A discussion of the risks and benefits of using rock terracing to limit soil erosion in Guizhou Province

摘要

The construction of stone terraces to minimise soil erosion is common throughout Guizhou. The technique, however, has high inherent risk. Stone terraces are usually much higher than those with earth risers. While they trap a greater thickness of soil on the slope they increase the risk of slope failures, reduce moisture and nutrient availability to plants, and thin more soil up slope. The stone risers also threaten long-term productivity. When a riser collapses debris is deposited over the terrace below making farming difficult. These breaches in the terrace focus surface runoff leading to gully formation and increased sediment transport down slope.