers of the Russian Ministry of Emergency Situations plan and prepare activities within their competence. At the level of the region, territory, republic, events are planned and prepared in their territories. During the period of threat of flooding, the management bodies of the Civil Defense and Emergency Situations of the constituent entities of the Russian Federation operate on high alert. When there is a threat of flooding, flood control commissions operate on standby:

organize round-the-clock monitoring of flood conditions in their area of ​​responsibility, using Roshydromet posts and their observers;

maintain constant contact and exchange information with emergency commissions and operational duty officers of civil and emergency situations management bodies;

conduct exercises (trainings) on flood control topics and organize training for the population on rules of conduct and actions during floods;

send reports to higher authorities;

clarify and adjust flood control plans taking into account the current situation;

by decision of the heads of territorial administrations, round-the-clock duty of rescue forces and equipment is organized;

specify (provide) places (areas) for the temporary resettlement of affected residents from flooded (destroyed) houses, organize the preparation of public buildings or tent camps to accommodate evacuees;

provide for the provision of the evacuated population with everything necessary for life;

coordinate with local authorities of the Ministry of Internal Affairs of the Russian Federation and local self-government the procedure for protecting property located in the flood zone;

organize round-the-clock duty to monitor changes in water levels at flood sources;

participate in the organization and equipment of bypass transport routes to replace flooded sections of roads;

organize (control) the strengthening of existing and construction of new dams and embankments;

organize and maintain interaction with the governing bodies of the Ministry of Defense of the Russian Federation, the Ministry of Internal Affairs of the Russian Federation, territorial departments (departments) of Roshydromet, territorial divisions of the All-Russian Service for Disaster Medicine.

During the period of threat of spring floods and floods on rivers, flood control commissions must provide for:

boundaries and sizes (areas) of flood zones, the number of administrative districts, settlements, economic facilities, roads, bridges, communication and power lines falling into flood and inundation zones;

the number of victims, as well as those temporarily resettled from the flood zone, destroyed (emergency) houses, buildings, etc.;

volumes of pumping water from flooded structures;

number of heads of dead farm animals;

location and dimensions of constructed dams, dams, embankments, fastenings of bank slopes, drainage channels, pits (siphons);

preliminary amount of material damage;

the number of forces and assets involved;

measures to protect the population.

During the preparatory period, an important role is played by analyzing the situation and forecasting possible flooding of populated areas. Analysis of the situation involves identifying possible causes of the threat of flooding of populated areas, which may include high water and high water, as well as factors contributing to the occurrence of flooding and flooding. At the same time, possible emergency scenarios are identified in which:

the living conditions of people on the territory of administrative districts of a constituent entity of the Russian Federation are significantly violated;

human casualties or damage to the health of a large number of people are possible;

there may be significant material losses;

significant damage to the environment is possible.

Identification of the listed emergency situations associated with flooding of territories is carried out on the basis of: statistical data on floods and long-term observation data for a given territory; studying action plans for industrial facilities in the event of an emergency; own assessments of the territorial management bodies of the RSChS.

Based on the identified factors contributing to the occurrence of emergencies, as well as secondary factors that pose a threat to the population and economic facilities, the following is carried out: an assessment of the likelihood of an emergency occurrence; assessment of the scale of a possible emergency.

The scale should be understood as: the number of deaths; number of victims; the amount of material damage; the volume of evacuation measures and protection associated with the evacuation of the population; costs of emergency response and restoration work; indirect losses (short production, costs of benefits, compensation payments, pensions, etc.), etc.

An assessment of the probability of occurrence and scale of emergencies caused by accidents at industrial facilities and life support systems due to the influence of secondary factors is carried out by the administration of the relevant facilities. Forecasting and assessing the scale of emergencies should be carried out taking into account the requirements of laws, other regulations and methods recommended by the Russian Ministry of Emergency Situations. In the absence of such documents for individual specific cases, the executive authorities of the constituent entities of the Russian Federation will organize research to assess the likelihood of an emergency occurrence and to assess the scale of the emergency by the forces of the constituent entity of the Russian Federation.

The results of identifying factors contributing to the occurrence of emergencies associated with flooding of territories and populated areas serve as the basis for making decisions on the implementation of preventive measures. Based on an analysis of the situation, flood prevention measures are planned. Planning is regulated by the Federal Law “On the Protection of the Population and Territories from Natural and Technogenic Emergencies”, regulatory legal acts of state authorities of the constituent entities of the Russian Federation and local governments. In this case, it is advisable to distinguish between subject (target) and operational planning.

Subject planning should include organizational, financial, economic, engineering and technical measures to prevent or reduce the risk of flooding. Operational planning provides for a set of organizational and technical measures to prepare the population, economic facilities and territories for an emergency situation. These measures should be reflected in plans for the socio-economic development of territories, plans for the development of economic sectors, and economic facilities.

A typical procedure for planning measures to prevent emergencies caused by flooding includes:

identification of organizations and institutions that may be involved in organizing and implementing emergency prevention measures;

development and feasibility study of organizational and engineering measures to prevent or reduce the risk of emergency situations;

development and feasibility study of measures to reduce the severity of the consequences of emergency situations on the population, economic facilities and the environment.

The developed plans are coordinated with interested bodies and organizations, approved by the relevant heads of executive authorities and sent to the implementers. Control over the implementation of plans is carried out by the executive power of the territory through the territorial management bodies of the RSChS.

Let's consider the main measures to reduce the consequences of congestion and gluttons. Congestion cannot be eliminated; it can only be loosened somewhat or moved to another location. When combating ice jam floods, it is necessary to regulate the flow of ice material. Effective measures to combat congestion are:

destruction by blowing up ice fields with explosive charges, bombing, and artillery shelling;

chemical destruction of ice by sprinkling with various salts;

ice breaking by icebreakers or hovercraft;

maneuvering water flow through a dam.

It is advisable to use an explosive method of control during the period of congestion. On wide rivers, the detonation of ice fields begins below the jam and along the banks. On narrow and medium-sized rivers, ice should be undermined from top to bottom downstream or simultaneously along the entire length of the jam.

With the chemical method of breaking ice, its melting point is lowered by distributing salt over its surface. Sometimes, to destroy the ice cover, it is sprinkled with ground slag with the addition of salt, that is, the ice is blackened at a consumption rate of 1-3 t/ha, scattered in strips 5-10 m wide in places of future cracks and near the coast.

When destroying ice fields and the body of the jam by icebreakers, the latter must move from bottom to top along the river bed and create a zigzag channel in the body of the jam with a width of at least the length of the vessel. Hovercraft are used to destroy ice cover up to 1 m thick.

The most radical means of combating congestion is to maneuver the flow of water through the dam. The effectiveness of this method depends on the power of the mash, the volume and duration of water flow, ice conditions and weather conditions.

1. Residents of any settlement should know whether the settlement in which they live is located in a possible flood zone. If it is, then you need to know: where, to which areas evacuation should be carried out in the event of a flood threat, and along what routes. Evacuation should be carried out upon receipt of information about the threat of flooding. If possible, pets are also evacuated.

2. Before leaving the house, you must turn off the electricity and gas. When evacuating, you must take with you documents, valuables, the most necessary things and a supply of food. It is advisable to protect part of the property that cannot be taken with you from flooding and move it to the upper floors, to high places.

3. During a flood, you must:

try to collect everything that may be useful: flotation devices, lifebuoys, ropes, ladders, signaling devices;

save people cut off from others by the elements, provide first aid to the victims;

if there is a danger of ending up in the water, then before help arrives, take off your shoes and get rid of heavy and tight clothing;

fill your shirt and trousers with light floating objects (balls, empty closed plastic bottles, etc.);

use tables, car tires, spare tires, life belts to stay on the surface;

before slipping into the water, you need to inhale the air, grab the first object you come across and float with the flow, trying to remain calm;

jump into the water only at the last moment, when there is no hope of salvation.

4. The crossing (exit) of people during a flood is permitted only along a ford with a depth of no more than 1 m designated for this purpose. If necessary, evacuation is carried out on rafts, boats, cutters, all-terrain vehicles and other means.

5. After the end of the flood, before entering the building, make sure that it does not threaten to collapse and inspect the existing damage. In this case, you must not use open fire. You should check whether the power supply is turned off, whether there are exposed electrical wiring or possible short circuits, or whether there is a gas leak.

6. You should not eat food that has been in contact with flood waters. Drinking water should also be tested before use.

7. Floods may be accompanied by natural phenomena such as landslides, mudflows, and the fact that the dangers caused by floods include outbreaks of epidemics, loss of livestock, destruction of agricultural crops, destruction of sewer lines, water pollution, destruction of gas and electricity supply lines .

earthquake fire tsunami

Hydrosphere("hydro" - water) - the water shell on the surface of the Earth, covering oceans, seas, rivers, lakes, swamps, groundwater, mountain and cover glaciers (frozen water).

Types of natural disasters in the hydrosphere are shown in Fig. 1.9.

Rice. 1.9. Types of natural disasters in the hydrosphere.

In table 1.11. classification of waves is given.

Table 1.11

Wave classification

The most dangerous waves are tsunamis.

Tsunami- gravitational waves of very long length and height, arising on the surface of the seas and oceans (translated from Japanese - a large wave in the bay).

Tsunami waves are similar to wind waves, but they have a different nature - seismic. The wave length - the distance between adjacent crests - is from 5 to 1500 km, which does not allow the second, third and subsequent waves to be seen.

In Russia, tsunamis are possible on the Kuril Islands, Kamchatka, Sakhalin, and on the Pacific coast.

In table 1.12. The damaging factors of a tsunami are given.

Table 1.12

Damaging factors

The number of waves reaches seven, with the second or third wave being the strongest and causing the most severe destruction. Tsunami force is estimated by magnitude M from 0 to 3 (up to 6 points).

Tsunami harbingers: - Earthquake; - Low tide at inopportune times (rapid exposure of the seabed), lasting up to 30 minutes; - Flight of wild and domestic animals from places of possible flooding to higher ground; - Thunderous noise heard before the waves approach; - The appearance of cracks in the ice cover off the coast.

Actions of the population during a tsunami

River Flood- flooding with water of the area within the river valley and settlements located above the annually flooded floodplain, due to a heavy influx of water as a result of snowmelt or rain, or blockage of the riverbed with ice and slush. The causes of floods and their classification are given in table. 1.13.

Table 1.13

Classification and causes of floods

The largest areas of floodplain flooding are observed on rivers flowing to the northern seas - Ob, Yenisei, Lena. Surge floods are observed in the Azov and Caspian Seas, at the mouth of the Neva rivers on the Baltic Sea and the Northern Dvina on the White Sea. In table 1.14 shows the damaging factors of floods.

Table 1.14

Damaging factors

Actions of the population during a flood.

The presentation “Natural natural phenomena of the hydrosphere” is intended to summarize the “Hydrosphere” section in 6th grade geography lessons. The purpose of this presentation is to summarize the material studied. And also show that water has a powerful destructive force. The presentation shows such natural phenomena of the hydrosphere as mudflows, avalanches, tsunamis, floods and sinkholes. Students can assess the damage caused by these natural disasters. This presentation can be demonstrated both in lessons and during discussions within the framework of the decade of geography.

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“Presentation on geography on the topic “Natural natural phenomena of the hydrosphere” (6th grade)”

Spontaneous natural

hydrosphere phenomena

Zaitseva Elena Vladimirovna

geography teacher

MBOU Irkutsk Secondary School No. 73

FLOOD -

this is a significant flooding of an area as a result of rising water levels in a river, lake or sea during snowmelt, rainfall, wind surges, congestion, etc.

Tsunami in Thailand,

Tsunami in Japan,

Heavy rainfall led to a mudflow

in Crimea.

Due to heavy rainfall, the village of St. Lorenz in Austria

was completely swept away by the mudflow.

Due to a sharp rise in water levels due to heavy rains

The village of Arshan was flooded and mudflows occurred.

SNOW AVALANCHE is a mass of snow falling or moving at a speed of 20 - 30 m/s or more.

Northern Norway

Everest

An avalanche occurred on the India-Pakistan border

Karst sinkhole –

This is a sinkhole of natural origin.

A sinkhole occurs when groundwater erodes soil and rocks, causing the ground to fall into the resulting void.