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Desertification as an environmental problem. The problem of desertification and ways to solve it. The problem of providing fresh water as a global environmental problem

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Desertification (desertion, progressive formation of the desert, or Sakhelsky syndrome) is the process of land degradation in relatively dry (arid, semi-criticism and arid sub-humid) regions of our planet, caused by various factors, including the natural change in climate and human activity.

This land degradation leads to the expansion or formation of the desert, or to the appearance of the conditions of the external environment similar to the conditions of the desert. At the same time, the step of formation of the steppes preceding desertification is called the steppe formation. Currently, as a result of this process, the total area of \u200b\u200bfertile lands on the planet is reduced annually by approximately 12 million hectares, which is approximately equal to the area of \u200b\u200barable land of Germany. At the same time, there is a tendency to further deterioration.

Deattification can progress under the action of wind erosion, denudation (washed with water), salinization and reduction of soil linations. An essential cause of desertification is human activity, i.e. Dissertation is largely anthropogenic. However, in addition, natural fluctuations in the volume of precipitation play an important role in this process, while drought periods can provoke or strengthen the deercion process.

The problem of desertification It has gained more serious importance in the early 70s of the 20th century due to drought and associated catastrophic hunger in the natural zone of the Sahal in Africa. In 1977, in the capital of Kenya Nairobi, within the framework of the first UN conference conference on combating desertification, it was recognized that the Biosphere was degraded on Earth, caused by the following human intervention factors in nature:

Eating vegetable cover pets,

Exhaustion of land as a result of their excessive use,

Cutting out forests

Irregular methods of irrigation.

The most common type of human intervention in nature is to eat vegetable cover with pets, while it is meant that the livestock livestock per unit area of \u200b\u200bland is too large for the arid climatic conditions of this territory. Therefore, due to the grazing of animals, plant cover is becoming increasingly rare, and soil breaks. This leads to an increase in soil erosion, which further worsens the conditions for plant growth.

The following in nature, the form of interventions in nature is the exorbitant use of arable land.

Abbreviated periods of rest of the Earth under the ferry, improper irrigation methods, contributing to erosion to sprinkle inclined land areas on the slopes of hills and inappropriate types of cultivated plants cause changes in the soil that lead to a reduction in plant cover and thereby enhancing erosion. The habitats in the soil deteriorate under the influence of chemicals, such as fertilizers or pesticides, as well as due to its mechanical sealing by agricultural machines, which can lead to the extermination of many species of animals living in the soil (for example, rainwrites).

And finally, the substantial cause of desertification is also cutting down forests in arid areas. The cutting of forests for the arable land and the need for heating and construction has led to a catastrophic reduction in forests in many arid areas of the Earth, in particular in many densely populated African regions, where wood is still the most important energy carrier.

However, the fight against desertion is extremely difficult. Excessive use of arable land and climatic changes may have the same consequences and be interrelated, which makes it very complicating the task of determining the causes of the onset of the desert and adopt adequate countermeasures. In this direction, a special role is assigned to the study of the past (ie, the history of desertification), as it allows to carry out a clearer border between natural and anthropogenic factors. At the same time, the results of recent studies of the history of desertion in Jordan questioned the effectiveness of the current measures to protect vegetation and land in conditions of progressive climate change and the human ability to change. So, for example, the enhancing climate warming, it may well lead to extinction of artificial forests.

Desertification or desertation - land degradation in arid, semi-derived (semi-samide) and arid (sub-day) regions of the globe, caused by both human activity (anthropogenic causes) and natural factors and processes.

The term "climatic desertification" was proposed in the 1940s by the French explorer wan. The concepts of "land" in this case means a bioproduct system consisting of soil, water, vegetation, other biomass, as well as environmental and hydrological processes inside the system.

Land degradation is a decrease in or loss of biological and economic productivity of arable land or pasture as a result of land use. It is characterized by the drainage of the Earth, the fading of vegetation, a decrease in the linations of the soil, as a result of which the rapid wind erosion and the formation of dust storms becomes possible.

Desertification refers to the difficult consensus effects of climate change, since the restoration of one conventional centimeter of fertile soil cover leaves in an arid zone on average from 70 to 150 years.

The consequences of desertification in environmental and economically, very significant and almost always negative.

The productivity of agriculture decreases, reduced the variety of species and the number of animals, which especially in poor countries leads to even greater dependence on natural resources. Desertification limits the availability of elementary ecosystem services and threatens the safety of people.

In recent years, disturbing signals are heard from different parts of the globe on the increasing occurrence of the desert on the territory owned by man.

For example, according to the UN, only in North America the desert annually takes about 100 thousand hectares of useful lands.

1. Desertification, nature of its occurrence, methods of struggle

The most likely reasons for this rather dangerous phenomenon are adverse weather conditions, the destruction of plant cover, irrationality of environmental management, mechanization of agriculture, transport without compensation for damage caused by nature. In connection with the strengthening of the desertification processes, individual scientists talk about the possibility of exacerbation of the food crisis.

According to UNESCO, over the past 50 years, the territory of a little less than half of South America is converted into fruitless deserts.

This happened as a result of excessive wrapping of pastures, predatory cutting of forests, unsystematic management of agriculture, construction of roads and other engineering structures.

The rapid growth of the population and technical means also leads to a number of areas of the world to strengthen desertification processes.

There are many different factors leading to desertification in the Aridal regions of the globe.

However, among the bottoms are allocated general, playing a special role in strengthening desertification processes. These include:

· Extermination of vegetation cover and destruction of soil cover with industrial, irrigation construction;

· Vegetable degradation with excessive grazing;

· Destruction of wood-shrub vegetation as a result of fuel workpiece;

· Deflation and soil erosion with intense bearer agriculture;

· Secondary salinization and soil fever in irrigated agriculture;

· Landscape destruction in mining areas due to industrial waste, waste and drainage discharge.

Among the natural processes leading to desertification are most dangerous:

· Climatic - an increase in arid, reducing moisture reserves caused by a change in macro - and microclimate;

· Hydrogeological - precipitation becomes irregular, nutrition underground water - episodic;

· Morphodynamic - geomorphological processes become more active (erosion, deflation, etc.);

· Soil - soil drying and their salinization;

· Phytogenic - degradation of soil cover;

· Zogenic - reducing the population and the number of animals.

The fight against desertification processes is carried out in the following directions:

· Early detection of desertification processes in order to prevent and eliminate, orientation on the formation of conditions for rational environmental management;

· Creation of protective forest strips on the outskirts of oases, field boundaries and along the channels;

· Creation of forests and green "umbrellas" from local breeds - Psamofitov in the depths of the desert to protect livestock from strong winds, scoring rays of the sun and strengthen the feed base;

· Restoration of plant cover in the territories of open mining developments, along the construction of an irrigation network, roads, pipelines and all places where it is destroyed;

· Fixing and afforesting movable sands in order to protect against sandy drifts and blowing irrigated land, channels, settlements, iron and highways, oil and gas pipelines, industrial enterprises.

The main lever of the successful solution of this global problem is international cooperation in the field of nature conservation and the fight against desertification.

From how timely and immediately, the tasks of controlling and managing natural processes will be solved, the life of the Earth and life on Earth depends in many ways.

Problems of combating adverse phenomena observed in the arid zone exist for a long time.

It is believed that from 45 revealed reasons for desertification, 87% fall on the irrational use of water, land, vegetation, animal peace and energy, and only 13% refers to natural processes.

Nature Protection is a very widespread concept.

It includes not only measures for the protection of specific areas of the desert or individual species of animals and plants. In modern conditions, this concept includes measures to develop rational methods of environmental management, restoration of ecosystem destroyed by man, predicting physico-geographical processes during the development of new territories, the creation of managed natural systems.

Impact of agriculture on the environment

3.5 Desertification

One of the global manifestations of soil degradation, and the whole environment as a whole, is desertification. According to B. G. Rozanov ...

Degradation of soil resources

2.1 Soil erosion (water and windy) and methods to combat it

Erosion is a natural process due to the flush of the top horizons of the soil predominantly storm sediments ...

Pollution of the atmosphere and its effect on the ozone layer of the Earth

Methods to combat the advent of ozone holes

The problem of the threat of the ozone layer led to the conclusion of one of the first, rigidly mandatory international agreements in the field of environmental protection, the Vienna Convention for the Protection of the Ozone Layer, signed in 1985

Forest and peat fires

2.2. Methods of struggle with forest and peat fires.

The liquidation of a fire consists of a fire stop, its localization, brave and oculion.

The elimination of mass forest and peat fires is often complicated to the inaccessibility of the extinguishing areas and their remoteness from the sources of water supply ...

New ecological consciousness

10. Concepts - "Object (person) - an object (nature)" and "Subject (person) - an object (nature)"

From a psychological point of view, it is important to note that the search for environmental problems is built in public consciousness using the same logic that led to their occurrence and means ...

Definition of the sanitary protection zone of the enterprise

1.4 Measures to combat pollution

The main measures to combat the contamination of the atmosphere are: the diplomatic application of economic sanctions (the procedure for pollution provides a multiple payment of payments when PDV or unauthorized emissions is exceeded) ...

2.
Desertification - Global Problem

Desertification is defined as the destruction of arid and semi-arid lands as a result of climate change and human activity and "listed among the main hazards for the environment of the entire planet and society" ...

Desertification of the Republic of Kalmykia

3.3 The influence of the climate and its changes to desertification

The processes of desertification in Kalmykia began to develop at the end of the 19th century.

Since then, the state of the land of Kalmykia has changed a lot, as is known for the worse. All this time segment can be divided into 3 periods ...

Plate heat exchangers

3. Problems of control of pollution

Many experts note the loss of thermal efficiency of PTO during operation due to contamination of the heating surface. For example, colleagues from ...

The problem of hunger in the concept of sustainable development

2.3 Attempts to combat hunger

How does humanity try to fight this global concerning all countries in general and each separately, a problem?

The world community has repeatedly put the goal of eliminating hunger or at least reduce its sharpness ...

Smoothing his causes and consequences.

Ways to reduce the pollution of the atmosphere

Methods of combating CO could

He was able to carry a greater danger to the entire biosphere. The fight against it is one of the most important tasks in solving an environmental issue. At the urban level, the struggle of CO was able to adopt various legislative measures ...

Man as a biological and social organism of nature

1.
Man as a biological and social organism of nature. Nature and human essence as a cause of an environmental problem. Contradictions between the biological and cultural evolution of human society

The history of human society on Earth is the history of environmental management. Thanks to the achievements of science and technology, a person has received powerful tools in its hands ...

Environmental problems of the world economy

2.4 deforest and desertification

The deforestation is the process of transformation of land engaged in the forest, in land without wood cover, such as pastures, cities, empty and others.

The most frequent cause of deforestation - cutting the forest without a sufficient landing of new trees ...

Ecological and Economic Justification of the selection of the reactor model for the process of catalytic purification of exhaust gas CHP from sulfur dioxide

3. Methods of combating SO2 emissions

For the disposal of exhaust gases from gaseous and vapor toxic substances, the following methods are used: absorption, adsorption, catalytic, thermal, condensation and compression.

Absorption methods of cleaning ...

Ecosystems tundra.

desertification in the world

Soil fertility. Biological pollutants

2. Salmon and soil desertification, fertility loss

Sparely called those soils (solonits, solones and solodys), which contain salts solutions in the upper horizons, in an amount of non-suitable cultivated plants (and sometimes for the life of plants in general) ...

Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

Posted by http://www.allbest.ru/

During the disarm of the fields of the Miriad, particles of fertile soil cover rise into the air, dissipated, demolished with fields of water flows, are deposited in new places, in huge quantities are irretrievably carried into the world ocean. The natural process of destroying with water and the wind of the upper layer of the soil, washing and dispelning its particles is repeatedly enhanced and accelerated when the lulils are unpacked too much lands and do not give the soil to relax.

Under the influence of living organisms, water and air on the surface layers of the lithosphere, the most important ecosystem, thin and fragile, - the soil called the "Skin of Earth" is gradually formed. This is a keeper of fertility and life. The handful of good soil contains millions of microorganisms that support fertility. In order for a layer of soil with a capacity of 1 cm, a century is required. It may be lost forever for one field season. According to the estimates of geologists, before people began to engage in agricultural activities, the mouth of cattle and break the lands, the rivers demolished about 9 billion tons of soil annually into the world ocean. Now this amount is estimated at about 25 billion tons.

Soil erosion is a purely local phenomenon - now gained universal. In the US, for example, about 44% of the treated lands are subject to erosion. In Russia, we disappeared with U4 Great rich blacks with a content of humus at 14-16%, which called the Citadel of Russian farming. In Russia, the area of \u200b\u200bthe most fertile lands with the content of Gumus 10-13% decreased almost 5 times.

A particularly heavy situation occurs when not only the soil layer is demolished, but also the mother breed, on which it develops. Then the threshold of irreversible destruction comes, an anthropogenic desert occurs. The striking picture is a Schillon Plateau in the Cherapunji area located in the north-east of India. This is the wet place of the world, where on average more than 12 meters of precipitation falls per year. But in the dry season, when monsoon livne ceases (in October - May), Cherapunji district resembles a semi-desert. Soils on the slopes of the plateau are practically washed, fruitless sandstones were exposed.

One of the global and fleeting processes of our time to expand desertification, fall and, in the most extreme cases, complete destruction biological potential Earth, which leads to conditions similar to the conditions of the natural desert.

Natural deserts and semi-deserts take more than 1/3 ground surface. About 15% of the world's population lives on these lands. The desert is the territory with an extremely dry continental climate, usually receiving on average 150-175 mm precipitation for the year. Evaporation from them is much higher than their moisturizing. The most extensive desert arrays are located on both sides of the equator, between 15 and 450 northern latitudes, and in Central Asia and Kazakhstan, the deserts reach 500 northern latitudes. Deserts are natural formations that play a certain role in the overall environmental balance of planet landscapes.

As a result of human activity by the last quarter of the XX century. There were also more than 9 million km2 deserts, and they have already embraced 43% of the total Sushi Square.

In the 90s. Desertification began to threaten 3.6 million hectares of arid lands. Is it 70% of potentially productive arid lands, or? The total area of \u200b\u200bthe sushi surface, and this data does not include the area of \u200b\u200bnatural deserts. About 1/6 of the world's population suffers from this process. Desertification can occur in different climatic conditions, but it is especially violent in hot, arid areas. Africa has almost a third of all arid areas of the world; They are also widespread in Asia, Latin America and in Australia. Desertification is subject to an average of 6 million hectares of the processed land, which are completely destroyed, and more than 20 million hectares reduce their productivity. Such is the rate of approximation to the threshold of irreversible destruction.

Desertification and emptying may occur in any climatic conditions as the result of the destruction of the natural system. But in the arid areas of the "engine" of desertification becomes also drought. Desertification, developing as a result of inept and unlimited economic activities, has repeatedly destroyed entire civilizations. In schools around the world in the history lessons, children explain that people need to know it in order to extract the lessons for the future. Did mankind learned the lessons from the history of the death of past civilizations covered with sand? The main difference in the experience of history from today is a pace and scope. Excessively active economic activity, the pressure of which was accumulated by centuries and even thousands of years, now turned out to be compressed in decades. If earlier individual civilizations were died, buried by sands, now the desertification process, borrowing in various places and having a different regional manifestation, adopted a global scale. The accumulation in the atmosphere of carbon dioxide, the amplification of dustiness and smoke atmosphere accelerates sushi aridization. This process covers not only the arid areas.

Sahel - on Arabic - shore, outskirts - this is called the transition zone to 400 km wide, which extends south of the Sahara desert to Savannan West Africa.

The surface of the lake Chad has decreased to 1/3its normal sizes. In the 80s. Disasters, brought by drought and desertification, acquired in Africa generalontinental scales. The consequences of these processes are 34 African countries and 150 million people. In 1985, about 1 million people were killed in Africa and 10 million people became "environmental refugees". The growth rates of desert boundaries in Africa places are up to 10 km a year.

Fate of forests and the history of humanity on all continents were closely interrelated between themselves. The forests served as the main source of food for primitive communities who lived by hunting and collecting. They were a source of fuel and building materials for the construction of housing. The forests served as a refuge for people and to a large extent - the basis of their economic activity. The life of forests and the lives of people, the relationship between them was reflected in culture, mythology, the religion of the majority of the peoples of the world. About 10 thousand years ago, before the birth of agricultural activities, dense forests and other space covered by the forest occupied more than 6 billion hectares of sushi surfaces. By the endXX centuries Their square declined almost 1/3 and now they take only a little more than 4 billion hectares. In France, for example, where the forests initially covered about 80% of the territory, by the end of the XX century. Their area has decreased to 14%; In the USA, where forests at the beginning of the XVII century. It was covered by almost 400 million hectares, by 1920 this forest cover was on 2/3 destroyed.

desertification Product Earth Ecological

Bibliography

Encyclopedia for children: T.3 (geography). - M., Avanta +, 1994. - 640 p.

Posted on Allbest.ur.

The problem of desertification

Desertification at the moment is one of the most significant global problems of humanity.

During the disarm of the fields of the Miriad, particles of fertile soil cover rise into the air, dissipated, demolished with fields of water flows, are deposited in new places, in huge quantities are irretrievably carried into the world ocean. The natural process of destruction by water and the wind of the upper layer of the soil, washing and dispelling its particles is repeatedly enhanced and accelerated when the lyuli is unpacked too much lands and do not give the soil to relax.

Under the influence of living organisms, water and air on the surface layers of the lithosphere, the most important ecosystem, subtle and fragile, - the soil called the "skin of the Earth" is gradually formed. This is a keeper of fertility and life. The handful of good soil contains millions of microorganisms that support fertility. In order for a layer of soil with a capacity of 1 cm, a century is required. It may be lost forever for one field season. According to the estimates of geologists, before people began to engage in agricultural activities, the mouth of cattle and break the lands, the rivers demolished about 9 billion tons of soil annually into the world ocean. Now this amount is estimated at about 25 billion tons.

Soil erosion is a purely local phenomenon - now gained universal. In the US, for example, about 44% of the treated lands are subject to erosion. In Russia, unique rich black mills disappeared with the content of humus in 14-16%, which called the Citadel of Russian farming. In Russia, the area of \u200b\u200bthe most fertile lands with the content of Gumus 10-13% decreased almost 5 times.

Soil erosion is especially great in the largest and densely populated countries. The Juanhe River in China annually demolides about 2 billion and soil into the world ocean. Soil erosion not only reduces fertility and reduces yield. As a result of soil erosion, much faster than is usually provided for in projects, artificially constructed aquatic tanks are declared, the possibility of irrigation of electricity from hydroelectric power plants is reduced.

One of the global and fleeting processes of modernity is the expansion of desertification, fall and, in the most extreme cases, the complete destruction of the biological potential of the Earth, which leads to conditions similar to the conditions of the natural desert.

Natural deserts and semi-deserts occupy more than 1/3 of the earth's surface. About 15% of the world's population lives on these lands. The desert is the territory with an extremely arid continental climate, usually receiving on average 150-175 mm precipitation for the year. Evaporation from them is much higher than their moisturizing. The most extensive desert arrays are located on both sides of the equator, between 15 and 45 0 northern latitude, and in Central Asia and Kazakhstan, the deserts reach 50 0 northern latitudes. Deserts are natural formations that play a certain role in the overall environmental balance of planet landscapes.

As a result of human activity by the last quarter of the XX century. There were also more than 9 million km 2 deserts, and they have already embraced 43% of the total Sushi Square.

In the 90s. Desertification began to threaten 3.6 million hectares of arid lands. This is 70% of potentially productive arid lands, or the total area of \u200b\u200bthe sushi surface area, and this data does not include the area of \u200b\u200bnatural deserts. About 1/6 of the world's population suffers from this process. Desertification can occur in different climatic conditions, but it is especially violent in hot, arid areas. Africa has almost a third of all arid areas of the world; They are also widespread in Asia, Latin America and in Australia. Desertification is subject to an average of 6 million hectares of the processed land, which are completely destroyed, and more than 20 million hectares reduce their productivity. Such is the rate of approximation to the threshold of irreversible destruction.

According to UN experts, modern losses of productive lands will lead to the fact that by the end of the century the world can lose almost 1/3 of its arable land. Such a loss in the period of unprecedented population growth and the increase in food need can be truly disastrous.

Desertification is the process of degradation of all natural life support systems: to survive, the local population must or get help from the side, or to go in search of lands suitable for life.

In the world, more and more people become environmental refugees.

The desertification process is usually caused by the cumulative action of nature and man. Especially detrimental is an action in arid areas with fragile, easily destructive ecosystems inherent. Destruction of poor vegetation due to excessive grazing, cutting down trees and shrubs, lace unifoxy, and other types of economic activities that violates a fragile equilibrium in nature, reinforce the effect of wind erosion, the drainage of the upper layers of the soil. The water balance is dramatically violated, the level of groundwater is reduced, the wells dry. The soil structure is destroyed, their saturation of mineral salts is enhanced. Due to excess economic load, organized basin-river systems are converted into primitively organized desert landscapes.

Desertification and emptying may occur in any climatic conditions as the result of the destruction of the natural system. But in the arid areas "engine" the desertification becomes also drought. Desertification, developing as a result of inept and unlimited economic activities, has repeatedly destroyed entire civilizations.

In schools around the world in the history lessons, children explain that people need to know it in order to extract the lessons for the future. Did mankind learned the lessons from the history of the death of past civilizations covered with sand?

Desertification of land

The main difference in the experience of history from today is a pace and scope. Excessively active economic activity, the pressure of which was accumulated by centuries and even thousands of years, now turned out to be compressed in decades. If earlier individual civilizations were died, buried by sands, now the desertification process, borrowing in various places and having a different regional manifestation, adopted a global scale. The accumulation in the atmosphere of carbon dioxide, the amplification of dustiness and smoke atmosphere accelerates sushi aridization. This process covers not only the arid areas.

The expanding area of \u200b\u200bthe desert contributes to the emergence of dry climatic conditions, which are likely to a large extent affect the participation of perennial droughts. The vicious circle closes.

Sahel - on Arabic - shore, outskirts - this is called the transition zone to 400 km wide, which extends south of the Sahara desert to Savannan West Africa.

In the late 60s. This zone broke out a long-term drought, which reached its apogee in 1973 as a result of this drought in the African countries of the Sachelian zone - Senegal, Gambia, in Mauritania, Mali, etc. Died about 250,000 people. There was a massive chamber of cattle - and cattle breeding is the basis of economic activity and the source of the existence of the majority of the population of these areas. Many wells were dry and even such large rivers as Niger and Senegal. The surface of the lake Chad has decreased to 1/3 of its normal sizes. In the 80s. Disasters, brought by drought and desertification, acquired in Africa generalontinental scales. The consequences of these processes are 34 African countries and 150 million people. In 1985, about 1 million people were killed in Africa and 10 million people became "environmental refugees". The growth rates of desert boundaries in Africa places are up to 10 km a year.

Fate of forests and the history of humanity on all continents were closely interrelated between themselves. The forests served as the main source of food for primitive communities who lived by hunting and collecting. They were a source of fuel and building materials for the construction of housing. The forests served as a refuge for people and to a large extent - the basis of their economic activity. The life of forests and the lives of people, the relationship between them was reflected in culture, mythology, the religion of the majority of the peoples of the world. About 10 thousand years ago, before the birth of agricultural activities, dense forests and other space covered by the forest occupied more than 6 billion hectares of sushi surfaces. By the end of the 20th century, their square was reduced by almost 1/3 and now they only occupy a little more than 4 billion hectares. In France, for example, where the forests initially covered about 80% of the territory, by the end of the XX century. Their area has decreased to 14%; In the USA, where forests at the beginning of the XVII century. It was covered by almost 400 million hectares, by 1920 this forest cover was on 2/3 destroyed.

All the considered aspects do not really affect not only our common well-being, but mainly on the well-being of our children and generally descendants. Therefore, we must provide them with a glorious and cloudless future: to develop and implement projects on limiting and eradicating such unwanted processes.

Bibliography:

Encyclopedia for children: T. 3 (geography). - M., Avanta +, 1994. - 640 p.

Desertification. The nature of desertification. Deduction degree. Depth and rate of desertification.

Desertification is a process leading to the loss of natural ecosystem of continuous vegetation cover with the further impossibility of its recovery without human participation. Roles two forms of desertification: 1. Expansion of the desert area, 2. deepening the desertification process in place.

The drought as a whole is a natural crisis that is periodically observed in many parts of the globe. It is a frequent guest in countries located in the southern borders of the Sahara. Today, lands in the south-west of America are desertified, as well as certain districts of Bolivia, Australia and Brazil. The problem of desertification and drought exists in Russia. One of the main causes of desertification is the grazing of a larger amount of cattle than the pasture can endure. The second cause of desertification serves intensive agriculture on non-very fertile lands of the arid zone. The desertification process is enhanced by the fact that people whose number increases, cut out whole forest arrays on firewood. Political and social factors also affect the distribution of the desertification process. All these consequences of human activity - overwhelming, excessive consumption of wood, intensive agriculture, combined with erosion, urbanization of arid areas, salinization and overrunning of groundwater - the result, at least in part, pressure on the nature of the human population.

Desertification is the process of degradation of all natural life support systems: to survive, the local population must or get help from the side, or to go in search of lands suitable for life. In the world, more and more people become environmental refugees. The expanding area of \u200b\u200bthe desert contributes to the emergence of dry climatic conditions, which are likely to a large extent affect the participation of perennial droughts. The vicious circle closes.

The International Convention on Combating Desertification is one of the main mechanisms for the participation of all countries of the world in solving this problem. It has been paid to improving fertility and soil restoration, as well as the protection and rational use of land and water resources.

Desertification. The reasons.

To reduce desertification processes, it is necessary: \u200b\u200b1. Programming of agricultural activities and grazing. 2.Agrese-production is a comprehensive activities for breeding cattle or cultivation of the Earth and the simultaneous cultivation of wood plants on the same territory. 3. Eugene in suitable technologies.

Scientists distinguish four degrees of desertification: weak, moderate, strong and very strong. Strong desertification was distributed in Asia to Africa, North and South America, Australia. To restore land affected by strong desertification, we need large investments and for a long time. A very strong desertification entails the complete and irreversible degradation of the Earth. Nevertheless, about 80 million people live in the districts of strong and very strong desertification. In the result of all these processes, the "load" increases on Earth all the time increases, and the provision of land resources is reduced.

The desertification process comes at a speed of 7 km2 / h.

Lektsii.net - lectures. No - 2014-2018. (0.006 sec.)

Desertification and its monitoring

Desertification

Desertification - The process of transformation (transition) of alturized fertile irrigated land in anhydrous and lifeless deserts with loss of soil fertility and vegetation.

Causes of desertification

Water deficiency - lack of water resources to meet the biological need of crops and other types of vegetation for their normal growth and development, as well as environmental requirements for stabilizing the development of environmental processes.

Drought - long period of season with an insufficient amount of precipitation at elevated air temperatures.

Aridization of climate - enhancing climate dryness due to an increase in air temperature, evaporation and decrease in precipitation, i.e. Enhance the humidity deficit of air through the torque and reducing the coefficient of moisture.

Deforestation - Adjusting the territory of growth and the development of forest plantations, which led to a disturbance of snow deposits, the accumulation of moisture views from rainwater. In addition, due to the deforestation of forests, the soil erosion occurs in the slopes of the mountains, the foothill plains in the form of a flushing and erosion, in also Oravagoration.

Calculating cattle - Gentlement or degree of pasture area from vegetation due to an increase in the number of cattle heads compared with the standard. The degradation of the territory of pastures leads to a sharp decrease in soil moisture meaders, formed under the action of poor atmospheric precipitation in the desert.

Biological death - Dapler vegetable world Due to the sharp violation of their need for water and increase harmful toxic substances in the soil and atmosphere.

Lack of drainage - the insecurity of groundwater outflow in the naturally historical development of the territory and the general drainage drainage with artificial drainage to prevent groundwater lifting and, as its consequences, flooding and secondary salinization in the irrigation process and land development.

Salted under the action of pressure groundwater. The accumulation in the corrunt layer or aeration zone (layer located between the surface of the Earth and the level of groundwater) by transferring them to underground tributaries, formed both beyond the irrigated territories and in them, later, the pressure complexes of aquifers are created in the absence or insufficient natural drainage. Under these conditions, piezometric pressure in the aquifers represented by well-permeable soils (sands, grave deposits, penetrates, etc.) are set above the level of groundwater, creating a certain flow of water and salts into the upper low-grade - aeration zone. The magnitude of the accumulation of salts depends on the intensity of the pressure of pressure water, salt reserves in the weak-dimensional coating fineness and mineralization of underground pressure water. On the territory represented by pressure underground waters, a surface salt profile is formed with the distribution of salt reserves in the aeration zone (above groundwater) due to the removal of them from the lower layers. An example of the formation of such a salt profile distribution is the territory Fergana Valley, the old irrigation zone of the Hungry steppe of the Republic of Uzbekistan, Vakhshskaya Valley of the Republic of Tajikistan.

Solesidetening on irrigation fields under the action of salts balance disorders. Such a type of saline on the irrigation fields is formed under conditions when the parish part of the water-salt balance of the field formed by water supply to watering the agricultural cells of filtration from intra-farm field channels, the inflow from groundwater over the consumable part (total evaporation, flow from the aeration zone to groundwater, The reserves of groundwater in the lower aquifers and drainage) with insufficient natural and artificial drainage.

Salencopter under the influence of the influx with the above-mentioned lands. This type of saline is formed by the transfer of groundwater salts in the areas of intercussive decreases, the end parts of the removal cones and the peripheral part of the proliferation slopes of the foothill plains, which are the unloading zone of groundwater. The intensity of saline depends on the salinity of rocks and soils is plasterometrically higher than the territories and the degree of mineralization of groundwater transit incoming in the lower the irrigated arrays. This type of saline is characteristic of large depressions (decreases) located in the plains.

Saletoplation under the influence of man-made violations. Salencopter is formed by emissions of waste of large mines, plants and factories, where residual products without purification are discharged into water sources - in ravines, collector.

Solesideum under the influence of eolo transfer. This type of accumulation is formed by transferring the weathered product of rocks and salts under the influence of the wind activity of the climate. The source of supply of salts can be along with a weathered product of rocks, separate highly saline parts of the desert, semi-deserts, dried by the bottom of the seas and salt lands located inside the irrigated territory.

Reducing the level of groundwater. Reducing the level of groundwater against their optimal depths and the regime due to the development of groundwater supplies and draining the bottom of the seas and water bodies. An example is the drained bottom of the Aral Sea, formed under the influence of insufficient flow of surface runoff along the rivers of Syrdarya and Amudarya.

Termination of irrigation. Irrigation ceases due to lack of water resources and the unprofitability of agricultural production on low-grade land included in the irrigated fund.

Disruption of water balance of the reservoir. The violation of water balance of water bodies most often arises due to the shortage of water resources in the region used mainly for the development of agricultural production, industry and utility and fisheries. Due to the shortage of water resources within the pool of the Aral Sea, more than 200-250 small and medium-sized lakes and reservoirs were drained.

Fertility loss. Most often arises due to the irrational and improper conduct of crops due to strong salinization and flooding of lands with weak drainage of the territory. Desertification under the influence of the loss of fertility of irrigated lands is most inherent in irrigated lands located in the delta areas of the rivers.

Types of desertification

Soil salinization. Saline soil - Non-coolery soils containing soluble salts in large quantitiesMastering the growth of most crops. Distinguish:

Power supply primary - natural accumulation in soil salts due to evaporation of groundwater, salty of mother breeds or when exposed to eol, biogenic or other factors.
The soil salinization is a secondary - accumulation in the soil of salts, which is due to the artificial change in the water regime, for example, in improper irrigation. The secondary soil salinity can occur in unexpected or primary saline soils.
In most cases, the secondary salinization is caused by moving to the surface of water-soluble salts from the deep layers of underlying rocks and groundwater, or the influx of mineralized water with the overlaid irrigated arrays.

Deforestation (deforestation) - Reduction or destruction of geographic landscape consisting of a combination of wood, shrub, grassy plants caused by the change in the conditions of their livelihoods or economic activities.

Degradation of land (and pastures) - deterioration of properties, fertility and productivity of lands as a result of economic activity.

The causes of land degradation in the Pool of the Aral Sea Steel: Long droughts, ineffective use of water for irrigation, leading to soil salinization, excessive grazing of livestock, reduced and deteriorating soil layer (blowing the humus horizon), unjustified use of chemicals causing soil and water pollution.

Drain of the bottom of the sea and reservoirs - Liberation of the bottom of the sea and water bodies as a result of the fall in the water level and reducing the water area due to the depletion of natural regeneration and increase water consumption over the influx.

Desertification indicators

The degree of salinization of the soils It is estimated according to the analysis of aquatic hoods (1: 5) or electrical conductivity. According to the degrees of soil salinization, 5 categories are divided into 5 categories: unfastened, weakly-free, medium-walled, strong and fatal and very strong.

Conditions for accumulation of salts in soils

Salts formation in soil

Changes in the density of trees or their species. Here it is necessary to consider plant formations that consist of various groups of green plants.

Fighting Land Desertification and Drought

V. Villiams allocates the following types of plant formations.

Rustic vegetation of coniferous and deciduous forests
Meadow grassy vegetation.
Steppe grassy vegetation (Kickl, Ticacher, Lena, Yellow Lucerne, Astragaly, ephemeral plants - tulips, bluish bulb, goose bow).
Desert vegetation is characterized by exceptional poverty (saksauli, pistachio, etc., ephemeral).

In refinery practice, forest phytocenoses are customary to be called plantings. The main distinctive features of phytocenosis include species or floral composition, longline, abundance of species, quantitative and qualitative ratio of species, occurrence, productivity, seasonal and one-year development rhythm, etc. Changing the density of trees and generally phytocenosis is studied by their species composition.

Bonics of soils - Comparative assessment of soil quality (agricultural) as a means of production in rural and forestry, expressed in quantitative indicators. The estimated properties are the power of the humus horizon, the content in the soil of the main nutrients, the capacity of the exchanging complex, the reaction of the medium (pH), mechanical composition, salinity, etc. Quantitative assessment of soils by their properties are carried out on 100 points scale.

Drain area (bottom) - The area of \u200b\u200bthe bare bottom of the sea or a water branch as a result of waste of the coastline and reducing the water level in the water reservoir (sea). The criterion of the drained bottom is the area of \u200b\u200bthe bare bottom (M 2, km 2, or% relative to the area of \u200b\u200bthe water area).

Monitoring methods

... saline soils and saline degrees

Ground shooting - includes terrestrial soil sampling from various soil profile horizons for further analysis of water exhaust in laboratory conditions in order to determine water-soluble substances (tight residue) and various ions. Sommers can also be used for ground-based soil salinity monitoring. Ground monitoring of soil salinity is carried out 2 times a year - in spring and autumn.

Remote monitoring of soil salinity is photographing the area (specified contour) from the air with aircraft or any other aircraft. In recent years, satellite shooting has been used to assess the salinity (especially spotlights of land in the degree of salinization). The resulting filming are decrypt using ground surveys and are used to compile cartographic materials for specific objects.

... deforesting

Ground monitoring is a terrestrial study of the vegetable composition - a set of plants growing together in a homogeneous territory, the nature of their addition, structure, type, vitality, age, saturation (on a certain area), etc. They can be used for geobotanic mapping.

Taxation - allocation of taxonomic categories of plants. It includes: associations, group of associations, formations, group of formations, class of formations, type of vegetation, types, subtypes, types, etc.

Remote monitoring is the use of aerospace and cosmic filming materials to study the vegetation cover and the subsequent geobotanic mapping.

Monitoring frequency - once every 3-5 years of forestry authorities (State Committee), land supervision and the Ministry of Agriculture.

... degradation processes

Terrestrial monitoring is carried out on the basis of field work (soil cuts, heating, touch) and soil laboratory tests, with the release of genetic units (types, subtypes), the degree of humidification, degree of godness, nutrient elements for the preparation of cartographic materials.

Mapping is one of the ways to study the soil cover, where the spatial distribution of soil is reflected; Their properties are outlined in a legend which accompanies cartridges. At these materials, agronomas, land routes, landorals, luragov and other specialists are based on the work of the best technical and economic decisions in accordance with natural conditions. By the details of mappings and the diversion of the territory, the soil cards are different: survey (scale smaller 1: 1 000 000) - schematicized; Small-scale (from 1: 1 000 000 to 1: 300 000); Medium-scale (from 1: 300,000 to 1: 100 000); Large-scale (from 1: 100,000 to 1:10 000).

The frequency of terrestrial monitoring is 1 time in 5 years - the land supervision and the Ministry of Agriculture and the Ministry of Agriculture are performed.

Remote monitoring is the use of aerospace and cosmic filming materials with soil mapping. The essence of the remote study of soils (and vegetation) is to decrypt (recognizing) photographs using photogrammetry and visual method. Theoretical Foundation remote methods - the law of correlation between the properties of the soil covering their communities of plants and environmental conditions. The surface of the soil is almost always closed to vegetation to a certain extent. Therefore, the composition and state of vegetation primarily affect the character of photographic images.

... drained bottom

Monitoring of the drained bottom - systematic observation and control of the change in the area of \u200b\u200bthe drained bottom (and processes) using remote and terrestrial (calculated) methods.

The remote method is the use of aero- and space filming materials for drawing up a plan (map) of a drained bottom and measuring the area of \u200b\u200bthe water area (sea).

Ground method - carrying out work on measuring water depths using a battery and drawing up a bottom relief plan (baaptic card).

Periodicity of monitoring - annual organs of the hydrometeorological service and land supervision.

One of the global manifestations of soil degradation, and the entire environmental environment in general is desertification. According to B. G. Rosanov (1984), desertification ¾ is the process of irreversible change in soil and vegetation and reduce biological productivity, which in extreme cases can lead to the complete destruction of the biosphere potential and the transformation of the territory in the desert.

In total, more than 1 billion hectares in almost all continents are subject to desertification (Fig. 15.3). Causes and main desertification factors are different (Fig. 15.4). As a rule, a combination of several factors leads to desertification, whose joint action has sharply impairs the environmental situation.

Fig. 15.3. Desert and territory subjected to desertification
(UN conference on desertification, 1977):

desertion degree: 1¾ very high; 2.¾ high;
3 ¾ moderate; four¾ Hyperarid deserts

Fig. 15.4. The main factors and causes of desertification

In the territory subject to desertification, worsen physical properties Soils, the vegetation dies, soil waters are diluted, biological productivity drops sharply, and therefore, the ability of ecosystems is undermined. "And if erosion can be called a mistrey of landscape, then desertification is his death" (Report of FAO UN). This process was so widespread, which was the subject of the international desertification program. In the UNEP report (UN Organization environment) It is emphasized that desertification of ¾ is the result of a long historical process, during which the adverse phenomena of nature and human activity, strengthening each other, lead to a change in the characteristics of the environment.

Desertification is at the same time socio-economic and natural process, it threatens about 3.2 billion hectares of land, on which more than 700 million people live.

The problem of desertification

A particularly dangerous position was in Africa in the Sahel zone (Senegal, Nigeria, Burkina Faso, Mali, etc.) ¾ transition bioclimatic zone (up to 400 km) between the Sugar desert in the north and Savana in the south.

The cause of the catastrophic position in the Sahel is due to the combination of two factors: 1) enhancing human impact on natural ecosystems in order to ensure food the rapidly growing population and 2) changed meteorological conditions (long droughts). Intensive grazing of livestock leads to excessive load on pastures and the destruction of the already sparse vegetation with low natural productivity. Desertification also contributes to the mass burning of last year's dry grass, especially after the rain period, an intense disintegration, a decrease in the level of groundwater and others. Embossed vegetation and strongly loose soils create conditions for intensive blowing (deflation) of the surface layer of the Earth. The change in natural complexes and their degradation is especially noticeable during the period of droughts. Many environmentalists believe that in the list of atrocities against the environment in second place after the death of forests, you can put "desertification".

In the territory of the CIS, desertification is subject to ancestor, Balmish, black lands in Kalmykia and the Astrakhan region and some other areas. All of them belong to the environmental disaster zones and their condition continues to deteriorate.

As a result of ill-conceived economic activity in these territories, deep irreversible degradation changes of the natural medium occurred and primarily its forced part. This led to a sharp decline in the biodiversity of phyto and zoecenosis and the destruction of natural ecosystems. Experts note that where, according to the terms of the relief, the quality of the soil, the capacity of the first one could fall out only one sheep, fell in tens of times more. As a result, herbaceous pastures turned into eroded lands. Only over the past five years, the area of \u200b\u200bmoving sands in Kalmykia increased by 50 thousand hectares.

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Consequences of soil degradation

1) decrease in soil fertility

2) the deterioration of people's health and increasing the incidence of animals.

Desertification

A lively organism sensibly reacts to changes in the chemical composition of the soil. The excess or disadvantage of one or another element in the soil leads to negative consequences for the body.

Nitrates and nitrites, falling into the human body, enter into interaction with hemoglobin blood. Hemoglobin contains 2-valence iron, and nitrates translate it into 3-valence, as a result of this, the erythrocytes are deprived of the ability to carry oxygen. When blocking 20% \u200b\u200bhemoglobin occurs oxygen deficiency (anomios). If 80% of hemoglobin is blocked - death.

3) the weakening of the self-cleaning ability of the soil. Soil microorganisms decompose pollutants for less toxic compounds.

4) soil salinization. It happens with poor drainage and irregular watering. This leads to an increase in the level of groundwater and accumulating in the soil of easily soluble chloride and sodium sulfate, potassium and sodium carbonate. Even weak salinity reduces the crop by 2 times.

5) Soil boiling. Soil acidity can be natural and secondary. Optimal pH soil: 5.5-8.0. If the pH drops to 3.6-4.0, on this basis almost nothing will grow.

Fighting land degradation

1) rational use of soil. The elimination of environmentally unfounded solutions.

2) The use of appropriate agrotechnical techniques is unrequited farming, the use of crop rotations and a refusal of heavy equipment.

3) Reducing the soil salinization (increase in water card)

4) The use of hydraulic activities (strengthening of slopes, detention of wastewater)

5) Forestorekeeration works (agrolesome disposal - landing of protective strips of forest, amelioration is the drainage of the moistened lands and swamps).

6) Chemical amelioration. It is divided into lime (soil acidity decreases, heavy metals are translated into insoluble compounds), drying (leads to a decrease in soil salinity) and the use of mineral and organic fertilizers.

7) Recultivation of land is a complex of work on the restoration of productivity and the economic value of disturbed lands. Passes in 2 stages:

· Technical recultivation (land delivery, layout ...)

· Biological recultivation (restoration biological properties land).

It is achieved by adding fertilizers, lime, disembarking shrubs and trees.

Types of influences on a lithosphere.

Lithosphere is a solid sheath of the Earth.

Soil - with fertility, a complex polyfunctional and polycomponent open multiphase structural system. Soil product joint activity 5 components

Priming
Animals and vegetable organisms
Climate
Relief area
Age of territory.

Luxury lands - 10% of land sushi, pastures and hayfields - 20%, the remaining 70% - cold climate zones and unsuitable for farming the territory.

The soil is involved in the formation of river flow, as well as due to hitting the soil compounds in the reservoirs is a factor in their bioproductivity.

Earth is the only planet of the solar system.

7 million hectares of arable land is lost annually due to the low culture of land use.

Mariinskaya Vpadina ©.

Earthy Baff

The soil, more precisely, the land is the only system that has the soil ©.

Disorders of the natural environment accompanied by mining and recycling of minerals, this is expressed as follows:

Creating significant quarries and embankments, which leads to the formation of man-made landscape, reducing land resources, depletion and destruction of soil.
Drainage of deposits, water intake for the technical needs of mining enterprises, reset of mine and wastewater depletes the reserves of underground and surface water, worsens their quality.
Drilling, explosion, loading the mountain mass causes deterioration in the quality of atmospheric air.
The above-mentioned processes, as well as production noise, contribute to deterioration of living conditions and habitats and reduce the number of plants and animals, reducing the yield of crops.
Mountain production, extraction of minerals, the burial of solid and liquid waste leads to a change in massifs of rocks, flooding deposits, contamination of subsoil.

Natural deposits are transported ©

The main reasons for reducing areas suitable for agriculture:

Erosion (Natural and Artificial)
Pollution (industrial, agricultural, transportation)
Decoration by construction
Negative economic activities (the destruction of forests, burning vegetation, changing the water regime of the territory).
Earth development for mining.

Erosion - the destruction of the soil under the influence of water, wind and mechanical path. Accelerated erosion is caused by human activity.

By the nature of the injury of soil particles, water and wind erosion are distinguished. The water erosion is to transfer the soil particles in the streams, rivers, the sea, as a result of which the entire cultural layer is washed off. Coastal erosion includes water erosion. Wind erosion - moving dry ground particles.

Soil contamination is achieved by industrial enterprises (mining, thermal power plants on solid fuel). In Russia, about 7000 hectares of land occupied by polygons of solid waste.

Testing underground nuclear weapons for peaceful purposes ©.

St. Petersburg ©.

Soil classification:

Tundra gley
Peat-bolds
Podzolic
Dernovo-podzolic
Bolt-podzolic
Gray-forest
Meadow-chernozem
Chernozem
Serozia
Brown desert-steppe
Solonsy

Man nature friend:

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5. Kiogoochemical cycles, their types and environmental role.

6.Arthrogen influence on the cycle of the main biogenic elements in the biosphere.

7. The main stages of the change in the relationship between a person with nature during its historical development.

8. The climate global climate change on the planet: Possible causes, consequences, solutions.

9. Sustaining land as a global environmental problem.

10.The complement to ensure fresh water as a global environmental problem.

11. Problem soil degradation: causes and consequences on a global scale.

12. Ecological assessment of the global demographic situation.

13.Glice environmental problem of pollution of the World Ocean. What are the causes and environmental danger of this process?

14. The ability to reduce biological diversity: causes, environmental consequences, possible ways to solve the problem.

15. Ecological factors: concept and classification. The main mechanisms of action of environmental factors on living organisms.

16.Adaptation: the concept of adaptation, its environmental role.

17. The main patterns of the action of environmental factors on living organisms.

18. Types of biotic relationships in nature, their environmental role.

19. Constitutions - shredding and esvibionism.

20. The attitude of the population, its biological and environmental meaning.

21. The number, density, population growth. Regulation of numbers.

22.Regability and mortality in the population: theoretical and environmental. The factors of their defining.

23. The population structure and the factors determining it.

24.The population structure, the main types of populations, depending on the age ratios.

25.Prost population structure and its factors defining.

26. Itological (behavioral) structure of the population and its factors defining.

27. Ecological strategies of populations (R- and Romatic strategies). Their environmental meaning.

28. The survivability and curves of the survival of organisms in the population, the ecological meaning of survival curves.

29. Curves growing populations, the environmental significance of each of the growth stages.

30. The effect of the ecosystem, its main components, types of ecosystems.

31. Pyramids of the number, biomass, energy in ecosystems, their ecological meaning.

32.Fot energy in the ecosystem. Rule 10% of energy.

33.Motions of the substance in the ecosystem. The principal difference in the flow of substance and energy.

34.pish chains. The effect of accumulation of toxicants in food chains.

35. Productivity of environmental systems. The most productive ecosystems of the globe, their environmental problems.

36. Ecological Suksessia, types of succias.

37.Producers, consversals and relegates, their place in the power chain and environmental role in ecosystems.

38.The person and the role of a person in the environmental system.

39. The excellent and artificial ecosystems, their environmental sustainability.

40.The Environmental Pollution, Natural and Anthropogenic Pollution.

41. The main types of anthropogenic environmental impact: chemical, energy, biological pollution of the medium.

42. Ecological situation and human health. Human adaptation to the action of extreme environmental factors.

43. Environmental of environmental quality: normalization goals, types of standards.

44. Principles underlying the MAC generation.

45.Initoring of the habitat: concept, purpose and types of monitoring.

46. \u200b\u200bEnvironmental problems of the Far East.

9. Sustaining land as a global environmental problem.

Desertification or desertation - land degradation in arid, semi-derivative (semi-samid) and arid (sub-day) regions of the globe, caused by both human activity (anthropogenic causes) and natural factors and processes.

Information about the arid regions of the world

Arid regions occupy 41 percent of the earthly sushi. More than 2 billion people live in this area (2000 information). 90 percent of the population are residents of developing countries that differ in low development rates.

Environmental consequences

The consequences of desertification in environmental and economically, very significant and almost always negative. The productivity of agriculture decreases, the variety of species and the number of animals are reduced, which especially in poor countries leads to even greater dependence on natural resources. Desertification limits the availability of elementary ecosystem services and threatens the safety of people. It is an important obstacle development, because of which the United Nations in 1995 established the World Day to combat desertification and drought, then proclaimed 2006 by the International Year of the Desert and Desertification, and in the future I designated the period from January 2010 to December 2020 decades of the UN devoted to deserts and fight desertification.

10.The complement to ensure fresh water as a global environmental problem.

During the period from 1900 to 1995, fresh water consumption in the world increased 6 times, which is more than 2 times higher than the growth rate of the population. Currently, almost 30% of the population of the Earth lacks clean water. If the current trends in fresh water consumption will continue, then by 2025, every two of the three inhabitants of the Earth will live in conditions of water deficit.

Underground waters provide the needs of 30% of the population of the Earth. The special concern of humanity causes their irrational use and methods of operation. The extraction of groundwater in many regions of the globe is carried out in such volumes that significantly exceed the ability of nature to renew them.

A difficult task is to protect the quality of water resources. The use of water for economic purposes is one of the links of the water cycle. But the anthropogenic level of the cycle is significantly different from the natural way that only a part of the water used by man in the process of evaporation returns to the atmosphere. Another part of it, especially with the water supply of cities and industrial enterprises, is reset back into rivers and water-water in the form of wastewater contaminated by production waste. This process continues for millennia. With the growth of the urban population, the development of industry, the use of mineral fertilizers and harmful chemicals in agriculture, pollution of surface freshwaters began to acquire a global scale.

The world ocean is the largest ecological system of the planet Earth is the water area of \u200b\u200bthe four oceans (atlantic, indian, quiet and northern ice-lit) with all interconnected adjacent seas. Sea water is 95% of the total hydrosphere. As an important link in the cycle of water, it provides the nutrition of glaciers, rivers and lakes, and thereby - the life of plants and animals. The Ocean plays a huge role in creating the necessary living conditions on the planet, its phytoplankton provides 50-70% of the total oxygen volume consumed by living beings.

Radical changes in the use of worldwide resources brought a scientific and technological revolution. At the same time, many negative processes are connected with HTR, and among them - pollution of the waters of the world's ocean. Ocean, chemicals, organic residues, burials of radioactive industries, etc. increase catastrophically increasing, etc. estimated that the world's ocean absorbs the main part of pollutants. The international community is actively looking for ways to effectively protect the marine environment. Currently, there are more than 100 conventions, agreements, contracts and other legal acts. International agreements regulate various aspects that determine the prevention of pollution of the World Ocean, among them:

prohibition or limitation by certain conditions for the discharges of pollutants generated during the normal operation process (1954);

preventing the deliberate pollution of the marine environment with operational waste from ships, and also partly from stationary and floating platforms (1973);

prohibition or limitation of disposal of waste and other materials (1972);

preventing pollution or reducing its consequences as a result of accidents and disasters (1969, 1978).

In the formation of a new international legal regime of the World Ocean, the leading place is held by the UN Convention on the Law of the Law (1982), which includes a set of problems of protection and use of the World Ocean in modern conditions of the scientific and technical revolution. The Convention proclaimed the International Sea District and its resources with the general heritage of mankind.

Desertification - the global problem of humanity

Skorodumova Nadezhda Sergeevna

student 2 Course, Department of Geography, Country Studies and Tourism Novgorod State University named after Yaroslav Wise,
RF, Great Novgorod

Friendly Margarita Petrovna

scientific director,cand. Ped. Sciences, Associate Professor of the Department of Geography, Country Studies and Tourism of the Novgorod State University named after Yaroslav Wise,
RF, Great Novgorod

In order to study the problem of exploiting land, survey was conducted, according to which fifty respondents were asked to respond to the six following questions:

1. What is the desert?

2. What are the types of deserts?

3. How can the desert in man's business activities can be used?

4. What is desertification?

5. What are you knowing the causes of desertification?

6. What measures to combat desertification can you list?

According to the survey results, a diagram was drawn up (Fig. 1), which visually showed a low level of knowledge of the population about the problem of desertification.

Picture 1 . The results of the survey

At first glance, it may seem that the study of this problem is unnecessary and irrelevant, but it is not at all. At the moment, the desert, not counting the Antarctic desert, occupy more than 17 million km 2 or about 12% of the entire surface of the sushi. Recently, these indicators are increasing mainly due to anthropogenic effects, as well as climate warming, which contributes to the increase in the number of droughts, therefore many scientists (B.V. Vinogradov, A.A. Chibilev, Vadid Erian and others) They talk about this problem as global, this is due to the fact that in some areas of the globe, the population will experience hunger, mainly developing African, Asian and Latin American countries (for example, South Sudan, Palestine, Cameroon, Kenya, Pakistan, Afghanistan, Peru), and due to the growing desertification of land, the number of fertile lands is declining annually, therefore, food reserves decrease. The time interval from January 2010 to December 2020 was declared a decade of the UN dedicated to the deserts and the fight against desertification, and since 1995, the World Day of Combating Desertification and Drought was introduced, which is celebrated on June 17.

The fight against desertification cannot be successful if the population of the planet will not represent what the desert is what they happen why they are formed and how this process can be prevented.

Definitions of the concept of "desert" there are quite a lot, for example:

The desert is a geographic area - a territory with an extremely dry climate, where evaporation from an open surface is many times the amount of atmospheric precipitation. (According to Petrov M.P.)

The desert is an extensive uninhabited area with a small amount of precipitation, sharp fluctuations in air and soil, with poor vegetation. (Encyclopedic Dictionary) .

The desert is a large uninhabited area with scanty vegetation. (According to the word Ushakov)

In my opinion, the most accurate definition will look like this: "The desert is an area of \u200b\u200bland with insufficient moisture (less than 200 millimeters of precipitation per year), dry air, high evaporation and large fluctuations in daily temperatures."

The formation, development and distribution of the earth's surface of the desert is associated with the following factors: a small amount of precipitation or their complete absence, high indicators of solar radiation, geographic latitude of the area, the features of the orographic structure of land, the conditions for the general circulation of the atmosphere, the locality of the ocean.

The deserts in a moderate belt can be found only in the northern hemisphere in intra-engineity areas (Central Asia), in subtropical and tropical belts - near the northern and southern tropics (23 ° 26'16 "northern and southern latitude). The deserts are also found in the polar regions, including Antarctica and Greenland, they are called snow deserts. All deserts are characterized by certain moisturizing conditions (the annual amount of precipitation from 200 mm and less, in extraarial areas - less than 50 mm, and there may not be decades in separate deserts). In the relief of the desert is a combination of a small-scale, Nagrai and Island Mountains with structural reservoir plains, ancient river valleys and closed laservit varnishes. Most of the deserts are deplex, you can find drying lakes and rivers that often change their outlines and sizes. Groundwater often mineralized. The soil is poorly developed, a characteristic feature is the predominance of water-soluble salts in the soil solution organic substances.

The types of the surface of the desert are sandy, stony, sandy-crubstone, clay, salt marsh, snowy, loss.

The surface sediments of the desert are inhomogeneous and diverse, depending on the geological structure of the plot of land and affecting it natural processes. I suggest to consider the few brightest types of deserts and see which deposits are their surface layer.

Stony deserts are one of the most common on the earth's surface. Often they include crubstone and gypsum deserts. Their common properties are rudeness, hardness and surface density. Kazakh nomads call such shock deserts, they are littered with stones and sand, weathered granites, represented in the form of huge cushions, solidly sandstone-quartzites that form gigantic combs, gneisses, leaving the surface of palcasters, marbles, clay shale. Since the surface of the shock is most often a rocky, fresh water accumulates in its cracks, thanks to which bright greens grow here, not dying from sunlight until autumn.

In the stone deserts there are areas where there are no rocks, and the whole surface is completely covered with small rubble, nomadic peoples call them "Hamada". These are black gloomy deserts, the color of which does not depend on the color of the crushed stone itself, it is formed under the influence of sunlight, pushing the rock moisture solutions consisting of iron orders, which is highlighted using bacteria and protects the stone from destruction.

There are desert sites that are sharply limited plateau and the local name "Kyr". For the most part, they are composed with different limestone, on the surface of which gypsum deserts are formed.

Clay deserts are widespread on all continents, are long lifeless spaces coated with a layer of solid clay, cracking on four-grooved and hex tiles resembling beesh cells. The surface is well absorbed precipitates, however the upper layers will quickly burst and stop passing the water, when the weather is established, the layer dries quickly, but if the grinding deposits include sand, the water permeability of the soil increases, which makes it possible to form a large water supply. In Central Asia, such sites are called "tactics", and in the desert Gobi - Toyrim.

Salon deserts are located on the shores and on the bottoms of the salted drying lakes. They consist of cooking salts, potassium and calcium salts, gypsum, miracular. In places of the greatest salt concentration, a solid salt crust is formed.

The sandy deserts (nomad nomads call "Ergy") is the most common type of desert in the arid zone and the most famous for most people of our planet. Surface deposits are represented by various types of sands. Because of the diverse wind regime in the sandy desert, you can meet a wide variety of relief forms. Most often it is the vehans, which in one place acquire the shape of the crescent, in the other become similar to the pyramid. Sand dunes and ridges are not less common. The latter can sometimes resemble bee honeycombs if bridges are connected to each other.

Deserted deserts are deserts formed from the lessisal deposits of subgrong plains. Lesses are a sedimentary rock, a homogeneous limestone, intolerable, loamy-samp, most often has a light yellow or fawn color. The size of the lesse includes particles mainly from the field spat and quartz, as well as horny decking, mica. Sometimes there are grains of volcanic ash.

Snow deserts are space of releger areas on the mainland islands. In these territories, eternal permafrost and cryogenic morphoschool are common. The surface layer is represented by large-grade material, due to the predominance of physical weathering processes. However, in lowering reliefs can be detected and finely.

Thus, it can be concluded that surface deposits are represented not only by sand, but also rubble, pebbles, clay, limestone, etc. You can even say that the sand plays a non-dominant place in the content, so, for example, the sands of the Sahara desert make up Only about 10% of its area, and the rest is represented by stony sediments (various types of rubble).

The deserts have significant economic use: pasture animal husbandry (about half of the livestock livestock around the world dwells on dry and semi-handful pastures), agriculture - about 45% of all world-treated lands are in arid areas, the production of the crop is possible only after land irrigation. A large amount of desert is rich in minerals (for the most part of the region in Asia), therefore they are made of their extraction, most often oil and gas.

In the floodplains and delta of major rivers crossing the territory of the desert (for example, the Volga and Amudarya), irrigated agriculture (cotton growing, rifling and other) is practiced.

Very favorable conditions for pasture animal husbandry (sheep and camel) are available in sandy deserts (for example, in Karakums, Uralsky), because groundwater levels lie close to the surface and sediment leaking into the soil, do not have time to evaporate, which provides richest vegetation. Pasture animal husbandry is also practiced in clay deserts, but the conditions are less favorable in them: the level of groundwater is lower, however, there are temporary watercourses and drying rivers filled with water in spring.

The definition of the concept of "desertification" was given by many scientists. For example, Yu. ODUD believes that desertification is the process of irreversible modification of soil and vegetation and lower biological productivity, which in some cases can lead to the complete destruction of the biosphere potential and the reference of the territory in the desert.

Desertification - loss of continuous vegetation area with the further impossibility of its recovery without human participation. As a rule, desertification is observed in arid, but not necessarily hot regions. Comes as a result of both natural and anthropogenic causes. (Definition from the emergency dictionary).

The UNEP (United Nations Environment) report states that desertification is the result of a long historical process, in which the adverse phenomena of nature and human activity lead to a change in the characteristics of the natural environment.

Based on these definitions, it can be concluded that there are two factors contributing to the process of desertification - natural and anthropogenic.

Natural factors include long droughts, which have recently become increasingly observed in the countries of the Middle East and North Africa (Syria, Sudan and others); Windproof (blowing the soil substrate of light granulometric composition and transferred it over long distances, the degree of manifestation largely depends on the wind speed, characteristic of open spaces) and water erosion (its activity leads to the destruction of the soil strata, then the formation of ravines, promoter, crystrine, which After a long period of time, it can turn into a desert (this factor is characteristic of the USA, India, China, various mountainous areas, for example on Ecuador). Simultaneous activities of water and wind erosion develops in the zone of insufficient moistening with alternating and drought-resistant years (or seasons) and can contribute to particularly large impairment of soil cover (in Russian Federation Characterized by forest-steppe and partially steppe areas of the Volga region, Zauralye, East and Western Siberia, Central Black Earth region). Another natural factor is soil salinization. Natural soil salinity is peculiar to territories with an arid climate. It occurs as a result of lifting salts to the surface layers of soil from groundwater, moisture is evaporated as moving upwards, and the salt contained in it remains and accumulates on the walls of the pore soil space. Under the action of this factor, salt deserts are formed (significant spaces of the coast of the Caspian and Aral Seas, separate sections of Central Asia).

Anthropogenic factors include cutting down of forests, as a result of which an increase in soil erosion occurs, which leads to a decrease in soil fertility, and then the total destruction of the soil layer; Realcate of livestock (with an increase in its livestock, enhances the load on pastures, and at the same time, their productivity falls, which makes it possible to intensive the development of wind and aquatic erosion). These factors are characteristic of Southeast and South Asia, Africa. Another anthropogenic factor is the salinization of the soil resulting from the artificial change in the hydrological regime, for example, with improper irrigation and amelioration. Anthropogenic salinization occurs as a result of soil enrichment with salt together with agricultural fertilizers. Significant territories of such soils are located in India, Pakistan, in the west of the United States, in North Africa, in the arid areas of Australia and South America,.

The consequences of desertification are the degradation of vegetation cover, reducing water resources, sand offensions, soil salinization, reduction in yield and as a result of hunger and poverty, deterioration in people's health due to the wind-brought dust, including eye, respiratory and allergic diseases. Economic, social and political tensions associated with the latest consequences can contribute to the emergence of conflicts, further depletion and increasing land degradation. Increasing the scale of desertification around the world threatens millions to raise the number of poor people forced to look for a new place of residence and livelihood. All this in the aggregate shows that modern world The problem of desertification has acquired a global scale and to solve it, it is necessary to use all possible ways to combat desertification.

The fight against the desertification process is mainly carried out in the following directions:

· Environmental monitoring of desertification processes, identifying them in order to attempt to prevent and liquidation. Monitoring includes hydrometeorological, agrochemical, biological, hydrological observations at stations, posts, platforms; Mapping of exploitation of desertification processes.

· Scolation of protective forest stripes in the outskirts of oasis, along the channels and boundaries of fields, in order to reduce the effect of wind and aquatic erosion.

· Reclamation of land destroyed by man-made method; The resumption of plant cover on open mountain development places, as well as in the construction territories, where the cover was destroyed.

· Improving the structure of agricultural land and seed areas, rational use of pastures.

· Search and mining of freshwater; protection of surface and groundwater from contamination; Surface Stream Regulation

· Adaptive landscape land use, development and study of landscape systems of agriculture, contributing to high and sustainable productivity, fixture of land use systems in relation to the multipleness of the management.

· Application of sand fixer plants with further inclusion in pasture.

· Protection of the biodiversity of the planet, which includes the creation of reserves and reserves.

· Conducting regular scientific observations, including the study of the impact of desertification factors, tracking the dynamics of desertification and the provision of forecast scenarios, taking into account the measures taken to combat desertification;

· International cooperation in the field of nature conservation and the fight against desertification.

· State control over environmental management, promoting environmental protection industries.

Support in the fight against desertification is expressed by various UN institutions (United Nations). For example, UNDP (UN Development Program) finances measures to combat desertification through the arid lands located in Nairobi Center. MFSR (International Fund for Agricultural Development) provides financial assistance to projects for the development of arid lands. The World Bank creates and finances programs concentrated on the protection of unstable arid lands and an increase in their agricultural productivity. FAO (Food and Agricultural Organization of the United Nations) contributes to sustainable agricultural development, providing practical assistance to governments. UNEP (United Nations Environment Program) supports regional action programs, data assessments, strengthening public informing about desertification.

The desertification process cannot be turned back, you can only try to suspend or do everything possible so that it does not develop. That is why the problem of desertification is the global problem of mankind, which in one way or another affects every country. The process of desertification in environmental and economic relations always has negative consequences. People from arid regions are forced to move into other places due to lack of food, which arises as a result of soil degradation, which leads to serious socio-economic consequences. In order to avoid this, every person should rationally use everything that nature gives us, because a serious change in one component, such as forests or vegetation cover, inevitably leads to a change in the rest, and this can lead, including to desertify land.

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