Soil Erosion & Desertification | Geography for GCSE/IGCSE - Year 11 PDF Download

Soil Erosion

• Soil erosion occurs when the topsoil is gradually worn away by the forces of wind or water.
• This natural process is exacerbated by human activities that leave the soil vulnerable to the erosive effects of wind and water.

• Salinisation poses a growing concern in many semi-arid regions. It occurs due to intense evaporation rates, causing groundwater to rise to the surface.
  • As the groundwater evaporates, it leaves behind salts on or within the topsoil, rendering the land unsuitable for many crops.
  • The accumulation of salts makes the soil toxic to crops, leading to the land becoming unusable for agricultural purposes.
• Prolonged soil erosion can eventually contribute to the process of desertification in affected areas.

Desertification

• Desertification is caused by both natural factors and human activities
• Many of the natural causes may be made worse by climate change

Sustainable Management of Soil Erosion and Desertification

• Sustainable management of soil erosion and desertification involves addressing underlying causes.
• Various political and social measures are necessary.

Education

Education plays a crucial role, encompassing:

• Teaching sustainable farming techniques like agroforestry and crop rotation to maintain soil health.
• Promoting family planning to curb population growth.

Agroforestry 

Agroforestry integrates agriculture with forestry, preserving trees, which:

• Mitigates deforestation.
• Offers shade, enhancing infiltration and interception, thus reducing soil erosion.
• Provides organic matter and nutrients to enrich the soil.

Afforestation

Afforestation, like the Great Green Wall initiative in the Sahel, aids in reversing desertification by:

• Root systems binding soil, thereby reducing erosion.
• Canopy providing shade, preventing soil dehydration and erosion from direct rainfall impact.
• Nutrient replenishment through fallen leaves and branches.
• Increasing animal and insect activity, improving soil health.

Contour Stones and Terraces

Contour stones and terraces are effective in minimizing soil erosion through:

• Preventing soil erosion caused by wind or water runoff.
• Enhancing water infiltration and minimizing surface runoff.
• Retaining dead organic matter in situ, facilitating decomposition and nutrient enrichment of the soil.