THE IMPACT OF UNDERLYING CONDITIONS ON FARMLAND RUNOFF AND SEDIMENT YIELDS IN THE LOESS HILLY AREAS OF SHAANXI, CHINA

摘要

Runoff plots were used to analyze the factors that affect surface runoff and sediment yields and there pattern in farmland with different crop cover on the hilly loess areas of Shaanxi, China. The results showed that less runoff was formed under denser vegetation after the same rainfall. Greater slope produced more runoff under the same rainfall intensity and underlying conditions. But when rainfall intensity exceeded a certain value, it had little impact on runoff formation. Analysis on sediment yields showed that more sediment was produced under longer slope. The main factors that affect the surface runoff and sediment yields in farmland on hilly loess area include rainfall intensity, time of rainfall, and slope and surface cover condition of the farmland.