Characteristics of Soil Erosion Intensity on Cultivated Hillslopes of Different Cultivation Ages in Loess Plateau Determined Using ~(137)Cs as a Tracer

WANG Xiao-yan~1, TIAN Jun-liang~2\;(1.Departmemt of Architecture, Changsha Science and Technology University, Changsha 410076, Hu'nan Province, China; 2.Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling District 712100, Shaanxi Province, China)

cultivation ages, cultivation hillslopes; erosion intensity; ~(137)Cs tracer; Loess Plateau

Yangou watershed in the Loess Plateau was selected as the study site to determine the characteristics of soil erosion intensity on cultivated hillslopes of different cultivation ages. The radionuclide tracer technique was employed as a new method and a method was developed to calculate average area concentrations of radionuclide and soil erosion intensity of whole hillslopes by using the average gradients of hillslopes and average area concentrations of radionuclide on hillslopes, with a weighting for slope length. The results of partial correlation analyses among soil erosion modulus, cultivation age, slope gradient and slope length show that the correlation coefficient between erosion modulus and cultivation age is high, higher than that between erosion modulus and slope gradient. The relationship between erosion modulus and slope length was not significant. The conclusion is that soil erosion intensity on hillslopes becomes more severe with increasing cultivation age, mainly due to the gradually effect of the destruction of forestland and grassland.