Land degradation and soil erosion are major global problems. Approximately 5 billion hectares of land, or 43% of the Earth's vegetated surface, is degraded with reduced productivity. Overgrazing accounts for about one-third of degraded land, while 3.6 billion hectares are associated with desertification. A major cause is overgrazing, while 0.5 billion hectares have been degraded due to tree felling in humid tropics. Soil degradation is responsible for about 2 billion hectares of degraded land, with 85% caused by wind and water erosion which involves raindrop detachment of soil particles, transport by overland water flow or runoff, and deposition in other areas.

1. Land Degradation and Soil Erosion

2. Degraded Land – resulting in reduced productivity
~ 5 billion ha (@ 43% of Earth’s vegetated surface)
~ @ 1/3 due to overgrazing
~ 3.6 billion ha associated with desertification
~ a major cause is overgrazing
~ 0.5 billion ha due to tree felling in humid tropics
Soil degradation is greatly responsible
for @ 2 billion ha of the 5 billion ha
@ 85% of this is due to wind & water erosion

4. Soil Erosion

12. Process 1. Rain drop detachment
2. Transport (overland flow or runoff)
3. Deposition