Oh! Desertification increases

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70% of drylands worldwide are degraded, equivalent to 3,600 million hectares (excluding hyper-arid deserts) .The drought is the world’s costliest natural disaster. In the case of the United States it represents an expense of approximately 6,000 to 8,000 million dollars a year, considering that this phenomenon affects more people than any other form of natural disaster.

ORIGIN OF REMEMBRANCE

In 1995 the General Assembly of the United Nations, proclaimed June 17 as the World Day to Combat Desertification and Drought (resolution 49/115) commemorating the adoption of the Convention of the United Nations Combat Desertification on 17 June 1994 to all member states of the United Nations were invited to devote the Day to sensitize public opinion on the need to cooperate at the international level to combat desertification and the effects of drought, as well as putting into action of the United Nations Convention to Combat Desertification (UNCCD) in those countries affected either by severe drought, by desertification, or both, particularly in Africa.
Until May 2012, 195 countries have approved, accepted, ratified or acceded to the Convention members, including Mexico, which ratified it in 1995 (UNCCD, 2012). The UNCCD is a unique instrument focused much attention to land degradation, including social and economic problems that this process generates. It has four strategic objectives: 1) improve the living conditions of affected populations; 2) improve the conditions of affected ecosystems; 3) generate global benefits through effective implementation of the Convention itself, and 4) mobilize resources to support the effective implementation of the Convention through building effective partnerships between national and international actors.
The themes of the 2013 World Day to combat desertification are water shortages and drought. In this regard, all the water on earth, only 2.5% is fresh kind, and of this, the total usable supply for ecosystems and humans is less than 1%. Therefore, when demand exceeds the available supply, results in scarcity. Drylands are particularly vulnerable to water shortages. Therefore, the intensification of freshwater scarcity will cause greater stress in drylands.
The purpose of the World Day to Combat Desertification and Drought, 2013, is to raise awareness about the risks of drought and water scarcity in drylands, drawing attention to the importance of maintaining healthy soils as part of the message Agenda Rio + 20, and the Development Agenda Post-2015. *
In the theme this year: “Do not let our future dry”, it calls on all member states of the United Nations to take steps to promote preparedness and resilience to water scarcity, desertification and drought . The theme is the message that we are all responsible for water and sustainable land use, and that there are solutions to these serious challenges of natural resources. The degradation of the land does not have to threaten our future.

Concept of desertification

Contrary to common belief, desertification is not the loss of land by its transformation into desert or by the movements of the sand dunes. Desertification refers to land degradation in arid, semi-arid and sub-humid areas due to various factors, such as loss of vegetative cover, soil erosion and lack of water, including climatic variations and human activities.

Desertification processes

There are seven processes that are responsible for desertification: degradation of plant cover, water erosion, wind erosion, salinization, reduction of soil organic matter, soil crusting and compaction and accumulation of toxic substances for plants or animals. Of these, the first four are considered primary processes of desertification and the last three, secondary. The primary processes are so called because their effects are large and have a significant impact on the production of the land.
It should be noted that the process of desertification is evaluated based on three criteria: state, speed and risk, and for each of these criteria are considered four types of desertification: mild, moderate, severe and very severe.
There is no linear process of cause and effect that allows fully explain desertification; however, complex interactions were detected engine operating as the process. These engines are climatic variations (such as low soil moisture, changing rainfall patterns and high evaporation) and human activities (such as overexploitation of land for agriculture, overgrazing, deforestation, the use of systems inadequate irrigation, market trends and even socio-political dynamics, UNCCD and Zoï, 2011). On this last point, poverty can function as cause and consequence of desertification.
The purpose of the World Day to Combat Desertification and Drought, 2013, is to raise awareness about the risks of drought and water scarcity in drylands, drawing attention to the importance of maintaining healthy soils as part of the message Agenda Rio + 20, and the Development Agenda Post-2015. *
In the theme this year: “Do not let our future dry”, it calls on all member states of the United Nations to take steps to promote preparedness and resilience to water scarcity, desertification and drought . The theme is the message that we are all responsible for water and sustainable land use, and that there are solutions to these serious challenges of natural resources. The degradation of the land does not have to threaten our future.

Concept of desertification

Contrary to common belief, desertification is not the loss of land by its transformation into desert or by the movements of the sand dunes. Desertification refers to land degradation in arid, semi-arid and sub-humid areas due to various factors, such as loss of vegetative cover, soil erosion and lack of water, including climatic variations and human activities.

Desertification processes

There are seven processes that are responsible for desertification: degradation of plant cover, water erosion, wind erosion, salinization, reduction of soil organic matter, soil crusting and compaction and accumulation of toxic substances for plants or animals. Of these, the first four are considered primary processes of desertification and the last three, secondary. The primary processes are so called because their effects are large and have a significant impact on the production of the land.
It should be noted that the process of desertification is evaluated based on three criteria: state, speed and risk, and for each of these criteria are considered four types of desertification: mild, moderate, severe and very severe.
There is no linear process of cause and effect that allows fully explain desertification; however, complex interactions were detected engine operating as the process. These engines are climatic variations (such as low soil moisture, changing rainfall patterns and high evaporation) and human activities (such as overexploitation of land for agriculture, overgrazing, deforestation, the use of systems inadequate irrigation, market trends and even socio-political dynamics, UNCCD and Zoï, 2011). On this last point, poverty can function as cause and consequence of desertification.

By April 2013, 168 countries are affected by desertification. Each year, 75 billion tons of fertile soil are lost to land degradation. Also, 12 million hectares of land disappear each year by desertification and drought. This is an area that could produce 20 million tons of grain.
DISTRIBUTION OF DRY LAND IN THE WORLD 3
According to the United Nations Convention to Combat Desertification (UNCCD) 2011, 12.1% of the Earth’s land surface corresponds to arid areas; 17.7% to 9.9% semi-arid and dry sub-humid to. They live just over 2,000 million people (about 1 in 3 people in the world), mostly in developing countries. In addition, the dry areas are home to some 50% of cattle and 44% of agricultural land in the world, and are very large territories that represent valuable habitats for wildlife. The largest areas of drylands are in Australia, China, Russia, the United States and Kazakhstan

The total population of the world’s drylands is around 2,000 million, excluding hyper-arid areas (deserts), today drylands are home to almost one in three people worldwide. Most of these are located in developing countries, live below the poverty line and without adequate access to running water, the highest percentage of the world population is in the dry sub-humid region where 15.3% grassland ecosystem is dominant and the minimum percentage of global population accounts for 4.1% living in the arid and semi-desert is the dominant ecosystem (Table 1).
Table 1. Distribution of world population in drylands

Ecosystem dominant soil type Percentage of Total Population
world population (%)
Total 2,008’085,000 33.8
Semidesierto arid 242’780,000 4.1
14.4 Semi-Arid Prairie 855’333,000
Pasture dry sub-humid 909’972,000 15.3

Extent of desertification
The United Nations Convention to Combat Desertification (UNCCD) estimates that between 71% and 75% of the world’s drylands are desertified

PHENOMENON OF DROUGHT

When the temperature rises and remains high for several months and the rains are rare and irregular, vegetation grows heavily. It is drought-term for the natural phenomenon that occurs when precipitation has been significantly below normal recorded levels, and produces serious hydrological imbalances that adversely affect agricultural production systems.
The United Nations, in its document of the Convention to Combat Desertification (UN, 1994) defines drought as “naturally occurring phenomenon that exists when precipitation has been significantly below normal recorded levels, causing serious hydrological imbalances that adversely production systems of land resources “.

WORLD vulnerability to drought

The recurring phenomenon of drought in vulnerable parts of Africa has drawn worldwide attention because of the famine that has already created social and economic disruptions caused large scale. The drought in the Sahel cereal production declined by 26% in 2012 compared to the figures recorded in 2011.
However, the drought also affects other regions, only in the last year, droughts have affected such diverse places as Australia, Brazil, Djibouti, southeastern Europe, Mexico, Russia, China, India, Somalia, Spain and the United States .
It has been estimated that droughts are the costliest natural disaster in the world, only for the United States represents an expense located between 6,000 and 8,000 billion a year and affects more people than any other form of natural disaster. Since 1900, over 11 million people have died as a result of drought and 2,000 million people have been affected. Women, children and the elderly are often those who pay the highest price.

In dry areas, the amount of rainfall is less than potentially evaporate into the atmosphere. From the ratio between precipitation and potential evapotranspiration, it can be classified as an area susceptible to desertification; if the ratio is between 0.05 and 0.65. Within this range are the arid, semi-arid and sub-humid regions. About a third of the planet is within these categories.

Estimates of the magnitude of desertification are very different. The document Down to Earth, published by the Secretariat of the United Nations Convention to Combat Desertification (UNCCD), figures suggested that double or quadruple those of the World Atlas of Desertification, produced by the United deNaciones Environment Programme (UNEP). The data presented in the Figure are among the most conservative.

20% of susceptible to desertification in the world have already been degraded areas, which is roughly equivalent to the area of ​​China. About 70% of arable land in dry areas has been desertified, knocking out power to millions of people. Annually, 12 million hectares of farmland are lost, leaving produce millions of tons of grain that could alleviate hunger to many countries. Recurring famines in Africa are the result of the degradation of agricultural soil and drought periods. It is estimated that at least 500 thousand people have become environmental refugees and a billion more are threatened in varying degrees by desertification.

Globally, 35 million hectares thousand suffer from desertification caused by man. Of these, two thirds are in Africa and Asia. Although estimates for American countries are considerably lower, the difference is that drylands are not tanextensas in the new world. According to the UNCCD, when the damage is assessed in proportion to the extent of vulnerable areas, desertified areas on all continents occupy between 71 and 75% of drylands.

The major causes of desertification are water erosion (45% of cases) and wind (42%). The first occurs in semi-arid and dry sub-humid areas, while the latter is characteristic of arid regions. Chemical erosion, salinization predominantly, is responsible for another 10%.

This June 17 is World Day to Combat Desertification, the date that aims to sensitize public opinion on the need to cooperate at the international level to combat the effects of drought.

The theme this year is “Do not let our future dry”, asks to take measures to prepare and anticipate water shortages, desertification and drought.

The idea is that everyone is responsible for the conservation and sustainable use of water and land. There are solutions to the serious problems of scarcity of natural resources and land degradation need not jeopardize our future. 10 facts known how drought affects us in the world.

1. What is desertification? A quarter of our planet is made up of drylands and one-sixth of the world population lives in them. Many drylands are threatened by desertification, a phenomenon which is defined as land degradation in arid, semi-arid and dry sub-humid, caused by various factors, including climatic variations and include abuse of resources natural part of being human.

2. Approximately 40% of the national territory in Mexico suffers from some degree of drought, being the most affected states Chihuahua, Durango, Coahuila, Zacatecas, Tamaulipas, San Luis Potosi, the mountainous area of ​​Queretaro, Aguascalientes, Sinaloa and Sonora.

3. An estimated 24 billion tons of fertile soil disappear annually and over the last 20 years has lost an equivalent to the agricultural land area of ​​the United States. Approximately one third of the Earth’s land is threatened by desertification.

4. Almost half of the land area consists of drylands (47% according to the World Atlas of Desertification, UNEP 1997), equivalent to about 6, 450 million hectares, which are distributed among all major regions the planet.

5. Desertification is accumulated in a difficult climate context and inappropriate land use result. Four human activities constitute the most direct causes: excessive wearing soil cultivation, overgrazing and deforestation which destroy the vegetation cover that protects the soil from erosion, drainage and inappropriate irrigation systems causing salinization soils.

6. Two-thirds of Africa is made up of desert or drylands. This region is afflicted by frequent and severe droughts. The survival of a large number of African countries is closely linked to its natural resources. Africa’s desertification is closely connected with the ills: poverty, migration and food security problems.

7. Although the Latin America and the Caribbean is known for their rain forests, it is recalled that 25% of its surface is composed deserts and drylands. These drylands are deteriorating due to abusive exploitation of its natural resources.

8. Desertification affects 30% of the land area of ​​the United States of America.

9. annually worldwide are lost between 20,000 and 50, 000 square kilometers of land, especially due to soil erosion. It is planned that by 2025 two-thirds of the arable land in Africa is lost.

10. Currently land degradation is causing an average loss of more than 3% of gross domestic product of agriculture in sub-Saharan Africa. More than half of the arable land in Africa remain out of use by 2050, and the region would reach only feed 25% of its population in 2025.


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