GCSE Geography | Impacts of Desertification (Hot Deserts 9)

Desertification in semi-arid areas such as the Sahel has many impacts, both on a local and global scale.

Soil erosion

Soil erosion is caused by deforestation, as well as poor farming practices.

Deforestation removes the leaf canopy which would have shaded the soil below and stopped from it drying out, and means there is no leaf litter to return nutrients to the soil, making it dry out further. Additionally there will be no roots to bind the soil together - this means that the top layer can be blown or washed away easily, leaving the soil vulnerable and exposed.

Poor farming practices also lead to soil erosion. Overgrazing means that animals trample the land and strip the vegetation so that there is nothing left to bind the soil together. Overcultivation means that the land is exhausted of water and nutrients so it completely dries out, meaning that it can be blown or washed away much easier.

Food supply and poverty

Desertification has a huge impact on the food supply of local communities.

Soil degradation and a lack of water means that soil will lose fertility, and without nutrients it will struggle to sustain plant growth. This often leads to crop failure where whole harvests are lost. If crops fail this has an impact on food supply, leading to malnutrition, making people weaker and more vulnerable to illness and diseases. In extreme cases this can lead to widespread famine, putting communities at risk of starvation.

Food insecurity means that farmers will also lose their only income - this will have many long-term impacts such as not being able to afford essential medication, which will lead to an increase in deaths, as well as not being able to afford to send children to school, meaning that children are unable to gain qualifications which may help them get out of poverty in the future.

On a global scale desertification can lead to increased food prices in other countries as crops become scarce.

Migration

The poor quality soil will cause people to migrate as the land they live on can no longer support them and their families - as people migrate this causes the problem to spread elsewhere as they potentially over-farm other areas. It will also cause some people to move to urban areas where they are most likely to live in informal settlements on the fringes of major cities, which will cause problems with over-population and a lack of access to adequate services, such as sanitation.

Water quality

Desertification means that less vegetation can grown and plants play an important role in keeping water clean and clear.

It also means that water sources will start to dry up - if there is less water in a river or pond then the water is more likely to become stagnant. Stagnant water encourages insects such as mosquitoes, which can then cause an increase in malaria in an area.

On the other hand, desertification can also lead to isolated incidents of flooding during heavy downpours in the wet season - the loss of vegetation leads to reduced interception and infiltration to increases surface run-off.