How does terracing reduce runoff and soil erosion on hillsides?

Terracing is an effective land management technique used to combat desertification by transforming steep hillsides into a series of graduated, flat levels that resemble steps.1

This method reduces runoff and soil erosion through several key mechanisms:

• Slowing Runoff: By creating flat surfaces across a slope, terracing significantly slows the velocity of water moving down the hillside.1
• Water Retention: Many terrace systems incorporate a low, flat ridge of earth along the edge of the terrace, often paired with a channel that captures runoff. This design allows water to move slowly toward an outlet or encourages it to infiltrate the soil, which retards overall water loss.21
• Infiltration: By breaking the continuous slope, terraces prevent water from gaining the momentum necessary to wash away topsoil, allowing more moisture to be absorbed by the ground rather than becoming destructive surface runoff.13

In areas with lower rainfall or highly permeable soils, level terraces are particularly effective at maximizing water capture and maintaining the biological productivity of the land.2