侵蚀泥沙研究的137Cs核示踪技术

^137Cs是上世纪50-70年代大气核试验产生的核尘埃，1963年产出量最大，半衰期30．1a。^137Cs主要伴随降水降落到地表，随即被土壤颗粒吸附，^137Cs以后的迁移主要伴随被吸附土壤颗粒的运移。上世纪80年代以来，^137Cs示踪技术已广泛应用于侵蚀泥沙研究中。简要介绍了^137Cs示踪技术的基本原理，和在黄土高原、长江上游等地侵蚀速率测定，泥沙来源调查，塘库沉积物断代等研究中的一些应用实例。

The 137Cs Nuclear Tracing Technique for Soil Erosion and Sedimentation Studies

^137 Cs is an artificial radionuclide with a half-life of 30.1 years which released into the environment as a result of atmospheric testing of nuclear weapons during the period of 1950s to 1970s with a peak deposition in 1963. ^137Cs fallout was strongly and rapidly adsorbed by soil particles when it deposited on the ground mostly with precipitation. Its following movements will associate with the adsorbed particles. ^137Cs tracing technique has been widely used in soil erosion and sedimentation studies since 1980s. The authors introduce the bases of the technique and show several case studies of assessment of soil erosion rates, investigation of sediment sources and dating of reservoir deposits by using the technique in the loess Plateau and the Upper Yangtze River Basin.