Boot V., Tsvetayeva O.

Oles Honchar Dnipropetrovsk National University

DESERTIFICATION

Nowadays desertification is one of the most important global problems.

Desertification – is a process of irreversible changes in soil and vegetation, redu­cing the biological productivity, which in extreme cases can lead to complete destruc­tion of the capacity of the biosphere and transformation of the territory into the desert.

In the issue of human activity more than 9 million square kilometers of deserts appeared in the last quarter of XX century and altogether they have already covered an around43 % of the total land area. This process spreads so widely that became the subject of an international program «Desertification».

The process of desertification is usually caused by the combined effect of nature and people. The destruction of sparse vegetation due to over-grazing, felling of trees and shrubs, plowing land unsuitable for agriculture and other economic activities, the fragile balance of nature, multiply the effects of wind erosion, desiccation topsoil. Because of this water balance greatly disturbed, the level of ground water reduced and dry wells. The soil structure was destroyed and its satu­ration with mineral salts is increasing. Due to excessive economic burden comp­lexly organized basin-river systems become organized primitive desert landscapes.

The consequences of desertification include:

• diminished food production and reduction of fertility of soils and the land's natural ability to recover;

• intensification of floods in down streams, degradation of water quality, sedimentation in rivers and lakes, siltation of reservoirs and navigation channels;

• worsening of people’s health because of wind-blown dust;

• violation of habitual way of life of affected people that forced to migrate to other areas.

This problem became threaten to 3.6 million hectares of arid land in the nineties. It’s 70 % of potentially productive dry lands and, what is more, these figures do not includethe area of ​​natural deserts. An around sixth of world population suffers from this process.

Desertification can take place in different weather conditions, but it occurs mostly in hot and dry parts of word. There are third of all arid regions of our planet are in Africa; they also are widespread in Asia, Latin America and Australia. 6 million hectares of cultivated agricultural areas are affected by desertifications, that damage them absolutely; and over 20 million hectares of them reduce their product ability. This is the speed of the moving forward the line of unrecoverable damages.

 UN experts say, today's loss of productive land will lead to the end of the century the world could lose almost one third of its arable land. Such a loss in a period of unprecedented population growth and increasing demand for food can be truly disastrous.

 We should try to solve this problem bya consolidation of our forces, first of all, because this process only in some measure due to natural factors. Mostly, desertification isa consequence of anthropogenic factors and it becomes so dangerous mainly because of irrational, and sometimes even haughty, people’s attitude to nature. That is why The General Assembly of the United Nations decided to declare the period from January 2010 to December 2020 the UN Decade that dedicated to deserts and combating desertification. The decade will become a good opportunity for realization of changes which are required for dry lands. It will be benefit for people for a long time.