Desertification is primarily exacerbated by which combination of factors?

Desertification is primarily exacerbated by which combination of factors?

• A. Reforestation and sustainable grazing
• B. Excessive rainfall and climate change
• C. Urbanization with impermeable surfaces
• D. Deforestation, overgrazing, and unsustainable farming

Answer: (D)

Desertification happens when dryland ecosystems lose their ability to support vegetation because the land is degraded by human actions and climate variability. The strongest driver is the combination of removing protective vegetation and soils through deforestation, overgrazing, and unsustainable farming. Deforestation takes away the roots and litter that stabilize soil and shade it from drying, making it easier for wind and water to carry soil away. Overgrazing removes the grasses and other ground cover, compacting the soil, reducing its porosity and infiltration, and increasing runoff and erosion. Unsustainable farming—like over-cropping, poor irrigation, and nutrient depletion—drains soil fertility and structure, leading to further erosion and salinization in some regions. Put together, these practices leave soils exposed, dry out more quickly, and lose organic matter, driving the spread of desert-like conditions.

Other options describe actions or conditions that don’t primarily drive desertification. Reforestation and sustainable grazing, for example, help prevent or reverse land degradation. Excessive rainfall isn’t the typical trigger for desertification, and while climate change can influence dryness, it doesn’t explain the same direct, combined impact as the trio of deforestation, overgrazing, and unsustainable farming. Urbanization with impermeable surfaces also reduces infiltration, but the problem of desertification is rooted in rural land degradation rather than city-driven changes.