Over the last 50 years, different approaches have been employed in order to predict environmental risk due to soil erosion and to propose effective strategies to control erosion and sedimentation. The use of fallout radionuclides, mainly caesium‐137 (¹³⁷Cs) and excess lead‐210 (²¹⁰Pb_ex), has proved to be a very effective complement to existing traditional methods, especially if a resampling strategy is employed. The resampling approach involves repeating soil sampling and radionuclide measurements within the same site, after a known amount of time (generally 10 to 15 years). This strategy, in the light of the possibility to obtain independent estimates of soil erosion for different periods, makes it possible to establish sediment budgets for different time windows. The use of sediment budgets represents an important tool for providing information on catchment behaviour regarding the relationship between the sediment output at the catchment outlet and rates of sediment redistribution within the catchment. For this reason, this approach can provide important indications of possible changes of sediment connectivity at the catchment scale. The study reported here focuses on the W1 catchment (1.47 ha), located in Calabria, Southern Italy, for which long‐term measurements of sediment yield are also available. The W1 catchment supports a rangeland vegetation cover, and no change in land use occurred during the last 100 years. The catchment was sampled for ¹³⁷Cs and ²¹⁰Pb_ex analyses in 2001 and resampled in 2014 to provide estimates of soil erosion and deposition for different time windows. The uncertainty associated with these estimates is also discussed, and some guidelines for the application of ²¹⁰Pb_ex as a soil erosion tracer are provided. The results provided by the measurements of sediment yield at the catchment outlet provide evidence of a general increase of soil erosion rates during the last 15–20 years. The estimates of sediment redistribution provided by the measurements of ²¹⁰Pb_ex demonstrated that these results reflect an increase in the sediment delivery ratio and also emphasized how the presence of some small depositional areas associated with the occurrence of high‐magnitude events influences the change in sediment connectivity at the catchment scale.

中文翻译：

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使用重复的137Cs和210Pbex测量来建立不同时间窗口的沉积物预算，并探索连通性对意大利南部一个小型实验流域的土壤侵蚀速率的影响

在过去的50年中，已经采用了不同的方法来预测由于土壤侵蚀引起的环境风险，并提出控制侵蚀和沉积的有效策略。辐射放射性核素的使用，主要是铯137（¹³⁷ Cs）和过量的铅210（_前²¹⁰ Pb）已被证明是对现有传统方法的非常有效的补充，尤其是在采用重采样策略的情况下。重采样方法涉及在已知的时间量（通常为10到15年）后，在同一站点内重复进行土壤采样和放射性核素测量。鉴于有可能获得不同时期土壤侵蚀的独立估计，这种策略使得有可能建立不同时间窗口的沉积物预算。沉积物预算的使用是一种重要的工具，可用于提供有关流域行为的信息，有关流域出口处的沉积物输出与流域内沉积物再分配速率之间的关系。为此原因，这种方法可以为流域尺度上的沉积物连通性可能变化提供重要指示。此处报道的研究重点是位于意大利南部卡拉布里亚的W1集水区（1.47公顷），该地区也可长期测量沉积物的产量。W1流域支持牧场植被覆盖，在过去100年中，土地利用没有发生变化。对流域进行了采样2001年进行了¹³⁷ Cs和²¹⁰ Pb的_ex分析，并于2014年进行了重新采样，以提供不同时间窗内土壤侵蚀和沉积的估算值。还讨论了与这些估计值相关的不确定性，并提供了一些有关将²¹⁰ Pb _ex用作土壤侵蚀示踪剂的指导原则。流域出口处沉积物产量的测量结果提供了过去15–20年土壤侵蚀率总体增加的证据。²¹⁰ Pb _ex的测量值提供了沉积物再分配的估算值 结果表明，这些结果反映了沉积物输送比的增加，并强调了一些与高强度事件发生有关的小沉积区域的存在如何影响流域尺度上沉积物连通性的变化。