Drought and Desertification

Arid Areas and Risks

Arid areas are dry areas and can be found close to above and below the equator.
About 40% of our total land area are arid areas.
Arid areas are most susceptible to drought and desertification.
Drought and desertification thus threatens a lot of the people who live in these areas.
In total arid areas are home to about 2 billion people.
Has an impact to ecosystems, food production and economy.
There are large deserts in central Asia, Africa, Australia and the Americas.
Areas which get the most sunlight are permanently low pressure areas.
This leads to usual rainfalls.
Meanwhile deserts like the Sahara are permanent high pressure areas.
This is because they're in the Horse Latitudes.
In Horse Latitudes the climate is dry because of the permanent high pressure and little to no rain.
There is little rainfall and harsh solar radiation as there are little to no clouds to block it.
Some areas are subject to dry winds and other weather events (such as the Atacama desert near the Peru current).
Others are in the centers of continents (such as the Gobi desert in Asia), making rainfall sparse.

Drought is caused by low precipitation relative to evaporation.
Long periods of drought are influenced by a number of factors, including the Pacific El Niño phenomenon and climate change.
Years of drought reduce agricultural productivity and the availability of water, making living conditions harsh.
Drought can cause desertification and wildfires.
It can cause famine, malnutrition, epidemics and migration waves among people.
Drought is a worldwide problem that is becoming ever more prominent due to global warming and deforestation.

The risk of forest fires depends on the dry season.
Most wildfires occur during August and January, depending on which period is the hottest.
This also leads to deforestation and loss of wildlife in most cases.

Desertification is the conversion of land in arid regions into land that cannot support plant growth.
The permanent degradation of soil quality in arid areas.
Less fertile and useable than before due to lack of nutrients and moisture.
In the Sahel region of Africa, population growth increases the need of fire wood. Losing vegetation increases desertification.
Overgrazing livestock and unsustainable farming can also lead to loss of vegetation and thus desertification.
Highest risks are in the areas closest to deserts.
Desertification can occur anywhere which doesn't have abundant vegetation or areas with loss of vegetation.
For example arid areas or deforested regions.

Overgrazing, is one of the main causes of desertification.
In the past, livestock numbers were limited by lack of water, but the digging of wells has made it possible to raise larger herds.
Ineffective farming practices such as unsuitable crops and slope-side ploughing also contribute to desertification.
Cutting down large areas of forest reduces water evaporation and thus clouds that would have formed to provide rainfall.
This is because trees and vegetation draw water from the soil, without them evaporation does not occur nearly as much.
Deforestation leads to increased erosion, because tree roots no longer bind the soil together.
Rainforests and savannas are cleared in tropical regions to make way for crop fields.
Over a third of the world's population uses firewood for cooking. Fuelwood is the main source of energy, especially in rural areas of sub-Saharan Africa. This leads a lot of people to depend on logging for their living.
Overpopulation forces societies to over-exploit arid and semi-arid areas.
Because governments and firms are unwilling to invest in these areas, their infrastructure and educational opportunities are inadequate.
This also makes it difficult to address livestock numbers, farming methods and deforestation.
Climate change and global warming further intensify desertification.
This makes the lives of the poorest people even more difficult.

Reduces agriculture and biodiversity.
Less habitable due to lack of plants and extreme weather conditions.
Desertification reduces biodiversity, agriculture, and the habitability of land the night.
More erosion
Dust storms and stronger winds
Famine and respiratory diseases
Social impacts such as conflicts and migration
Erosion, dust storms, strong winds, salinization, famine and respiratory diseases are all risks of living in desertified areas.
This can cause conflicts and migration.

Problem in dry areas, where irrigation is used.
Dissolved salts in water which evaporates can lead the salts to accumulate on the land.
These salts make the area inhospitable.

The Aral Sea is one of the most prominent examples of modern desertification.
The Aral sea was once the fourth largest lake on Earth.
It dried up in about 40 years, when the Amu Darya river that flows into it was redirected to irrigate rice and cotton fields.
There have been some projects to try and save the lake, such as a dam and the planting of trees.
Only a very small region of the lake as been secured however.