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Where does desertification occur? Desertification is a global problem for humanity

The development of civilization is almost always accompanied by the emergence of problems that subsequently affect humanity as a whole. In the middle of the last century, the UN provided data that over the past 100 years the amount of land suitable for cultivation has decreased by 25%. After such a statement, the problem became obvious - we are dealing with drought and desertification. Human resistance to these processes is of global significance today and includes a whole range of measures. “Popular about health” will tell you what the fight against drought and desertification is, the causes of these phenomena and their consequences.

Desertification and drought

What is land desertification?

This term means that land that was previously used for cultivation becomes unusable. In such areas, environmental conditions gradually become similar to deserts. Every year, about 12 million hectares of land on the planet turn into deserts. This problem has a global scale, and its further aggravation will entail many social problems. An example of this can be the African continent, where, as a result of severe drought, famine occurred, from which almost the entire local population suffered. It has become obvious that soil degradation and desertification have a serious impact on humanity. In 1977, a conference was organized in the capital of Kenya at which this global problem was discussed for the first time, its causes were voiced and measures to combat it were proposed.

Causes of drought and desertification of lands

At the conference in Nairobi, the causes of desertification were examined in detail. Of these, two main ones were identified:

Human activity;
Features of the climate.

The increase in air temperature on the planet occurs constantly; it is almost impossible to influence this process. Therefore, ways to solve the problem of desertification by changing the influence of human activities were voiced. How can land desertion be stopped?

The struggle for land suitable for agricultural cultivation

Measures aimed at solving the global problem are related to understanding the reasons leading to the formation of deserts as a result of anthropogenic activities. There are several of them:

Irrational use of land;
Livestock grazing;
Deforestation.

In addition to the above, natural factors are also directly related to desertification. Long periods of drought contribute to overdrying of the soil, and as a result, vegetation dies, and entire huge areas gradually turn into deserts. Natural factors also include soil salinization and wind erosion. To change the situation, the causes of drought and desertification must be eliminated. How?

1. Planting trees on arable land.
2. Planting forest belts and forests.
3. Protecting forests from deforestation.
4. Construction of fences to retain precipitation.
5. Rational use of arable land.
6. Extending the soil rest period when growing crops.
7. Combating soil salinity.

Measures to combat drought include reducing the impact of wind erosion on the soil. Planting green areas and banning their felling in arid areas will prevent the rapid evaporation of moisture and protect the land from drying out the surface layer and destroying the soil structure. Planting forest belts along the perimeter of fields and oases will protect pastures from drying out and strengthen the food supply. As a result, livestock will not destroy natural green spaces and contribute to desertification of lands. Installation of dams and sediment collection structures – effective measure against drought and combating soil weathering.

This also includes horizontal cultivation of soils on sloping areas, which contributes to the accumulation of snow. As a result of its melting, soil irrigation will occur where moisture is usually not retained. In this way, it will be possible to preserve unsuitable areas for use in agriculture. Other agricultural practices to combat drought include maintaining normal soil structure. This includes the following:

1. Deep loosening.
2. Organization of proper crop rotation.
3. Strengthening the water-absorbing qualities of the soil cover.
4. Reduce the use of pesticides.

How land desertification is related to economic and social factors?

In fact, these measures are not enough to successfully combat desertification and drought. The problem is so global that its solution affects political, social and economic aspects. For example, how can improving a country's economic performance contribute to solving the problem of desertification? Let's take the example of Africa, where the question of this initially arose. People living below the poverty line are forced to extract wood for heating food, and massive destruction of forests occurs. The result of such activity is known to us.

Only comprehensive measures taken by humanity will help effectively combat drought and desertification. But the beginning of this path has already been made - awareness of the problem has already occurred, various programs have been developed, the implementation of which will allow us to save our planet and life on it.

1 Desertification. Causes

2 Desertification problem

3 Information on dry regions of the world

4 Environmental consequences

5 International fight against the problem of desertification

6 Conclusion

4. Kolbasov O.S. International legal protection of the environment. – M., 2007.

5.http://www.grandars.ru/shkola/geografiya/opustynivanie.html

6. International Convention of the General Assembly to Combat Desertification in Those Countries Experiencing Serious Drought or Desertification, Particularly in Africa.

Desertification. Causes.

The set of natural and anthropogenic processes leading to the destruction of equilibrium in ecosystems and the degradation of all forms of organic life in a specific territory is called desertification. Desertification also has another term - desertification. The term "climate desertification" was coined in the 1940s by the French explorer Auberwil. The concept of “land” in this case means a bioproductive system consisting of soil, water, vegetation, other biomass, as well as environmental and hydrological processes within the system.

Land degradation is the reduction or loss of biological and economic productivity of arable land or pastures as a result of land use. It is characterized by a small member of the earth, withering of vegetation, and a decrease in soil cohesion, as a result of which rapid wind erosion becomes possible. Desertification is one of the hard-to-compensate consequences of climate change, since it takes an average of 70 to 150 years to restore one conventional centimeter of fertile soil cover in the arid zone.

The main reason for the current increase in desertification in various countries of the world is the environmental crisis caused by the inconsistency of the existing structure of economic use natural resources with the potential natural capabilities of a given landscape, population growth, increase anthropogenic loads, imperfection of the socio-economic structure of a number of countries. Acid rain also contributes to the growth of desertification.

Desertification occurs in all natural areas peace. Currently, more than 9 million km are occupied by deserts of anthropogenic origin, and up to 7 million hectares are lost from productive land use every year. An example of modern desertification of territories of anthropogenic origin is the saline plain of the drained part of the Aral Sea bottom.

BRIEFLY Desertification is the process of turning fertile land into desert. Due to critical weather conditions, especially droughts, and as a result human activity, polluting and destroying land (including over-cultivation, over-grazing and deforestation), turning arable land into desert. As ecosystems change and deserts expand, food production decreases, water sources dry up, and certain populations are forced to move to areas with more favorable conditions.

Potential health effects of desertification include:

· worsening threat of malnutrition due to decreasing food and water supplies;

· increased prevalence of water and food borne diseases due to poor hygiene resulting from lack of clean water;

· respiratory diseases caused by atmospheric dust as a result of wind erosion and other air pollutants;

· spread of infectious diseases due to population migration.

The problem of desertification.

Desertification processes currently threaten a vast territory, covering some regions in southern Russia and the Asian CIS countries.

In Russia, an area of 50 million hectares is subject to this process. Irrational use of land, in particular uncontrolled grazing, led to the emergence of the only desert in Europe, “Black Lands” in Kalmykia. With a grazing rate of no more than 750 thousand sheep, 1 million 650 thousand were constantly grazing here. In addition, over 200 thousand saigas constantly lived in this territory. Overload of pastures exceeded the norm by 2.5-3 times. As a result, more than a third of the pasture area (650 thousand hectares) has been converted into moving sand. Gradually, the Kalmyk steppe becomes a barren desert.

Experts have calculated that if the process continues at the same pace, then in 15-20 years the area of desertified lands in this republic will reach 1 million hectares.

Cleared lands in the Komi Republic are also subject to desertification.

Every year in southern region In Russia, sands occupy 40-50 thousand hectares. In the Caspian region alone, about 800 thousand hectares are occupied by sand. There is an increase in the area of harvested pastures. Over the five years since 1985 in Dagestan, Saratov and Astrakhan regions, these areas increased by 14,260 and 394.2 thousand hectares, respectively.

The desertification process is an important problem for Uzbekistan. According to the latest data, deserts and semi-deserts occupy about 4/5 of the territory of the republic. As a result of the drying of the Aral Sea, an additional 33,400 km2 of dry seabed and secondary deserts (Aral-Kum) were formed. About 70% of the deserts of the Aral Sea region arose as a result of degradation of the vegetation cover, so a scientifically based selection of drought-resistant plants and their zoning is necessary. It is important to identify promising heat-, drought-, salt- and gas-resistant species adapted to the conditions of the arid zone. It must be taken into account that for Central Asia The region is characterized by a warm climate and low precipitation; long periods of drought are common here, causing a high risk of desertification.

Annual global losses fertile soils on cultivated lands currently amount, according to some estimates, to 24 million tons. For comparison: the same area is sown with grain throughout Australia.

One of the main reasons for the destruction of the fertile layer is soil erosion. It occurs mainly due to the so-called “agro-industrial” farming: soils are plowed over large areas, and then the fertile layer is blown away by the wind or washed away by water. As a result, to date there has been a partial loss of soil fertility on an area of 152 million hectares, or 2/3 total area arable land. It has been established that a 20-centimeter layer of soil on gentle slopes is destroyed by erosion under a cotton crop in 21 years, under a corn crop in 50 years, under meadow grasses in 25 thousand years, under a forest canopy in 170 thousand years.

Soil erosion has now become widespread. In the United States, for example, about 44% of cultivated land is susceptible to erosion. In Russia, unique rich chernozems with a humus content of 14-16%, which were called “the citadel of Russian agriculture,” have disappeared, and the areas of the most fertile lands with a humus content of 10-13% have decreased by almost 5 times.

Soil erosion is especially severe in the largest and most populous countries. The Yellow River in China annually carries about 2 billion tons of soil into the World Ocean. Soil erosion not only reduces fertility and reduces crop yields. As a result of erosion, artificially constructed water reservoirs become silted much faster than is usually envisaged in projects, reducing the possibility of irrigation and obtaining electricity from hydroelectric power plants.

Processes associated with desertification cause great damage to the condition of the Earth's soil cover. This is one of the most significant global problems of humanity.

The United Nations Convention to Combat Desertification was signed and entered into force in December 1996. It emphasizes the need for a new participatory approach to addressing desertification. Desertification affects the condition of topsoil, which is of great importance for agriculture and food production.

Desertification can be caused by deforestation, irrational land use and irrigation (waterlogging and salinization), drought, overgrazing, soil degradation and other reasons.

As a result of irrational land use, soil productivity decreases, its surface layer dries out, yields decrease, the erosion of the fertile layer increases, sand dunes encroach on irrigated lands and destroy crops with sandstorms.

Deforestation and slash-and-burn agriculture also contribute to soil destruction. Deforestation of mountain forests is especially dangerous. From mountain slopes devoid of greenery, rains wash away the soil, making the changes irreversible. New forest plantations will no longer take root here. Soil erosion occurs on the plains, their fertility decreases, and the local population is deprived of their main bread - rice. Rivers carry soil washed away from fields into the sea. If there are coral reefs rich in animal and plant life nearby, then the smallest soil particles settle on coastal corals. This means that at the same time another forest is being destroyed - the underwater one. The silted water does not allow the sun's rays to pass through, and the unique coral world dies, and the local population is deprived of fish.

One of the reasons leading to desertification, - overgrazing of livestock. As the population increases, the load on pastures increases, and at the same time their productivity decreases.

The destruction of forest and grassy vegetation, overgrazing, water and wind erosion have transformed the territories of the once “green” countries of the Middle East and North Africa in deserts and semi-deserts. There is an opinion that all the deserts of the Middle East are the work of man. Historians believe that it was the desertification of the Sahara and Arabia that gave impetus to the development of modern civilization, displacing people from lands that had lost fertility into the disastrous swampy valleys of the Nile, Tigris and Euphrates, where they were forced, willy-nilly, to improve technology and social relations.

Over the 100 years from 1882 to 1982, the proportion of areas defined as deserts increased from 9.4% to 23.3%. The deserts keep coming.

Great damage to the Earth's soil layer is caused by salinization as a result of improper reclamation. Irrational irrigation leads to flooding and waterlogging of the soil. Salts come to the surface or are washed with water if drainage systems do not remove this water. Deforestation causes floods, which also contribute to the salinization process, as salt is washed out along with the water.

Anthropogenic salinization of the territory occurs due to the enrichment of soil and other substrates with various salts - waste products of animals and humans or technogenic influence (domestic wastewater, industrial wastewater, runoff from roads on which salt is used together with sand to prevent ice).

Compaction of soil and other substrates causes disruption of the air-gas regime and other physical properties. As a result, the density and porosity of the substrate and the oxygen content in the root layer change, which leads to disruption of root nutrition and other physiological processes in plants, and ultimately to the disappearance from ecosystems of species that are not resistant to this influence.

Chemical methods of weed control in agriculture and forestry also damage soils. They cause such negative phenomena as a violation of biological balance, a decrease in the species diversity of communities of soil organisms, a decrease in biochemical processes, changes in the physical and chemical properties of the soil, and a decrease in the resistance of the soil ecosystem to unfavorable environmental factors. With the current level of chemicalization in agriculture, the issue of protecting soils, especially those with low levels of biogenicity, is of particular relevance.

Some experts believe that desertification is just one phase of a natural climate process that occurs very slowly. Others believe that droughts only provoke the process of desertification, but are not its cause. In their opinion, it is irrational land use and overgrazing, which significantly deplete the land and reduce its productivity, that is the true cause of desertification.

Information about the dry regions of the world

Dry regions occupy 41 percent of the earth's landmass. More than 2 billion people live in this territory (information from 2000). 90 percent of the population are from developing countries with low development indicators. Infant mortality in dryland countries is higher and gross national product (GNP) per capita is lower than in the rest of the world. Due to difficult access to water, the market for agricultural products, and a small number of natural resources, poverty is widespread in arid regions.

According to UN estimates, desertification could potentially affect more than a billion people and about a third of all land used for agricultural purposes. This particularly applies to large parts of North Africa, Central Asia, Southeast Asia, Australia, parts of North and South America, and Southern Europe.

In 1994 in Paris it was adopted United Nations Convention to Combat Desertification in those countries that are experiencing serious drought and/or desertification, especially in Africa (The United Nations Convention to Combat Desertification in Those Countries Experiencing Serious Drought and/or Desertification, Particularly in Africa, UNCCD). Its task is to unite the efforts of government and public organizations at the international, regional, national and local levels to combat desertification, land degradation and mitigate the effects of drought.

Consequences of desertification.

The consequences of desertification include:

· reduction in food production, reduction in soil fertility and the natural ability of the land to recover;

· increased floods in the lower reaches of rivers, deterioration of water quality, sedimentation in rivers and lakes, siltation of reservoirs and shipping canals;

· deterioration of human health due to wind-blown dust, including eye, respiratory and allergic diseases and psychological stress;

· disruption of the usual way of life of the affected population, forced to migrate to other areas.

For dry areas Poverty is still common because:

· the poor living in these areas, and especially women, rarely participate in political life and often lack access to basic services such as health care, agricultural information and education; at the same time, women are systematically subjected to discrimination, manifested in the deprivation of their right to own land;

· Dryland populations often lack agricultural essentials such as tools, fertilizers, water, pesticides and seeds, lack adequate access to markets, and their produce is rarely sold at a reasonable price due to its poor quality;

· local communities are often unable to benefit from local resources such as minerals or wild nature and other attractions that attract tourists;

· access to water and the exercise of rights to use this resource are often difficult, and water resources are usually managed ineffectively, which leads to their overuse and salinization;

· land is often subjected to excessive cultivation and overgrazing, which leads to a decrease in its productivity;

· communities living in dry areas are most affected by drought; They are mainly engaged in raising livestock and subsistence farming and have no food reserves, money, insurance or other forms of social protection, which would help them survive the lean years.

International legal principles of cooperation in solving environmental problems

First of all, you should realize that the problem of desertification is pressing and relevant in these living conditions. Therefore, international cooperation is necessary to combat this problem.

At its fifty-eighth session, the General Assembly decided to proclaim 2006 as the International Year of Deserts and Desertification (resolution 58/211 of 23 December 2003). The Assembly invited all countries to establish national committees and focal points and celebrate the Year through appropriate activities. She called on all relevant international organizations and Member States to support activities related to desertification, including land degradation, to be organized by affected countries, in particular African countries and least developed countries.

On 22 December 2005, the Assembly expressed its strong resolve to strengthen the implementation of the United Nations Convention to Combat Desertification in Those Countries Experiencing Serious Drought and/or Desertification, Particularly in Africa, to address the causes of desertification and land degradation, as well as poverty-related land degradation, through, inter alia, the mobilization of sufficient financial resources on a predictable basis, technology transfer and capacity-building at all levels. She welcomed the appointment of honorary representatives of the United Nations for the International Year of Deserts and Desertification and recommended Secretary General to appoint additional representatives in this regard to facilitate the successful implementation of the Year's program throughout the world.

According to the legal and semantic significance, the declared principles of environmental protection can be divided into nine groups, at the head of which, of course, it is necessary to determine the principles that affirm the right of citizens to a favorable environment, although 20 years ago priority was given to the sovereignty of states to use natural resources and protect the environment environment.

So, the first group includes principles that establish the priorities of human rights to a favorable environment and sustainable development. Caring for people is central to efforts to achieve sustainable development. People have the right to a healthy and productive life in harmony with nature. The right to development must be realized to ensure that needs are met equitably

present and future generations in the field of development and the environment. To achieve sustainable development, environmental protection must be an integral part of the development process and cannot be considered in isolation from it.

Principle 2 of the Stockholm Declaration declares that the Earth's natural resources, including air, water, land, flora and fauna, and especially representative examples of natural ecosystems, should be conserved for the benefit of present and future generations through careful planning and management as appropriate.

The second group of principles proclaims the sovereignty of states over the use of natural resources. This provision is particularly reflected in the principle of the 21st Stockholm Conference, which states: “In accordance with the Charter of the United Nations and the principles of international law, States have the sovereign right to use their own resources in accordance with their national policies in approaching environmental problems, and it is their responsibility to responsibility to ensure that activities within their jurisdiction or control do not cause damage to the environment in other States or areas beyond national jurisdiction.”

States adopt effective environmental legislation. Environmental standards, regulatory objectives and priorities should reflect the environmental and development contexts in which they apply. Standards applied by some countries may be inappropriate and impose unreasonable economic and social costs in other countries, particularly developing countries.

Like the Stockholm Declaration, the World Charter for Nature contains guiding principles for the conduct of states and peoples in relation to surrounding nature, with the special quality, however, that they are addressed not only and even not so much to the sphere of interstate relations, but to intrastate legal relations, to the sphere of real behavior of people, individual or collective. The World Charter for Nature states that the principles set out in the Charter should be reflected in the legislation and practice of each State, as well as at the international level: taking full account of the sovereignty of States over their natural resources, each State must apply the provisions of this Charter through its competent authorities and in cooperation with other states.

International law in the fight against desertification

As defined by the UN Convention to Combat Desertification, “desertification means the degradation of land in arid, semi-arid and dry sub-humid areas as a result of various factors, including climate change and human action”, and combating desertification includes activities that are part of integrated process for sustainable development.

The development of the UN Convention to Combat Desertification was initiated by the decision of the World Conference on Environment and Sustainable Development, held in Rio de Janeiro in 1992.

The UN Convention to Combat Desertification, developed by the Intergovernmental Negotiating Committee to develop an International Convention to Combat Desertification in Those Countries Experiencing Severe Drought and/or Desertification, Particularly in Africa, was adopted by the UN General Assembly on 17 June 1994. This day, June 17, has been declared by the UN as World Day to Combat Desertification. The Convention entered into force on December 26, 1996. Currently, the Convention has been ratified by 124 countries.

Let's consider the most significant areas of the Earth in which the fight against desertification plays a significant role.

International law in the fight against desertification in Kazakhstan

Desertification is one of the most important problems of our time. Currently, the area of degraded lands in Kazakhstan is 179.9 million hectares, or more than 66% of its territory.

Thus, in Kazakhstan there is an urgent need to take preventive measures to prevent further land degradation and take measures to restore and further rationally use the country’s natural resources, including land and water.

The decrease in the fertility of arable land, the degradation of pastures and the reduction in the area of hayfields, chemical and radioactive contamination of soils and water bodies have greatly worsened the condition of natural lands and led to a decrease in the volume of agricultural production, a deterioration in living conditions and public health. Thus, Kazakhstan is faced with the urgent issue of taking preventive measures to prevent further land degradation and taking measures to restore and further rationally use the country’s natural resources, including land and water. At present, when the land has been transferred to private land users, there is an urgent need to increase public awareness about the processes of desertification in Kazakhstan, the impact of these processes on the economic and social situation of the rural population, the goals and objectives of the Convention.

To solve these problems, the Republic of Kazakhstan signed in 1996 and ratified the UN Convention to Combat Desertification on June 7, 1997 and thereby committed itself to steadily implementing the main provisions of the Convention.

In 1996, work began in Kazakhstan to prepare a national action program. A group of scientists, with the participation of all interested ministries and departments, broad public participation and with the financial support of UNEP and UNDP, completed the draft “National Program of Action to Combat Desertification in Kazakhstan” (NACP) in December 1997. In 1999, the development of the National Strategy and Action Plan to Combat Desertification (NSDSAP) began.

With the support of the UN Development Program/UNSO, the Republic of Kazakhstan developed the “Pastures” project, management of pasture ecosystems. The purpose of developing this project is to organize actions together with local administrations to preserve biodiversity, combat desertification and poverty in remote villages along the coast of the Kazakh part of the Aral Sea to support grazing livestock. This project involves providing effective assistance local communities in the restoration, improvement and sustainable use of pasture lands, restoration and rational use of water for the development of livestock, and the acquisition of self-sufficiency by the local population.

Strategic directions for combating desertification are being developed as an integral part of the country’s broader national sustainable development policy, as set out in the “Kazakhstan 2030” Strategy.

During the implementation of the Convention, the following priority areas for combating desertification were identified:

1. Monitoring of desertification. A basic territorial-zonal municipality is being formed in the republic

monitoring network. Currently it is represented by 36 stationary and 16 semi-stationary environmental sites. To create a basic monitoring network covering the entire territory of the republic, it is necessary to significantly increase their number, develop and implement a set of desertification indicators. As part of the Regional Action Plan for Asia, Kazakhstan made its proposals and became a member of the Thematic Program Network “Organization of a regional network for monitoring and assessing desertification in Asia.” Kazakhstan is participating in the work carried out by the BWC Secretariat on indicators and impact indicators. The importance of this work for assessing the implementation of the BWC in affected countries must be noted. We are ready to continue this work, and propose to test the methodology developed by the BWC Secretariat in Kazakhstan.

2. Ecological zoning and system creation effective management environmental management. The basis of ecological zoning is the ecosystem principle and the establishment of the potential capabilities of ecosystems for self-healing - the ecological capacity of the area.

3. Measures for the rational use of natural resources of the Republic of Kazakhstan include the main directions of combating desertification:

· On arable land: conducting intensive grain farming on more fertile lands; restoration of fertility of arable land; transformation of part of low-productive arable land into forage lands; introduction of soil protection farming system, etc.

· For pastures: inventory of pastures; watering and surface improvement of pastures; development and implementation of a system of fenced pastures, etc.

· On afforestation and protection of the forest fund: carrying out reforestation work on the lands of the State Forest Fund; organization of monitoring of desert, tugai and mountain forests, etc.

· On water resources: introduction of water-saving irrigation technologies; replacing moisture-loving crops with drought-resistant, less moisture-loving crops.

The Convention Secretariat decided to develop a Regional Action Program to Combat Desertification in Asia on the basis of regional thematic networks. As part of strengthening regional cooperation, Kazakhstan entered as a participating country into the already created thematic program networks:

1. Monitoring and assessment of desertification (responsible country - China);

2. Agroforestry and soil conservation (responsible country - India).

Currently, Kazakhstan is actively participating in the development of regional cooperation. Active work is underway to include Kazakhstan in the international network to combat desertification. The main actions are aimed at strengthening the role of Kazakhstan in regional level, raising awareness of the local population about the goals and objectives of the BWC through seminars, meetings, and appearances in the media. Great importance is attached to the issue of participation of non-governmental organizations in the process of implementation of the Convention at the local level.

Particular attention is paid to the issue of finding possible donors to attract investments and implement project proposals.

The fight against desertification in Kazakhstan, concern for the conservation of natural resources is a national task that can be successfully solved only with the direct and active participation of all administrative, legislative, executive bodies, public associations and the entire population as a whole.

International law in the fight against desertification in Africa

Probably one of the most problematic zones in terms of desertification globe is Africa. Significant efforts of international cooperation in the fight against desertification are aimed specifically at Africa. Below are excerpts from the 2002 Johannesburg Convention to Combat Desertification in Africa.

The main priority in combating desertification should be to implement preventive measures on lands that have not yet been degraded or that have only been degraded to a small extent. However, severely degraded lands should not be ignored. In the fight against desertification and drought, the participation of local communities, rural organizations, national governments, non-governmental organizations, and international and regional organizations is essential.

The following are the program areas covered by the Convention:

· strengthening the knowledge base and developing information and monitoring systems for regions prone to desertification and drought, including economic and social aspects these ecosystems;

· combating land degradation by, in particular, intensifying activities for the conservation of soil resources, afforestation and reforestation;

· developing and strengthening comprehensive programs to eradicate poverty and promote the development of alternative livelihoods in areas prone to desertification;

· development and consideration of comprehensive programs to combat desertification in national development plans and in the process of planning environmental measures at the national level;

· development comprehensive plans Drought preparedness and management, including self-help measures, for drought-prone areas and development of programs to address environmental refugees;

· encouraging and stimulating public participation and environmental education with a focus on combating desertification and eliminating the consequences of drought .

Vulnerable ecosystems are important ecosystems that have unique features and resources. Vulnerable ecosystems include deserts, semi-arid lands, mountains, wetlands, small islands and some coastal areas. Most of these ecosystems are regional in scale and transcend national boundaries.

Quite a lot important role The 2006 UN General Assembly convention played a role in the international fight against desertification in Africa.

The fundamental factors for the adoption of the Convention were the following provisions:

· people in affected or threatened areas are placed at the center of efforts to combat desertification and mitigate the effects of drought;

· the presence of serious concern of the international community, including states and international organizations, about the adverse consequences of desertification and drought;

· recognition that arid, semi-arid and dry sub-humid areas together account for a significant proportion of the Earth's land surface and provide habitat and livelihoods for a large proportion of its population;

· recognition that desertification and drought are global problems, affecting all regions of the world, and that cooperative action by the international community is required to combat desertification and/or mitigate the effects of drought;

· the presence of a significant proportion of developing countries, especially least developed countries, among the countries experiencing severe

I know drought and/or desertification, and especially the tragic consequences of these phenomena in Africa;

· desertification is caused by a complex interaction of physical, biological, political, social, cultural and economic factors;

· the impact of trade and other aspects of international economic relations on the ability of affected countries to adequately combat desertification;

· recognition that sustainable economic growth, social development and poverty eradication are the primary objectives of affected developing countries, especially in Africa, and necessary conditions for achieving sustainable development goals;

· desertification and drought have an adverse impact on sustainable development due to their relationship with such important social problems such as poverty, poor health and nutrition, food insecurity, and challenges arising from migration, displacement and demographic dynamics;

· the high value of past efforts and experiences of States and international organizations in the field of combating desertification and mitigating the effects of drought, in particular in the implementation of the United Nations Plan of Action to Combat Desertification, which was adopted by the United Nations Conference to Combat Desertification in 1977 year;

· recognition of the impact and relevance of the decisions adopted by the United Nations Conference on Environment and Development, in particular Agenda 21 and its Chapter 12, which provides a framework for action to combat desertification;

· National governments play a critical role in combating desertification and mitigating the effects of drought, and that progress in this area depends on local implementation of action programs in affected areas;

· the great importance and necessity of international cooperation and partnership in combating desertification and mitigating the effects of drought;

· the importance of providing affected developing countries, especially in Africa, effective means and, in particular, substantial financial resources, including the provision of new and additional sources of funding and the importance of providing access to technology, without which it will be difficult for them to fully comply with their obligations under the Convention;

· the impact of desertification and drought on the affected countries of Central Asia and the Caucasus;

· the important role played by women in regions affected by desertification and/or drought, especially in rural areas of developing countries, and the importance of ensuring the full participation of both men and women at all levels in programs to combat desertification and mitigate the effects of drought;

· the special role of non-governmental organizations and other large groups in programs to combat desertification and mitigate the effects of drought;

· the relationship between desertification and other global environmental problems faced by international and national communities;

· the contribution that combating desertification can make to achieving the goals of the United Nations Framework Convention on Climate Change, the Convention on Biological Diversity and other environmental conventions;

· Strategies to combat desertification and mitigate the effects of drought will be most effective if they are based on appropriate systematic observation and accurate scientific knowledge and if they are continually re-evaluated;

· the urgent need for increased efficiency and better coordination of international cooperation to facilitate the implementation of national plans and priorities.

Conclusion

Among many global problems, the problem of desertification is the least known, although everyone knows that desert areas are characterized by an extremely hot climate, a large deficit of moisture and a rather fragile ecological system, but at the same time these lands have high economic potential. In the scientific literature and official documents, it is characterized as the last stage of the process of slow environmental degradation in the arid zone and is the product of a complex interaction between the socio-economic system and natural and anthropogenic factors.

Thus, it is mandatory the international cooperation in the direction of combating desertification of lands, especially African ones, should significantly help in solving this problem in order to preserve the rich natural and environmentally friendly heritage for future generations.

State budget educational institution higher professional education First Moscow State Medical University named after I.M. Sechenov of the Ministry of Health of the Russian Federation.

Essay on Ecology on the topic:

"Desertification of territories"

Performed:

student of the Faculty of Pharmacy

8 gr, Ilyina A.A.

07/30/2017 article

Drylands make up 41.3% of all land on the globe. This means that almost half of the lands available to humanity are potential deserts and, under certain conditions, can turn into them, which is happening slowly but inevitably.

56% of dry lands are used as pastures for livestock, 30% are given over to agriculture, and only 2% of them are occupied settlements. The remaining lands are deserts - hyperarid regions (Atakami, Namib, Gobi and part of Mongolia).

46% of the planet's carbon stores are stored in drylands Fact

Desertification is the process of turning once fertile lands located in arid areas into deserts. The second name for desertification is desertification (from the English word desert - desert).

Why is this happening?

There are many reasons for desertification. All of them can be divided into natural and resulting from human activity. It often happens that human intervention simply speeds up the process caused by natural phenomena characteristic of a particular area.

Natural causes of desertification

The most common reasons leading to desertification are the following: natural phenomena and disasters:

Limited rainfall.
Landslides and erosion caused by the destruction of vegetation as a result of strong winds or rainfall.
Soil salinization as a consequence of flooding of areas located on the sea coast.

The role of humans in desertification

Human activity plays an important role in desertification.

Plants cultivated in drylands make up 30% of all cultivated plants on the planet

Irrational use of land as pastures, excessive use of fertilizers and pesticides for soil cultivation, and incorrectly designed irrigation systems lead to irreversible processes, the end result of which is desertification of lands. Each of these mistakes in business activities leads to certain consequences.

Despite the many natural factors contributing to the desertification of drylands, main reason This process still leaves an environmental crisis - the result of incorrect use of the natural resources of each individual region.

It is believed that all deserts located in the Middle East are the result of human activity. It was the depletion of these territories (namely the Sahara and Arabia) as a result of overgrazing of livestock that prompted enterprising citizens to create cities on the swampy banks of the Tigris, Euphrates and Nile, as well as to develop industry and social relations.

Consequences of desertification

By reducing soil productivity, desertification leads not only to the depletion of arable land, but also to the disruption of the entire ecosystem of a certain region. The depletion of vegetation cover entails the death of many representatives of the animal world, which, in turn, has a significant impact on the standard of living of the population of these lands and leads to even greater errors and violations in the use of natural resources. Thus, desertification is often both a cause and a consequence of poverty and even hunger among the population of certain regions. The lower the social and economic level of the country's population, the higher the risk of excessive use of natural resources and, as a result, accelerating the process of desertification. And vice versa: the barrenness of the soil is always accompanied by hunger and poverty.

Ecological consequences of desertification

The most obvious results of desertification are represented by a number of changes in the region's ecosystem:

Climate change in a given area, in particular humidity.
Disruption of groundwater supply.
Drying and increasing soil salinity.
Activation of geomorphological processes - deflation, erosion, etc.
Significant depletion of vegetation cover.
Reduction in the number of fauna.

The share of drylands on the planet is 44% of all cultivated areas Fact

Economic consequences of desertification

The depletion of a country's natural resources invariably leads to economic consequences, and it is not a coincidence that most of the drylands belong to developing countries.

The most noticeable consequences of desertification:

The decline of agriculture as the most important sector in the country's economy.
There is a shortage of fresh water needed by the local population, the provision of which constitutes an additional expense item.
Siltation of artificially created reservoirs. The result is significant problems in the supply of electricity to nearby lands and their irrigation.

The fight against desertification: can it be stopped?

Lands susceptible to desertification make up almost a quarter of our planet's land area. If the pace of the process transforming fertile lands into uninhabitable territories does not slow down in the near future, then in the next 15-20 years in Russia alone this area promises to grow to 1 million hectares. This prospect forces us to take urgent measures to combat the process of desertification.

International Year combat desertification

Since desertification is a global environmental problem, the activities of many international organizations are aimed at combating it. In particular, on December 26, 1996, the United Nations International Convention to Combat Desertification came into force.

The largest areas of land with arid climates are located in Russia, Kazakhstan, Australia, China and the USA

In 2006, the UN General Assembly appealed to a number of relevant international organizations and heads of state to support efforts to combat desertification in developing countries. This year has gone down in history as the International Year of Deserts and Desertification.

UN Decade Dedicated to Deserts and the Fight against Desertification

The Year of Deserts and Desertification was only the first step in the international struggle for drylands. The period from mid-winter 2010 to December 2020 has been declared the Decade dedicated to deserts and the fight against desertification. The main goal of the grandiose event was to increase awareness of the populations of lands suffering from desertification about the causes of this process, as well as help in overcoming the current situation.

Local fight against desertification

The international scale of the problem of desertification does not mean that local measures to prevent it are impossible.

Countries whose territory is 99% dryland: Iraq, Kazakhstan, Turkmenistan, Botswana, Burkina Faso

On the contrary, conservation of natural resources is the primary task of the population living in a given territory. In particular, the following measures can be very effective at the local government level:

Improving land use models taking into account the specifics of a given territory and factors that can lead to degradation.
Carrying out work to preserve special ecological areas at the legislative level.
Promote the use of alternative energy sources to reduce pressure on wood resources.
Control of the rational use of natural resources by the population, in particular pastures and arable lands.

What can each of us do?

The fight against desertification implies not only the restoration of affected lands, but also the prevention of the development of this process in new territories.

Globally, the number of people living in drylands reaches 2 billion.

The simplest and most effective steps to achieve this are available to everyone.

Enriching the soil with plant cover - numerous landscaping activities carried out in cities and towns bring much greater results than it might seem at first. No one is stopping each of us from organizing such a mini-event on a family scale and planting several new trees.
Reducing the use of wood as fuel by replacing it with other types of fuel and using improved types of equipment.
Rational approach to pasture use.
Efficiency in the consumption of water resources: banal saving of water in every home can play an important role in preventing soil degradation in the region.
Every third inhabitant of the planet lives on land that threatens to turn into a desert

Of course, the importance of rational use of natural resources directly depends on the volume of consumption. For example, the influence of an ordinary family on the condition of the soil cannot be compared with the activities farm or enterprises. However, the fight against desertification cannot concern anyone selectively - this task, which has acquired an international scale, faces every inhabitant of the planet today.

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

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During the plowing of fields, myriads of particles of fertile soil cover rise into the air, disperse, are carried away from the fields by streams of water, are deposited in new places, and are irretrievably carried away in huge quantities into the World Ocean. The natural process of destruction by water and wind of the top layer of soil, washing away and dispersing its particles is greatly enhanced and accelerated when the lyuli plow up too much land and do not allow the soil to “rest.”

Under the influence of living organisms, water and air on surface layers The lithosphere gradually forms the most important ecosystem, thin and fragile - soil, which is called the “skin of the Earth”. This is the guardian of fertility and life. A handful of good soil contains millions of microorganisms that maintain fertility. It takes a century for a layer of soil 1 cm thick to form. It can be lost forever in one field season. According to geologists, before people began to engage in agricultural activities, graze livestock and plow land, rivers annually carried about 9 billion tons of soil into the World Ocean. Nowadays this amount is estimated at approximately 25 billion tons.

Soil erosion, a purely local phenomenon, has now become universal. In the United States, for example, about 44% of cultivated land is susceptible to erosion. In Russia, unique rich chernozems with a humus content of 14-16%, which were called the citadel of Russian agriculture, disappeared. In Russia, the area of the most fertile lands with a humus content of 10-13% has decreased by almost 5 times.

A particularly difficult situation arises when not only the soil layer is demolished, but also the parent rock on which it develops. Then the threshold of irreversible destruction comes, and an anthropogenic desert arises. The Shillong plateau in the Cherrapunji region, located in northeast India, presents a striking picture. This is the wettest place in the world, where on average more than 12 m of precipitation falls per year. But in the dry season, when the monsoon rains stop (October - May), the Cherrapunji region resembles a semi-desert. The soils on the slopes of the plateau have been practically washed away, exposing barren sandstones.

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

Natural deserts and semi-deserts occupy more than 1/3 of the earth's surface. These lands are home to about 15% of the world's population. Deserts are areas with an extremely arid continental climate, usually receiving an average of only 150-175 mm of precipitation per year. Evaporation from them is much higher than their moisture. The most extensive desert massifs are located on both sides of the equator, between 15 and 450 northern latitude, and in Central Asia and Kazakhstan, deserts reach 500 north latitude. Deserts are natural formations that play a certain role in the overall ecological balance of the planet’s landscapes.

As a result of human activity, by the last quarter of the 20th century. More than 9 million km2 of deserts appeared, and they already covered 43% of the total land area.

In the 90s Desertification began to threaten 3.6 million hectares of drylands. This represents 70% of potentially productive drylands, or? total land surface area, and these data do not include the area of natural deserts. About 1/6 of the world's population suffers from this process. Desertification can occur in different climatic conditions, but it occurs especially rapidly in hot, arid regions. Africa contains almost a third of all arid regions of the world; they are also widespread in Asia, Latin America and in Australia. On average, 6 million hectares of cultivated land are subject to desertification per year, which are completely destroyed, and over 20 million hectares reduce their productivity. This is the speed of approaching the threshold of irreversible destruction.

Desertification and devastation can occur in any climate as a result of destruction natural system. But in arid regions, drought also becomes the “engine” of desertification. Desertification, developing as a result of inept and immoderate economic activity, has more than once destroyed entire civilizations. In schools all over the world, during history lessons, children are taught that people need to know history in order to learn lessons for the future. Has humanity learned lessons from the history of the collapse of past civilizations buried under sand? The main difference between the experience of history and today consists of pace and scale. Excessively active economic activity, the pressure of which had accumulated over centuries and even millennia, has now been compressed into decades. If earlier individual civilizations perished, buried by sands, now the process of desertification, originating in different places and having different regional manifestations, has assumed a global scale. Accumulation in the atmosphere carbon dioxide, increased dust and smoke in the atmosphere accelerate the aridization of land. This process covers not only arid regions.

Sahel - in Arabic - coast, outskirts - this is the name of the transition zone up to 400 km wide, which extends south from the Sahara Desert to the savannahs of West Africa.

At the end of the 60s. a long-term drought broke out in this zone, which reached its climax in 1973. As a result of this drought, about 250,000 people died in the African countries of the Sahel zone - Senegal, Gambia, Mauritania, Mali, etc. There was a massive loss of livestock - and cattle breeding forms the basis of economic activity and the source of livelihood for the majority of the population in these areas. Many wells and even large rivers such as the Niger and Senegal have dried up.

Lake Chad's surface has been reduced to 1/3 his normal sizes. In the 80s Disasters caused by drought and desertification have become continent-wide in Africa. The consequences of these processes are experienced by 34 African countries and 150 million people. In 1985, about 1 million people died in Africa and 10 million people became “environmental refugees.” The rate of advance of desert boundaries in Africa in some places is up to 10 km per year.

The fate of forests and the history of humanity on all continents were closely interconnected. Forests served as the main source of food for primitive communities that lived by hunting and gathering. They were a source of fuel and building materials for the construction of dwellings. Forests served as a refuge for people and, to a large extent, as their basis. economic activity. The life of forests and the life of people, the connections between them are reflected in the culture, mythology, and religion of most peoples of the world. About 10 thousand years ago, before the advent of agricultural activity, dense forests and other forested areas occupied more than 6 billion hectares of land surface. By the end During the 20th century, their area decreased by almost 1/3 and now they occupy only a little more than 4 billion hectares. In France, for example, where forests initially covered about 80% of the territory, by the end of the 20th century. their area decreased to 14%; in the USA, where forests at the beginning of the 17th century. Almost 400 million hectares were covered; by 1920, 2/3 of this forest cover was destroyed.

desertification productive land ecological

Bibliography

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

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Desertification problem

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

Under the influence of living organisms, water and air, the most important ecosystem, thin and fragile, is gradually formed on the surface layers of the lithosphere - soil, which is called the “skin of the Earth”. This is the guardian of fertility and life. A handful of good soil contains millions of microorganisms that maintain fertility. It takes a century for a layer of soil 1 cm thick to form. It can be lost forever in one field season. According to geologists, before people began to engage in agricultural activities, graze livestock and plow land, rivers annually carried about 9 billion tons of soil into the World Ocean. Nowadays this amount is estimated at approximately 25 billion tons.

Soil erosion is especially severe in the largest and most populous countries. The Yellow River in China annually carries about 2 billion soils into the World Ocean. Soil erosion not only reduces fertility and reduces crop yields. As a result of soil erosion, artificially constructed water reservoirs become silted much faster than is usually envisaged in projects, and the possibility of irrigation and obtaining electricity from hydroelectric power plants is reduced.

A particularly difficult situation arises when not only the soil layer is demolished, but also the parent rock on which it develops. Then the threshold of irreversible destruction comes, and an anthropogenic desert arises. The Shillong plateau in the Cherrapunji region, located in northeast India, presents a striking picture. This is the wettest place in the world, where on average more than 12 m of precipitation falls per year. But during the dry season, when the monsoon rains stop (October - May), the Cherrapunji region resembles a semi-desert. The soils on the slopes of the plateau have been practically washed away, exposing barren sandstones.

One of the most global and fleeting processes of our time is the expansion of desertification, the decline and, in the most extreme cases, the complete destruction of the Earth's biological potential, which leads to conditions similar to those of a natural desert.

Natural deserts and semi-deserts occupy more than 1/3 of the earth's surface. These lands are home to about 15% of the world's population. Deserts are areas with extremely arid continental climates, typically receiving an average of only 150-175 mm of precipitation per year. Evaporation from them is much higher than their moisture. The most extensive desert massifs are located on both sides of the equator, between 15 and 45 0 northern latitude, and in Central Asia and Kazakhstan deserts reach 50 0 northern latitude. Deserts are natural formations that play a certain role in the overall ecological balance of the planet’s landscapes.

As a result of human activity, by the last quarter of the 20th century. More than 9 million km2 of deserts appeared, and they already covered 43% of the total land area.

In the 90s Desertification began to threaten 3.6 million hectares of drylands. This represents 70% of the potentially productive drylands, or ½ of the total land surface area, and does not include the area of natural deserts. About 1/6 of the world's population suffers from this process. Desertification can occur in different climatic conditions, but it occurs especially rapidly in hot, arid regions. Africa contains almost a third of all arid regions of the world; they are also widespread in Asia, Latin America and Australia. On average, 6 million hectares of cultivated land are subject to desertification per year, which are completely destroyed, and over 20 million hectares reduce their productivity. This is the speed of approaching the threshold of irreversible destruction.

According to UN experts, current losses of productive land will lead to the fact that by the end of the century the world could lose almost 1/3 of its arable land. Such a loss, at a time of unprecedented population growth and increasing food demand, could be truly disastrous.

More and more people around the world are becoming environmental refugees.

The desertification process is usually caused by the combined action of nature and humans. This effect is especially destructive in arid regions with their inherent fragile, easily destroyed ecosystems. Destruction sparse vegetation due to excessive grazing of livestock, cutting down trees and shrubs, plowing of lands unsuitable for agriculture, and other types of economic activities that disrupt the fragile balance in nature, greatly increase the effect of wind erosion and drying out of the upper layers of the soil. Sharply disrupted water balance, the groundwater level is decreasing, wells are drying up. The soil structure is destroyed, and their saturation with mineral salts increases. Due to excessive economic load, complexly organized river basin systems turn into primitively organized desert landscapes.

In schools all over the world, during history lessons, children are taught that people need to know history in order to learn lessons for the future. Has humanity learned lessons from the history of the collapse of past civilizations buried under sand?

Desertification of lands

The main difference between the experience of history and today is the pace and scale. Excessively active economic activity, the pressure of which had accumulated over centuries and even millennia, has now been compressed into decades. If earlier individual civilizations perished, buried by sands, now the process of desertification, originating in different places and having different regional manifestations, has assumed a global scale. The accumulation of carbon dioxide in the atmosphere, increased dust and smoke levels in the atmosphere accelerate the aridization of land. This process covers not only arid regions.

The expanding area of deserts contributes to the development of dry climatic conditions, which are likely to have a large influence on the frequency of multi-year droughts. The vicious circle closes.

Sahel - in Arabic - coast, outskirts - this is the name of the transition zone up to 400 km wide, which extends south from the Sahara Desert to the savannahs of West Africa.

At the end of the 60s. A long-term drought broke out in this zone, which reached its climax in 1973. As a result of this drought, about 250,000 people died in the African countries of the Sahel zone - Senegal, Gambia, Mauritania, Mali, etc. There was a massive loss of livestock - and cattle breeding forms the basis of economic activity and the source of livelihood for the majority of the population in these areas. Many wells and even large rivers such as the Niger and Senegal have dried up. The surface of Lake Chad has shrunk to 1/3 of its normal size. In the 80s Disasters caused by drought and desertification have become continent-wide in Africa. The consequences of these processes are experienced by 34 African countries and 150 million people. In 1985, about 1 million people died in Africa and 10 million people became “environmental refugees”. The rate of advance of desert boundaries in Africa in some places is up to 10 km per year.

The fate of forests and the history of humanity on all continents were closely interconnected. Forests served as the main source of food for primitive communities that lived by hunting and gathering. They were a source of fuel and building materials for the construction of dwellings. Forests served as a refuge for people and, to a large extent, as the basis for their economic activity. The life of forests and the life of people, the connections between them are reflected in the culture, mythology, and religion of most peoples of the world. About 10 thousand years ago, before the advent of agricultural activity, dense forests and other forested areas occupied more than 6 billion hectares of land surface. By the end of the 20th century, their area decreased by almost 1/3 and now they occupy only a little more than 4 billion hectares. In France, for example, where forests initially covered about 80% of the territory, by the end of the 20th century. their area decreased to 14%; in the USA, where forests at the beginning of the 17th century. Almost 400 million hectares were covered; by 1920, 2/3 of this forest cover was destroyed.

All the aspects considered do not have the best effect not only on our general well-being, but, mainly, on the well-being of our children and descendants in general. Therefore, we must provide them with a glorious and cloudless future: develop and implement projects to limit and eradicate such undesirable processes in general.

Bibliography:

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

Desertification. The nature of desertification. Desertification degree. Depth and speed of desertification.

Desertification is a process that leads to the loss of continuous vegetation cover by a natural ecosystem with the further impossibility of its restoration without human intervention. There are two forms of desertification: 1. expansion of the desert area, 2. deepening of the process of desertification in place.

Drought in general is a natural crisis that occurs periodically in many parts of the globe. She is a frequent visitor to countries located near the southern borders of the Sahara. Today, lands in the southwest of America, as well as certain areas of Bolivia, Australia and Brazil, are undergoing desertification. The problem of desertification and drought also exists in Russia. One of the main causes of desertification is the grazing of more cattle than the pasture can support. The second cause of desertification is intensive agriculture on the not very fertile lands of the arid zone. The process of desertification is intensifying due to the fact that people, whose numbers are increasing, are cutting down entire forests for firewood. The spread of desertification is also influenced by political and social factors. All these consequences of human activity - overgrazing, excessive consumption of wood, intensive Agriculture combined with erosion, urbanization of arid regions, salinization and overdrafting of groundwater - the result, at least in part, of human population pressure on nature.

Desertification is the process of degradation of all natural life support systems: in order to survive, the local population must either receive outside help or leave in search of land suitable for life. More and more people around the world are becoming environmental refugees. The expanding area of deserts contributes to the development of dry climatic conditions, which are likely to have a large influence on the frequency of multi-year droughts. The vicious circle closes.

The International Convention to Combat Desertification is one of the main mechanisms for the participation of all countries of the world in solving this problem. Its main focus is on improving soil fertility and restoration, as well as protecting and rationally using land and water resources.

Desertification. Causes.

To reduce desertification processes it is necessary: 1. Limiting agricultural activities and grazing. 2.Agroforestry is the integrated activity of raising livestock or cultivating land and simultaneously growing woody plants on the same area. 3. The need for suitable technologies.

Scientists distinguish four degrees of desertification: weak, moderate, strong and very strong. Severe desertification has become widespread in Asia, Africa, North and South America, and Australia. Restoring lands affected by severe desertification requires large investments and long time. And very severe desertification entails complete and irreversible degradation of the land. Nevertheless, about 80 million people live in areas of severe and very severe desertification. As a result of all these processes, the “load” on the land is constantly increasing, and the availability of land resources is decreasing.

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

Lektsii.net - Lectures.Net - 2014-2018. (0.006 sec.)

Desertification and its monitoring

Desertification

Desertification- the process of transformation (transition) of cultivated fertile irrigated lands into waterless and lifeless deserts with loss of soil fertility and vegetation.

Causes of desertification

Water shortage— lack of water resources to satisfy the biological needs of crops and other types of vegetation for their normal growth and development, as well as environmental requirements to stabilize the development of environmental processes.

Drought- a long period of time of year with insufficient precipitation at elevated air temperatures.

Climate aridization— increased climate aridity due to increased air temperature, evaporation and decreased precipitation, i.e. increasing the air humidity deficit according to Torveit and reducing the humidity coefficient.

Deforestation— denudation of the area of growth and development of forest plantations, which led to disruption of snow retention, accumulation of moisture reserves from rainwater. In addition, due to deforestation, soil erosion occurs on mountain slopes and foothill plains in the form of washout and erosion, as well as gully formation.

Livestock herding— denudation or thinning of pasture areas from vegetation due to an increase in the number of livestock compared to the standard. Denudation or thinning of pasture areas leads to a sharp decrease in soil moisture reserves formed under the influence of scanty atmospheric precipitation in the desert.

Biological death— necrosis of the plant world due to a sharp disruption of their need for water and an increase in harmful toxic substances in the soil and atmosphere.

Lack of drainage- lack of groundwater outflow in the natural-historical development of the territory and general drainage flow during artificial drainage to prevent the rise of groundwater and, as its consequences, flooding and secondary salinization in the process of irrigation and land development.

Salt accumulation under the influence of pressure groundwater. Accumulation in the root layer or aeration zone (the layer located between the surface of the earth and the groundwater level) due to their transfer by underground tributaries, formed both outside the irrigated areas and in them, as a result of which pressure complexes of aquifers are created in the absence or insufficient natural drainage. Under these conditions, piezometric pressures in aquifers represented by highly permeable soils (sands, gravel deposits, pebbles, etc.) are established above the groundwater level, creating a certain flow of water and salts into the upper weakly permeable fine earth - the aeration zone. The amount of salt accumulation depends on the intensity of the flow of pressure waters, the reserves of salts in low-permeable cover fine soils and the mineralization of underground pressure waters. In the territory represented by pressure groundwater, a surface salt profile is formed with the distribution of salt reserves in the aeration zone (above groundwater) due to their removal from the lower layers. An example of the formation of such a distribution of the salt profile is the territory of the Fergana Valley, the old irrigation zone of the Hungry Steppe of the Republic of Uzbekistan, and the Vakhsh Valley of the Republic of Tajikistan.

Salt accumulation in irrigation fields under the influence of salt imbalance. This type of salt accumulation in irrigation fields is formed in conditions when the incoming part of the water-salt balance of the field is formed due to water supply for irrigation of crops, filtration from on-farm field canals, influx from groundwater above the outgoing part (evapotranspiration, flow from the aeration zone into groundwater, groundwater reserves in lower aquifers and drainage flow) with insufficient natural and artificial drainage.

Salt accumulation under the influence of influx from higher lands. This type of salt accumulation is formed due to the transport of salts by groundwater in the areas of interconal depressions, the end parts of alluvial fans and the peripheral part of the proluvial slopes of the foothill plains, which are a zone of groundwater discharge. The intensity of salt accumulation depends on the salinity of rocks and soils hypsometrically located above the territories and the degree of mineralization of groundwater transiting into the lower irrigated areas. This type of salt accumulation is characteristic of large depressions (depressions) located in the plains.

Salt accumulation under the influence of technogenic disturbances. Salt accumulation is formed due to the release of waste from large mines, plants and factories, where residual products are discharged into water sources without treatment - into ravines and sewers.

Salt accumulation under the influence of aeolian transport. This type of accumulation is formed by the transport of weathered rock products and salts under the influence of wind-driven climate action. The source of supply of salts can be, along with weathered rock products, individual highly saline parts of deserts, semi-deserts, dried sea bottoms and saline lands located inside the irrigated area.

Decrease in groundwater level. Reduction of groundwater levels against their optimal depths and regime due to the depletion of groundwater reserves and drainage of the bottom of seas and reservoirs. An example is the dried bottom of the Aral Sea, formed under the influence of insufficient supply of surface runoff along the Syrdarya and Amu Darya rivers.

Stopping irrigation. Irrigation is stopped due to a lack of water resources and the unprofitability of agricultural production on low-fertility lands included in the irrigated fund.

Violation of the water balance of the reservoir. Violation of the water balance of water bodies most often occurs due to a shortage of water resources in the region, used mainly for the development of agricultural production, industry, public utilities and fisheries. Due to the shortage of water resources within the Aral Sea basin, more than 200-250 small and medium-sized lakes and reservoirs were drained.

Loss of fertility. Most often it occurs due to irrational and improper management of agricultural crops due to severe salinization and flooding of land with poor drainage of the territory. Desertification under the influence of loss of fertility of irrigated lands is most characteristic of irrigated lands located in river delta regions.

Types of desertification

Soil salinization. Saline soil is non-alkaline soil containing soluble salts in large quantities, preventing the growth of most crops. There are:

Primary soil salinization is the natural accumulation of salts in the soil due to evaporation of groundwater, salinity of parent rocks, or under the influence of aeolian, biogenic or other factors.
Secondary soil salinization is the accumulation of salts in the soil resulting from artificial changes water regime, for example due to improper irrigation. Secondary soil salinization can occur in non-saline or primary saline soils.
In most cases, secondary salinization is caused by the movement of water-soluble salts to the surface from deep layers of underlying rocks and groundwater, or by the influx of mineralized water from higher-lying irrigated areas.

Deforestation (deforestation)- reduction or destruction of the geographical landscape consisting of a set of woody, shrubby, herbaceous plants caused by changes in their living conditions or economic activities.

Land (and pasture) degradation— deterioration of the properties, fertility and productivity of land as a result of economic activity.

The reasons for land degradation in the Aral Sea basin are: long-term droughts, inefficient use of water for irrigation, leading to soil salinization, excessive grazing of livestock, which reduces and deteriorates the soil layer (blowing out the humus horizon), unjustified use of chemicals that cause soil and water pollution.

Draining the bottom of the sea and reservoirs— exposure of the seabed and reservoirs as a result of a drop in water level and a decrease in water area due to the depletion of natural restoration resources and an increase in water flow over the inflow.

Desertification indicators

Degree of soil salinity assessed by analysis of aqueous extracts (1:5) or electrical conductivity. According to the degree of salinity, soils are divided into 5 categories: non-saline, slightly saline, moderately saline, highly saline and very highly saline.

Conditions for salt accumulation in soils

Formation of salts in the soil

Changes in tree density or tree species. Here it is necessary to consider plant formations, which consist of various groups of green plants.

Combating desertification and drought

V.R. Williams identifies the following types of plant formations.

Woody vegetation of coniferous and deciduous forests
Meadow herbaceous vegetation.
Steppe herbaceous vegetation (feather grass, fescue, wheatgrass, yellow alfalfa, astragalus, ephemeral plants - tulips, bulbous bluegrass, goose onion).
Desert vegetation is characterized by exceptional poverty (saxauls, pistachios, etc., ephemeral).

In forestry practice, forest phytocenoses are usually called plantations. The main distinctive features of a phytocenosis include species or floristic composition, layering, abundance of species, quantitative and qualitative ratio of species, occurrence, productivity, seasonal and annual rhythm of development, etc. Changes in the density of trees and the phytocenosis in general are studied by their species composition.

Soil grading- a comparative assessment of the quality of soils (farmland) as a means of production in agriculture and forestry, expressed in quantitative indicators. The estimated properties are the thickness of the humus horizon, the content of basic nutrients in the soil, the exchange capacity of the absorbed complex, the reaction of the environment (pH), mechanical composition, salinity, etc. Quantitative assessment of soils based on their properties is carried out on a 100-point scale.

Drainage area (bottom)- the area of the bare bottom of the sea or reservoir as a result of the retreat of the coastline and a decrease in the water level in the reservoir (sea). The criterion for a dried bottom is the area of the bare bottom (m2, km2 or% relative to the area of the water area).

Monitoring methods

… soil salinity and salinity levels

Ground surveys - includes ground sampling of soils from various horizons of the soil profile for further analysis of water extract in laboratory conditions in order to determine water-soluble substances (dense residue) and various ions. Sommers can also be used for ground-based monitoring of soil salinity. Ground monitoring of soil salinity is carried out twice a year - in spring and autumn.

Remote monitoring of soil salinity - photographing a terrain (a given contour) from the air using an airplane or some other aircraft. In recent years, satellite imagery has also been used to assess salinity (especially soil patchiness according to the degree of salinity). The resulting surveys are interpreted using ground surveys and used to compile cartographic materials for specific objects.

...deforestation

Ground monitoring is a ground-based study of plant composition - a set of plants growing together on a homogeneous territory, the nature of their composition, structure, species, species vitality, age, saturation (in a certain area), etc. They can be used for geobotanical mapping.

Taxation is the identification of taxonomic categories of plants. It includes: associations, group of associations, formations, group of formations, class of formations, type of vegetation, types, subtypes, species, etc.

Remote monitoring is the use of aerial photographs and satellite materials to study vegetation cover and their subsequent geobotanical mapping.

The frequency of monitoring is once every 3-5 years by forestry authorities (Goskompriroda), land supervision and the Ministry of Agriculture and Water Resources.

... degradation processes

Ground monitoring is carried out on the basis of field work(soil cuts, half cuts, digging) and laboratory tests soils, highlighting genetic divisions (types, subtypes), degree of moisture, degree of erosion, nutrients for compiling cartographic materials.

Mapping is one of the ways to study soil cover, which reflects the spatial distribution of soils; their properties are set out in the legend that accompanies the map materials. Agronomists, land managers, land reclamation workers, meadow farmers and other specialists base their work on these materials to select the best technical and economic solutions in accordance with natural conditions. In terms of the detail of display and the allocation of territory, soil maps are different: Overview (scale smaller than 1:1,000,000) - schematized; 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 ground monitoring - once every 5 years - is carried out by the land supervision authorities and the Ministry of Agriculture and Water Resources.

Remote monitoring - the use of aerial photographs and satellite materials for soil mapping. The essence of remote sensing of soils (and vegetation) is the decoding (recognition) of photographs using photogrammetry and the visual method. The theoretical basis of remote sensing methods is the law of correlation between the properties of soils, the plant communities covering them and environmental conditions. The soil surface is almost always covered to some extent by vegetation. Therefore, the composition and condition of vegetation primarily influence the nature of the photographic image.

...drained bottom

Dry bottom monitoring - systematic observation and monitoring changes in the area of the drained bottom (and processes) using remote and ground-based (calculation) methods.

Remote sensing method is the use of aerial and space photography materials to draw up a plan (map) of the drained bottom and measure the area of the water body of a reservoir (sea).

Ground method - carrying out work to measure water depths using a bathometer and drawing up a plan of the bottom relief (bathymetric map).

The frequency of monitoring is annually by the Hydrometeorological Service and Land Supervision.

One of the global manifestations of soil degradation, and indeed the entire environment natural environment in general, is desertification. According to B. G. Rozanov (1984), desertification is a process of irreversible changes in soil and vegetation and a decrease in biological productivity, which in extreme cases can lead to the complete destruction of the biosphere potential and the transformation of the territory into a desert.

In total, more than 1 billion hectares are subject to desertification in the world on almost all continents (Fig. 15.3). The causes and main factors of desertification are different (Fig. 15.4). As a rule, desertification is caused by a combination of several factors, the combined action of which sharply worsens the environmental situation.

Rice. 15.3. Deserts and areas subject to desertification
(UN Conference on Desertification, 1977):

desertification degree: 1¾ very high; 2¾ high;
3 ¾ moderate; 4¾ hyperarid deserts

Rice. 15.4. Main factors and causes of desertification development

In areas prone to desertification, the physical properties of soils deteriorate, vegetation dies, groundwater becomes saline, biological productivity drops sharply, and, consequently, the ability of ecosystems to recover is undermined. “And if erosion can be called a landscape ailment, then desertification is its death” (UN FAO Report). This process has become so widespread that it has become the subject of the international Desertification program. The UNEP (UN Environment Organization) report emphasizes that desertification is the result of a long historical process, during which adverse natural phenomena and human activities, reinforcing each other, lead to changes in the characteristics of the natural environment.

Desertification is both socio-economic and natural process, it threatens approximately 3.2 billion hectares of land, which is home to more than 700 million people.

Desertification problem

A particularly dangerous situation has developed in Africa in the Sahel zone (Senegal, Nigeria, Burkina Faso, Mali, etc.), a transitional bioclimatic zone (up to 400 km wide) between the Sahara Desert in the north and the savanna in the south.

The cause of the catastrophic situation in the Sahel is due to a combination of two factors: 1) increased human impact on natural ecosystems in order to provide food for a rapidly growing population and 2) changed meteorological conditions (prolonged droughts). Intensive grazing leads to excessive pressure on pastures and the destruction of already sparse vegetation with low natural productivity. Desertification is also facilitated by massive burning of last year's dry grass, especially after a period of rain, intensive plowing, lowering the groundwater level, etc. Knocked-out vegetation and highly loosened soils create conditions for intensive deflation of the surface layer of the earth. Changes in natural complexes and their degradation are especially noticeable during droughts. Many environmentalists believe that in the list of atrocities against the environment, desertification can be placed second after the destruction of forests.

In the CIS, the Aral Sea region, the Balkhash region, the Black Lands in Kalmykia and the Astrakhan region and some other areas are susceptible to desertification. All of them belong to environmental disaster zones and their condition continues to deteriorate.

As a result of ill-conceived economic activities in these territories, deep irreversible degradation changes have occurred in the natural environment and, first of all, in its edaphic part. This resulted in a sharp decrease in the biodiversity of phyto- and zoocenoses and the destruction of natural ecosystems. Experts note that where, due to the conditions of the relief, soil quality, and the thickness of the first stand, only one sheep could be grazed, tens of times more were grazed. As a result, grassy pastures turned into eroded land. Over the past five years alone, the area of shifting sands in Kalmykia has increased by 50 thousand hectares.

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Consequences of soil degradation

1) Decrease in soil fertility

2) Deterioration of human health and increased morbidity in animals.

Desertification

A living organism is sensitive to changes in chemical composition soil. An excess or deficiency of one or another element in the soil leads to negative consequences for the body.

Nitrates and nitrites, entering the human body, interact with hemoglobin in the blood. Hemoglobin contains 2-valent iron, and nitrates convert it into 3-valent iron, as a result of which red blood cells lose their ability to carry oxygen. When 20% of hemoglobin is blocked, oxygen deficiency (anomia) occurs. If 80% of hemoglobin is blocked - death.

3) Weakening the self-cleaning ability of the soil. Soil microorganisms break down pollutants into less toxic compounds.

4) Soil salinization. Occurs when there is poor drainage and improper watering. This leads to a rise in groundwater levels and the accumulation of easily soluble sodium chloride and sulfate, potassium and sodium carbonate in the soil. Even mild salinity reduces yield by 2 times.

5) Soil acidification. Soil acidity can be natural or secondary. Optimal soil pH: 5.5-8.0. If the pH drops to 3.6-4.0, virtually nothing will grow in that soil.

Combating land degradation

1) Rational use of soils. Elimination of environmentally unsound decisions.

2) Application of appropriate agricultural practices - no-moldboard farming, the use of crop rotation and the rejection of heavy equipment.

3) Reducing soil salinity (increasing water fees)

4) Application of hydraulic measures (strengthening slopes, retention of runoff)

5) Forest reclamation work (agroforestry - planting protective forest strips, land reclamation - drainage of waterlogged lands and swamps).

6) Chemical reclamation. It is divided into liming (soil acidity decreases, heavy metals are converted into insoluble compounds), gypsuming (leads to a decrease in soil salinity) and the use of mineral and organic fertilizers.

7) Land reclamation - a set of works to restore the productivity and economic value of disturbed lands. It takes place in 2 stages:

· Technical reclamation (delivery of land, planning...)

· Biological remediation(restoration of the biological properties of the earth).

This is achieved by adding fertilizers, liming, and planting shrubs and trees.

Types of impacts on the lithosphere.

Lithosphere is the hard shell of the Earth.

Soil is a complex, multifunctional and multicomponent open multiphase structural system with fertility. Soil is a product of the joint activity of 5 components

Priming
Animals and plant organisms
Climate
Terrain
Age of the territory.

Arable land is 10% of the Earth's land area, pastures and hayfields are 20%, the remaining 70% are cold climate zones and areas unsuitable for agriculture.

The soil participates in the formation of river flow, and also, due to the entry of soil compounds into water bodies, is a factor in their bioproductivity.

Earth is the only planet in the solar system.

Every year, 7 million hectares of arable land are lost due to poor land management practices.

Earth's crust©

Violations of the natural environment are accompanied by the extraction and processing of minerals, this is expressed in the following:

The creation of large-sized quarries and embankments, which leads to the formation of a technogenic landscape, a reduction in land resources, and the depletion and destruction of soils.
Drainage of deposits, water intake for the technical needs of mining enterprises, discharge of mine and waste water depletes groundwater and surface water reserves and deteriorates their quality.
Drilling, blasting, and loading of rock mass causes deterioration in the quality of atmospheric air.
The processes mentioned above, as well as industrial noise, contribute to the deterioration of living conditions and habitats, a reduction in the number of plants and animals, and a decrease in agricultural yields.
Mining, extraction of minerals, burial of solid and liquid waste lead to changes in rock masses, flooding of deposits, and contamination of the subsoil.

The main reasons for the decrease in areas suitable for agriculture:

Erosion (natural and artificial)
Pollution (industrial, agricultural, transport, household)
Construction allotment
Negative economic activities (destruction of forests, burning of vegetation, changes in the water regime of territories).
Development of land for mining.

Erosion is the destruction of soil under the influence of water, wind and mechanical means. Accelerated erosion is caused by human activities.

Based on the nature of the removal of soil particles, water and wind erosion are distinguished. Water erosion involves the transfer of soil particles into streams, rivers, and seas, as a result of which the entire cultural layer is washed away. Water erosion also includes coastal erosion. Wind erosion is the movement of dry soil particles.

Soil contamination is achieved industrial enterprises(mining workings, solid fuel thermal power plants). In Russia, about 7,000 hectares of land are occupied by solid waste landfills.

Soil classification:

Tundra gley
Peat bogs
Podzolic
Sod-podzolic
Swamp-podzolic
Forest gray
Meadow-chernozem
Chernozems
Serozems
Brown desert-steppe
Solontsy

Man is nature's friend:

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Desertification is currently one of the most significant global problems of humanity.

As a result of human activity, by the last quarter of the 20th century. More than 9 million km2 of deserts appeared, and they already covered 43% of the total land area.

In the 90s Desertification began to threaten 3.6 million hectares of drylands. This represents 70% of potentially productive drylands, or ¼ of the total land surface area, and does not include natural deserts. About 1/6 of the world's population suffers from this process. Desertification can occur in different climatic conditions, but it occurs especially rapidly in hot, arid regions. Africa contains almost a third of all arid regions of the world; they are also widespread in Asia, Latin America and Australia. On average, 6 million hectares of cultivated land are subject to desertification per year, which are completely destroyed, and over 20 million hectares reduce their productivity. This is the speed of approaching the threshold of irreversible destruction.

The desertification process is usually caused by the combined action of nature and humans. This effect is especially destructive in arid regions with their inherent fragile, easily destroyed ecosystems. The destruction of sparse vegetation due to excessive grazing of livestock, cutting down trees and shrubs, plowing of lands unsuitable for agriculture, and other types of economic activities that disrupt the fragile balance in nature greatly increase the effect of wind erosion and drying out of the upper layers of the soil. The water balance is sharply disrupted, the groundwater level decreases, and wells dry up. The soil structure is destroyed, and their saturation with mineral salts increases. Due to excessive economic load, complexly organized river basin systems turn into primitively organized desert landscapes.

Desertification and devastation can occur in any climate as a result of the destruction of the natural system. But in arid regions, drought also becomes the “engine” of desertification. Desertification, developing as a result of inept and immoderate economic activity, has more than once destroyed entire civilizations. In schools all over the world, during history lessons, children are taught that people need to know history in order to learn lessons for the future. Has humanity learned lessons from the history of the collapse of past civilizations buried under sand? The main difference between the experience of history and today is the pace and scale. Excessively active economic activity, the pressure of which had accumulated over centuries and even millennia, has now been compressed into decades. If earlier individual civilizations perished, buried by sands, now the process of desertification, originating in different places and having different regional manifestations, has assumed a global scale. The accumulation of carbon dioxide in the atmosphere, increased dust and smoke levels in the atmosphere accelerate the aridization of land. This process covers not only arid regions.

The expanding area of deserts contributes to the development of dry climatic conditions, which are likely to have a large influence on the frequency of multi-year droughts. The vicious circle closes.

Sahel - in Arabic - coast, outskirts - this is the name of the transition zone up to 400 km wide, which extends south from the Sahara Desert to the savannahs of West Africa.

At the end of the 60s. A long-term drought broke out in this zone, which reached its climax in 1973. As a result of this drought, about 250,000 people died in the African countries of the Sahel zone - Senegal, Gambia, Mauritania, Mali, etc. There was a massive loss of livestock - and cattle breeding forms the basis of economic activity and the source of livelihood for the majority of the population in these areas. Many wells and even large rivers such as the Niger and Senegal have dried up. The surface of Lake Chad has shrunk to 1/3 of its normal size. In the 80s Disasters caused by drought and desertification have become continent-wide in Africa. The consequences of these processes are experienced by 34 African countries and 150 million people. In 1985, about 1 million people died in Africa and 10 million people became “environmental refugees.” The rate of advance of desert boundaries in Africa in some places is up to 10 km per year.

The fate of forests and the history of humanity on all continents were closely interconnected. Forests served as the main source of food for primitive communities that lived by hunting and gathering. They were a source of fuel and building materials for the construction of dwellings. Forests served as a refuge for people and, to a large extent, as the basis for their economic activity. The life of forests and the life of people, the connections between them are reflected in the culture, mythology, and religion of most peoples of the world. About 10 thousand years ago, before the advent of agricultural activity, dense forests and other forested areas occupied more than 6 billion hectares of land surface. By the end of the 20th century, their area decreased by almost 1/3 and now they occupy only a little more than 4 billion hectares. In France, for example, where forests initially covered about 80% of the territory, by the end of the 20th century. their area decreased to 14%; in the USA, where forests at the beginning of the 17th century. Almost 400 million hectares were covered; by 1920, 2/3 of this forest cover was destroyed.

Bibliography:

1. Encyclopedia for children: T.3 (Geography). – M., Avanta+, 1994. – 640 p.